Patent Description:
<NPL> provides provide the discussion on the handover requirements for DAPS based handover solution in NR. Qualcomm Incorporated: "On NR enhanced MBB Requirements" XP051794559 provides a further discussion on NR enhanced MBB HO requirements.

In some aspects, a method of wireless communication in accordance with claim <NUM> is, performed by a base station and may include configuring a bandwidth part (BWP) switching configuration of a user equipment (UE) in connection with a dual active protocol stack (DAPS) handover based at least in part on a BWP switching rule; and performing the DAPS handover.

In some aspects, a method of wireless communication in accordance with claim <NUM> is performed by a UE, may include receiving a BWP switching configuration in connection with a DAPS handover, wherein the BWP switching configuration is based at least in part on a BWP switching rule; and performing the DAPS handover.

In some aspects, a base station according to claim <NUM>, may include means for configuring a BWP switching configuration of a UE in connection with a DAPS handover based at least in part on a BWP switching rule; and means for performing the DAPS handover.

In some aspects, a user equipment, UE, according to claim <NUM>, may include means for receiving a BWP switching configuration in connection with a DAPS handover, wherein the BWP switching configuration is based at least in part on a BWP switching rule; and means for performing the DAPS handover.

Aspects generally include a method, apparatus, system, computer program product, non-transitory computer-readable medium, user equipment, base station, wireless communication device, and/or processing system as substantially described herein with reference to and as illustrated by the accompanying drawings.

Controller/processor <NUM> of base station <NUM>, controller/processor <NUM> of UE <NUM>, and/or any other component(s) of <FIG> may perform one or more techniques associated with bandwidth part (BWP) switching for a dual active protocol stack (DAPS) handover, as described in more detail elsewhere herein. For example, controller/processor <NUM> of base station <NUM>, controller/processor <NUM> of UE <NUM>, and/or any other component(s) of <FIG> may perform or direct operations of, for example, process <NUM> of <FIG>, process <NUM> of <FIG>, and/or other processes as described herein. Memories <NUM> and <NUM> may store data and program codes for base station <NUM> and UE <NUM>, respectively. In some aspects, memory <NUM> and/or memory <NUM> may comprise a non-transitory computer-readable medium storing one or more instructions for wireless communication. For example, the one or more instructions, when executed by one or more processors of the base station <NUM> and/or the UE <NUM>, may perform or direct operations of, for example, process <NUM> of <FIG>, process <NUM> of <FIG>, and/or other processes as described herein.

In some aspects, UE <NUM> may include means for receiving a BWP switching configuration in connection with a DAPS handover, wherein the BWP switching configuration is based at least in part on a BWP switching rule, means for performing the DAPS handover, and/or the like. In some aspects, such means may include one or more components of UE <NUM> described in connection with <FIG>, such as controller/processor <NUM>, transmit processor <NUM>, TX MIMO processor <NUM>, MOD <NUM>, antenna <NUM>, DEMOD <NUM>, MIMO detector <NUM>, receive processor <NUM>, and/or the like.

In some aspects, base station <NUM> may include means for configuring a BWP switching configuration of a UE in connection with a DAPS handover based at least in part on a BWP switching rule; means for performing the DAPS handover; means for configuring the UE to switch at least one of a source BWP or a target BWP during the DAPS handover; means for configuring a source BWP of the UE as a first component carrier; means for configuring a target BWP of the UE as a second component carrier; means for configuring a source BWP of the UE as a first leg of a multi-TRP communication; means for configuring a target BWP of the UE as a second leg of the multi-TRP communication; and/or the like. In some aspects, such means may include one or more components of base station <NUM> described in connection with <FIG>, such as antenna <NUM>, DEMOD <NUM>, MIMO detector <NUM>, receive processor <NUM>, controller/processor <NUM>, transmit processor <NUM>, TX MIMO processor <NUM>, MOD <NUM>, antenna <NUM>, and/or the like.

A UE in connected mode may perform a handover from a source cell to a target cell. For example, the source cell may be provided by a source base station (e.g., BS <NUM>) and the target cell may be provided by a target base station (e.g., BS <NUM>). Some forms of handover may be associated with an interruption as the UE is handed over from the source cell to the target cell. Certain techniques may be employed to mitigate the interruption, such as a DAPS handover, which may also be referred to as a reduction in user data interruption (RUDI) handover or a make-before-break (MBB) handover. In a DAPS handover, the UE may contemporaneously connect to a source cell and a target cell so that the UE can communicate with less interruption than a break-before-make handover.

In a DAPS handover, a handover command may be conveyed to a UE using a radio resource control (RRC) message, such as an RRC reconfiguration message. The UE may maintain contemporaneous connections to the source cell and the target cell during the DAPS handover. For example, the UE may perform downlink and uplink communication on the source cell and a random access procedure on the target cell, or may perform downlink and uplink communication on the source cell and on the target cell. The UE may release the connection with the source cell after receiving an RRC message (e.g., an RRC reconfiguration message) indicating to release the connection with the source cell.

A UE may communicate using bandwidth parts (BWPs). A BWP may be defined by various parameters, such as a frequency resource (e.g., a starting or center frequency and a bandwidth), a numerology (e.g., indicating a subcarrier spacing), and/or one or more other parameters for physical channel configuration, such as for a physical downlink control channel, a physical downlink shared channel, a physical uplink control channel, a physical uplink shared channel, a random access channel, and/or the like. Different BWPs can have the same or different bandwidths, center frequencies, subcarrier spacing, and/or the like depending on the BWP configuration. Multiple BWPs can be configured for a UE, and a BWP can be activated using downlink control information (DCI). An active BWP of the UE may be switched from a first configured BWP to a second BWP using DCI. Frequency resources for uplink signals and channels of the UE may be within an uplink BWP, and frequency resources for downlink signals and channels may be within a downlink BWP.

BWP switching during a DAPS handover may present challenges. For example, some UEs may not have sufficient capabilities for switching from one active BWP to another active BWP during a DAPS handover, since this may cause interruption of the UE's communications. As another example, an impact of BWP switching may be different for an inter-frequency handover (e.g., wherein the source cell and the target cell are non-overlapped or are associated with different center frequencies) than for an intra-frequency handover, due to UE capabilities regarding retuning or communication on multiple frequencies. Still further, an impact of BWP switching may be different when a BWP of the source cell at least partially overlaps a BWP of the target cell than when the BWPs of the source cell and the target cell are non-overlapped.

Some techniques and apparatuses described herein provide rules for BWP switching during a DAPS handover. For example, a BWP switching rule may indicate that BWP switching during the DAPS handover is permitted or is not permitted. As another example, a BWP switching rule may indicate that BWP switching is permitted or not permitted for a particular communication link (e.g., uplink or downlink) during the DAPS handover. As yet another example, a BWP switching rule may be based at least in part on whether BWPs of the source cell and the target cell are overlapped, partially overlapped, or non-overlapped. Furthermore, some techniques and apparatuses described herein provide configuration of BWP switching rules for a DAPS handover, configuration of BWP switching during a DAPS handover, and/or the like. In this way, approaches for BWP switching during DAPS handover (or the prevention thereof) are provided, which improve stability and reliability of DAPS handover.

<FIG> is a diagram illustrating an example <NUM> of a DAPS handover, in accordance with various aspects of the present disclosure. A source gNB-DU (such as BSs 110a-110d depicted and described in <FIG>, or BS <NUM> depicted and described in <FIG>) may provide a source cell for a UE (such as UEs 120a-120e depicted and described in <FIG>, or UE <NUM> depicted and described in <FIG>). The UE may be handed over from the source cell to a target cell provided by a target gNB-DU (such as BSs 110a-110d and BS <NUM>). A gNB may include a central unit (CU) and/or a distributed unit (DU). A CU is a logical node that performs gNB functions such as transfer of user data, mobility control, radio access network (RAN) sharing, positioning, session management and/or other functions not allocated exclusively to the DU. The CU may control the operation of DUs over a front-haul interface. A DU may perform gNB functions that are allocated to the DU based at least in part on a functional split between the DU and the CU. For example, a DU may perform one or more of packet data convergence protocol (PDCP) functions, radio link control (RLC) functions, medium access control (MAC) functions, physical (PHY) layer functions, radio frequency (RF) functions, or a combination thereof. In some aspects, one or more of the above functions may be allocated to the CU and one or more of the above functions may be allocated to the DU based at least in part on the functional split.

As shown by reference number <NUM>, the UE may detect an event trigger. For example, the event trigger may relate to a measurement threshold for triggering a handover from a source cell or source master cell group (MCG) to a target cell or target MCG. When the measurement threshold is satisfied, the UE may determine that the event trigger is detected.

As shown by reference number <NUM>, the UE may transmit a measurement report based at least in part on detecting the event trigger. For example, the UE may transmit a measurement report to the gNB-CU via the source gNB-DU. The measurement report may identify neighbor cell measurements for one or more cells or cell groups.

As shown by reference number <NUM>, the gNB-CU may determine that a DAPS based handover is to be performed based at least in part on the measurement report. For example, the gNB-CU may select the target gNB-DU based at least in part on a measurement identified by the measurement report.

As shown by reference number <NUM>, the gNB-CU may transmit a UE context setup request to the target gNB-DU, and the target gNB-DU may provide a UE context setup response. The UE context setup request may indicate that the UE is to be handed over to the target gNB-DU. The target gNB-DU may set up a UE context for the UE based at least in part on the UE context setup request, and may provide a UE context setup response indicating that the UE context has been set up.

As shown by reference number <NUM>, the gNB-CU may provide an RRC reconfiguration message to the UE. The RRC reconfiguration message shown by reference number <NUM> may reconfigure a cell group configuration of the UE and may indicate that the UE is to perform a DAPS handover from a source MCG (such as associated with the source gNB-DU) to the target MCG (such as associated with the target gNB-DU). In some aspects, the RRC reconfiguration message shown by reference number <NUM> may be referred to as a handover command.

As shown by reference number <NUM>, the UE may maintain a connection to the source gNB and the target gNB during the DAPS based handover. For example, the UE may maintain respective RRC connections with the source gNB-DU and the target gNB-DU until an RRC reconfiguration message indicating to release the source MCG associated with the source gNB-DU is received. User plane interruption and handover latency may be reduced.

As shown by reference number <NUM>, the UE may continue data transmission or reception with the source gNB-DU as the UE connects to the target gNB-DU, shown by reference number <NUM>. For example, the UE may continue communication with the source gNB-DU as synchronization and a random access channel (RACH) procedure are performed for the target gNB-DU.

As shown by reference number <NUM>, the UE may transmit an indication to the gNB-CU, via the target gNB-DU, that the RRC connection reconfiguration is complete. For example, the UE may transmit the indication based at least in part on successfully establishing a connection with the target gNB-DU. As shown by reference number <NUM>, the gNB-CU may determine, based at least in part on the RRC reconfiguration complete message shown by reference number <NUM>, that the connection with the source gNB-DU is to be released. Accordingly, as shown by reference number <NUM>, the gNB-CU may provide, to the source gNB-DU, a UE context modification request to switch the UE's MCG from the source gNB-DU to the target gNB-DU. The source gNB-DU may provide a UE context modification response to the gNB-CU based at least in part on performing the UE context modification in accordance with the UE context modification request.

As shown by reference number <NUM>, the gNB-CU may provide an RRC reconfiguration message to the UE. The RRC reconfiguration message may indicate that the UE is to release the source gNB-DU cell group (such as the source MCG). Accordingly, as shown by reference number <NUM>, the UE may release the connection to the source gNB. In some aspects, a duration of the DAPS handover may be considered to be between the RRC reconfiguration message shown by reference number <NUM> and the UE context release shown by reference number <NUM> of <FIG>. Some techniques and apparatuses described herein provide rules for BWP switching before, during, and/or after the duration of the DAPS handover.

As shown by reference number <NUM>, the UE may provide an RRC reconfiguration complete message to the gNB-CU via the target gNB-DU. The RRC reconfiguration complete message may indicate that the UE has established the connection with the target gNB-DU. Accordingly, as shown by reference number <NUM>, the gNB-CU may release a UE context with the source gNB-DU based at least in part on receiving the RRC reconfiguration complete message from the UE. Thus, the UE, the source gNB, and the target gNB may perform a DAPS based handover. In some aspects, a DAPS based handover may be referred to herein as a DAPS handover.

<FIG> is a diagram illustrating an example <NUM> of BWP switching in association with a DAPS handover, in accordance with various aspects of the present disclosure. As shown, example <NUM> includes a UE <NUM>, a gNB-CU (e.g., the gNB-CU of <FIG>, BS <NUM>), a source cell, and a target cell. The source cell may be provided by or associated with a source gNB-DU (e.g., the source gNB-DU of <FIG>, BS <NUM>), and the target cell may be provided by or associated with a target gNB-DU (e.g., the target gNB-DU of <FIG>, BS <NUM>). In some aspects, the source cell and/or the target cell may be associated with the gNB-CU. For example, the source cell and/or the target cell may be provided by a gNB-DU associated with the gNB-CU. In some aspects, neither the source cell nor the target cell may be associated with the gNB-CU. In example <NUM>, the source cell is a cell to which the UE <NUM> is connected before performing a DAPS handover, and the target cell is a cell to which the UE is connected after performing the DAPS handover, as described in more detail below.

As shown in <FIG>, and by reference number <NUM>, the gNB-CU may provide configuration information to the UE <NUM>. In some aspects, the gNB-CU may provide the configuration information via the source cell. In some aspects, as shown, the configuration information may configure one or more source BWPs and/or one or more target BWPs. A source BWP is a BWP used by the UE <NUM> to communicate via the source cell, and a target BWP is a BWP used by the UE <NUM> to communicate via the target cell. A source BWP can include one or more of an uplink BWP or a downlink BWP. A target BWP can include one or more of an uplink BWP or a downlink BWP. In some aspects, the configuration information may configure a BWP for the UE <NUM> (e.g., a dedicated BWP configured using dedicated signaling and/or an initial BWP configured via system information). In some aspects, the configuration information may activate a configured BWP. The configuration information may include system information, RRC signaling, MAC signaling, DCI, or a combination thereof.

While example <NUM> shows the configuration information as being received prior to the DAPS handover, in some aspects, at least part of the configuration may be received during the DAPS handover. For example, the gNB-CU may activate a BWP (e.g., a source BWP or a target BWP) during the DAPS handover, thereby triggering the UE <NUM> to switch BWPs during the handover in accordance with a BWP switching rule, as described in more detail below.

In some aspects, the configuration information (e.g., and/or the gNB-CU) may configure a BWP switching configuration. A BWP switching configuration may indicate information regarding BWP switching. For example, the BWP switching configuration may indicate information regarding BWP switching in association with a DAPS handover. In some aspects, the BWP switching configuration may indicate a set of source BWPs, a set of target BWPs, an active source BWP, an active target BWP, a time at which the UE <NUM> is to switch an active source BWP or an active target BWP, a BWP switching rule (described in more detail below), and/or the like.

In some aspects, the configuration information may indicate a BWP switching rule. A BWP switching rule may indicate whether a UE <NUM> can perform a BWP switch during a DAPS handover. For example, a BWP switching rule may indicate whether a UE <NUM> is permitted to perform a BWP switch during a handover. The BWP switching rule may relate to at least one of a source BWP or a target BWP of the UE <NUM>. In some aspects, the UE <NUM> may be preconfigured with the BWP switching rule. Various examples of BWP switching rules are provided below. As used herein, a time "during a DAPS handover" can refer to a time that is between the event trigger <NUM> and the UE context release shown by reference number <NUM> of <FIG>. In some aspects, a time "during a DAPS handover" can refer to a time that is between the RRC reconfiguration message shown by reference number <NUM> and the connection release of the source gNB-DU shown by reference number <NUM> of <FIG>. In other words, the BWP switching rule may apply when the UE is associated with both a source connection on the source cell and a target connection on the target cell.

In some aspects, the BWP switching rule indicates that the UE is not permitted to switch a source BWP during the DAPS handover. For example, the BWP switching rule may indicate that source BWP switching (including at least one of an uplink BWP or a downlink BWP) during the DAPS handover is not allowed. As used herein, "source BWP switching" refers to changing from a first active BWP on the source cell to a second active BWP on the source cell. In some aspects, the BWP switching rule indicates that the UE is not permitted to switch a target BWP during the DAPS handover. For example, the BWP switching rule may indicate that target BWP switching (including at least one of an uplink BWP or a downlink BWP) is not allowed. As used herein, "target BWP switching" refers to changing from a first active BWP on the target cell to a second active BWP on the target cell.

In some aspects, the BWP switching rule indicates that the UE is permitted to switch a source BWP during the DAPS handover. For example, the BWP switching rule may indicate that source BWP switching (including at least one of an uplink BWP or a downlink BWP) is enabled. Additionally, or alternatively, the BWP switching rule may indicate that the UE is permitted to switch a target BWP during the DAPS handover. For example, the BWP switching rule may indicate that target BWP switching (including at least one of an uplink BWP or a downlink BWP) is enabled.

In some aspects, the BWP switching rule indicates that only one of a downlink BWP or an uplink BWP can be switched during the DAPS handover. For example, the BWP switching rule may indicate that only one of a BWP associated with a source cell or a BWP associated with a target cell can be switched during the DAPS handover. For example, for a cell (e.g., a source cell or a target cell), a downlink BWP may be allowed to be switched and an uplink BWP may not be allowed to be switched, or vice versa. As another example, a source downlink BWP may be allowed to be switched whereas a target downlink BWP may not be allowed to be switched, or vice versa.

In some aspects, the BWP switching rule may indicate that BWP switching is permitted for a target BWP if the target BWP is a subset of a source BWP. For example, for an intra-frequency DAPS handover, the UE <NUM> may expect that an active downlink bandwidth part of a target cell is confined within an active downlink bandwidth part of a source cell. As another example, for an intra-frequency DAPS handover, the UE <NUM> may expect that an active uplink bandwidth part of a target cell is confined within an active uplink bandwidth part of a source cell. Additionally, or alternatively, the BWP switching rule may indicate that BWP switching is permitted for a source BWP if the source BWP is a subset of a target BWP. A first BWP is a subset of a second BWP if a bandwidth of the first BWP is included within or is coextensive with a bandwidth of the second BWP. By mandating that the first BWP be within a bandwidth of the second BWP, the UE can use a BWP capability of the second BWP to process signals and channels of the first cell and the second cell during the DAPS handover.

In some aspects, the BWP switching rule may indicate that the first BWP is to be a subset of the second BWP before the BWP switch is performed. For example, in a case of an initial first BWP and a switched first BWP, the BWP switching rule may indicate that the initial first BWP is to be a subset of the second BWP before the BWP switch is performed. In some aspects, the BWP switching rule may indicate that the first BWP is to be a subset of the second BWP after the BWP switch is performed. For example, in a case of an initial first BWP and a switched first BWP, the BWP switching rule may indicate that the switched first BWP is to be a subset of the second BWP after the BWP switch is performed.

<FIG> is a diagram illustrating an example <NUM> of a target BWP that is a subset of a source BWP, in accordance with various aspects of the present disclosure. As shown, example <NUM> includes a source BWP, a first target BWP (e.g., Target BWP <NUM>), and a second target BWP (e.g., Target BWP <NUM>). As shown, in <FIG>, the vertical axis represents frequency. Furthermore, with regard to the first target BWP and the second target BWP, the horizontal axis represents time. For example, the UE <NUM> may switch from the first target BWP to the second target BWP. As shown, the first target BWP is within a bandwidth of the source BWP (e.g., is a subset of the source BWP) and the second target BWP is not within the bandwidth of the source BWP.

If the BWP switching rule indicates that the UE <NUM> is permitted to switch a target BWP if the target BWP is a subset of the source BWP before the BWP switch is performed, then the UE <NUM> may be permitted to switch to the first target BWP, since the first target BWP is within the source BWP. If the BWP switching rule indicates that the UE <NUM> is permitted to switch a target BWP if the target BWP is a subset of the source BWP after the BWP switch is performed, then the UE <NUM> may not be permitted to switch to the second target BWP, since the second target BWP is not within the source BWP. In some aspects, the BWP switching rule may indicate, for an intra-frequency DAPS handover, that the UE <NUM> expects that an active bandwidth part of a target cell is confined within an active bandwidth part of a source cell. Thus, the UE <NUM> may determine that the first target BWP can be used or switched to, whereas the second target BWP cannot be used or switched to.

Returning to <FIG>, in some aspects, the BWP switching rule may be based at least in part on whether the DAPS handover is an intra-frequency handover. In an example covered by the claims, the BWP switching rule indicates that BWP switching is not permitted on a communication link for an intra-frequency handover when the UE <NUM> is associated with a single communication chain for the communication link, thus reducing interruption on the communication link. As another example covered by the claims, the BWP switching rule indicates that BWP switching is permitted on a communication link for an intra-frequency handover when the UE is associated with multiple communication chains for the communication link, thus improving flexibility of BWP switching.

In some aspects, the BWP switching rule may indicate that BWP switching is permitted for a first link direction and not for a second link direction. For example, the BWP switching rule may indicate that BWP switching is permitted for an uplink BWP and not for a downlink BWP. In some aspects, the BWP switching rule may indicate that BWP switching is permitted for a source BWP and not for a target BWP. In some aspects, the BWP switching rule may indicate that BWP switching is permitted for a target BWP and not for a source BWP.

As shown by reference number <NUM>, in example <NUM>, the BWP switching rule indicates that the UE <NUM> is permitted to switch BWPs during the DAPS handover, and that BWP switching is permitted for a target BWP if the target BWP is a subset of the source BWP. For example, the rule may indicate that BWP switching is permitted for the target BWP if the target BWP is a subset of the source BWP before the BWP switch, or that BWP switching is permitted for the target BWP if the target BWP is a subset of the source BWP after the BWP switch.

As shown by reference number <NUM>, the UE <NUM> and the gNB-CU may perform the DAPS handover. For example, the UE <NUM> and the gNB-CU may perform one or more of the operations described with regard to <FIG>. As further shown, the UE <NUM> may be associated with one or more source BWPs and one or more target BWPs during the DAPS handover. For example, the one or more source BWPs and the one or more target BWPs may be based at least in part on the configuration information shown by reference number <NUM>.

In some aspects, if downlink BWPs in the source cell (e.g., a downlink source BWP) and the target cell (e.g., a downlink target BWP) are not the same (e.g., are not fully overlapped), then the DAPS handover may use a downlink carrier aggregation (CA) framework (described in more detail below) or a multi-TRP framework. In some aspects, if the uplink BWPs in the source cell and the target cell are not the same (e.g., are not fully overlapped), then the DAPS handover may use an uplink CA framework or a multi-TRP framework. As used herein, in the context of BWPs, "fully overlapped" refers to two or more BWPs with the same center frequency and the same bandwidth.

In some aspects, if the downlink BWPs and the uplink BWPs in the source cell and the target cell are not the same (e.g., the downlink BWPs are not fully overlapped with each other and the uplink BWPs are not fully overlapped with each other), then the DAPS handover may use a downlink CA framework or a multi-TRP framework, and an uplink CA framework or a multi-TRP framework.

In some aspects, the DAPS handover may be an intra-frequency handover, meaning that the source cell and the target cell may be associated with a same center frequency and/or a same bandwidth. In some aspects, for an intra-frequency handover, the configuration information may configure the same active BWP for source and target cells. For example, the configuration information may configure the same active BWP for source and target cells based at least in part on the UE having a single transmit chain (e.g., for an uplink BWP) or a single receive chain (e.g., for a downlink BWP). As another example, for intra-frequency handover, the BWP switching rule may indicate that the BWP may not be switched when the UE <NUM> has a single transmit chain and/or a single receive chain, and may indicate that the BWP may be switched when the UE has multiple transmit chains and/or multiple receive chains. If the source BWP and the target BWP are partially overlapped, then the UE <NUM> may use an inter-frequency handover framework for the DAPS handover.

In some aspects, the DAPS handover may be an inter-frequency handover, meaning that the source cell and the target cell may be associated with different center frequencies and/or different bandwidths. For an inter-frequency handover, the UE <NUM> and the gNB-CU may use a CA framework or a multi-TRP framework for handling different BWPs in source and target cells. In some aspects, the BWP switching rule may indicate that BWP switching is enabled for inter-frequency handover and not for intra-frequency handover.

As shown by reference number <NUM>, the UE <NUM> may perform BWP switching based at least in part on the BWP switching rule. For example, the UE <NUM> may switch a target BWP associated with the target cell based at least in part on the target BWP being a subset of the source BWP (e.g., before the BWP switch or after the BWP switch, as described in more detail elsewhere herein).

As shown by reference number <NUM>, the UE <NUM> may release a connection to the source cell. As shown by reference number <NUM>, the UE <NUM> may transmit an RRC reconfiguration complete message to the gNB-CU (e.g., via the target cell) indicating that the DAPS handover is complete, as described in more detail in connection with <FIG>.

As indicated above, <FIG> and <FIG> are provided as one or more examples.

<FIG> is a diagram illustrating an example process <NUM> performed, for example, by a base station, in accordance with various aspects of the present disclosure. Example process <NUM> is an example where the base station (e.g., base station <NUM>, a gNB-CU, a gNB-DU, and/or the like) performs operations associated with BWP switching for a DAPS handover.

As shown in <FIG>, in some aspects, process <NUM> may include configuring a BWP switching configuration of a UE in connection with a DAPS handover based at least in part on a BWP switching rule (block <NUM>). For example, the base station (e.g., using antenna <NUM>, DEMOD <NUM>, MIMO detector <NUM>, receive processor <NUM>, controller/processor <NUM>, and/or the like) may configure a BWP switching configuration of a UE in connection with a DAPS handover based at least in part on a BWP switching rule, as described above. In some aspects, the base station may switch the UE from a first BWP to a second BWP in accordance with the BWP switching rule, or may determine that the UE cannot be switched from a first BWP to the second BWP in accordance with the BWP switching rule. In some aspects, configuring a BWP switching configuration of the UE may refer to providing DCI to the UE that causes the UE to switch an active BWP, or refraining from switching the active BWP, in accordance with the BWP switching rule. In other words, configuring the BWP switching configuration may not refer to performing an RRC configuration or a similar type of configuration for the UE, and may refer to the act of switching the active BWP.

As further shown in <FIG>, in some aspects, process <NUM> may include performing the DAPS handover (block <NUM>). For example, the base station (e.g., using antenna <NUM>, DEMOD <NUM>, MIMO detector <NUM>, receive processor <NUM>, controller/processor <NUM>, and/or the like) may perform the DAPS handover, as described above. The base station may provide a source cell of the DAPS handover and/or a target cell of the DAPS handover.

In a first aspect, the BWP switching rule indicates that the UE is not permitted to switch a source BWP during the DAPS handover. For example, the BWP switching rule may indicate that source BWP switching (including at least one of an uplink BWP or a downlink BWP) is not allowed.

In a second aspect, alone or in combination with the first aspect, the BWP switching rule indicates that the UE is not permitted to switch a target BWP during the DAPS handover. For example, the BWP switching rule may indicate that target BWP switching (including at least one of an uplink BWP or a downlink BWP) is not allowed.

In a third aspect, alone or in combination with one or more of the first and second aspects, the BWP switching rule indicates that the UE is permitted to switch a source BWP during the DAPS handover. For example, the BWP switching rule may indicate that source BWP switching (including at least one of an uplink BWP or a downlink BWP) is enabled.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the BWP switching rule indicates that the UE is permitted to switch a target BWP during the DAPS handover. For example, the BWP switching rule may indicate that target BWP switching (including at least one of an uplink BWP or a downlink BWP) is enabled.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, configuring the BWP switching configuration further comprises configuring the UE to switch at least one of a source BWP or a target BWP during the DAPS handover. This may include switching the UE's source BWP and/or target BWP (e.g., using DCI).

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the BWP switching rule indicates that only one of a downlink BWP or an uplink BWP can be switched during the DAPS handover. In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the BWP switching rule indicates that only one of a BWP associated with a source cell or a BWP associated with a target cell can be switched during the DAPS handover. For example, for a cell (e.g., a source cell or a target cell), a downlink BWP may be allowed to be switched but an uplink BWP may not be allowed to be switched, or vice versa. As another example, a source downlink BWP may be allowed to be switched and a target downlink BWP may not be allowed to be switched, or vice versa.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the BWP associated with the source cell and the BWP associated with the target cell are one of downlink BWPs or uplink BWPs.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the BWP switching rule indicates that BWP switching is permitted for a target BWP if the target BWP is a subset of a source BWP before the BWP switching is performed. In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, the BWP switching rule indicates that BWP switching is permitted for a target BWP if the target BWP is a subset of a source BWP after the BWP switching is performed. In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, the BWP switching rule indicates that BWP switching is permitted for a source BWP if the source BWP is a subset of a target BWP before the BWP switching is performed. In a twelfth aspect, alone or in combination with one or more of the first through eleventh aspects, the BWP switching rule indicates that BWP switching is permitted for a source BWP if the source BWP is a subset of a target BWP after the BWP switching is performed. A first BWP may be a subset of a second BWP if a bandwidth of the first BWP is included within or coextensive with a bandwidth of the second BWP. For example, the first BWP may be associated with a first cell (e.g., a source cell or a target cell) and the second BWP may be associated with a second cell (e.g., a target cell or a source cell). In this case, the UE can use a BWP capability of the second BWP to process signals and channels of the first cell and the second cell during the DAPS handover.

In a thirteenth aspect, alone or in combination with one or more of the first through twelfth aspects, the DAPS handover is an intra-frequency handover. Additionally, or alternatively, the UE may be associated with a single communication chain, and configuring the BWP switching configuration may further include configuring a same active BWP to be used for a source cell and for a target cell. In a fourteenth aspect, alone or in combination with one or more of the first through thirteenth aspects, the single communication chain is an uplink communication chain and the same active BWP is an uplink BWP. In a fifteenth aspect, alone or in combination with one or more of the first through fourteenth aspects, the single communication chain is a downlink communication chain and the same active BWP is a downlink BWP. For example, configuring the same active BWP for the source cell and the target cell may be permitted at least for the case when the UE has a single transmit chain (for an uplink BWP) and/or a single receive chain (for a downlink BWP). This enables a UE with a single communication chain to perform contemporaneous communication on the source cell and the target cell. If the source BWP and the target BWP are partially overlapped, then for the DAPS handover, UE may use an inter-frequency handover framework (e.g., a carrier aggregation or multi-TRP framework, described below).

In a sixteenth aspect, alone or in combination with one or more of the first through fifteenth aspects, when the DAPS handover is an inter-frequency handover, configuring the BWP switching configuration further comprises: configuring a source BWP of the UE as a first component carrier; and configuring a target BWP of the UE as a second component carrier. In some aspects, the UE may configure a source BWP as a first component carrier and a target BWP as a second component carrier. This may be referred to as a carrier aggregation (CA) framework.

In a seventeenth aspect, alone or in combination with one or more of the first through sixteenth aspects, when the DAPS handover is an inter-frequency handover, configuring the BWP switching configuration further comprises: configuring a source BWP of the UE as a first leg of a multi-transmit/receive point (multi-TRP) communication, and configuring a target BWP of the UE as a second leg of the multi-TRP communication. This may be referred to as a multi-TRP framework.

In an eighteenth aspect, alone or in combination with one or more of the first through seventeenth aspects, the BWP switching rule indicates that BWP switching is not permitted on a communication link for an intra-frequency handover when the UE is associated with a single communication chain for the communication link.

In a nineteenth aspect, alone or in combination with one or more of the first through eighteenth aspects, the BWP switching rule indicates that BWP switching is permitted on a communication link for an intra-frequency handover when the UE is associated with multiple communication chains for the communication link.

In a twentieth aspect, alone or in combination with one or more of the first through nineteenth aspects, the BWP switching rule indicates BWP switching is permitted for a source BWP if the source BWP contains a target BWP. In some aspects, the source BWP contains a target BWP if the target BWP is a subset of the source BWP.

In a twenty-first aspect, alone or in combination with one or more of the first through twentieth aspects, the BWP switching rule indicates BWP switching is permitted for a source BWP and a target BWP if the source BWP contains a target BWP.

In some aspects, if the downlink BWPs in the source cell and the target cell are not the same (e.g., are not fully overlapped), then the DAPS handover may use a downlink CA framework or a multi-TRP framework.

In some aspects, if the uplink BWPs in the source cell and the target cell are not the same (e.g., are not fully overlapped), then the DAPS handover may use an uplink CA framework or a multi-TRP framework.

In some aspects, if the downlink BWPs and the uplink BWPs in the source cell and the target cell are not the same (e.g., the downlink BWPs are not fully overlapped with each other and the uplink BWPs are not fully overlapped with each other), then the DAPS handover may use a downlink CA framework or a multi-TRP framework and an uplink CA framework or a multi-TRP framework.

<FIG> is a diagram illustrating an example process <NUM> performed, for example, by a UE, in accordance with various aspects of the present disclosure. Example process <NUM> is an example where the UE (e.g., UE <NUM> and/or the like) performs operations associated with BWP switching for a DAPS handover.

As shown in <FIG>, in some aspects, process <NUM> may include receiving a BWP switching configuration in connection with a DAPS handover, wherein the BWP switching configuration is based at least in part on a BWP switching rule (block <NUM>). For example, the UE (e.g., using antenna <NUM>, DEMOD <NUM>, MIMO detector <NUM>, receive processor <NUM>, controller/processor <NUM>, and/or the like) may receive a BWP switching configuration in connection with a DAPS handover, as described above. In some aspects, the BWP switching configuration is based at least in part on a BWP switching rule.

As further shown in <FIG>, in some aspects, process <NUM> may include performing the DAPS handover (block <NUM>). For example, the UE (e.g., using antenna <NUM>, DEMOD <NUM>, MIMO detector <NUM>, receive processor <NUM>, controller/processor <NUM>, and/or the like) may perform the DAPS handover, as described above.

In a first aspect, the BWP switching rule indicates that the UE is not permitted to switch a source BWP during the DAPS handover.

In a second aspect, alone or in combination with the first aspect, the BWP switching rule indicates that the UE is not permitted to switch a target BWP during the DAPS handover. When the BWP switching rule indicates that the UE is not permitted to switch a BWP, then the UE may assume that the BWP will not be switched, may not expect the BWP to be switched, may determine an error if the BWP is switched, and/or the like.

In a third aspect, alone or in combination with one or more of the first and second aspects, the BWP switching rule indicates that the UE is permitted to switch a source BWP during the DAPS handover.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the BWP switching rule indicates that the UE is permitted to switch a target BWP during the DAPS handover.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, the BWP switching configuration configures the UE to switch at least one of a source BWP or a target BWP during the DAPS handover.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the BWP switching rule indicates that only one of a downlink BWP or an uplink BWP can be switched during the DAPS handover.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the BWP switching rule indicates that only one of a BWP associated with a source cell or a BWP associated with a target cell can be switched during the DAPS handover.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the BWP associated with the source cell and the BWP associated with the target cell are one of: downlink BWPs, or uplink BWPs.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the BWP switching rule indicates BWP switching is permitted for a target BWP if the target BWP is a subset of a source BWP before the BWP switching is performed.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, the BWP switching rule indicates that BWP switching is permitted for a target BWP if the target BWP is a subset of a source BWP after the BWP switching is performed.

In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, the BWP switching rule indicates BWP switching is permitted for a source BWP if the source BWP is a subset of a target BWP before the BWP switching is performed.

In a twelfth aspect, alone or in combination with one or more of the first through eleventh aspects, the BWP switching rule indicates that BWP switching is permitted for a source BWP if the source BWP is a subset of a target BWP after the BWP switching is performed.

In a thirteenth aspect, alone or in combination with one or more of the first through twelfth aspects, when the DAPS handover is an inter-frequency handover and the UE is associated with a single communication chain, the BWP switching configuration configures a same active BWP to be used for a source cell and for a target cell.

In a fourteenth aspect, alone or in combination with one or more of the first through thirteenth aspects, the single communication chain is an uplink communication chain and the same active BWP is an uplink BWP.

In a fifteenth aspect, alone or in combination with one or more of the first through fourteenth aspects, the single communication chain is a downlink communication chain and the same active BWP is a downlink BWP.

In a sixteenth aspect, alone or in combination with one or more of the first through fifteenth aspects, when the DAPS handover is an inter-frequency handover, the BWP switching configuration configures a source BWP of the UE as a first component carrier and a target BWP of the UE as a second component carrier.

In a seventeenth aspect, alone or in combination with one or more of the first through sixteenth aspects, when the DAPS handover is an inter-frequency handover, the BWP switching configuration configures a source BWP of the UE as a first leg of a multi-TRP communication and a target BWP of the UE as a second leg of the multi-TRP communication.

In a twentieth aspect, alone or in combination with one or more of the first through nineteenth aspects, when the DAPS handover is an intra-frequency handover and when the source BWP and the target BWP are not fully overlapped, the UE configures a source BWP of the UE as a first component carrier and a target BWP of the UE as a second component carrier.

In a twenty-first aspect, alone or in combination with one or more of the first through twentieth aspects, the BWP switching rule indicates BWP switching is permitted for a source BWP if the source BWP contains a target BWP. In some aspects, the source BWP contains a target BWP if the target BWP is a subset of the source BWP.

In a twenty-second aspect, alone or in combination with one or more of the first through twenty-first aspects, the BWP switching rule indicates BWP switching is permitted for a source BWP and a target BWP if the source BWP contains a target BWP.

<FIG> is a block diagram of an example apparatus <NUM> for wireless communication. The apparatus <NUM> may be a base station, or a base station may include the apparatus <NUM>. In some aspects, the apparatus <NUM> includes a reception component <NUM> and a transmission component <NUM>, which may be in communication with one another (for example, via one or more buses and/or one or more other components). As shown, the apparatus <NUM> may communicate with another apparatus <NUM> (such as a UE, a base station, or another wireless communication device) using the reception component <NUM> and the transmission component <NUM>. As further shown, the apparatus <NUM> may include one or more of a configuration component <NUM> or a handover component <NUM>, among other examples.

In some aspects, the apparatus <NUM> may be configured to perform one or more operations described herein in connection with <FIG>. Additionally or alternatively, the apparatus <NUM> may be configured to perform one or more processes described herein, such as process <NUM> of <FIG>. In some aspects, the apparatus <NUM> and/or one or more components shown in <FIG> may include one or more components of the base station described above in connection with <FIG>. Additionally, or alternatively, one or more components shown in <FIG> may be implemented within one or more components described above in connection with <FIG>. Additionally or alternatively, one or more components of the set of components may be implemented at least in part as software stored in a memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by a controller or a processor to perform the functions or operations of the component.

In some aspects, the reception component <NUM> may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a controller/processor, a memory, or a combination thereof, of the base station described above in connection with <FIG>.

In some aspects, the transmission component <NUM> may include one or more antennas, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the base station described above in connection with <FIG>. In some aspects, the transmission component <NUM> may be collocated with the reception component <NUM> in a transceiver.

The configuration component <NUM> may configure a BWP switching configuration of a UE in connection with a DAPS handover based at least in part on a BWP switching rule. In some aspects, the configuration component <NUM> may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the base station described above in connection with <FIG>. The handover component <NUM> may perform the DAPS handover. In some aspects, the handover component <NUM> may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the base station described above in connection with <FIG>.

In some aspects, the configuration component <NUM> may configure a same active BWP to be used for a source cell and for a target cell. In some aspects, the configuration component <NUM> may configure a source BWP of the UE as a first component carrier. In some aspects, the configuration component <NUM> may configure a target BWP of the UE as a second component carrier. In some aspects, the configuration component <NUM> may configure a source BWP of the UE as a first leg of a multi-TRP communication. In some aspects, the configuration component <NUM> may configure a target BWP of the UE as a second leg of the multi-TRP communication.

<FIG> is a block diagram of an example apparatus <NUM> for wireless communication, in accordance with various aspects of the present disclosure. The apparatus <NUM> may be a UE, or a UE may include the apparatus <NUM>. In some aspects, the apparatus <NUM> includes a reception component <NUM> and a transmission component <NUM>, which may be in communication with one another (for example, via one or more buses and/or one or more other components). As shown, the apparatus <NUM> may communicate with another apparatus <NUM> (such as a UE, a base station, or another wireless communication device) using the reception component <NUM> and the transmission component <NUM>. As further shown, the apparatus <NUM> may include a handover component <NUM>, among other examples.

In some aspects, the apparatus <NUM> may be configured to perform one or more operations described herein in connection with <FIG>. Additionally or alternatively, the apparatus <NUM> may be configured to perform one or more processes described herein, such as process <NUM> of <FIG>. In some aspects, the apparatus <NUM> and/or one or more components shown in <FIG> may include one or more components of the UE described above in connection with <FIG>. Additionally, or alternatively, one or more components shown in <FIG> may be implemented within one or more components described above in connection with <FIG>. Additionally or alternatively, one or more components of the set of components may be implemented at least in part as software stored in a memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by a controller or a processor to perform the functions or operations of the component.

In some aspects, the transmission component <NUM> may be collocated with the reception component <NUM> in a transceiver.

The reception component <NUM> may receive a BWP switching configuration in connection with a DAPS handover, wherein the BWP switching configuration is based at least in part on a BWP switching rule. The handover component <NUM> may perform the DAPS handover. In some aspects, the handover component <NUM> may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the UE described above in connection with <FIG>.

Claim 1:
A method of wireless communication performed by a base station (<NUM>), comprising:
configuring (<NUM>) a bandwidth part, BWP, switching configuration of a user equipment, UE, (<NUM>) in connection with a dual active protocol stack, DAPS, handover based at least in part on a BWP switching rule wherein the BWP switching rule indicates that BWP switching is not permitted on a communication link for an intra-frequency handover when the UE is associated with a single communication chain for the communication link or wherein the BWP switching rule indicates that BWP switching is permitted on a communication link for an intra-frequency handover when the UE is associated with multiple communication chains for the communication link; and
performing the DAPS handover.