Communications – Peter Pui Lok Ang, Peter Gaal, Tao Luo, Juan Montojo, Wanshi Chen, Heechoon Lee, Qualcomm Inc
Abstract for “Secondary Cell Activation and Deactivation Enhancements in New Radio”
These are methods, systems and devices for wireless communication. One method could include sending a first signal instructing a UE to change the state of a secondary cells associated with it; determining the allocation of resources for the UE in order to communicate with the secondary cells; and then transmitting a second message including an indication that the active bandwidth part (BWP), which is used to allocate resources based upon the determining. The second signal and active BWP may be used to indicate that the secondary cell has changed its state.
Background for “Secondary Cell Activation and Deactivation Enhancements in New Radio”
“The following pertains to wireless communication in general, but more specifically to secondary cell activation or deactivation enhancements in a new radio.
Wireless communications systems are used to transmit various communication types, including voice, video, packet data and messaging. These systems can support communication with multiple users by sharing system resources (e.g. time, frequency and power). These systems can be fourth-generation (4G) systems like LTE-Advanced (LTE A) or Long Term Evolutions (LTE-A), and fifth-generation (5G) systems that may also be called new radio systems. These systems may employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform-spread-orthogonal frequency division multiplexing (DFT-s-OFDM). Wireless multiple-access communication systems may have a variety of base stations or network access points that support communication with multiple communication devices. These communication devices may also be known as user equipment (UE).
A UE can be configured for dual connectivity and carrier aggregation. The UE may receive data from two network nodes, or transmit data to two different networks nodes. One network node could be a primary cell (next generation NodeB) and the other may be a secondary network node (sgNB). A UE that operates in dual-connectivity or carrier aggregation mode may have greater data transmission capabilities but also consumes more power.
“The techniques described herein relate to improved methods and systems, devices, or apparatuses that support secondary cells activation and deactivation enhancements using new radio. Based on a change in the data throughput requirements of the UE, a base station can instruct a user equipment to activate or deactivate a second cell. A medium access control (MAC), control element (CE) may signal a secondary cell activation to the UE in some cases. A bit field in the MAC CE could indicate activation or deactivation of the secondary cells. Using MACCE to indicate secondary cell activation/deactivation in next-generation fifth generation (5G), or millimeterwave (mmW) radio systems can introduce latency that could affect the UE. The UE’s power consumption may increase if the secondary cell is left activated for longer periods of time when activation is not necessary. This could be due to the physical downlink channel (PDCCH), monitoring the activated secondary cells. To reduce latency signaling related to secondary cell activation or deactivation, the base stations may set up a downlink information (DCI), which may include a bitmap that allows secondary cell activation or deactivation. The base station might also support a combination of MAC CE signaling, bandwidth part (BWP), DCI for secondary cells activation and deactivation.
“A method of wireless communication is described. This method can include: transmitting a first message instructing a UE that it is time to change the state of a secondary cells associated with the UE; determining the allocation of resources for the UE communicating with the secondary Cell; and transmitting a 2nd signal indicating an active BWP which will be used to allocate resources based at minimum in part on the determining of the active BWP as well as the first signal indicating that the secondary cell has been changed.
“A wireless communication apparatus is described. The apparatus can include means to transmit a first signal instructing a UE that it should transition to a secondary state associated with the UE; methods for determining the allocation of resources for UE communication with the secondary cells; and means to transmit a second signal indicating an active BWP which is used to allocate resources based at minimum in part on the determining, and the first signal indicating transition of the secondary-cell’s state.
“Another apparatus is described for wireless communication. The apparatus could include a processor and memory in electronic communication with it. Instructions stored in the memory may also be included. The instructions can be used to instruct the processor to transmit a signal instructing a UE transition a state to a secondary cells associated with it; determine an allocation for resources for the UE and communicate with the secondary cells; and transmit a second message comprising an indication that an active BWP is being used to allocate resources based at minimum in part on the determining, and the first signal indicating transition of the secondary’s cell to active.
“A non-transitory computer readable medium for wireless communication” is described. Instructions may be included that instruct a processor to transmit a signal instructing a UE transition a state to a secondary cells associated with the UE. The second signal will indicate an active BWP which is used to allocate resources based at minimum in part on the determining, and the first signal indicating transition of the secondary cells.
“In some cases of the non-transitory computer readable medium, the first signal is a MAC CE, while the second signal is a BWP DCI. The non-transitory computer readable medium, apparatus and method described above may also include processes, features or instructions for transmitting to the UE a BWP changing DCI on the secondary cells. This indicates that the secondary cell has switched to a zero-based WP. In this case, the BWP switching DCI is not transmitted with a grant. The non-transitory computer readable medium and the method described above may also include instructions, features, or means for transmitting to the UE a BWP changing DCI on the primary cells indicating that the secondary cell is switching to a zero-BWP. The BWP DCI carries BWP activation information for secondary cells associated with the UE in some instances of the above-described method, apparatus, or non-transitory computer readable medium.
“Some examples of non-transitory computer readable media, apparatus and method may also include processes, features and means or instructions for configuring secondary cells to be fully activated based at minimum in part on the transmitted initial signal and active BWP being non-zero. The non-transitory computer readable medium, as well as the method and apparatus described above, may also include instructions, features, means or processes for configuring the secondary cells to be partially activated based at minimum in part on the transmitted second signal and the active WP being a zero.
“Some examples of the non-transitory computer readable medium and method described above may also include processes, features or instructions for configuring one, or more secondary cell to switch from the partially activated to a fully activated status based at minimum in part on a BWP changing DCI transmitted on a primary cells without a grant. The BWP switching DCI includes BWP activation information for one or more secondary cell associated with the UE. The method, apparatus and non-transitory computer readable medium may also include instructions, processes, features, or instructions to configure the secondary cell to change from the partially activated to fully activated state. This is done based at minimum in part on a transmitted BWP changing DCI on a primary cells, wherein the BWP shifting DCI includes at least a CIF.
“Some examples of non-transitory computer readable media and method described above may also include features, means or instructions for configuring secondary cells to be in a fully deactivated state, based at most in part on the transmitted initial signal. The active BWP can be deactivated in some cases according to the non-transitory computer readable medium and apparatus described above. This is at least partially due to the secondary cell being fully deactivated. The non-transitory computer readable medium, apparatus and method described above may also include features, means or instructions that configure the secondary cell to be fully deactivated based at most in part on the expiration of a deactivation period. The non-transitory computer readable medium, apparatus and method described above may also include instructions, features, means or processes for configuring secondary cells to switch to a default WP consisting of a zero-BWP, based at most in part on expiring BWP times. The state can be fully activated, partially activated, or fully deactivated depending on the non-transitory medium and apparatus described above.
“Another method of wireless communication is described. This could include configuring at most one bit of a field within a BWP DCI to indicate whether a secondary cell is activated or disabled, and then transmitting the BWP DCI to a UE based at minimum in part on that configuring.
“Another apparatus is described for wireless communication. This apparatus can include the following: means to configure at least one bit in a BWP field to indicate whether a secondary cell is activated or disabled; and means to transmit the BWP DCI to a UE based at most in part on the configuration.
“Another apparatus is described for wireless communication. The apparatus can include a processor and memory for electronic communication with it. Instructions stored in the memory may also be included. Instructions may be used to instruct the processor to set at least one bit in a BWP field for a base station to indicate whether a secondary cell is activated or disabled; and to transmit the BWP to a UE that is at least partially based on the configuration.
“Another nontransitory computer-readable medium is described for wireless communication. Instructions may be included that allow a processor configure at least one bit in a field of a BWP DCI to indicate whether a secondary cell is activated or deactivated; and transmit the BWP DCI to a UE based at most in part on the configuration.
“Some examples of the non-transitory computer readable medium and method described above may also include features, means, and instructions for configuring the primary cell associated to the base station to switch on a default BWP, based at minimum in part on the expiration of an timer. The default BWP can be configured in some of the above-described methods, apparatuses, and non-transitory computers-readable media to be a nonzero BWP.
“Some examples of non-transitory computer readable media and method described above may also include features, means or instructions for configuring subsets of or all secondary cell groups to switch between a fully activated state and a partially activated status based at minimum in part on the expiration of a timingr. The partially activated state in some of the non-transitory computer readable medium and apparatus described above is associated with a default WP consisting of a zero-BWP.
“Some examples of the non-transitory computer readable medium and method described above may also include features, means or instructions for configuring a MACCE to indicate the group secondary cells based at most in part on the BWP DCI. The BWP DCI for a primary cell that is associated with a base station contains BWP activation control information.
“Another method of wireless communication is described. This could include configuring a bitmap within a BWP DCI that indicates a state associated to each secondary cell in a group of secondarycells; and then transmitting the BWP DCI from a UE.
“Another apparatus is described for wireless communication. This apparatus can include the following: means to configure a bitmap in a BWP DCI; the bitmap indicating a particular state with each secondary cell within a group of secondary cells; means to transmit the BWP DCI from UE.
“Another apparatus is described for wireless communication. The apparatus can include a processor and memory for electronic communication with it. Instructions stored in the memory may also be included. The instructions can be used to instruct the processor to create a BWP DCI bitmap, which indicates a state associated to each secondary cell in a group of secondary cells; then transmit the BWP DCI to a U.
“Another nontransitory computer-readable medium is described for wireless communication. Instructions may be included that allow a processor configure a bitmap within a BWP DCI, the bitmap indicating a particular state for each secondary cell in a group of secondary Cells; and then transmit the BWP DCI to a U.
“Some of the non-transitory computer readable media described above include methods, features, means or instructions for identifying a certain number of bits associated to the bitmap; configuring at most one bit of bitmap to indicate an target BWP ID, based at minimum in part on the number; and configuring at the least a remainder of bits for control information that indicates the state of each secondary cell within the group of secondary cells.”
“Some examples of the non-transitory computer readable medium and method described above may also include features, means or instructions for transmitting each secondary cell’s state using higher layer signaling. The higher layer signaling in some cases of the apparatus and method described above includes radio resource control (RRC), or MAC CE signaling during secondary cell configuration procedures.
“Some examples of the non-transitory computer readable medium, apparatus and method described above include: processes, features, means or instructions for transmitting a MAC CE instructing UE to change a state of at most one secondary cell in the group of secondary cells; determining a allocation of resources for UE to communicate the at least one second cell; and transmitting an indication that an active BWP is used for the allocation resources in the BWP.
“Some examples of non-transitory computer readable media, apparatus and method may also include processes, features and means or instructions for configuring at least one secondary cells to be fully activated based at minimum in part on the transmitted MAC CE, the active BWP, and a nonzero BWP.” The method, apparatus and non-transitory computer readable medium may also include instructions, features, means or processes for configuring at least one secondary cells to be activated. This is based at minimum in part on the active BWP and transmitted MAC CE.
“Some examples of the non-transitory computer readable medium and method described above may also include features, means, or procedures for configuring at least one secondary cells to switch from the partially activated to fully activated states based at minimum in part on a BWP shifting DCI transmitted on an primary cell without a grant. The switching from the partially activated to fully activated state in some of the above-described methods, apparatuses, and non-transitory computers-readable media is also based at minimum in part on at most one bit of the bitmap.
“Some of the methods, apparatus, and nontransitory computer-readable media described above may also include processes, features or means for configuring at least one secondary cells to be in a fully deactivated state based at minimum in part on the transmitted MAC CE. The non-transitory computer readable medium and the method described above may also include instructions, features, means or processes for configuring a MACCE to indicate the group secondary cells based at most in part on the BWP DCI. The method, apparatus and non-transitory computers-readable medium may also include instructions, features, means or processes for configuring at most one bit of the bitmap in order to indicate a selection or state of a primary or secondary cell. Some examples of the non-transitory computerreadable medium and method described above include at least one bit that contains a secondary cell indicator. The non-transitory computer readable medium, apparatus and method described above may also include features, means or instructions to configure at least one bit from the bitmap, based at most in part on zero resource allocation.
“Another method of wireless communication is described. This could include receiving a MAC CE, receiving a DCI BWP indicating an active BWP that is used to allocate resources for the UE to talk with the secondary cell, and then transitioning to a secondary cell’s state based at most in part on the MAC CE or the active BWP.
“Another apparatus is described for wireless communication. This apparatus can include means to receive a MAC CE; methods for receiving a BWP DCI indicating an active BWP that is used to allocate resources for the UE; and means to transition a secondary cell’s state based at most in part on the MAC CE or the active BWP.
“Another apparatus is described for wireless communication. The apparatus could include a processor and memory in electronic communication with it. Instructions stored in the memory may also be included. Instructions may be used to instruct the processor to: receive a MAC CE; get a BWP DCI indicating an active BWP that is used to allocate resources to the UE to the secondary cell; and transition a secondary state based at most in part on the MAC CE or the active BWP.
“Another nontransitory computer-readable medium is described for wireless communication. Instructions may be included that allow a processor to: receive a MAC CE; get a BWP DCI indicating an active BWP to allocate resources to the UE for communication with the secondary cells; and transition a secondary-cell state based at most in part on the MAC CE or the active BWP.
“In some cases of the non-transitory computer readable medium, apparatus and method described above, the state includes a fully activated, partially activated, or fully deactivated state. The non-transitory computer readable medium and apparatus described may also include features, means or instructions that allow the secondary cell’s state to be activated. These are based at least partially on the received MAC CE, the active BWP, and the non-zero WP. The method, apparatus and non-transitory computer readable medium may also include instructions, features, means or processes for transitioning the secondary cell’s state to a partially activated status based at minimum in part on the active BWP and the received MAC CE.
“Some examples of non-transitory computer readable media and method described above may also include processes, features or means for transitioning the state the secondary cell to a fully deactivated state based at minimum in part on the received MAC CE. The method, apparatus and non-transitory computer readable medium may also include features, means or instructions to transition the secondary cell’s state to a fully deactivated state, based at most in part on the expiring deactivation timer.
“Another method of wireless communication is described. This could include receiving a BWP DCI signal from a base station and identifying a primary cell or group of secondary cells. The identification is based at most in part on at minimum one bit of the BWP DCI field.
“Another apparatus is described for wireless communication. This apparatus can be used to receive a BWP DCI from the base station and for identifying a primary cell or group of secondary cells. It is based at most in part on at minimum one bit of a field within the BWP DCI.
“Another apparatus is described for wireless communication. The apparatus could include a processor and memory that allows electronic communication between the processor and the processor. Instructions may be stored in the memory. Instructions may be used to instruct the processor to receive a BWP DCI from a base station and to identify a primary cell or a group of secondary-cell states based at most in part on at minimum one bit of the BWP DCI.
“Another nontransitory computer-readable medium is described for wireless communication. Instructions may be included that allow a processor to receive a BWP DCI from a base station. They can also identify a primary cell or group of secondary cells, based at most in part on at minimum one bit of the BWP DCI.
A base station can instruct a user equipment (UE), based on a change to the UE’s data throughput requirements, to activate or deactivate a secondary cells. A delay in activating or deactivating a secondary cell can be proportional to the latency involved with adapting radio frequency bandwidth. In some wireless communication systems, such as Long-Term Evolution(LTE), secondary cell activation can be sent to a UE via a medium control (MAC) control element. A bit field in the MAC CE could indicate activation or deactivation of one or more secondary cell. Secondary cell activation can be signaled via a MACCE or alternatively using a timer (e.g. expiration of a secondary cells deactivation timer).
“In some cases, MAC CE may not be able to indicate secondary cell activation/deactivation in next-generation 5G or millimeterwave (mmW). In these cases, MAC CE might have a greater latency than providing an indication of bandwidth (BWP), adaptation to the UE via Downlink Control Information (DCI) signaling. This means that the secondary cell remains active for a longer time after activation. This is to reduce signaling due to the higher overhead and latency of MAC CE signaling secondary cell activation/deactivation. The secondary cell may be activated for longer periods to reduce power consumption. This is due to the physical downlink control channel monitoring (PDCCH), on the activated secondary cells. For intra-band carrier aggregate, the receiver bandwidth for a UE might be a wideband frequency. If secondary cell activation/deactivation becomes a bottleneck, the benefits of low latency BWP adaption for the UE could be lost. Consistency between BWP, secondary cell activation and deactivation is possible. To reduce latency signaling related to secondary cell activation or deactivation, the base stations may set up a DCI format, which may include a bitmap for secondary cells activation and activation. The base station might also support MAC CE signaling in combination with BWP DCI for secondary cells activation and deactivation.
“The base station might transmit a first signal instructing UE to change the state of a secondary cells associated with it. The base station might determine the allocation of resources necessary for the UE in order to communicate with the secondary cells. It may also transmit a second signal that includes an indication of an active BWP which is used for the allocation. The transition of the secondary cell’s state may be indicated by the active BWP and first signal. The first signal could include a MAC CE, while the second signal might include a BWP DICI. The UE might receive the MAC CE signal from the base station and then also receive the BWP DCI, which indicates an active BWP that was used to allocate resources to the UE in order for it to communicate with the secondary cells. Based on the MAC CE, the active BWP, the UE can transition to a secondary state. An active BWP could be a nonzero BWP, which may be equivalent to the situation where at least one of the BWPs is activated. Non-zero BWPs can be narrowband or broadband. A non-zero BWP can include one or more BWPs with bandwidth greater that zero, up to a minimum maximum of the UE bandwidth, and a component carrier bandwidth.
“In certain cases, a base station might configure a secondary cells to be fully activated based on the transmitted 1st signal and the active WP being a nonzero BWP. The base station might configure the secondary cell to be dormant (previously known as a “gated state”) in some cases. Based on the transmitted first signal and the active WP being zero, A partially activated state can also be called the dormant condition. Alternately, the base station can configure the secondary cell to be fully activated based on the transmitted initial signal. The UE may change the state of the secondary cells to a fully activated state in some cases based on the received MAC CE. Based on the received MAC CE, the active BWP being a non-zero BWP, the UE can transition the secondary cell’s state to a dormant condition. Based on the received MAC CE, the UE can transition the secondary cell’s state to a fully deactivated state.
“Aspects are first described in the context a wireless communication system. Afterwards, exemplary UEs and bases stations (e.g. next generation NodeBs, gNBs), systems, methods and flow that support secondary cell activation/deactivation enhancements are described. The disclosure is further illustrated and described using apparatus diagrams, system diagrams and flowcharts that pertain to secondary cell activation/deactivation enhancements in a new radio.
“FIG. “FIG. The system 100 comprises base stations 105 and UEs 115 as well as a core network 130. The system 100 could be a LTE network, an LTE Advanced (LTE-A), or a new radio network. The system 100 can support enhanced broadband communications, ultra reliable (e.g. mission critical), communications, low latency communications or communications with low cost and low complexity devices.
Base stations 105 can wirelessly communicate with UEs 115 using one or more base station antennas. The base stations 105 described in this document may include, or be referred by those skilled as the art, a base transceiver station or radio base station, a radio access point, or a radio transceiver (either of these may be called a gNB), Home NodeB or a Home eNodeB or any other appropriate terminology). Base stations 105 may be of various types (e.g. macro or small-cell base stations). These UEs 115 may communicate with different types of base stations 105 as well as network equipment, including small cell eNBs and relay base stations.
“Each base station 105 can be associated with a specific geographic coverage area 110, in which communications are supported with different UEs 115. Each base station 105 can provide communication coverage within a particular geographic coverage area 110 through communication links 125. Communication links 125 between a UE 115 and a base station 105 could use one or more carriers. The communication links 125 in the system 100 can include either uplink transmissions between a UE 115 and a base stations 105 or downlink transmissions between a basestation 105 and a UE 115. Forward link transmissions can also be called downlink transmissions, while uplink transmissions could also be known as reverse link transmissions. One or more downlink bandwidth parts may be configured by the system 100. For each UE-specific service cell (e.g., a cell that is associated with a basestation 105), one or more uplink broadband parts (BWPs). The dedicated radio resource control (RRC), for a UE 115, may be used to configure the downlinks BWPs or the uplink BWPs in some cases.
“The geographic coverage area 110 of a base station 110 may be divided into sections, each section may be associated to a cell. Each base station 105 could provide communication coverage for a micro cell, small cell, hot spot, or other types or combinations thereof. A base station 105 could be mobile and provide coverage for a geographical coverage area 110. Different technologies can have different coverage areas 110. In these cases, the base station 105 may support different coverage areas 110. System 100 could include, for instance, heterogeneous LTE/LTE A or a new radio network that uses different types of base stations to provide coverage in various geographical coverage areas 110.
“The term “cell” is defined as: “Cell” is a logical communication entity that can communicate with a base station (e.g. over a carrier) and may be associated to an identifier that allows for the identification of neighboring cells (e.g. a physical cell ID (PCID), or a virtual cell ID (VCID),) which operates via the same carrier or another. A carrier may support multiple cell types. Different cells can be configured using different protocols (e.g. machine-type communication, narrowband Internet-of-Things, enhanced mobile broadband (eMBB), and others) to allow access for different devices. Sometimes, the term “cell” may refer to a portion of a geographic coverage area 110 (e.g., a sector). The term “cell” may be used to refer to an area of 110 that the logical entity covers.
“UEs 115 can be distributed throughout the system 100. Each UE 115 could be stationary or mobile. A UE 115 can also be called a mobile device or wireless device, a remote or handheld device, or a subscriber or other appropriate terminology. A client, a client, a station or terminal may also be called a unit. A UE 115 could also refer to a personal electronic device, such as a cellular telephone, a personal assistant (PDA), a tablet or laptop computer, and a personal computer. A UE 115 could also be used to refer to a wireless loop (WLL), an Internet of Things device, an Internet of Everything device (IoE), or a MTC device. These devices can be integrated in many articles, such as appliances, meters, vehicles, and the like.
“In certain cases, base station 105 might transmit a first signal instructing UE 115 transition a state to a secondary cell that is associated with UE 115. Base station 105 could be a primary cell to UE 115 and another base station 105 could be a secondary cells for UE 115. Base station 105 could determine the allocation of resources to the UE 115, and transmit a second signal that includes an indication of an active WP used in the allocating of resources based upon the determining. The first signal and active BWP may indicate that the secondary cell is in transition. The first signal could include a MAC CE, while the second signal may contain a BWP DCI. UE 115 could receive a MAC CE at base station 105. UE 115 could also be given a BWP DCI indicating that UE 115 has an active BWP which is used to allocate resources to the UE in order for it to communicate with the secondary cells. The UE 115 could transition to a secondary state based on the MAC CE or the active BWP.
Base station 105 can configure secondary cells to be fully activated based on the transmitted 1st signal and active BWP. Base station 105 might configure the secondary cell to remain dormant in some cases based on the transmitted 1st signal and the active WP being zero. An activated secondary cell can quickly go dormant during periods of low activity. UE 115 can rely on a primary cells to maintain a connection while in the dormant condition (e.g., a connection with a base station 105). For activated secondary cells, the dormant condition can be described as the deactivation of all BWP. Sometimes, the secondary cells may be in a dormant condition when their active BWP equals zero. Sometimes, the default BWP of a secondary cell might be the zero BWP. In these cases, the secondary cells may switch to the dormant status when the BWP timer expires. UE 115 can have a lower active radio frequency bandwidth support and less power consumption when the secondary cell is dormant.
The transmitted first signal may also be used by base station 105 to configure the secondary cell to be fully deactivated. Base station 105 might configure the secondary cell to be fully deactivated if a timer expires. UE 115 can change the state of the secondary cells to a fully activated state in some cases. This is based on the received MAC CE, and active BWP being a nonzero BWP. UE 115 could transition the secondary cell’s state to a dormant condition based on the active BWP and the received MAC CE. UE 115 could transition the secondary cell’s state to a fully deactivated state based upon the received MAC CE. UE 115 can transition the secondary cell’s state to a fully deactivated state based upon the expiration of a deactivation period. An activated BWP can remain active up to the expiration of a BWP-timer or until a subsequent DCI indicates that it is to be deactivated. A table may be created that lists the activated and deactivated BWPs. The DCI may also include an index to the table that indicates which BWPs have been active and which are inactive. The DCI may contain a bitmap that indicates which BWPs have been activated and which are inactive. The UE 115 can transmit acknowledgment (ACK), or non-acknowledgment(NACK) receipts of the DCI to base station 105. This may be done using either resources specified in the DCI, or preconfigured acknowledgment resource.
“Base station 105 might configure at least one bit in a field of a BWP DCI to indicate whether a secondary cell is activated or disabled. The BWP DCI will then be transmitted to UE115. The configuration could include base station105 changing to a default BWP upon expiration of a timer. The timer could be a BWP-timer that can be associated with an active BWP duration for a primary and/or secondary cell. A default BWP can be set to a non-zero value. The configuration could include all or a subset (or all) of secondary cells that can be configured to change from a fully activated to a dormant status based on the expiration of a timer. A default BWP, including a zero-BWP, may be used to indicate the dormant status. Base station 105 could also be configured to indicate the group secondary cells that are based on the BWP DCI. UE 115 could receive the BWP DCI at base station 105 to identify a selected primary cell or a group of secondary neurons based on at most one bit of a field from the BWP DCI.
“A default BWP (e.g. a default WP of base station 105) could be active with any remaining BWPs, e.g. other BWPs at the base station105 or one or several BWPs from one or more secondary cell, deactivated, unless activated by base station105. The UE 115 can perform channel state information measurements (CSI) and transmit a measurement record upon activation of a corresponding BWP. This may allow for less monitoring and measurement of deactivated BWPs, which can lead to power savings and better resource utilization. Secondary cell activation or deactivation can be determined based on whether or no DCI indicates that a BWP is active in one or more secondary cells. If a BWP for a secondary cells is activated, it may be considered that the secondary cell has been activated. However, if all BWPs have been deactivated, then the secondary may be considered deactivated. This allows for separate signaling to activate and deactivate secondary cells.
“System 100 may allow for the configuration of a special (e.g. a zero) BWP. This corresponds to all BWPs being deactivated for secondary cells when they become active BWPs on secondary cells. System 100 can also support zero BWP, which may be used as a default downlink-BWP for a secondary cell. The zero BWP might not be permitted to be used as the first active BWP for a secondary cell in some cases. System 100 may be able to schedule DCI with zero assignment in some cases. This is for active downlink or uplink BWP switching. For downlink scheduling DCI, UEs 115 may transmit positive HARQ ACK for zero-size physical downlink shared channel (PDSCH) transmission. Base stations 105 (e.g. gNB), may transmit a BWP switch DCI (with zero assignment on the secondary cells) to activate a zero BWP that will transition the secondary cell into a dormant (or partially activated) state. Base stations 105 may transmit BWP switching DCI (with zero assignment) to a primary cell. In these cases, it may contain a secondary cell control indicator and bitmap that selects which secondary cell’s active BWP will switch to the first active. A zero BWP can be an original active WP. This may switch the secondary cell from dormancy. Base station 105 could configure a secondary cell (e.g. base station 105) in order to change from a dormant to fully activated state. This is based on a BWP switching DCI transmitted on a primary cells without a grant.
“Some UEs 115 such as MTC and IoT devices may be low-cost or low-complexity devices that allow for automated communication between machines (e.g. via Machine-to Machine (M2M), communication). M2M communication, or MTC, may be used to refer to data communication technologies that allow devices or a base station to communicate with each other without the need for human intervention. M2M communication, or MTC, may refer to communications between devices that use sensors or meters to capture or measure information. The information is relayed to a central server to make use of it or to present it to the human user. Some UEs 115 can be used to collect data or allow automated behavior of machines. MTC devices can be used for monitoring and controlling many things, including inventory, water level, equipment, monitoring, health monitoring, wildlife monitoring and fleet management.
“Some UEs 115 might be configured to use operating modes that reduce power consumption such as half-duplex communication (e.g. a mode that supports one way communication via transmission or receipt, but not simultaneous transmission and reception). Half-duplex communications can be carried out at a lower peak rate in some cases. Another power-saving technique for UEs 115 is to enter a power-saving?deep sleep? Mode when the user is not engaged in active communication or operating on a narrow bandwidth (e.g. according to narrowband communications). In certain cases, UEs 115 might be used to support mission-critical functions. The system 100 may also be set up to provide reliable communications for such functions.
“In certain cases, a UE 115 might also be able communicate directly with other UEs 115 (e.g. using a device-to?device (D2D), protocol or peer-to?peer (P2P). A group of UEs 115 using D2D communications could be located within the geographical coverage area 110 of a base stations 105. Other UEs 115 may not be able to receive transmissions from a 105 base station 105 because they are outside of the geographical coverage area 110. Sometimes, groups of UEs 115 communicating via D2D communications can use a one to many (1:M) system where each UE 115 transmits information to all UE 115 within the group. A base station 105 may be used to schedule resources for D2D communications. D2D communications can be carried out between UEs 115 and UEs 105 in other cases.
“Base stations105 may communicate with each other and the core network 130. Base stations 105, for example, may communicate with the core network 130 via backhaul links132 (e.g. via an 51 interface or another interface). Base stations 105 can communicate over backhaul link 134 with each other (e.g. via an X2 interface or another interface), either directly (e.g. between base stations 105) oder indirectly (e.g. via the core network 130).
The core network 130 could provide access authorization, tracking and user authentication. It may also be used to access routing and mobility functions, as well as access routing. Core network 130 could be an evolved packet core (EPC), with at least one mobility management entity, at least one serving gateway (S?GW), and at most one Packet Data Network gateway (PDN) gateway. The MME can manage non-access stratum functions (e.g. control plane), such as mobility, authentication and bearer management for UEs 115 that are served by base stations 105. The S-GW may allow user IP packets to be transmitted. This may also be connected with the P-GW. The P-GW can provide IP address allocation and other functions. The P-GW can be connected to network operators IP services. Operators may offer access to Intranet(s), the Internet, or an IP Multimedia Subsystem IMS.
“At minimum some network devices such as a basestation 105 may include subcomponents like an access network entity. This could be an example access node controller (ANC). Each access network entity may communicate with UEs 115 through a number of other access network transmission entities, which may be referred to as a radio head, a smart radio head, or a transmission/reception point (TRP). In some configurations, different functions of an access network entity (or base station 105) may be spread across multiple network devices (e.g. radio heads and access controllers), or combined into one network device (e.g. a base station 105)
“System 100 can operate in one or more frequency bands. Typically, it operates between 300 MHz and 300 GHz. The region between 300 MHz and 3 GHz is generally known as the ultra high frequency (UHF), or decimeter band. These wavelengths are approximately one to one meter long. Buildings and other environmental features can block or redirect UHF waves. The waves can penetrate buildings sufficiently to allow a macro cell to service UEs 115 indoors. UHF transmission may require shorter antennas and a shorter range (e.g. less than 100km) as compared to transmission using smaller frequencies and longer waves at the very high frequency (HF), or very high frequency(VHF) portion below 300 MHz.
“The system 100 could also operate in the super high frequency (SHF), region that uses frequency bands between 3 GHz and 30 GHz. Also known as the centimeter range, SHF includes bands such the 5GHz industrial, scientific, or medical (ISM), which can be used opportunistically with devices that are able to tolerate interference from other users. The system 100 can also operate in the extremely high frequency (EHF), region of spectrum (30 GHz to 300GHz), also known by the millimeter band. The system 100 may allow millimeter wave (mmW), communications between UEs 115, base stations 105. EHF antennas may be smaller and closer than UHF antennas. This may allow for the use of antenna arrays within a UE 115 in certain cases. EHF transmissions can be propagated at a lower frequency and with a shorter range than UHF or SHF transmissions. The techniques described herein can be applied to transmissions that use different frequency regions. However, the designated use of bands across frequency regions may vary by country or regulating agency.
“In certain cases, system 100 could use both licensed and unlicensed radio frequency bands. The system 100 might use License Assisted Access (LAA), LTE Unlicensed (LTE?U) radio access technology or new radio technology in unlicensed bands such as the 5 GHz ISM. Wireless devices, such as base stations (105) and UEs (115), may use listen-before-talk procedures to ensure that a frequency channel is clear prior to transmitting data when operating in unlicensed radio frequency bands. Sometimes, operations in unlicensed band may be based upon a CA configuration along with CCs operating within a licensed spectrum (e.g. LAA). Operation in unlicensed spectrum can include peer-to-peer transmissions or downlink transmissions. Duplexing in unlicensed frequency spectrum can be done using either frequency division duplexing or time division duplexing (TDD), as well as a combination of both.
“Base station 105 and UE 115 may have multiple antennas. These can be used to transmit diversity, receive diversity (MIMO), multiple-input multiple output (BEAMFORMING) communications. The system 100 could use a transmission method between a transmitting device (e.g. a base station 105) or a receiving device (e.g. a UE 115), in which the transmitting device has multiple antennas, while the receiving devices have one or more antennas. Multipath signal propagation may be used in MIMO communications to improve the spectral efficiency of multiple signals being transmitted or received via different spatial layers. This may also be known as spatial multiplexing. Multiple signals can be transmitted, for instance, by different antennas or different combinations. The multiple signals can also be received by the receiver device using different antennas or different combinations. Each signal may be called a distinct spatial stream and may contain bits that are associated with the same data stream (e.g. the same codeword or different data streams). Different antenna ports may have different spatial layers that are used to measure and report channel measurements. MIMO techniques can be used in two ways: single-user MIMO, where multiple spatial layer are transmitted to the same receiver device; and multi-user MIMO where multiple spatial levels are transmitted to multiple devices.
“Beamforming” (also known as spatial filtering, directional transmit, or directional receipt) is a signal processing technique used at a transmitter device or receiver device (e.g. a base station 105, UE 115) in order to steer or shape an antenna beam (e.g. a transmit beam, receive beam) along a path between the receiving device and transmitting device. Combining signals from antenna elements can be used to beamform signals. Signals propagating in particular directions with respect to antenna arrays may experience constructive interference, while others will experience destructive interference. An antenna element may be used to adjust signals. A transmitting device, or a receiver device, can apply certain phase offsets and amplitudes to the signals transmitted via each antenna element. An antenna element may have a beamforming weight that is associated with it. This can be used to adjust the signal to a specific orientation (e.g. with respect the antenna array of the receiving device or transmitting device) or any other orientation.
“A base station 105 might use multiple antennas, or arrays, to perform beamforming operations in order to direct communications with a UE 115. Some signals, such as synchronization signals, reference signals, beam selection signals or other control signals may be transmitted by a base station 105. Some signals (e.g., synchronization signals or reference signals, beam selection signal, or other control signals), may be transmitted multiple times by a base station. This could include signals being transmitted according to different beamforming weigh sets that correspond with different directions of transmission. Transmissions in different beam directions can be used to identify (e.g. by the base stations 105 or a receiver device, such as a UE 115), a beam direction for further transmission and/or reception at the base station 105. A base station 105 may transmit signals in a single direction, such data signals that are associated with a specific receiving device. Some examples show that the beam direction of transmissions along a single beam direction can be determined by a signal transmitted in different beam directions. A UE 115 might receive signals from the base station 105 in various directions. The UE 115 could report to the base stations 105 a signal quality indicator or other acceptable signal quality. These techniques are only applicable to signals that are transmitted by a base station 105 in one or more directions. However, a UE 115 could use similar techniques to transmit signals multiple times in different directions.
A receiving device, such as a UE 115 which could be an example of a mmW receiver device, may attempt multiple receive beams while receiving signals from base station 105. These signals may include synchronization signals and reference signals. A receiving device might try multiple receive directions, for example by receiving signals via different antenna subarrays or processing received signals using different receive beamforming weigh sets. Signals received at different antenna elements may also be processed according to different weight sets. This is known as “listening”. Depending on the receive beams and directions. A receiving device might use one receive beam to receive data signals along a single direction in some cases. A single receive beam can be aligned in a direction determined at least partly by listening to different beam directions. (e.g., a beam directed that has the highest signal strength, highest signal to noise ratio or other acceptable signal quality, determined at least in part by listening to multiple beam directions).
“In certain cases, antennas from a base station 105 and UE 115 could be found within one or more antenna arrays. These arrays may support MIMO operations or transmit/receive beamforming. An antenna tower, for example, may have one or more antenna arrays or base station antennas. Antennas and antenna arrays that are associated with base station 105 can be found in different geographic locations. An antenna array may be used by a base station 105 to beamform communications with a UE 115. A UE 115 could also have an array of antennas that can support different MIMO or beamforming operations.
“In certain cases, system 100 could be a packet-based network operating according to a layer protocol stack. The user plane may have IP-based communications with the bearer (or Packet Data Convergence protocol (PDCP) layer). In some cases, a Radio Link Control layer (RLC), may perform packet segmentation and reassembly in order to communicate over logical channel. Medium Access Control (MAC), a layer that handles priority handling and multiplexing logical channels into transport channel, may be used. To improve link efficiency, the MAC layer can also use hybrid automated repeat request (HARQ). The Radio Resource Control protocol layer (RRC) may be used to establish, configure, and maintain an RRC connection between a UE 115, a base station 105, or core network 130 that supports radio bearers for user-plan data. Transport channels can be mapped to physical channels at the Physical (PHY). layer.
“In certain cases, UEs 115 or base stations 105 may allow retransmissions to increase the probability that data is received successfully. One technique to increase the probability that data is correctly received over communication links 125 is HARQ feedback. The HARQ can include error detection (e.g. using a cyclic Redundancy Check (CRC), forward error corrections (FEC), and transmission (e.g. automatic repeat request (ARQ). HARQ can improve throughput at MAC layer under poor radio conditions (e.g. signal-to-noise). A wireless device may be able to provide same-slot feedback for HARQ. In this case, the device might provide HARQ feedback in a particular slot for data received in a prior symbol. Other cases may see HARQ feedback provided in a different slot or at a different time.
Time intervals in LTE and new radio can be expressed in multiples a basic unit. This could, for instance, refer to a sampling time of Ts=1/30720,000 seconds. The time intervals for a communication resource can be organized using radio frames, each with a duration of 10 ms. In this case, the frame period could be Tf=307200 Ts. A system frame number (SFN), ranging from 0-1023, can be used to identify the radio frames. Each frame can contain 10 subframes, each numbered from 0-9, and each subframe could have a duration between 0.5 and 7 ms. Each slot may also include 6 or 7, depending on how long the cyclic prefix is added to each symbol period. Each symbol period can contain 2048 sampling times, excluding the cyclic prefix. A subframe can be the smallest unit in the system 100 and is sometimes referred to as a transmission interval (TTI). Other cases may see a smaller scheduling unit of system 100 than a subframe. In these cases, it may also be dynamically selected (e.g. in short TTIs (sTTIs), or in select component carriers using TTIs).
“In some wireless communication systems, a slot can further be divided into several mini-slots that contain one or more symbols. A symbol of a mini slot or a small-sized slot may be the smallest unit for scheduling. The frequency band or subcarrier spacing of an operation may affect the duration of each symbol. Some wireless communication systems also allow for slot aggregation, where multiple slots or mini-slots can be combined and used to communicate between a UE 115 (or a base station 105).
“The term “carrier” refers to a set of radio frequency spectrum resources that are used to transport communications. A set of radio frequency resources that support communications over a communication line 125. A carrier for a communication link 125 might include a part of a radio frequency band that is used according to radio access technology physical layer channels. Each channel can carry user data, control information or other signaling. An associated carrier can be assigned a frequency channel (e.g. an Evolved Universal Terrestrial Radio Access, (E-UTRA), absolute radio frequency channel number (EARFCN),) and may be positioned according a channel raster to be discovered by UEs 115. Either downlink or upwards (e.g. in an FDD or TDD mode), carriers can be configured to carry both downlink and uplink communications (e.g. in a TDD or downlink mode). In some examples, signal waveforms transmitted over a carrier may be made up of multiple sub-carriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform-spread-OFDM (DFT-s-OFDM)).”
“The organization structure of carriers can be different for different radio accessibility technologies (e.g. LTE, LTE A, new radio, etc.). Communications over a carrier might be structured according to TTIs (or slots), each of which could include user data, as well as control information, signaling, or information to assist decoding that user data. A carrier might also contain dedicated acquisition signaling (e.g. synchronization signals, system information, etc.). Control signaling that coordinates the operation of the carrier. Some carriers may have acquisition signaling and control signaling that coordinates the operations of other carriers, such as in a carrier consolidation configuration.
Multiplexing physical channels on a carrier may be possible using different techniques. Multiplexing a physical control channel and a data channel on a downlink carrier may be possible using different techniques. For example, time division multiplexing techniques, frequency division multiplexing techniques, or hybrid TDM/FDM techniques. Some examples show control information being distributed in a physical channel between different control areas in a cascaded fashion (e.g. between a common control area or common search space, and one or more UE specific control regions or UEspecific search spaces).
“A carrier can be associated with a specific bandwidth of the radiofrequency spectrum. In some cases, the carrier bandwidth might be called a?system bandwidth? The system 100 or the carrier. The carrier bandwidth could be, for example, one of several predetermined bandwidths that are available to carriers of a specific radio access technology (e.g. 1.4, 3, 5, 10, 15, 20 40, 80 MHz). Each UE 115 served may be configured to operate over a portion or all of the carrier bandwidth. Some UEs 115 can be configured to operate using a narrowband protocol type. This type is associated with a predefined range or portion (e.g. set of subcarriers, RBs, or RFs) within a carrier (e.g.?in-band). ”
“In MCM systems, a resource element can be composed of one symbol period (e.g. a duration of one module symbol) and one Subcarrier. The symbol period and the subcarrier spacing may be inversely related. The modulation scheme (e.g. the order of the modulation scheme) may affect the number of bits each resource element can carry. The data rate for UE 115 may increase if it receives more resource elements and the order of the modulation scheme. MIMO systems may use a combination radio frequency spectrum, a time and a spatial resource to define a wireless communications resource. Multiple spatial layers can increase the data rate when communicating with a UE 115.
“Devices 100 (e.g. base stations 105 and UEs 115) may have hardware configurations that support communications over a specific carrier bandwidth or may be configured to support communications over a number of carriers bandwidths. The system 100 might include base stations 105 or UEs that support simultaneous communications over carriers with multiple carrier bandwidths. System 100 may allow communication with a UE 115 over multiple carriers or cells. This feature is sometimes called carrier aggregation (CA), or multi-carrier operations. A UE 115 can be configured with multiple downlink CCs, and one or more of the uplink CCs depending on a carrier aggregation configuration. Carrier aggregation can be used with FDD or TDD component carriers.
“In certain cases, system 100 may use enhanced component carriers (eCCs). An eCC can be distinguished by one or more of the following features: a wider carrier or frequency channel bandwidth; shorter symbol duration; shorter TTI duration; or modified control channel configuration. An eCC can be associated with a carrier aggregation or dual connectivity configuration in some cases (e.g. when multiple serving cells have a suboptimal backhaul link). An eCC can also be used in unlicensed or shared spectrum, where more than one operator has access to the spectrum. A eCC with a large carrier bandwidth could include one or more segments that UEs 115 may use to monitor the entire carrier bandwidth.
“In some cases, eCCs may use a different symbol length than other CCs. This may mean that eCCs may use a shorter symbol duration than other CCs. An increased spacing between subcarriers may be caused by a shorter symbol duration. A device such as a UE 115, base station 105, that uses eCCs can transmit wideband signals (e.g. according to frequency channels or carrier bandwidths of 20, 40 and 60 MHz, 80 MHz, etc.). At reduced symbol durations (e.g. 16.67 microseconds). TTIs in eCC can be composed of multiple symbol periods. Sometimes, the TTI duration, that is, the number and length of symbol periods in an eCC TTI, may be variable.
“Wireless communication systems, such as a radio system, may use any combination of licensed and unlicensed spectrum band, including shared spectrum bands. Flexibility in eCC symbol length and subcarrier spacing may permit the use of eCC across multiple frequencies. New radio shared spectrum can increase spectrum utilization and efficiency in certain cases, particularly through dynamic vertical (e.g. across frequency) or horizontal (e.g. across time) sharing.
“FIG. “FIG. 2” illustrates an example system 200 that supports secondary cells activation and deactivation in new radios, in accordance to various aspects of this disclosure. System 200 may implement some aspects of system 100 in certain examples. System 200 could include a basestation 205, a 210 base station, and a UE 215, all of which can be examples of the corresponding devices shown in FIG. 1. System 200 can operate using a radio access technology, such as next generation 5G, or millimeter wave(mmW) radio system. However, the techniques described herein may also be applied to other radio access technologies (e.g. LTE, LTE-advanced, LTE-A), and systems that may simultaneously use multiple radio access technologies (e.g. next generation 5G, mmW radio, and LTE). Base station 205 could be associated to a coverage of 235 and base station 220 may be associated for a coverage of 240. The following communication examples may occur between base station 205 and base station 210.
Dual-connectivity may be used to configure “UE 215 so that it can receive and transmit data from base stations 205 and 210. Base station 205 could be a primary cell of the next generation NodeB (gNB), or evolved NodeBss (eNBs), while base station 210 might be a secondary cell such as a secondary gNB(SgNB). Dual-connectivity mode may result in UE 215 having increased data transmission capabilities but also consuming more power. Dual-connectivity may result in UE 215’s power consumption being higher because UE 215 could be receiving and monitoring data transmissions from base stations 205 and 210. System 200 can efficiently manage data transmission capabilities while decreasing power consumption for UE 215 through improved secondary cell activation/deactivation techniques for base stations 205 and UE 215.”
“Base station 205 can configure UE 215 using one or more component carriers. Some examples may see a subset or all of the component carriers being deactivated, except for a primary carrier. Base station 205 might activate one or more secondary components carriers in order to increase downlink throughput. Base station 205 may be used as a primary cell to instruct UE 215, for example, to activate or deactivate a secondary cells (e.g. base station 210). UE 215 can also be configured for carrier aggregation, which allows data transmissions from base station 205 and base station 210 to have a higher bandwidth. A component carrier is a carrier that is aggregated. UE 215 might use contiguous component carrier within the same operating frequency band (e.g. intra-band carrier aggregation) or non-contiguous components carriers that are located at the same frequency but with a gap between them. Sometimes, UE 215’s power consumption during downlink operations increases with increasing radio frequency receiver bandwidth. UE 215 can support variable receiver bandwidth because it receives data transmissions continuously from base station 205 and base station 210. One example is that UE 215’s receiver bandwidth may be a wideband radio frequency. Another example is that UE 215 might monitor a downlink channel (e.g. physical downlink channel (PDCCH),) using a narrowband radio frequency bandwidth and then receive data using a wider radio frequency bandwidth (e.g. wideband), based upon a bandwidth configuration.
“Bandwidth configuration could include base station 205 adapting UE 215. BWPs may contain a number resource blocks that are allocated to UE 215 in order to communicate with base station 205 and base station 210. Multiple component carriers can be configured using carrier aggregation techniques. This may include a primary carrier (also known as a primary cell carrier, primary cell, or primary cell), and one or more secondary carriers (also known as secondary cell carriers, or secondary cells). Each component carrier can have one or more BWPs. One BWP can be used to transmit data between UE 215 (base station 205) if the data transfer is relatively short. Two or more BWPs could be used if large amounts of data are to be transmitted. Different bandwidths may be used for different bandwidth parts. If the data being transferred is very small, a narrow bandwidth can be used. However, a wider bandwidth may be used. Based on the bandwidth configuration, UE 215 can dynamically switch between BWPs.
Base station 205 can configure BWPs to UE 215 in order to enable dynamic bandwidth adaptation. Base station 205 can signal BWP activation or deactivation or a switching of BWPs, or any combination thereof, via DCI signaling. UE 215 can dynamically adjust a radio frequency bandwidth based upon a BWP switching signaled by base station 205. UE 215 may be able to save power by dynamically switching between a BWP having a narrowband bandwidth or a broadband bandwidth.
“Power saving for UE 215 in some cases of carrier aggregation may be more difficult than for a single carrier case. A BWP adaptation to each carrier may not produce the same power saving results for UE 215 as a single carrier case. For example, a BWP that has a narrowband bandwidth might be more effective than a BWP that has a widerband bandwidth. Power saving may not be as evident in intra-band contiguous carrier aggregation which employs a wideband receiver radio frequency. Sometimes, multiple activated secondary cell (e.g. SgNBs) may be used. However, even if the secondary cells use narrowband BWPs, the overall receiver’s (i.e. UE 215) radiofrequency bandwidth may not be significantly reduced. This is because the receiver’s radiofrequency bandwidth may be based upon the total span of all secondary serving cells active bandwidths and not the bandwidth of a single BWP.
“Base station 205” may indicate activation of a BWP from UE 215 based upon DCI signaling. DCI signaling could be independent of a BWP and a downlink grant. DCI signaling can be used to activate a BWP. This may reduce the power consumption of UE 215 due to the low latency associated to DCI signaling. In certain cases, UE 215 might establish a connection to base station 205 where one or more component carriers can be configured with one of the BWPs. Base station 205 might indicate which BWP is currently active for a transmission of DCI. This may be done after the configuration of one or more component carriers. UE 215 could activate a corresponding component carrier or BWP based on this indication.
“Base station 205 might configure one or more secondary cell to switch from a dormant to fully activated state using a BWP switching DCI transmitted to a primary cell. This is possible in certain cases. BWP switching DCIs may contain information about the activation of BWP for one or more secondary cells that are associated with UE 215. Base station 205 might configure the secondary cell to change from a dormant to fully activated state using a BWP switch DCI transmitted to a primary cell. A control field indicator (CIF) may be included in the BWP switching DCI.
Base station 205 might instruct UE 215 in some cases to activate or deactivate a secondary cells (e.g. base station 210) based upon a change of data throughput requirements for UE 215 Some cases may show that the time it takes to activate or deactivate secondary cells (e.g. base station 215) is directly proportional to latency involved in performing radio frequency bandwidth adaption. In some wireless communication systems, such as Long-Term Evolution(LTE), secondary cell activation can be sent to a UE via a medium control (MAC) control element. A bit field in the MAC CE could indicate activation or deactivation of one or more secondary cell (e.g. base station 210). Secondary cell activation can be signaled via a MACCE or alternatively using a timer (e.g. expiration of a secondary cells deactivation timer). However, MAC CE may not be as effective in indicating secondary cell activation/deactivation in next-generation 5G and mmW radio systems, e.g. to UE 215 because it uses a longer latency than DCI signaling to indicate BWP adaptation to UE 215 for this purpose. Secondary cell activation has a higher overhead due to the long latency associated base station 205 instructing UE 215, to deactivate a secondary cells (e.g. Base station 210) uses MAC CE signaling. This is in contrast to the DCI signaling used for the BWP adaptation signal. The secondary cell is kept active for longer periods of time to reduce power consumption. This is due to the PDCCH monitoring of the activated secondary cells by UE 215. If secondary cell activation/deactivation becomes a bottleneck in system 200, then the benefits of low latency BWP adaptation to UE 215 will be diminished. Consistency between BWP, secondary cell activation/deactivation and BWP may therefore be desirable.
“UE 215 could be configured with a new radio tracking reference signal framework. This may enable express BWP adaption in some cases of next-generation 5G and mmW radio systems. UE 215 might be able to report channel state information earlier that the 24-millisecond (ms), limit (e.g., n+24 time in LTE). MAC CE signaling could have a greater impact on the overall reporting of channel information than DCI signaling.
DCI signaling can be used to activate or deactivate secondary cells faster than conventional methods. MAC CE signaling can have the following limitations that could affect data throughput, efficiency and processing resources as well as power consumption of UE 215. DCI signaling, however, may address some or all these shortcomings of MAC CE signaling. DCI signaling may reduce latency by at minimum 60% even though similar acknowledgement or non-acknowledgment delays related to PDSCH data transmitting.
“In some cases, base station205 may configure DCI (downlink control information) formats that include bitmaps for secondary cell activation or deactivation to reduce latency in secondary cell activation. The bitmap may be able to follow features in MAC CE. Base station 205 might reconfigure a DCI format in order to include bitmap from existing MAC CEs. This DCI format reconfigured may also be called a L1 CE. This means that control elements sent using MAC CE signaling can be transmitted by base station 205 via DCI signaling.
“In certain cases, a BWP of a primary cell (e.g. base station 205) might carry a control bitmap that is associated with one or more secondary layers. Individual secondary cells can be signaled to change to another BWP based on the control bitmap. Each secondary cell may have at least one bit assigned in order to conserve bits. One bit may contain a secondary cell indicator, such as an identifier (ID), and at least one bit can be included in the bitmap. If at least one bit is set in some cases, the secondary cell can transition to a preconfigured first BWP. Alternativly, activated secondary cells can be mapped to a control bitmap in some cases.
“Base station 205 can reconfigure a downlink grants to include an instruction instructing UE 215, to activate or deactivate a secondary cells (e.g. base station 210). Base station 205 might configure a DCI with a bitmap to allow secondary cell activation or deactivation. Base station 205 might configure a field within a BWP DCI to indicate a BWP identification (ID) field. For a downlink grant from base station 205, UE 215, UE 215 could identify the intended BWP. UE 215, for example, may receive and operate on a first BWP. A first field may contain a bitmap for secondary cells activation or deactivation. A second field may indicate a BWP ID. UE 215 could then transition to this second BWP. Base station 205 could transmit a BWP DCI that includes information about downlink grants, secondary cell activation or deactivation, as well as a bitmap for secondary cells activation or deactivation and a BWP ID to UE 215.
Base station 205, or base station 210, may be a mmW station that transmits a beamformed transmission using an active beam to UE 215 Base station 205 could transmit a BWP DCI 225 via active beam to UE 215 using beamformed transmission 220-a. A bitmap may be included in the BWP DCI 225. It could include a number bits that relate to one or more secondary cell. A bitmap can include several bits, such as at least one bit and eight bits. Base station 205 might use each bit to indicate the status of secondary cells, e.g. an activation or deactivation of secondary cells. A bit value of?1 could indicate that a secondary cell is activated or to be activated by UE 215. A bit value of?1? could indicate that a secondary cells is activated or will be activated by UE 215; a bit value of?0? may indicate that a secondarycell is deactivated or will be deactivated by UE 215 UE 215 may indicate that a secondary cells is activated or to be activated by UE 215 and a bit value?0? Some examples may show that at least one bit in the bitmap is reserved (e.g. for padding purposes).
“In some cases, the number of secondary cells configured and supported by base station205 may exceed what is necessary to indicate all secondary cells in BWP DCI 2225. This means that a bitmap might be longer than the number of bits available in the BWP DCI DCI 225. Base station 205 might also be able to support M secondary cells with M bits. N and M can be positive integers. Base station 205 could have 31 secondary cells configured (including base station 211). The BWP 225 may only have eight bits for bitmaps and may not be able to support bitmaps with 31 bits. Base station 205 can group secondary cells together to be associated with at most one bit to address the bit availability issues in the BWP DCI 225. A first set of secondary cell (e.g. secondary cells 1 through 8) can be assigned to C1, while a second set (e.g. secondary cells 9 through 16 may be assigned (C2)), etc.
Summary for “Secondary Cell Activation and Deactivation Enhancements in New Radio”
“The following pertains to wireless communication in general, but more specifically to secondary cell activation or deactivation enhancements in a new radio.
Wireless communications systems are used to transmit various communication types, including voice, video, packet data and messaging. These systems can support communication with multiple users by sharing system resources (e.g. time, frequency and power). These systems can be fourth-generation (4G) systems like LTE-Advanced (LTE A) or Long Term Evolutions (LTE-A), and fifth-generation (5G) systems that may also be called new radio systems. These systems may employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform-spread-orthogonal frequency division multiplexing (DFT-s-OFDM). Wireless multiple-access communication systems may have a variety of base stations or network access points that support communication with multiple communication devices. These communication devices may also be known as user equipment (UE).
A UE can be configured for dual connectivity and carrier aggregation. The UE may receive data from two network nodes, or transmit data to two different networks nodes. One network node could be a primary cell (next generation NodeB) and the other may be a secondary network node (sgNB). A UE that operates in dual-connectivity or carrier aggregation mode may have greater data transmission capabilities but also consumes more power.
“The techniques described herein relate to improved methods and systems, devices, or apparatuses that support secondary cells activation and deactivation enhancements using new radio. Based on a change in the data throughput requirements of the UE, a base station can instruct a user equipment to activate or deactivate a second cell. A medium access control (MAC), control element (CE) may signal a secondary cell activation to the UE in some cases. A bit field in the MAC CE could indicate activation or deactivation of the secondary cells. Using MACCE to indicate secondary cell activation/deactivation in next-generation fifth generation (5G), or millimeterwave (mmW) radio systems can introduce latency that could affect the UE. The UE’s power consumption may increase if the secondary cell is left activated for longer periods of time when activation is not necessary. This could be due to the physical downlink channel (PDCCH), monitoring the activated secondary cells. To reduce latency signaling related to secondary cell activation or deactivation, the base stations may set up a downlink information (DCI), which may include a bitmap that allows secondary cell activation or deactivation. The base station might also support a combination of MAC CE signaling, bandwidth part (BWP), DCI for secondary cells activation and deactivation.
“A method of wireless communication is described. This method can include: transmitting a first message instructing a UE that it is time to change the state of a secondary cells associated with the UE; determining the allocation of resources for the UE communicating with the secondary Cell; and transmitting a 2nd signal indicating an active BWP which will be used to allocate resources based at minimum in part on the determining of the active BWP as well as the first signal indicating that the secondary cell has been changed.
“A wireless communication apparatus is described. The apparatus can include means to transmit a first signal instructing a UE that it should transition to a secondary state associated with the UE; methods for determining the allocation of resources for UE communication with the secondary cells; and means to transmit a second signal indicating an active BWP which is used to allocate resources based at minimum in part on the determining, and the first signal indicating transition of the secondary-cell’s state.
“Another apparatus is described for wireless communication. The apparatus could include a processor and memory in electronic communication with it. Instructions stored in the memory may also be included. The instructions can be used to instruct the processor to transmit a signal instructing a UE transition a state to a secondary cells associated with it; determine an allocation for resources for the UE and communicate with the secondary cells; and transmit a second message comprising an indication that an active BWP is being used to allocate resources based at minimum in part on the determining, and the first signal indicating transition of the secondary’s cell to active.
“A non-transitory computer readable medium for wireless communication” is described. Instructions may be included that instruct a processor to transmit a signal instructing a UE transition a state to a secondary cells associated with the UE. The second signal will indicate an active BWP which is used to allocate resources based at minimum in part on the determining, and the first signal indicating transition of the secondary cells.
“In some cases of the non-transitory computer readable medium, the first signal is a MAC CE, while the second signal is a BWP DCI. The non-transitory computer readable medium, apparatus and method described above may also include processes, features or instructions for transmitting to the UE a BWP changing DCI on the secondary cells. This indicates that the secondary cell has switched to a zero-based WP. In this case, the BWP switching DCI is not transmitted with a grant. The non-transitory computer readable medium and the method described above may also include instructions, features, or means for transmitting to the UE a BWP changing DCI on the primary cells indicating that the secondary cell is switching to a zero-BWP. The BWP DCI carries BWP activation information for secondary cells associated with the UE in some instances of the above-described method, apparatus, or non-transitory computer readable medium.
“Some examples of non-transitory computer readable media, apparatus and method may also include processes, features and means or instructions for configuring secondary cells to be fully activated based at minimum in part on the transmitted initial signal and active BWP being non-zero. The non-transitory computer readable medium, as well as the method and apparatus described above, may also include instructions, features, means or processes for configuring the secondary cells to be partially activated based at minimum in part on the transmitted second signal and the active WP being a zero.
“Some examples of the non-transitory computer readable medium and method described above may also include processes, features or instructions for configuring one, or more secondary cell to switch from the partially activated to a fully activated status based at minimum in part on a BWP changing DCI transmitted on a primary cells without a grant. The BWP switching DCI includes BWP activation information for one or more secondary cell associated with the UE. The method, apparatus and non-transitory computer readable medium may also include instructions, processes, features, or instructions to configure the secondary cell to change from the partially activated to fully activated state. This is done based at minimum in part on a transmitted BWP changing DCI on a primary cells, wherein the BWP shifting DCI includes at least a CIF.
“Some examples of non-transitory computer readable media and method described above may also include features, means or instructions for configuring secondary cells to be in a fully deactivated state, based at most in part on the transmitted initial signal. The active BWP can be deactivated in some cases according to the non-transitory computer readable medium and apparatus described above. This is at least partially due to the secondary cell being fully deactivated. The non-transitory computer readable medium, apparatus and method described above may also include features, means or instructions that configure the secondary cell to be fully deactivated based at most in part on the expiration of a deactivation period. The non-transitory computer readable medium, apparatus and method described above may also include instructions, features, means or processes for configuring secondary cells to switch to a default WP consisting of a zero-BWP, based at most in part on expiring BWP times. The state can be fully activated, partially activated, or fully deactivated depending on the non-transitory medium and apparatus described above.
“Another method of wireless communication is described. This could include configuring at most one bit of a field within a BWP DCI to indicate whether a secondary cell is activated or disabled, and then transmitting the BWP DCI to a UE based at minimum in part on that configuring.
“Another apparatus is described for wireless communication. This apparatus can include the following: means to configure at least one bit in a BWP field to indicate whether a secondary cell is activated or disabled; and means to transmit the BWP DCI to a UE based at most in part on the configuration.
“Another apparatus is described for wireless communication. The apparatus can include a processor and memory for electronic communication with it. Instructions stored in the memory may also be included. Instructions may be used to instruct the processor to set at least one bit in a BWP field for a base station to indicate whether a secondary cell is activated or disabled; and to transmit the BWP to a UE that is at least partially based on the configuration.
“Another nontransitory computer-readable medium is described for wireless communication. Instructions may be included that allow a processor configure at least one bit in a field of a BWP DCI to indicate whether a secondary cell is activated or deactivated; and transmit the BWP DCI to a UE based at most in part on the configuration.
“Some examples of the non-transitory computer readable medium and method described above may also include features, means, and instructions for configuring the primary cell associated to the base station to switch on a default BWP, based at minimum in part on the expiration of an timer. The default BWP can be configured in some of the above-described methods, apparatuses, and non-transitory computers-readable media to be a nonzero BWP.
“Some examples of non-transitory computer readable media and method described above may also include features, means or instructions for configuring subsets of or all secondary cell groups to switch between a fully activated state and a partially activated status based at minimum in part on the expiration of a timingr. The partially activated state in some of the non-transitory computer readable medium and apparatus described above is associated with a default WP consisting of a zero-BWP.
“Some examples of the non-transitory computer readable medium and method described above may also include features, means or instructions for configuring a MACCE to indicate the group secondary cells based at most in part on the BWP DCI. The BWP DCI for a primary cell that is associated with a base station contains BWP activation control information.
“Another method of wireless communication is described. This could include configuring a bitmap within a BWP DCI that indicates a state associated to each secondary cell in a group of secondarycells; and then transmitting the BWP DCI from a UE.
“Another apparatus is described for wireless communication. This apparatus can include the following: means to configure a bitmap in a BWP DCI; the bitmap indicating a particular state with each secondary cell within a group of secondary cells; means to transmit the BWP DCI from UE.
“Another apparatus is described for wireless communication. The apparatus can include a processor and memory for electronic communication with it. Instructions stored in the memory may also be included. The instructions can be used to instruct the processor to create a BWP DCI bitmap, which indicates a state associated to each secondary cell in a group of secondary cells; then transmit the BWP DCI to a U.
“Another nontransitory computer-readable medium is described for wireless communication. Instructions may be included that allow a processor configure a bitmap within a BWP DCI, the bitmap indicating a particular state for each secondary cell in a group of secondary Cells; and then transmit the BWP DCI to a U.
“Some of the non-transitory computer readable media described above include methods, features, means or instructions for identifying a certain number of bits associated to the bitmap; configuring at most one bit of bitmap to indicate an target BWP ID, based at minimum in part on the number; and configuring at the least a remainder of bits for control information that indicates the state of each secondary cell within the group of secondary cells.”
“Some examples of the non-transitory computer readable medium and method described above may also include features, means or instructions for transmitting each secondary cell’s state using higher layer signaling. The higher layer signaling in some cases of the apparatus and method described above includes radio resource control (RRC), or MAC CE signaling during secondary cell configuration procedures.
“Some examples of the non-transitory computer readable medium, apparatus and method described above include: processes, features, means or instructions for transmitting a MAC CE instructing UE to change a state of at most one secondary cell in the group of secondary cells; determining a allocation of resources for UE to communicate the at least one second cell; and transmitting an indication that an active BWP is used for the allocation resources in the BWP.
“Some examples of non-transitory computer readable media, apparatus and method may also include processes, features and means or instructions for configuring at least one secondary cells to be fully activated based at minimum in part on the transmitted MAC CE, the active BWP, and a nonzero BWP.” The method, apparatus and non-transitory computer readable medium may also include instructions, features, means or processes for configuring at least one secondary cells to be activated. This is based at minimum in part on the active BWP and transmitted MAC CE.
“Some examples of the non-transitory computer readable medium and method described above may also include features, means, or procedures for configuring at least one secondary cells to switch from the partially activated to fully activated states based at minimum in part on a BWP shifting DCI transmitted on an primary cell without a grant. The switching from the partially activated to fully activated state in some of the above-described methods, apparatuses, and non-transitory computers-readable media is also based at minimum in part on at most one bit of the bitmap.
“Some of the methods, apparatus, and nontransitory computer-readable media described above may also include processes, features or means for configuring at least one secondary cells to be in a fully deactivated state based at minimum in part on the transmitted MAC CE. The non-transitory computer readable medium and the method described above may also include instructions, features, means or processes for configuring a MACCE to indicate the group secondary cells based at most in part on the BWP DCI. The method, apparatus and non-transitory computers-readable medium may also include instructions, features, means or processes for configuring at most one bit of the bitmap in order to indicate a selection or state of a primary or secondary cell. Some examples of the non-transitory computerreadable medium and method described above include at least one bit that contains a secondary cell indicator. The non-transitory computer readable medium, apparatus and method described above may also include features, means or instructions to configure at least one bit from the bitmap, based at most in part on zero resource allocation.
“Another method of wireless communication is described. This could include receiving a MAC CE, receiving a DCI BWP indicating an active BWP that is used to allocate resources for the UE to talk with the secondary cell, and then transitioning to a secondary cell’s state based at most in part on the MAC CE or the active BWP.
“Another apparatus is described for wireless communication. This apparatus can include means to receive a MAC CE; methods for receiving a BWP DCI indicating an active BWP that is used to allocate resources for the UE; and means to transition a secondary cell’s state based at most in part on the MAC CE or the active BWP.
“Another apparatus is described for wireless communication. The apparatus could include a processor and memory in electronic communication with it. Instructions stored in the memory may also be included. Instructions may be used to instruct the processor to: receive a MAC CE; get a BWP DCI indicating an active BWP that is used to allocate resources to the UE to the secondary cell; and transition a secondary state based at most in part on the MAC CE or the active BWP.
“Another nontransitory computer-readable medium is described for wireless communication. Instructions may be included that allow a processor to: receive a MAC CE; get a BWP DCI indicating an active BWP to allocate resources to the UE for communication with the secondary cells; and transition a secondary-cell state based at most in part on the MAC CE or the active BWP.
“In some cases of the non-transitory computer readable medium, apparatus and method described above, the state includes a fully activated, partially activated, or fully deactivated state. The non-transitory computer readable medium and apparatus described may also include features, means or instructions that allow the secondary cell’s state to be activated. These are based at least partially on the received MAC CE, the active BWP, and the non-zero WP. The method, apparatus and non-transitory computer readable medium may also include instructions, features, means or processes for transitioning the secondary cell’s state to a partially activated status based at minimum in part on the active BWP and the received MAC CE.
“Some examples of non-transitory computer readable media and method described above may also include processes, features or means for transitioning the state the secondary cell to a fully deactivated state based at minimum in part on the received MAC CE. The method, apparatus and non-transitory computer readable medium may also include features, means or instructions to transition the secondary cell’s state to a fully deactivated state, based at most in part on the expiring deactivation timer.
“Another method of wireless communication is described. This could include receiving a BWP DCI signal from a base station and identifying a primary cell or group of secondary cells. The identification is based at most in part on at minimum one bit of the BWP DCI field.
“Another apparatus is described for wireless communication. This apparatus can be used to receive a BWP DCI from the base station and for identifying a primary cell or group of secondary cells. It is based at most in part on at minimum one bit of a field within the BWP DCI.
“Another apparatus is described for wireless communication. The apparatus could include a processor and memory that allows electronic communication between the processor and the processor. Instructions may be stored in the memory. Instructions may be used to instruct the processor to receive a BWP DCI from a base station and to identify a primary cell or a group of secondary-cell states based at most in part on at minimum one bit of the BWP DCI.
“Another nontransitory computer-readable medium is described for wireless communication. Instructions may be included that allow a processor to receive a BWP DCI from a base station. They can also identify a primary cell or group of secondary cells, based at most in part on at minimum one bit of the BWP DCI.
A base station can instruct a user equipment (UE), based on a change to the UE’s data throughput requirements, to activate or deactivate a secondary cells. A delay in activating or deactivating a secondary cell can be proportional to the latency involved with adapting radio frequency bandwidth. In some wireless communication systems, such as Long-Term Evolution(LTE), secondary cell activation can be sent to a UE via a medium control (MAC) control element. A bit field in the MAC CE could indicate activation or deactivation of one or more secondary cell. Secondary cell activation can be signaled via a MACCE or alternatively using a timer (e.g. expiration of a secondary cells deactivation timer).
“In some cases, MAC CE may not be able to indicate secondary cell activation/deactivation in next-generation 5G or millimeterwave (mmW). In these cases, MAC CE might have a greater latency than providing an indication of bandwidth (BWP), adaptation to the UE via Downlink Control Information (DCI) signaling. This means that the secondary cell remains active for a longer time after activation. This is to reduce signaling due to the higher overhead and latency of MAC CE signaling secondary cell activation/deactivation. The secondary cell may be activated for longer periods to reduce power consumption. This is due to the physical downlink control channel monitoring (PDCCH), on the activated secondary cells. For intra-band carrier aggregate, the receiver bandwidth for a UE might be a wideband frequency. If secondary cell activation/deactivation becomes a bottleneck, the benefits of low latency BWP adaption for the UE could be lost. Consistency between BWP, secondary cell activation and deactivation is possible. To reduce latency signaling related to secondary cell activation or deactivation, the base stations may set up a DCI format, which may include a bitmap for secondary cells activation and activation. The base station might also support MAC CE signaling in combination with BWP DCI for secondary cells activation and deactivation.
“The base station might transmit a first signal instructing UE to change the state of a secondary cells associated with it. The base station might determine the allocation of resources necessary for the UE in order to communicate with the secondary cells. It may also transmit a second signal that includes an indication of an active BWP which is used for the allocation. The transition of the secondary cell’s state may be indicated by the active BWP and first signal. The first signal could include a MAC CE, while the second signal might include a BWP DICI. The UE might receive the MAC CE signal from the base station and then also receive the BWP DCI, which indicates an active BWP that was used to allocate resources to the UE in order for it to communicate with the secondary cells. Based on the MAC CE, the active BWP, the UE can transition to a secondary state. An active BWP could be a nonzero BWP, which may be equivalent to the situation where at least one of the BWPs is activated. Non-zero BWPs can be narrowband or broadband. A non-zero BWP can include one or more BWPs with bandwidth greater that zero, up to a minimum maximum of the UE bandwidth, and a component carrier bandwidth.
“In certain cases, a base station might configure a secondary cells to be fully activated based on the transmitted 1st signal and the active WP being a nonzero BWP. The base station might configure the secondary cell to be dormant (previously known as a “gated state”) in some cases. Based on the transmitted first signal and the active WP being zero, A partially activated state can also be called the dormant condition. Alternately, the base station can configure the secondary cell to be fully activated based on the transmitted initial signal. The UE may change the state of the secondary cells to a fully activated state in some cases based on the received MAC CE. Based on the received MAC CE, the active BWP being a non-zero BWP, the UE can transition the secondary cell’s state to a dormant condition. Based on the received MAC CE, the UE can transition the secondary cell’s state to a fully deactivated state.
“Aspects are first described in the context a wireless communication system. Afterwards, exemplary UEs and bases stations (e.g. next generation NodeBs, gNBs), systems, methods and flow that support secondary cell activation/deactivation enhancements are described. The disclosure is further illustrated and described using apparatus diagrams, system diagrams and flowcharts that pertain to secondary cell activation/deactivation enhancements in a new radio.
“FIG. “FIG. The system 100 comprises base stations 105 and UEs 115 as well as a core network 130. The system 100 could be a LTE network, an LTE Advanced (LTE-A), or a new radio network. The system 100 can support enhanced broadband communications, ultra reliable (e.g. mission critical), communications, low latency communications or communications with low cost and low complexity devices.
Base stations 105 can wirelessly communicate with UEs 115 using one or more base station antennas. The base stations 105 described in this document may include, or be referred by those skilled as the art, a base transceiver station or radio base station, a radio access point, or a radio transceiver (either of these may be called a gNB), Home NodeB or a Home eNodeB or any other appropriate terminology). Base stations 105 may be of various types (e.g. macro or small-cell base stations). These UEs 115 may communicate with different types of base stations 105 as well as network equipment, including small cell eNBs and relay base stations.
“Each base station 105 can be associated with a specific geographic coverage area 110, in which communications are supported with different UEs 115. Each base station 105 can provide communication coverage within a particular geographic coverage area 110 through communication links 125. Communication links 125 between a UE 115 and a base station 105 could use one or more carriers. The communication links 125 in the system 100 can include either uplink transmissions between a UE 115 and a base stations 105 or downlink transmissions between a basestation 105 and a UE 115. Forward link transmissions can also be called downlink transmissions, while uplink transmissions could also be known as reverse link transmissions. One or more downlink bandwidth parts may be configured by the system 100. For each UE-specific service cell (e.g., a cell that is associated with a basestation 105), one or more uplink broadband parts (BWPs). The dedicated radio resource control (RRC), for a UE 115, may be used to configure the downlinks BWPs or the uplink BWPs in some cases.
“The geographic coverage area 110 of a base station 110 may be divided into sections, each section may be associated to a cell. Each base station 105 could provide communication coverage for a micro cell, small cell, hot spot, or other types or combinations thereof. A base station 105 could be mobile and provide coverage for a geographical coverage area 110. Different technologies can have different coverage areas 110. In these cases, the base station 105 may support different coverage areas 110. System 100 could include, for instance, heterogeneous LTE/LTE A or a new radio network that uses different types of base stations to provide coverage in various geographical coverage areas 110.
“The term “cell” is defined as: “Cell” is a logical communication entity that can communicate with a base station (e.g. over a carrier) and may be associated to an identifier that allows for the identification of neighboring cells (e.g. a physical cell ID (PCID), or a virtual cell ID (VCID),) which operates via the same carrier or another. A carrier may support multiple cell types. Different cells can be configured using different protocols (e.g. machine-type communication, narrowband Internet-of-Things, enhanced mobile broadband (eMBB), and others) to allow access for different devices. Sometimes, the term “cell” may refer to a portion of a geographic coverage area 110 (e.g., a sector). The term “cell” may be used to refer to an area of 110 that the logical entity covers.
“UEs 115 can be distributed throughout the system 100. Each UE 115 could be stationary or mobile. A UE 115 can also be called a mobile device or wireless device, a remote or handheld device, or a subscriber or other appropriate terminology. A client, a client, a station or terminal may also be called a unit. A UE 115 could also refer to a personal electronic device, such as a cellular telephone, a personal assistant (PDA), a tablet or laptop computer, and a personal computer. A UE 115 could also be used to refer to a wireless loop (WLL), an Internet of Things device, an Internet of Everything device (IoE), or a MTC device. These devices can be integrated in many articles, such as appliances, meters, vehicles, and the like.
“In certain cases, base station 105 might transmit a first signal instructing UE 115 transition a state to a secondary cell that is associated with UE 115. Base station 105 could be a primary cell to UE 115 and another base station 105 could be a secondary cells for UE 115. Base station 105 could determine the allocation of resources to the UE 115, and transmit a second signal that includes an indication of an active WP used in the allocating of resources based upon the determining. The first signal and active BWP may indicate that the secondary cell is in transition. The first signal could include a MAC CE, while the second signal may contain a BWP DCI. UE 115 could receive a MAC CE at base station 105. UE 115 could also be given a BWP DCI indicating that UE 115 has an active BWP which is used to allocate resources to the UE in order for it to communicate with the secondary cells. The UE 115 could transition to a secondary state based on the MAC CE or the active BWP.
Base station 105 can configure secondary cells to be fully activated based on the transmitted 1st signal and active BWP. Base station 105 might configure the secondary cell to remain dormant in some cases based on the transmitted 1st signal and the active WP being zero. An activated secondary cell can quickly go dormant during periods of low activity. UE 115 can rely on a primary cells to maintain a connection while in the dormant condition (e.g., a connection with a base station 105). For activated secondary cells, the dormant condition can be described as the deactivation of all BWP. Sometimes, the secondary cells may be in a dormant condition when their active BWP equals zero. Sometimes, the default BWP of a secondary cell might be the zero BWP. In these cases, the secondary cells may switch to the dormant status when the BWP timer expires. UE 115 can have a lower active radio frequency bandwidth support and less power consumption when the secondary cell is dormant.
The transmitted first signal may also be used by base station 105 to configure the secondary cell to be fully deactivated. Base station 105 might configure the secondary cell to be fully deactivated if a timer expires. UE 115 can change the state of the secondary cells to a fully activated state in some cases. This is based on the received MAC CE, and active BWP being a nonzero BWP. UE 115 could transition the secondary cell’s state to a dormant condition based on the active BWP and the received MAC CE. UE 115 could transition the secondary cell’s state to a fully deactivated state based upon the received MAC CE. UE 115 can transition the secondary cell’s state to a fully deactivated state based upon the expiration of a deactivation period. An activated BWP can remain active up to the expiration of a BWP-timer or until a subsequent DCI indicates that it is to be deactivated. A table may be created that lists the activated and deactivated BWPs. The DCI may also include an index to the table that indicates which BWPs have been active and which are inactive. The DCI may contain a bitmap that indicates which BWPs have been activated and which are inactive. The UE 115 can transmit acknowledgment (ACK), or non-acknowledgment(NACK) receipts of the DCI to base station 105. This may be done using either resources specified in the DCI, or preconfigured acknowledgment resource.
“Base station 105 might configure at least one bit in a field of a BWP DCI to indicate whether a secondary cell is activated or disabled. The BWP DCI will then be transmitted to UE115. The configuration could include base station105 changing to a default BWP upon expiration of a timer. The timer could be a BWP-timer that can be associated with an active BWP duration for a primary and/or secondary cell. A default BWP can be set to a non-zero value. The configuration could include all or a subset (or all) of secondary cells that can be configured to change from a fully activated to a dormant status based on the expiration of a timer. A default BWP, including a zero-BWP, may be used to indicate the dormant status. Base station 105 could also be configured to indicate the group secondary cells that are based on the BWP DCI. UE 115 could receive the BWP DCI at base station 105 to identify a selected primary cell or a group of secondary neurons based on at most one bit of a field from the BWP DCI.
“A default BWP (e.g. a default WP of base station 105) could be active with any remaining BWPs, e.g. other BWPs at the base station105 or one or several BWPs from one or more secondary cell, deactivated, unless activated by base station105. The UE 115 can perform channel state information measurements (CSI) and transmit a measurement record upon activation of a corresponding BWP. This may allow for less monitoring and measurement of deactivated BWPs, which can lead to power savings and better resource utilization. Secondary cell activation or deactivation can be determined based on whether or no DCI indicates that a BWP is active in one or more secondary cells. If a BWP for a secondary cells is activated, it may be considered that the secondary cell has been activated. However, if all BWPs have been deactivated, then the secondary may be considered deactivated. This allows for separate signaling to activate and deactivate secondary cells.
“System 100 may allow for the configuration of a special (e.g. a zero) BWP. This corresponds to all BWPs being deactivated for secondary cells when they become active BWPs on secondary cells. System 100 can also support zero BWP, which may be used as a default downlink-BWP for a secondary cell. The zero BWP might not be permitted to be used as the first active BWP for a secondary cell in some cases. System 100 may be able to schedule DCI with zero assignment in some cases. This is for active downlink or uplink BWP switching. For downlink scheduling DCI, UEs 115 may transmit positive HARQ ACK for zero-size physical downlink shared channel (PDSCH) transmission. Base stations 105 (e.g. gNB), may transmit a BWP switch DCI (with zero assignment on the secondary cells) to activate a zero BWP that will transition the secondary cell into a dormant (or partially activated) state. Base stations 105 may transmit BWP switching DCI (with zero assignment) to a primary cell. In these cases, it may contain a secondary cell control indicator and bitmap that selects which secondary cell’s active BWP will switch to the first active. A zero BWP can be an original active WP. This may switch the secondary cell from dormancy. Base station 105 could configure a secondary cell (e.g. base station 105) in order to change from a dormant to fully activated state. This is based on a BWP switching DCI transmitted on a primary cells without a grant.
“Some UEs 115 such as MTC and IoT devices may be low-cost or low-complexity devices that allow for automated communication between machines (e.g. via Machine-to Machine (M2M), communication). M2M communication, or MTC, may be used to refer to data communication technologies that allow devices or a base station to communicate with each other without the need for human intervention. M2M communication, or MTC, may refer to communications between devices that use sensors or meters to capture or measure information. The information is relayed to a central server to make use of it or to present it to the human user. Some UEs 115 can be used to collect data or allow automated behavior of machines. MTC devices can be used for monitoring and controlling many things, including inventory, water level, equipment, monitoring, health monitoring, wildlife monitoring and fleet management.
“Some UEs 115 might be configured to use operating modes that reduce power consumption such as half-duplex communication (e.g. a mode that supports one way communication via transmission or receipt, but not simultaneous transmission and reception). Half-duplex communications can be carried out at a lower peak rate in some cases. Another power-saving technique for UEs 115 is to enter a power-saving?deep sleep? Mode when the user is not engaged in active communication or operating on a narrow bandwidth (e.g. according to narrowband communications). In certain cases, UEs 115 might be used to support mission-critical functions. The system 100 may also be set up to provide reliable communications for such functions.
“In certain cases, a UE 115 might also be able communicate directly with other UEs 115 (e.g. using a device-to?device (D2D), protocol or peer-to?peer (P2P). A group of UEs 115 using D2D communications could be located within the geographical coverage area 110 of a base stations 105. Other UEs 115 may not be able to receive transmissions from a 105 base station 105 because they are outside of the geographical coverage area 110. Sometimes, groups of UEs 115 communicating via D2D communications can use a one to many (1:M) system where each UE 115 transmits information to all UE 115 within the group. A base station 105 may be used to schedule resources for D2D communications. D2D communications can be carried out between UEs 115 and UEs 105 in other cases.
“Base stations105 may communicate with each other and the core network 130. Base stations 105, for example, may communicate with the core network 130 via backhaul links132 (e.g. via an 51 interface or another interface). Base stations 105 can communicate over backhaul link 134 with each other (e.g. via an X2 interface or another interface), either directly (e.g. between base stations 105) oder indirectly (e.g. via the core network 130).
The core network 130 could provide access authorization, tracking and user authentication. It may also be used to access routing and mobility functions, as well as access routing. Core network 130 could be an evolved packet core (EPC), with at least one mobility management entity, at least one serving gateway (S?GW), and at most one Packet Data Network gateway (PDN) gateway. The MME can manage non-access stratum functions (e.g. control plane), such as mobility, authentication and bearer management for UEs 115 that are served by base stations 105. The S-GW may allow user IP packets to be transmitted. This may also be connected with the P-GW. The P-GW can provide IP address allocation and other functions. The P-GW can be connected to network operators IP services. Operators may offer access to Intranet(s), the Internet, or an IP Multimedia Subsystem IMS.
“At minimum some network devices such as a basestation 105 may include subcomponents like an access network entity. This could be an example access node controller (ANC). Each access network entity may communicate with UEs 115 through a number of other access network transmission entities, which may be referred to as a radio head, a smart radio head, or a transmission/reception point (TRP). In some configurations, different functions of an access network entity (or base station 105) may be spread across multiple network devices (e.g. radio heads and access controllers), or combined into one network device (e.g. a base station 105)
“System 100 can operate in one or more frequency bands. Typically, it operates between 300 MHz and 300 GHz. The region between 300 MHz and 3 GHz is generally known as the ultra high frequency (UHF), or decimeter band. These wavelengths are approximately one to one meter long. Buildings and other environmental features can block or redirect UHF waves. The waves can penetrate buildings sufficiently to allow a macro cell to service UEs 115 indoors. UHF transmission may require shorter antennas and a shorter range (e.g. less than 100km) as compared to transmission using smaller frequencies and longer waves at the very high frequency (HF), or very high frequency(VHF) portion below 300 MHz.
“The system 100 could also operate in the super high frequency (SHF), region that uses frequency bands between 3 GHz and 30 GHz. Also known as the centimeter range, SHF includes bands such the 5GHz industrial, scientific, or medical (ISM), which can be used opportunistically with devices that are able to tolerate interference from other users. The system 100 can also operate in the extremely high frequency (EHF), region of spectrum (30 GHz to 300GHz), also known by the millimeter band. The system 100 may allow millimeter wave (mmW), communications between UEs 115, base stations 105. EHF antennas may be smaller and closer than UHF antennas. This may allow for the use of antenna arrays within a UE 115 in certain cases. EHF transmissions can be propagated at a lower frequency and with a shorter range than UHF or SHF transmissions. The techniques described herein can be applied to transmissions that use different frequency regions. However, the designated use of bands across frequency regions may vary by country or regulating agency.
“In certain cases, system 100 could use both licensed and unlicensed radio frequency bands. The system 100 might use License Assisted Access (LAA), LTE Unlicensed (LTE?U) radio access technology or new radio technology in unlicensed bands such as the 5 GHz ISM. Wireless devices, such as base stations (105) and UEs (115), may use listen-before-talk procedures to ensure that a frequency channel is clear prior to transmitting data when operating in unlicensed radio frequency bands. Sometimes, operations in unlicensed band may be based upon a CA configuration along with CCs operating within a licensed spectrum (e.g. LAA). Operation in unlicensed spectrum can include peer-to-peer transmissions or downlink transmissions. Duplexing in unlicensed frequency spectrum can be done using either frequency division duplexing or time division duplexing (TDD), as well as a combination of both.
“Base station 105 and UE 115 may have multiple antennas. These can be used to transmit diversity, receive diversity (MIMO), multiple-input multiple output (BEAMFORMING) communications. The system 100 could use a transmission method between a transmitting device (e.g. a base station 105) or a receiving device (e.g. a UE 115), in which the transmitting device has multiple antennas, while the receiving devices have one or more antennas. Multipath signal propagation may be used in MIMO communications to improve the spectral efficiency of multiple signals being transmitted or received via different spatial layers. This may also be known as spatial multiplexing. Multiple signals can be transmitted, for instance, by different antennas or different combinations. The multiple signals can also be received by the receiver device using different antennas or different combinations. Each signal may be called a distinct spatial stream and may contain bits that are associated with the same data stream (e.g. the same codeword or different data streams). Different antenna ports may have different spatial layers that are used to measure and report channel measurements. MIMO techniques can be used in two ways: single-user MIMO, where multiple spatial layer are transmitted to the same receiver device; and multi-user MIMO where multiple spatial levels are transmitted to multiple devices.
“Beamforming” (also known as spatial filtering, directional transmit, or directional receipt) is a signal processing technique used at a transmitter device or receiver device (e.g. a base station 105, UE 115) in order to steer or shape an antenna beam (e.g. a transmit beam, receive beam) along a path between the receiving device and transmitting device. Combining signals from antenna elements can be used to beamform signals. Signals propagating in particular directions with respect to antenna arrays may experience constructive interference, while others will experience destructive interference. An antenna element may be used to adjust signals. A transmitting device, or a receiver device, can apply certain phase offsets and amplitudes to the signals transmitted via each antenna element. An antenna element may have a beamforming weight that is associated with it. This can be used to adjust the signal to a specific orientation (e.g. with respect the antenna array of the receiving device or transmitting device) or any other orientation.
“A base station 105 might use multiple antennas, or arrays, to perform beamforming operations in order to direct communications with a UE 115. Some signals, such as synchronization signals, reference signals, beam selection signals or other control signals may be transmitted by a base station 105. Some signals (e.g., synchronization signals or reference signals, beam selection signal, or other control signals), may be transmitted multiple times by a base station. This could include signals being transmitted according to different beamforming weigh sets that correspond with different directions of transmission. Transmissions in different beam directions can be used to identify (e.g. by the base stations 105 or a receiver device, such as a UE 115), a beam direction for further transmission and/or reception at the base station 105. A base station 105 may transmit signals in a single direction, such data signals that are associated with a specific receiving device. Some examples show that the beam direction of transmissions along a single beam direction can be determined by a signal transmitted in different beam directions. A UE 115 might receive signals from the base station 105 in various directions. The UE 115 could report to the base stations 105 a signal quality indicator or other acceptable signal quality. These techniques are only applicable to signals that are transmitted by a base station 105 in one or more directions. However, a UE 115 could use similar techniques to transmit signals multiple times in different directions.
A receiving device, such as a UE 115 which could be an example of a mmW receiver device, may attempt multiple receive beams while receiving signals from base station 105. These signals may include synchronization signals and reference signals. A receiving device might try multiple receive directions, for example by receiving signals via different antenna subarrays or processing received signals using different receive beamforming weigh sets. Signals received at different antenna elements may also be processed according to different weight sets. This is known as “listening”. Depending on the receive beams and directions. A receiving device might use one receive beam to receive data signals along a single direction in some cases. A single receive beam can be aligned in a direction determined at least partly by listening to different beam directions. (e.g., a beam directed that has the highest signal strength, highest signal to noise ratio or other acceptable signal quality, determined at least in part by listening to multiple beam directions).
“In certain cases, antennas from a base station 105 and UE 115 could be found within one or more antenna arrays. These arrays may support MIMO operations or transmit/receive beamforming. An antenna tower, for example, may have one or more antenna arrays or base station antennas. Antennas and antenna arrays that are associated with base station 105 can be found in different geographic locations. An antenna array may be used by a base station 105 to beamform communications with a UE 115. A UE 115 could also have an array of antennas that can support different MIMO or beamforming operations.
“In certain cases, system 100 could be a packet-based network operating according to a layer protocol stack. The user plane may have IP-based communications with the bearer (or Packet Data Convergence protocol (PDCP) layer). In some cases, a Radio Link Control layer (RLC), may perform packet segmentation and reassembly in order to communicate over logical channel. Medium Access Control (MAC), a layer that handles priority handling and multiplexing logical channels into transport channel, may be used. To improve link efficiency, the MAC layer can also use hybrid automated repeat request (HARQ). The Radio Resource Control protocol layer (RRC) may be used to establish, configure, and maintain an RRC connection between a UE 115, a base station 105, or core network 130 that supports radio bearers for user-plan data. Transport channels can be mapped to physical channels at the Physical (PHY). layer.
“In certain cases, UEs 115 or base stations 105 may allow retransmissions to increase the probability that data is received successfully. One technique to increase the probability that data is correctly received over communication links 125 is HARQ feedback. The HARQ can include error detection (e.g. using a cyclic Redundancy Check (CRC), forward error corrections (FEC), and transmission (e.g. automatic repeat request (ARQ). HARQ can improve throughput at MAC layer under poor radio conditions (e.g. signal-to-noise). A wireless device may be able to provide same-slot feedback for HARQ. In this case, the device might provide HARQ feedback in a particular slot for data received in a prior symbol. Other cases may see HARQ feedback provided in a different slot or at a different time.
Time intervals in LTE and new radio can be expressed in multiples a basic unit. This could, for instance, refer to a sampling time of Ts=1/30720,000 seconds. The time intervals for a communication resource can be organized using radio frames, each with a duration of 10 ms. In this case, the frame period could be Tf=307200 Ts. A system frame number (SFN), ranging from 0-1023, can be used to identify the radio frames. Each frame can contain 10 subframes, each numbered from 0-9, and each subframe could have a duration between 0.5 and 7 ms. Each slot may also include 6 or 7, depending on how long the cyclic prefix is added to each symbol period. Each symbol period can contain 2048 sampling times, excluding the cyclic prefix. A subframe can be the smallest unit in the system 100 and is sometimes referred to as a transmission interval (TTI). Other cases may see a smaller scheduling unit of system 100 than a subframe. In these cases, it may also be dynamically selected (e.g. in short TTIs (sTTIs), or in select component carriers using TTIs).
“In some wireless communication systems, a slot can further be divided into several mini-slots that contain one or more symbols. A symbol of a mini slot or a small-sized slot may be the smallest unit for scheduling. The frequency band or subcarrier spacing of an operation may affect the duration of each symbol. Some wireless communication systems also allow for slot aggregation, where multiple slots or mini-slots can be combined and used to communicate between a UE 115 (or a base station 105).
“The term “carrier” refers to a set of radio frequency spectrum resources that are used to transport communications. A set of radio frequency resources that support communications over a communication line 125. A carrier for a communication link 125 might include a part of a radio frequency band that is used according to radio access technology physical layer channels. Each channel can carry user data, control information or other signaling. An associated carrier can be assigned a frequency channel (e.g. an Evolved Universal Terrestrial Radio Access, (E-UTRA), absolute radio frequency channel number (EARFCN),) and may be positioned according a channel raster to be discovered by UEs 115. Either downlink or upwards (e.g. in an FDD or TDD mode), carriers can be configured to carry both downlink and uplink communications (e.g. in a TDD or downlink mode). In some examples, signal waveforms transmitted over a carrier may be made up of multiple sub-carriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform-spread-OFDM (DFT-s-OFDM)).”
“The organization structure of carriers can be different for different radio accessibility technologies (e.g. LTE, LTE A, new radio, etc.). Communications over a carrier might be structured according to TTIs (or slots), each of which could include user data, as well as control information, signaling, or information to assist decoding that user data. A carrier might also contain dedicated acquisition signaling (e.g. synchronization signals, system information, etc.). Control signaling that coordinates the operation of the carrier. Some carriers may have acquisition signaling and control signaling that coordinates the operations of other carriers, such as in a carrier consolidation configuration.
Multiplexing physical channels on a carrier may be possible using different techniques. Multiplexing a physical control channel and a data channel on a downlink carrier may be possible using different techniques. For example, time division multiplexing techniques, frequency division multiplexing techniques, or hybrid TDM/FDM techniques. Some examples show control information being distributed in a physical channel between different control areas in a cascaded fashion (e.g. between a common control area or common search space, and one or more UE specific control regions or UEspecific search spaces).
“A carrier can be associated with a specific bandwidth of the radiofrequency spectrum. In some cases, the carrier bandwidth might be called a?system bandwidth? The system 100 or the carrier. The carrier bandwidth could be, for example, one of several predetermined bandwidths that are available to carriers of a specific radio access technology (e.g. 1.4, 3, 5, 10, 15, 20 40, 80 MHz). Each UE 115 served may be configured to operate over a portion or all of the carrier bandwidth. Some UEs 115 can be configured to operate using a narrowband protocol type. This type is associated with a predefined range or portion (e.g. set of subcarriers, RBs, or RFs) within a carrier (e.g.?in-band). ”
“In MCM systems, a resource element can be composed of one symbol period (e.g. a duration of one module symbol) and one Subcarrier. The symbol period and the subcarrier spacing may be inversely related. The modulation scheme (e.g. the order of the modulation scheme) may affect the number of bits each resource element can carry. The data rate for UE 115 may increase if it receives more resource elements and the order of the modulation scheme. MIMO systems may use a combination radio frequency spectrum, a time and a spatial resource to define a wireless communications resource. Multiple spatial layers can increase the data rate when communicating with a UE 115.
“Devices 100 (e.g. base stations 105 and UEs 115) may have hardware configurations that support communications over a specific carrier bandwidth or may be configured to support communications over a number of carriers bandwidths. The system 100 might include base stations 105 or UEs that support simultaneous communications over carriers with multiple carrier bandwidths. System 100 may allow communication with a UE 115 over multiple carriers or cells. This feature is sometimes called carrier aggregation (CA), or multi-carrier operations. A UE 115 can be configured with multiple downlink CCs, and one or more of the uplink CCs depending on a carrier aggregation configuration. Carrier aggregation can be used with FDD or TDD component carriers.
“In certain cases, system 100 may use enhanced component carriers (eCCs). An eCC can be distinguished by one or more of the following features: a wider carrier or frequency channel bandwidth; shorter symbol duration; shorter TTI duration; or modified control channel configuration. An eCC can be associated with a carrier aggregation or dual connectivity configuration in some cases (e.g. when multiple serving cells have a suboptimal backhaul link). An eCC can also be used in unlicensed or shared spectrum, where more than one operator has access to the spectrum. A eCC with a large carrier bandwidth could include one or more segments that UEs 115 may use to monitor the entire carrier bandwidth.
“In some cases, eCCs may use a different symbol length than other CCs. This may mean that eCCs may use a shorter symbol duration than other CCs. An increased spacing between subcarriers may be caused by a shorter symbol duration. A device such as a UE 115, base station 105, that uses eCCs can transmit wideband signals (e.g. according to frequency channels or carrier bandwidths of 20, 40 and 60 MHz, 80 MHz, etc.). At reduced symbol durations (e.g. 16.67 microseconds). TTIs in eCC can be composed of multiple symbol periods. Sometimes, the TTI duration, that is, the number and length of symbol periods in an eCC TTI, may be variable.
“Wireless communication systems, such as a radio system, may use any combination of licensed and unlicensed spectrum band, including shared spectrum bands. Flexibility in eCC symbol length and subcarrier spacing may permit the use of eCC across multiple frequencies. New radio shared spectrum can increase spectrum utilization and efficiency in certain cases, particularly through dynamic vertical (e.g. across frequency) or horizontal (e.g. across time) sharing.
“FIG. “FIG. 2” illustrates an example system 200 that supports secondary cells activation and deactivation in new radios, in accordance to various aspects of this disclosure. System 200 may implement some aspects of system 100 in certain examples. System 200 could include a basestation 205, a 210 base station, and a UE 215, all of which can be examples of the corresponding devices shown in FIG. 1. System 200 can operate using a radio access technology, such as next generation 5G, or millimeter wave(mmW) radio system. However, the techniques described herein may also be applied to other radio access technologies (e.g. LTE, LTE-advanced, LTE-A), and systems that may simultaneously use multiple radio access technologies (e.g. next generation 5G, mmW radio, and LTE). Base station 205 could be associated to a coverage of 235 and base station 220 may be associated for a coverage of 240. The following communication examples may occur between base station 205 and base station 210.
Dual-connectivity may be used to configure “UE 215 so that it can receive and transmit data from base stations 205 and 210. Base station 205 could be a primary cell of the next generation NodeB (gNB), or evolved NodeBss (eNBs), while base station 210 might be a secondary cell such as a secondary gNB(SgNB). Dual-connectivity mode may result in UE 215 having increased data transmission capabilities but also consuming more power. Dual-connectivity may result in UE 215’s power consumption being higher because UE 215 could be receiving and monitoring data transmissions from base stations 205 and 210. System 200 can efficiently manage data transmission capabilities while decreasing power consumption for UE 215 through improved secondary cell activation/deactivation techniques for base stations 205 and UE 215.”
“Base station 205 can configure UE 215 using one or more component carriers. Some examples may see a subset or all of the component carriers being deactivated, except for a primary carrier. Base station 205 might activate one or more secondary components carriers in order to increase downlink throughput. Base station 205 may be used as a primary cell to instruct UE 215, for example, to activate or deactivate a secondary cells (e.g. base station 210). UE 215 can also be configured for carrier aggregation, which allows data transmissions from base station 205 and base station 210 to have a higher bandwidth. A component carrier is a carrier that is aggregated. UE 215 might use contiguous component carrier within the same operating frequency band (e.g. intra-band carrier aggregation) or non-contiguous components carriers that are located at the same frequency but with a gap between them. Sometimes, UE 215’s power consumption during downlink operations increases with increasing radio frequency receiver bandwidth. UE 215 can support variable receiver bandwidth because it receives data transmissions continuously from base station 205 and base station 210. One example is that UE 215’s receiver bandwidth may be a wideband radio frequency. Another example is that UE 215 might monitor a downlink channel (e.g. physical downlink channel (PDCCH),) using a narrowband radio frequency bandwidth and then receive data using a wider radio frequency bandwidth (e.g. wideband), based upon a bandwidth configuration.
“Bandwidth configuration could include base station 205 adapting UE 215. BWPs may contain a number resource blocks that are allocated to UE 215 in order to communicate with base station 205 and base station 210. Multiple component carriers can be configured using carrier aggregation techniques. This may include a primary carrier (also known as a primary cell carrier, primary cell, or primary cell), and one or more secondary carriers (also known as secondary cell carriers, or secondary cells). Each component carrier can have one or more BWPs. One BWP can be used to transmit data between UE 215 (base station 205) if the data transfer is relatively short. Two or more BWPs could be used if large amounts of data are to be transmitted. Different bandwidths may be used for different bandwidth parts. If the data being transferred is very small, a narrow bandwidth can be used. However, a wider bandwidth may be used. Based on the bandwidth configuration, UE 215 can dynamically switch between BWPs.
Base station 205 can configure BWPs to UE 215 in order to enable dynamic bandwidth adaptation. Base station 205 can signal BWP activation or deactivation or a switching of BWPs, or any combination thereof, via DCI signaling. UE 215 can dynamically adjust a radio frequency bandwidth based upon a BWP switching signaled by base station 205. UE 215 may be able to save power by dynamically switching between a BWP having a narrowband bandwidth or a broadband bandwidth.
“Power saving for UE 215 in some cases of carrier aggregation may be more difficult than for a single carrier case. A BWP adaptation to each carrier may not produce the same power saving results for UE 215 as a single carrier case. For example, a BWP that has a narrowband bandwidth might be more effective than a BWP that has a widerband bandwidth. Power saving may not be as evident in intra-band contiguous carrier aggregation which employs a wideband receiver radio frequency. Sometimes, multiple activated secondary cell (e.g. SgNBs) may be used. However, even if the secondary cells use narrowband BWPs, the overall receiver’s (i.e. UE 215) radiofrequency bandwidth may not be significantly reduced. This is because the receiver’s radiofrequency bandwidth may be based upon the total span of all secondary serving cells active bandwidths and not the bandwidth of a single BWP.
“Base station 205” may indicate activation of a BWP from UE 215 based upon DCI signaling. DCI signaling could be independent of a BWP and a downlink grant. DCI signaling can be used to activate a BWP. This may reduce the power consumption of UE 215 due to the low latency associated to DCI signaling. In certain cases, UE 215 might establish a connection to base station 205 where one or more component carriers can be configured with one of the BWPs. Base station 205 might indicate which BWP is currently active for a transmission of DCI. This may be done after the configuration of one or more component carriers. UE 215 could activate a corresponding component carrier or BWP based on this indication.
“Base station 205 might configure one or more secondary cell to switch from a dormant to fully activated state using a BWP switching DCI transmitted to a primary cell. This is possible in certain cases. BWP switching DCIs may contain information about the activation of BWP for one or more secondary cells that are associated with UE 215. Base station 205 might configure the secondary cell to change from a dormant to fully activated state using a BWP switch DCI transmitted to a primary cell. A control field indicator (CIF) may be included in the BWP switching DCI.
Base station 205 might instruct UE 215 in some cases to activate or deactivate a secondary cells (e.g. base station 210) based upon a change of data throughput requirements for UE 215 Some cases may show that the time it takes to activate or deactivate secondary cells (e.g. base station 215) is directly proportional to latency involved in performing radio frequency bandwidth adaption. In some wireless communication systems, such as Long-Term Evolution(LTE), secondary cell activation can be sent to a UE via a medium control (MAC) control element. A bit field in the MAC CE could indicate activation or deactivation of one or more secondary cell (e.g. base station 210). Secondary cell activation can be signaled via a MACCE or alternatively using a timer (e.g. expiration of a secondary cells deactivation timer). However, MAC CE may not be as effective in indicating secondary cell activation/deactivation in next-generation 5G and mmW radio systems, e.g. to UE 215 because it uses a longer latency than DCI signaling to indicate BWP adaptation to UE 215 for this purpose. Secondary cell activation has a higher overhead due to the long latency associated base station 205 instructing UE 215, to deactivate a secondary cells (e.g. Base station 210) uses MAC CE signaling. This is in contrast to the DCI signaling used for the BWP adaptation signal. The secondary cell is kept active for longer periods of time to reduce power consumption. This is due to the PDCCH monitoring of the activated secondary cells by UE 215. If secondary cell activation/deactivation becomes a bottleneck in system 200, then the benefits of low latency BWP adaptation to UE 215 will be diminished. Consistency between BWP, secondary cell activation/deactivation and BWP may therefore be desirable.
“UE 215 could be configured with a new radio tracking reference signal framework. This may enable express BWP adaption in some cases of next-generation 5G and mmW radio systems. UE 215 might be able to report channel state information earlier that the 24-millisecond (ms), limit (e.g., n+24 time in LTE). MAC CE signaling could have a greater impact on the overall reporting of channel information than DCI signaling.
DCI signaling can be used to activate or deactivate secondary cells faster than conventional methods. MAC CE signaling can have the following limitations that could affect data throughput, efficiency and processing resources as well as power consumption of UE 215. DCI signaling, however, may address some or all these shortcomings of MAC CE signaling. DCI signaling may reduce latency by at minimum 60% even though similar acknowledgement or non-acknowledgment delays related to PDSCH data transmitting.
“In some cases, base station205 may configure DCI (downlink control information) formats that include bitmaps for secondary cell activation or deactivation to reduce latency in secondary cell activation. The bitmap may be able to follow features in MAC CE. Base station 205 might reconfigure a DCI format in order to include bitmap from existing MAC CEs. This DCI format reconfigured may also be called a L1 CE. This means that control elements sent using MAC CE signaling can be transmitted by base station 205 via DCI signaling.
“In certain cases, a BWP of a primary cell (e.g. base station 205) might carry a control bitmap that is associated with one or more secondary layers. Individual secondary cells can be signaled to change to another BWP based on the control bitmap. Each secondary cell may have at least one bit assigned in order to conserve bits. One bit may contain a secondary cell indicator, such as an identifier (ID), and at least one bit can be included in the bitmap. If at least one bit is set in some cases, the secondary cell can transition to a preconfigured first BWP. Alternativly, activated secondary cells can be mapped to a control bitmap in some cases.
“Base station 205 can reconfigure a downlink grants to include an instruction instructing UE 215, to activate or deactivate a secondary cells (e.g. base station 210). Base station 205 might configure a DCI with a bitmap to allow secondary cell activation or deactivation. Base station 205 might configure a field within a BWP DCI to indicate a BWP identification (ID) field. For a downlink grant from base station 205, UE 215, UE 215 could identify the intended BWP. UE 215, for example, may receive and operate on a first BWP. A first field may contain a bitmap for secondary cells activation or deactivation. A second field may indicate a BWP ID. UE 215 could then transition to this second BWP. Base station 205 could transmit a BWP DCI that includes information about downlink grants, secondary cell activation or deactivation, as well as a bitmap for secondary cells activation or deactivation and a BWP ID to UE 215.
Base station 205, or base station 210, may be a mmW station that transmits a beamformed transmission using an active beam to UE 215 Base station 205 could transmit a BWP DCI 225 via active beam to UE 215 using beamformed transmission 220-a. A bitmap may be included in the BWP DCI 225. It could include a number bits that relate to one or more secondary cell. A bitmap can include several bits, such as at least one bit and eight bits. Base station 205 might use each bit to indicate the status of secondary cells, e.g. an activation or deactivation of secondary cells. A bit value of?1 could indicate that a secondary cell is activated or to be activated by UE 215. A bit value of?1? could indicate that a secondary cells is activated or will be activated by UE 215; a bit value of?0? may indicate that a secondarycell is deactivated or will be deactivated by UE 215 UE 215 may indicate that a secondary cells is activated or to be activated by UE 215 and a bit value?0? Some examples may show that at least one bit in the bitmap is reserved (e.g. for padding purposes).
“In some cases, the number of secondary cells configured and supported by base station205 may exceed what is necessary to indicate all secondary cells in BWP DCI 2225. This means that a bitmap might be longer than the number of bits available in the BWP DCI DCI 225. Base station 205 might also be able to support M secondary cells with M bits. N and M can be positive integers. Base station 205 could have 31 secondary cells configured (including base station 211). The BWP 225 may only have eight bits for bitmaps and may not be able to support bitmaps with 31 bits. Base station 205 can group secondary cells together to be associated with at most one bit to address the bit availability issues in the BWP DCI 225. A first set of secondary cell (e.g. secondary cells 1 through 8) can be assigned to C1, while a second set (e.g. secondary cells 9 through 16 may be assigned (C2)), etc.
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