Patent Description:
Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (for example, bandwidth, transmit power, etc.).

A user equipment (UE) may communicate with a base station (BS) via the downlink (DL) and uplink (UL). The DL (or forward link) refers to the communication link from the BS to the UE, and the UL (or reverse link) refers to the communication link from the UE to the BS. As will be described in more detail herein, a BS may be referred to as a NodeB, an LTE evolved nodeB (eNB), a gNB, an access point (AP), a radio head, a transmit receive point (TRP), a New Radio (NR) BS, or a <NUM> NodeB.

The above multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different UEs to communicate on a municipal, national, regional, and even global level. NR, which also may be referred to as <NUM>, is a set of enhancements to the LTE mobile standard promulgated by the Third Generation Partnership Project (3GPP). NR is designed to better support mobile broadband Internet access by improving spectral efficiency, lowering costs, improving services, making use of new spectrum, and better integrating with other open standards using orthogonal frequency-division multiplexing (OFDM) with a cyclic prefix (CP) (CP-OFDM) on the DL, using CP-OFDM or SC-FDM (for example, also known as discrete Fourier transform spread OFDM (DFT-s-OFDM)) on the UL (or a combination thereof), as well as supporting beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation.

<CIT> discloses to techniques for performing handover from a source base station to a target base station. According to one aspect, a method generally includes receiving a handover request from a source base station for hand-over of communication of a user equipment from the source base station to the target base station, generating a scheduling uplink grant for the user equipment to transmit a handover complete message based on receiving the handover request, and communicating the grant to the user equipment.

<CIT> discloses a terminal apparatus and a base station apparatus which efficiently continue communication with each other. A terminal apparatus is configured to perform a handover from a source cell to a target primary cell, the terminal apparatus includes: a receiver configured to receive a handover command; and a transmitter configured to transmit an RRC complete message after starting synchronization with a downlink of the target primary cell, in which, in a case that a parameter MobilityControlInfo included in the handover command includes a parameter associated with a TA and in a case of detecting, in the target primary cell, a PDCCH to which a CRC parity hit scrambled by a C-RNTI is attached, a T304 timer is stopped.

<CIT> discloses an apparatus for wireless communication, including a memory and at least one processor coupled to the memory. The at least one processor is configured to receive a pre-allocation resource for a target cell via a handover command and transmit a physical layer acknowledgment based on a target cell downlink packet. The at least one processor is also configured to receive an indication for a communication with the target cell in response to the physical layer acknowledgement and access the target cell using the pre-allocated resource based on the indication for the communication with the target cell.

<CIT> provides methods and apparatus for seamless hand-over of a User Equipment (UE) between base stations using dual connectivity. The UE receives an indication of a handover of the UE from a source Base Station (BS) to a target BS, wherein the source BS and the target BS are associated with the same Radio Access Technology (RAT). The UE allocates a portion of UE resources for initiating a handover procedure with the target BS, while maintaining connectivity with the source BS. The UE terminates connectivity with the source BS after completion of the handover procedure, wherein the UE is connected to both the source BS and the target BS during at least a portion of the handover procedure.

<CIT> discloses an inter-MeNB handover method in a small cell system, including: making, by a source MeNB and/or target MeNB, a determination as to whether to maintain a SeNB when handover is performed; and triggering different handover processes according to a result of the determination as to whether to maintain the SeNB. Another embodiment of the present disclosure may further provide an inter-MeNB handover device in a small cell system. According to <CIT>, unnecessary deletion and reestablishment of the bearers at the SeNB for the UE may be reduced. False bearer deletion may be avoided and data forwarding may be reduced. Furthermore, the SeNB may be maintained according to network deployment and SGW re-selection may be supported. Therefore, system capacity and transmission speed of the data may be improved.

There is still a need to improve the service quality during handover.

The systems, methods, and devices of this disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein.

One innovative aspect of the subject matter described in this disclosure can be implemented in a method of wireless communication performed by a user equipment (UE), as defined in claim <NUM>.

In some aspects, the trigger is associated with a radio resource control (RRC) reconfiguration complete message provided to the target cell. In some aspects, switching from the source cell to the target cell is based at least in part on upon receiving an acknowledgment (ACK) of the RRC reconfiguration complete message. In some aspects, switching from the source cell to the target cell is based at least in part on upon receiving a physical downlink control channel (PDCCH) addressed to a cell radio network temporary identifier (C-RNTI) associated with the UE.

In some aspects, the trigger is associated with the UE being scheduled for a transmission of a PUSCH communication. In some aspects, switching from the source cell to the target cell is based at least in part on upon receiving downlink control information (DCI) including a PUSCH grant associated with the PUSCH communication. In some aspects, switching from the source cell to the target cell occurs at a time of a first configured grant occasion associated with the PUSCH communication. In some aspects, switching from the source cell to the target cell occurs at a time of a PUSCH grant associated with the PUSCH communication.

In some aspects, the trigger is associated with a configuration of the UE.

In some aspects, switching from the source cell to the target cell is based at least in part on an assessment of channel conditions.

In some aspects, switching from the source cell to the target cell for transmitting PUSCH communications occurs at substantially a same time that the UE switches from the source cell to the target cell for receiving downlink communications.

In some aspects, the method can include transmitting PUSCH communications, physical uplink control channel (PUCCH) communications, and sounding reference signal (SRS) transmissions to the source cell until switching from the source cell to the target cell.

In some aspects, the UE is to continue to transmit PUCCH communications and SRS transmissions to the source cell for a period of time after the UE switches from the source cell to the target cell.

In some aspects, information indicating that the UE has ended transmissions of uplink communications to the source cell is provided to the source cell. In some aspects, the information indicating that the UE has ended transmissions of uplink communications to the source cell is provided by the UE via at least one of RRC signaling, a medium access control (MAC) control element, or a PUCCH format. In some aspects, the information indicating that the UE has ended transmissions of uplink communications to the source cell is provided by the target cell. In some aspects, an uplink data packet is forwarded from the source cell to the target cell based at least in part on the information indicating that the UE has ended transmissions of uplink communications to the source cell.

In some aspects, the method can include switching from a limited capability mode to a full capability mode based at least in part on switching from the source cell to the target cell for transmitting PUSCH communications. In some aspects, information indicating that the UE has switched to the full capability mode is provided to the target cell.

Another innovative aspect of the subject matter described in this disclosure can be implemented in a corresponding UE for wireless communication. The UE may include memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to detect a trigger to switch from a source cell to a target cell for transmitting PUSCH communications, where the trigger is detected in association with a handover from the source cell to the target cell, where the UE is connected to the source cell and to the target cell during the handover; and execute a switch from the source cell to the target cell for transmitting PUSCH communications based at least in part on detecting the trigger.

Another innovative aspect of the subject matter described in this disclosure can be implemented in a non-transitory computer-readable medium or a computer program. The non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a UE, may cause the one or more processors to detect a trigger to switch from a source cell to a target cell for transmitting PUSCH communications, where the trigger is detected in association with a handover from the source cell to the target cell, where the UE is connected to the source cell and to the target cell during the handover; and switch from the source cell to the target cell for transmitting PUSCH communications based at least in part on detecting the trigger.

Another innovative aspect of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication. The apparatus may include means for detecting a trigger to switch from a source cell to a target cell for transmitting PUSCH communications, where the trigger is detected in association with a handover from the source cell to the target cell, where the apparatus is connected to the source cell and to the target cell during the handover; and means for switching from the source cell to the target cell for transmitting PUSCH communications based at least in part on detecting the trigger.

Another innovative aspect of the subject matter described in this disclosure can be implemented in a method of wireless communication performed by a base station, as defined in claim <NUM>. The method may include determining that a source cell has ended a downlink communication transmission to a UE, where the downlink communication transmission to the UE ends in association with a handover from the source cell to a target cell, where the UE is connected to the source cell and to the target cell during the handover; and providing, based at least in part on determining that the source cell has ended the downlink communication transmission to the UE, an indication that the UE is to cease SRS transmissions to the source cell, or release PUCCH resources associated with the source cell.

In some implementations, the indication is provided via at least one of a MAC control element, a PDCCH, or RRC signaling.

In some aspects, the indication includes information indicating that the source cell has ended the downlink communication transmission to the UE.

In some aspects, the indication is an explicit indication to cease the SRS transmissions to the source cell to release the PUCCH resources associated with the source cell.

In some aspects, the UE is to switch from a limited capability mode to a full capability mode based at least in part on the indication that the UE is to cease the SRS transmissions to the source cell, or to release the PUCCH resources associated with the source cell. In some aspects, when the UE switches to the full capability mode, an indicator is provided to the target cell.

In some aspects, the UE is to cease monitoring and reception of downlink transmissions from the source cell based at least in part on the indication that the UE is to cease the SRS transmissions to the source cell, or to release the PUCCH resources associated with the source cell.

Another innovative aspect of the subject matter described in this disclosure can be implemented in a base station for wireless communication. The base station may include memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to determine that a source cell has ended a downlink communication transmission to a UE, where the downlink communication transmission to the UE ends in association with a handover from the source cell to a target cell, where the UE is connected to the source cell and to the target cell during the handover; and provide, based at least in part on determining that the source cell has ended the downlink communication transmission to the UE, an indication that the UE is to cease SRS transmissions to the source cell, or release PUCCH resources associated with the source cell.

Another innovative aspect of the subject matter described in this disclosure can be implemented in a non-transitory computer-readable medium or a computer program. The non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a base station, may cause the one or more processors to determine that a source cell has ended a downlink communication transmission to a UE, where the downlink communication transmission to the UE ends in association with a handover from the source cell to a target cell, where the UE is connected to the source cell and to the target cell during the handover; and provide, based at least in part on determining that the source cell has ended the downlink communication transmission, an indication that the UE is to cease SRS transmissions to the source cell, or release PUCCH resources associated with the source cell.

Another innovative aspect of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication. The apparatus may include means for determining that a source cell has ended a downlink communication transmission to a UE, where the downlink communication transmission to the UE ends in association with a handover from the source cell to a target cell, where the UE is connected to the source cell and to the target cell during the handover; and means for providing, based at least in part on determining that the source cell has ended the downlink communication transmission to the UE, an indication that the UE is to cease SRS transmissions to the source cell, or release PUCCH resources associated with the source cell.

Another innovative aspect of the subject matter described in this disclosure can be implemented in a method of wireless communication performed by a UE, as defined in claim <NUM>. The method may include receiving an indication that the UE is to cease SRS transmissions to a source cell or release PUCCH resources associated with the source cell, where the indication is received after the source cell has ended a downlink transmission to the UE in association with a handover from the source cell to a target cell, and where the UE is connected to the source cell and the target cell during the handover; and ceasing, based at least in part on the indication, SRS transmissions to the source cell, or releasing PUCCH resources associated with the source cell.

In some aspects, the indication is received via at least one of a MAC control element, a PDCCH, or RRC signaling.

In some aspects, the indication includes information indicating that the source cell has ended the downlink transmission to the UE.

In some aspects, the indication is an explicit indication to cease the SRS transmissions to the source cell, or to release the PUCCH resources associated with the source cell.

In some aspects, the method can include switching from a limited capability mode to a full capability mode based at least in part on the indication that the UE is to cease the SRS transmissions to the source cell, or to release the PUCCH resources associated with the source cell. In some aspects, when the UE switches to the full capability mode, an indicator is provided to the target cell.

In some aspects, the method can include ceasing monitoring and reception of downlink transmissions from the source cell based at least in part on the indication that the UE is to cease the SRS transmissions to the source cell, or to release the PUCCH resources associated with the source cell.

Another innovative aspect of the subject matter described in this disclosure can be implemented in a UE for wireless communication. The UE may include memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to receive an indication that the UE is to cease SRS transmissions to a source cell or release PUCCH resources associated with the source cell, where the indication is received after the source cell has ended a downlink transmission to the UE in association with a handover from the source cell to a target cell, and where the UE is connected to the source cell and the target cell during the handover; and cease, based at least in part on the indication, SRS transmissions to the source cell, or release PUCCH resources associated with the source cell.

Another innovative aspect of the subject matter described in this disclosure can be implemented in a non-transitory computer-readable medium or a computer program. The non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a UE, may cause the one or more processors to receive an indication that the UE is to cease SRS transmissions to a source cell or release PUCCH resources associated with the source cell, where the indication is received after the source cell has ended a downlink transmission to the UE in association with a handover from the source cell to a target cell, and where the UE is connected to the source cell and the target cell during the handover; and cease, based at least in part on the indication, SRS transmissions to the source cell, or release PUCCH resources associated with the source cell.

Another innovative aspect of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication. The apparatus may include means for receiving an indication that the apparatus is to cease SRS transmissions to a source cell or release PUCCH resources associated with the source cell, where the indication is received after the source cell has ended a downlink transmission to the apparatus in association with a handover from the source cell to a target cell, and where the apparatus is connected to the source cell and the target cell during the handover; and means for ceasing, based at least in part on the indication, SRS transmissions to the source cell, or releasing PUCCH resources associated with the source cell.

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

The following description is directed to certain implementations for the purposes of describing the innovative aspects of this disclosure. However, a person having ordinary skill in the art will readily recognize that the teachings herein can be applied in a multitude of different ways. Some of the examples in this disclosure are based on wireless and wired local area network (LAN) communication according to the Institute of Electrical and Electronics Engineers (IEEE) <NUM> wireless standards, the IEEE <NUM> Ethernet standards, and the IEEE <NUM> Powerline communication (PLC) standards. However, the described implementations may be implemented in any device, system or network that is capable of transmitting and receiving radio frequency signals according to any of the wireless communication standards, including any of the IEEE <NUM> standards, the Bluetooth® standard, code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), Global System for Mobile communications (GSM), GSM/General Packet Radio Service (GPRS), Enhanced Data GSM Environment (EDGE), Terrestrial Trunked Radio (TETRA), Wideband-CDMA (W-CDMA), Evolution Data Optimized (EV-DO), 1xEV-DO, EV-DO Rev A, EV-DO Rev B, High Speed Packet Access (HSPA), High Speed Downlink Packet Access (HSDPA), High Speed Uplink Packet Access (HSUPA), Evolved High Speed Packet Access (HSPA+), Long Term Evolution (LTE), AMPS, or other known signals that are used to communicate within a wireless, cellular or internet of things (IOT) network, such as a system utilizing <NUM>, <NUM> or <NUM>, or further implementations thereof, technology.

In a wireless communication system, such as an LTE system or a New Radio (NR) system, a handover may cause a user equipment (UE) to be handed over from a source cell to a target cell. In a conventional wireless communication system, the UE disconnects from the source cell and then connects to the target cell (i.e., the UE is not connected to both the source cell and the target cell at any time during the handover). However, this conventional technique often results in service interruption since the UE, after disconnection from the source and before establishment of the connection with the target cell is complete, is not connected to any cell.

Providing mobility enhancements that reduce the service interruption experienced during a handover (such as to <NUM> milliseconds (ms), or as close as possible to <NUM>) may be desirable. Such a reduction in handover interruption may, in some cases, be enabled by configuring the UE to maintain a connection to both the source cell (such as a cell from which the UE is being handed over) and the target cell (such as a cell to which the UE is being handed over) during the handover. Being concurrently connected to both the source cell and the target cell can reduce service interruption (such as communication latency) because the UE will remain connected to both cells such that the UE can communicate with the source cell or the target cell. For downlink communications, the UE may receive downlink transmissions from both the source cell and the target cell while connected to both the source cell and the target cell.

Managing uplink communication may be challenging when the UE is connected to both the source cell and the target cell. For example, when the UE has a single antenna, and in some cases even when the UE has multiple antennas, transmitting uplink communications on the same frequency to different base stations (BSs) (such as a base station associated with the source cell and a base station associated with the target cell) may not be performed easily. Further, even when configuring the UE to transmit to different BSs on the same frequency is possible, issues arise on the network side because uplink data associated with a given uplink communication may be received at different BSs. To address this issue, the UE may be configured to refrain from transmitting on an uplink data channel (such as a physical uplink shared channel (PUSCH)) to both the source cell and the target cell. Thus, there should be point at which the UE switches from the source cell to the target cell for transmitting PUSCH communications. A manner in which the UE switches from the source cell to the target cell for transmitting PUSCH communications to minimize service interruption needs to be defined. Some aspects described herein provide techniques and apparatuses for uplink switching for enhanced mobility.

In some aspects, a UE may detect a trigger to switch from a source cell to a target cell for transmitting PUSCH communications. Here, the UE may detect the trigger in association with a handover from the source cell to the target cell, and the UE may be connected to the source cell and to the target cell during the handover. The UE may switch from the source cell to the target cell for transmitting PUSCH communications based at least in part on detecting the trigger.

Particular implementations of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages. In some aspects, service interruption experienced during a handover may be reduced or eliminated. Further, simplified or improved uplink communications may be provided while a UE is connected to both a source cell and a target cell during a handover.

Another issue when a UE is connected to both a source cell and a target cell during a handover is that the UE should cease transmitting an uplink reference signal (such as sounding reference signal (SRS)) and release uplink control resources (such as physical uplink control channel (PUCCH) resources) associated with the source cell after the source cell has ended transmissions of downlink communications to the UE. For example, since SRS transmissions and PUCCH resources are used in association with downlink communications, the SRS transmission and PUCCH resources are often no longer needed after the source cell has ended transmissions of downlink communications to the UE.

In some aspects, as described herein, a UE may receive an indication that the UE is to cease SRS transmissions to a source cell or to release PUCCH resources associated with a source cell. Here, the UE may receive the indication after the source cell has ended transmission of downlink communications to the UE in association with a handover from the source cell to a target cell, and the UE may be connected to the source cell and the target cell during the handover. The UE may cease SRS transmissions to the source cell or release PUCCH resources associated with the source cell based at least in part on the indication.

Particular implementations of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages. In some aspects, ceasing SRS transmission or releasing PUCCH resources may reduce power consumption because, for example, the UE need not transmit the SRS or maintain reservation of the PUCCH resources. Further, in some aspects, resource utilization may be improved because, for example, SRS resources associated with the SRS transmissions, or the PUCCH can be reused for a transmission by another device (such as configured by the network).

<FIG> is a block diagram conceptually illustrating an example of a wireless network <NUM>. A BS is an entity that communicates with user equipment (UEs) and also may be referred to as a base station, a NR BS, a Node B, a gNB, a <NUM> node B (NB), an access point, a transmit receive point (TRP). In 3GPP, the term "cell" can refer to a coverage area of a BS, a BS subsystem serving this coverage area, or a combination thereof, depending on the context in which the term is used.

A BS may provide communication coverage for a macro cell, a pico cell, a femto cell, another type of cell, or a combination thereof. A macro cell may cover a relatively large geographic area (for example, several kilometers in radius) and may allow unrestricted access by UEs with service subscription. A femto cell may cover a relatively small geographic area (for example, a home) and may allow restricted access by UEs having association with the femto cell (for example, UEs in a closed subscriber group (CSG)). A BS may support one or multiple (for example, three) cells.

In some examples, the BSs may be interconnected to one another as well as to one or more other BSs or network nodes (not shown) in the wireless network <NUM> through various types of backhaul interfaces, such as a direct physical connection, a virtual network, or a combination thereof using any suitable transport network.

Wireless network <NUM> also may include relay stations. A relay station is an entity that can receive a transmission of data from an upstream station (for example, a BS or a UE) and send a transmission of the data to a downstream station (for example, a UE or a BS). A relay station also may be a UE that can relay transmissions for other UEs. A relay station also may be referred to as a relay BS, a relay base station, a relay, etc..

Wireless network <NUM> may be a heterogeneous network that includes BSs of different types, for example, macro BSs, pico BSs, femto BSs, relay BSs, etc. These different types of BSs may have different transmit power levels, different coverage areas, and different impacts on interference in wireless network <NUM>. For example, macro BSs may have a high transmit power level (for example, <NUM> to <NUM> Watts) whereas pico BSs, femto BSs, and relay BSs may have lower transmit power levels (for example, <NUM> to <NUM> Watts).

The BSs also may communicate with one another, for example, directly or indirectly via a wireless or wireline backhaul.

UEs <NUM> (for example, 120a, 120b, 120c) may be dispersed throughout wireless network <NUM>, and each UE may be stationary or mobile. A UE also may be referred to as an access terminal, a terminal, a mobile station, a subscriber unit, a station, etc. A UE may be a cellular phone (for example, a smart phone), a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device or equipment, biometric sensors/devices, wearable devices (smart watches, smart clothing, smart glasses, smart wrist bands, smart jewelry (for example, smart ring, smart bracelet)), an entertainment device (for example, a music or video device, or a satellite radio), a vehicular component or sensor, smart meters/sensors, industrial manufacturing equipment, a global positioning system device, or any other suitable device that is configured to communicate via a wireless or wired medium.

MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc., that may communicate with a base station, another device (for example, remote device), or some other entity. A wireless node may provide, for example, connectivity for or to a network (for example, a wide area network such as Internet or a cellular network) via a wired or wireless communication link. Some UEs may be considered Internet-of Things (IoT) devices or may be implemented as NB-IoT (narrowband internet of things) devices. UE <NUM> may be included inside a housing that houses components of UE <NUM>, such as processor components, memory components, similar components, or a combination thereof.

A RAT also may be referred to as a radio technology, an air interface, etc. A frequency also may be referred to as a carrier, a frequency channel, etc. Each frequency may support a single RAT in a given geographic area in order to avoid interference between wireless networks of different RATs.

In some examples, access to the air interface may be scheduled, where a scheduling entity (for example, a base station) allocates resources for communication among some or all devices and equipment within the scheduling entity's service area or cell.

That is, in some examples, a UE may function as a scheduling entity, scheduling resources for one or more subordinate entities (for example, one or more other UEs). A UE may function as a scheduling entity in a peer-to-peer (P2P) network, in a mesh network, or another type of network.

In some aspects, two or more UEs <NUM> (for example, shown as UE 120a and UE 120e) may communicate directly using one or more side link channels (for example, without using a base station <NUM> as an intermediary to communicate with one another). For example, the UEs <NUM> may communicate using peer-to-peer (P2P) communications, device-to-device (D2D) communications, a vehicle-to-everything (V2X) protocol (which may include a vehicle-to-vehicle (V2V) protocol, a vehicle-to-infrastructure (V2I) protocol, or similar protocol), a mesh network, or similar networks, or combinations thereof. In this case, the UE <NUM> may perform scheduling operations, resource selection operations, as well as other operations described elsewhere herein as being performed by the base station <NUM>.

<FIG> is a block diagram conceptually illustrating an example <NUM> of a base station <NUM> in communication with a UE <NUM>. In some aspects, base station <NUM> and UE <NUM> may respectively be one of the base stations and one of the UEs in wireless network <NUM> of <FIG>.

At base station <NUM>, a transmit processor <NUM> may receive data from a data source <NUM> for one or more UEs, select one or more modulation and coding schemes (MCS) for each UE based at least in part on channel quality indicators (CQIs) received from the UE, process (for example, encode and modulate) the data for each UE based at least in part on the MCS(s) selected for the UE, and provide data symbols for all UEs. The transmit processor <NUM> also may process system information (for example, for semi-static resource partitioning information (SRPI), etc.) and control information (for example, CQI requests, grants, upper layer signaling, etc.) and provide overhead symbols and control symbols. The transmit processor <NUM> also may generate reference symbols for reference signals (for example, the cell-specific reference signal (CRS)) and synchronization signals (for example, the primary synchronization signal (PSS) and secondary synchronization signal (SSS)). A transmit (TX) multiple-input multiple-output (MIMO) processor <NUM> may perform spatial processing (for example, precoding) on the data symbols, the control symbols, the overhead symbols, or the reference symbols, if applicable, and may provide T output symbol streams to T modulators (MODs) 232a through 232t. Each modulator <NUM> may process a respective output symbol stream (for example, for OFDM, etc.) to obtain an output sample stream. Each modulator <NUM> may further process (for example, convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal.

At UE <NUM>, antennas 252a through 252r may receive the downlink signals from base station <NUM> or other base stations and may provide received signals to demodulators (DEMODs) 254a through 254r, respectively. Each demodulator <NUM> may condition (for example, filter, amplify, downconvert, and digitize) a received signal to obtain input samples. Each demodulator <NUM> may further process the input samples (for example, for OFDM, etc.) to obtain received symbols. A receive processor <NUM> may process (for example, demodulate and decode) the detected symbols, provide decoded data for UE <NUM> to a data sink <NUM>, and provide decoded control information and system information to a controller or processor (controller/processor) <NUM>. A channel processor may determine reference signal received power (RSRP), received signal strength indicator (RSSI), reference signal received quality (RSRQ), channel quality indicator (CQI), etc. In some aspects, one or more components of UE <NUM> may be included in a housing.

On the uplink, at UE <NUM>, a transmit processor <NUM> may receive and process data from a data source <NUM> and control information (for example, for reports including RSRP, RSSI, RSRQ, CQI, etc.) from controller/processor <NUM>. Transmit processor <NUM> also may generate reference symbols for one or more reference signals. The symbols from transmit processor <NUM> may be precoded by a TX MIMO processor <NUM> if applicable, further processed by modulators 254a through 254r (for example, for DFT-s-OFDM, CP-OFDM, etc.), and transmitted to base station <NUM>. Receive processor <NUM> may provide the decoded data to a data sink <NUM> and the decoded control information to a controller or processor (i.e., controller/processor) <NUM>. The base station <NUM> may include communication unit <NUM> and communicate to network controller <NUM> via communication unit <NUM>. The network controller <NUM> may include communication unit <NUM>, a controller or processor (i.e., controller/processor) <NUM>, and memory <NUM>.

The controller/processor <NUM> of base station <NUM>, the controller/processor <NUM> of the UE <NUM>, or any other component(s) of <FIG> may perform one or more techniques associated with uplink switching for enhanced mobility, as described in more detail elsewhere herein. For example, the controller/processor <NUM> of the base station <NUM>, the controller/processor <NUM> of UE <NUM>, or any other component(s) (or combinations of components) of <FIG> may perform or direct operations of, for example, process <NUM> of <FIG>, process <NUM> of <FIG>, process <NUM> of <FIG>, or other processes as described herein. The memories <NUM> and <NUM> may store data and program codes for base station <NUM> and UE <NUM>, respectively. A scheduler <NUM> may schedule UEs for data transmission on the downlink, the uplink, or a combination thereof.

In some implementations, the controller/processor <NUM> may be a component of a processing system. A processing system may generally refer to a system or series of machines or components that receives inputs and processes the inputs to produce a set of outputs (which may be passed to other systems or components of, for example, the UE <NUM>). For example, a processing system of the UE <NUM> may refer to a system including the various other components or subcomponents of the UE <NUM>.

The processing system of the UE <NUM> may interface with other components of the UE <NUM>, and may process information received from other components (such as inputs or signals), output information to other components, etc. For example, a chip or modem of the UE <NUM> may include a processing system, a first interface to receive or obtain information, and a second interface to output, transmit or provide information. In some cases, the first interface may refer to an interface between the processing system of the chip or modem and a receiver, such that the UE <NUM> may receive information or signal inputs, and the information may be passed to the processing system. In some cases, the second interface may refer to an interface between the processing system of the chip or modem and a transmitter, such that the UE <NUM> may transmit information output from the chip or modem. A person having ordinary skill in the art will readily recognize that the second interface also may obtain or receive information or signal inputs, and the first interface also may output, transmit or provide information.

In some implementations, the controller/processor <NUM> may be a component of a processing system. A processing system may generally refer to a system or series of machines or components that receives inputs and processes the inputs to produce a set of outputs (which may be passed to other systems or components of, for example, the base station <NUM>). For example, a processing system of the base station <NUM> may refer to a system including the various other components or subcomponents of the base station <NUM>.

The processing system of the base station <NUM> may interface with other components of the base station <NUM>, and may process information received from other components (such as inputs or signals), output information to other components, etc. For example, a chip or modem of the base station <NUM> may include a processing system, a first interface to receive or obtain information, and a second interface to output, transmit or provide information. In some cases, the first interface may refer to an interface between the processing system of the chip or modem and a receiver, such that the base station <NUM> may receive information or signal inputs, and the information may be passed to the processing system. In some cases, the second interface may refer to an interface between the processing system of the chip or modem and a transmitter, such that the base station <NUM> may transmit information output from the chip or modem. A person having ordinary skill in the art will readily recognize that the second interface also may obtain or receive information or signal inputs, and the first interface also may output, transmit or provide information.

The stored program codes, when executed by the controller/processor <NUM> or other processors and modules at the UE <NUM>, may cause the UE <NUM> to perform operations described with respect to the process <NUM> of <FIG>, the process <NUM> of <FIG>, or other processes as described herein. The stored program codes, when executed by the controller/processor <NUM> or other processors and modules at the base station <NUM>, may cause the base station <NUM> to perform operations described with respect to the process <NUM> of <FIG> or other processes as described herein. A scheduler <NUM> may schedule UEs for data transmission on the downlink, the uplink, or a combination thereof.

The UE <NUM> may include means for performing one or more operations described herein, such as the process <NUM> of <FIG>, the process <NUM> of <FIG>, or other processes as described herein. In some aspects, such means may include one or more components of UE <NUM> described in connection with <FIG>.

The base station <NUM> may include means for performing one or more operations described herein, such as the process <NUM> of <FIG> or other processes as described herein. In some aspects, such means may include one or more components of base station <NUM> described in connection with <FIG>.

For example, the functions described with respect to the transmit processor <NUM>, the receive processor <NUM>, the TX MIMO processor <NUM>, or another processor may be performed by or under the control of controller/processor <NUM>.

<FIG> is a diagram illustrating an example <NUM> associated with a UE <NUM> switching from a source cell to a target cell for transmitting PUSCH communications. The example <NUM> may occur when the UE <NUM> is connected to the source cell and to the target cell during a handover. The UE <NUM> of <FIG> can be an implementation of the UE <NUM> depicted and described in <FIG> and <FIG>.

In <FIG>, the UE <NUM> is being handed over from a source cell (such as a cell associated with a first base station <NUM>, which can be an implementation of the base station <NUM> depicted and described in <FIG> and <FIG>) to a target cell (such as a cell associated with a second base station <NUM>, which can be an implementation of the base station <NUM> depicted and described in <FIG> and <FIG>). As indicated in <FIG>, and as described above, the UE <NUM> may be connected to both the source cell and the target cell during the handover (HO) from the source cell to the target cell.

As shown by reference number <NUM>, the target cell may, in association with the handover from the source cell to the target cell, provide a trigger associated with the UE <NUM> switching from the source cell to the target cell for transmitting PUSCH communications. As shown, by reference number <NUM>, the UE <NUM> may detect the trigger to switch from the source cell to the target cell for transmitting PUSCH communications. Notably, in some aspects, the providing of the trigger by the target cell is not required. In such cases, the UE <NUM> may detect the trigger in another manner, such as based at least in part on a configuration of the UE <NUM>, as described below.

In some aspects, the trigger may be associated with a radio resource control (RRC) reconfiguration complete message provided to the target cell. For example, such as in the case of a two-step random access procedure, the target cell may receive an RRC reconfiguration complete message (such as msgA) transmitted by the UE <NUM> in association with the performing the handover and may provide, to the UE <NUM>, a response indicating that the RRC reconfiguration complete message was received. Here, the response indicating that the RRC reconfiguration complete message was received may serve as the trigger. In some aspects, the response indicating that the RRC reconfiguration complete message was received may include, for example, an acknowledgment (ACK) of the RRC reconfiguration complete message (such as a layer <NUM> ACK, a layer <NUM> ACK). In such a case, the UE <NUM> may receive the ACK, and the ACK may be the trigger associated with causing the UE <NUM> to switch (that is, execute a switch) from the source cell to the target cell for transmitting PUSCH communications. As another example, the target cell may receive the RRC reconfiguration complete message transmitted by the UE <NUM> and may provide a physical downlink control channel (PDCCH) addressed to an identifier associated with the UE <NUM> (such as a cell radio network temporary identifier (C-RNTI) associated with the UE <NUM>). Here, the UE <NUM> may receive the PDCCH based at least in part on the PDCCH being addressed to the identifier associated with the UE <NUM>, and the PDCCH may be the trigger associated with causing the UE <NUM> to switch from the source cell to the target cell for transmitting PUSCH communications. As another example, such as in the case of a four-step random access procedure, the UE <NUM> may provide an RRC reconfiguration complete message (such as msg3) in association with the performing the handover. Here, the transmission of the RRC reconfiguration complete message may serve as the trigger. That is, in some aspects, the transmission of the RRC reconfiguration complete message itself may act as the trigger to switch from the source cell to the target cell for transmitting PUSCH communications.

In some aspects, the trigger may be associated with the UE <NUM> being scheduled for a transmission of a PUSCH communication. For example, the UE <NUM> may receive downlink control information (DCI) including a PUSCH grant associated with a PUSCH communication. Here, the PUSCH grant associated with the PUSCH communication may act as the trigger associated with causing the UE <NUM> to switch from the source cell to the target cell for transmitting PUSCH communications. As another example, the UE <NUM> may be scheduled (such as based at least in part on information received in a handover command) for a transmission of PUSCH communication based at least in part on a configured grant. Here, timing of the first configured grant occasion may act as the trigger associated with causing the UE <NUM> to switch from the source cell to the target cell for transmitting PUSCH communications. In other words, in some aspects, the trigger may cause the UE <NUM> to switch from the source cell to the target cell for transmitting PUSCH communications at a time of a first configured grant occasion associated with the PUSCH communication. As another example, the UE <NUM> may be scheduled for a transmission of PUSCH communication based at least in part on a PUSCH grant. Here, timing of the PUSCH grant may act as the trigger associated with the UE <NUM> to switch from the source cell to the target cell for transmitting PUSCH communications. In other words, in some aspects, the trigger may cause the UE <NUM> to switch from the source cell to the target cell for transmitting PUSCH communications at a time of a PUSCH grant associated with the PUSCH communication.

In some aspects, the trigger to switch from the source cell to the target cell for transmitting PUSCH communications may be left to UE implementation. That is, in some aspects, the trigger may be associated with a configuration of the UE <NUM>. For example, the trigger may be based at least in part on an assessment of channel conditions as determined by the UE <NUM> (i.e., the switching may be based at least in part on the assessment of channel conditions). As another example, the trigger may be based at least in part on the UE <NUM> switching from the source cell to the target cell for downlink communication (i.e., the trigger may cause the UE <NUM> to switch from the source cell to the target cell for PUSCH communications at a same time that the UE <NUM> switches from the source cell to the target cell for receiving downlink communications).

As further shown in <FIG> by reference number <NUM>, the UE <NUM> may switch from the source cell to the target cell for transmitting PUSCH communications based at least in part on detecting the trigger. In some aspects, the UE <NUM> may switch from the source cell to the target cell for transmitting PUSCH communications carrying data to be processed for transmission after the switching from the source cell to the target cell (that is, data that is not in the process of being transmitted). That is, the UE <NUM> may switch from the source cell to the target cell for transmitting PUSCH communications carrying new data, and may not switch from the source cell to the target cell for transmitting ongoing PUSCH communications (that is, PUSCH communications already in the process of being transmitted).

In some aspects, the UE <NUM> may transmit PUSCH communications, PUCCH communications, or SRS transmissions to the source cell until switching from the source cell to the target cell. That is, in some aspects, the UE <NUM> may continue to transmit PUSCH communications, PUCCH communications, or SRS transmissions to the source cell until the UE <NUM> switches from the source cell to the target cell for transmitting PUSCH communications.

In some aspects, the UE <NUM> may be configured to continue to transmit PUCCH communications or SRS transmissions to the source cell for a period of time after the UE <NUM> switches from the source cell to the target cell. Such a configuration may be used because, for example, downlink transmissions from the source cell may continue after the UE <NUM> switches from the source cell to the target cell for transmitting PUSCH communications.

In some aspects, information indicating that the UE <NUM> has ended transmissions of uplink communications to the source cell may be provided to the source cell. In some aspects, the UE <NUM> may provide the information indicating that the UE <NUM> has ended uplink communications to the source cell. In some aspects, the UE <NUM> may provide such information via, for example, RRC signaling (such as layer <NUM> signaling), a medium access control (MAC) control element (such as layer <NUM> signaling), or via a PUCCH format to the source cell (such as layer <NUM> signaling). In some aspects, the target cell may provide the information indicating that the UE <NUM> has ended uplink communications to the source cell. In some aspects, the target cell may provide such information when, for example, the target cell schedules a PUSCH grant associated with the UE <NUM>. In some aspects, based at least in part on the indication that the UE <NUM> has ended transmission of uplink communications to the source cell, the source cell may cease providing uplink grants to the UE <NUM> or may begin forwarding uplink data, associated with the UE <NUM>, to the target cell.

In some aspects, the UE <NUM> may switch from a limited capability mode to a full capability mode based at least in part on switching from the source cell to the target cell for transmitting PUSCH communications. For example, after switching from the source cell to the target cell for transmitting PUSCH communications and for receiving downlink communications, the UE <NUM> may switch from the limited capability mode to the full capability mode. In some aspects, switching from the limited capability mode to the full capability mode may include, for example, moving all antennas from the source cell to the target cell, updating a number of monitored cells, updating a monitored bandwidth, or modifying one or more other configurations of the UE <NUM>. In some aspects, information indicating that the UE <NUM> has switched to the full capability mode may be provided to the target cell (such as via a MAC control element, an RRC message). In some aspects, based at least in part on this information, the target cell may begin scheduling the UE <NUM> at full capability.

<FIG> is a diagram illustrating an example <NUM> associated with a UE <NUM> ceasing SRS transmissions to a source cell or releasing PUCCH resources after the source cell has ended transmission of downlink communications to the UE <NUM>. The example <NUM> may occur in association with a handover from the source cell to a target cell during which the UE <NUM> is connected to the source cell and the target cell. The UE <NUM> of <FIG> can be an implementation of the UE <NUM> depicted and described in <FIG> and <FIG>.

As shown by reference number <NUM>, the source cell may determine that the source cell has ended a downlink communication transmission (also referred to herein as a downlink transmission) to the UE <NUM> in association with a handover of the UE <NUM> from the source cell to a target cell. For example, the source cell may determine that the source cell does not have any data for the UE <NUM> and, therefore, that the source cell has ended a downlink communication transmission to the UE <NUM>. As another example, the source cell may detect poor channel conditions (such as which may be the cause of the UE <NUM> being handed over from the source cell to the target cell) that cause the source cell to cease transmitting downlink communications to the UE <NUM> and, therefore, may determine to end the downlink communication to the UE <NUM>.

As shown by reference number <NUM>, the source cell may provide, to the UE <NUM> and based at least in part on determining that the source cell has ended the downlink communication transmission to the UE <NUM>, an indication that the UE <NUM> is to cease SRS transmissions to the source cell, or to release PUCCH resources associated with the source cell. In some aspects, the indication may be provided via a MAC control element, via a PDCCH, or via RRC signaling.

In some aspects, the indication may be an indication that the source cell has ended the downlink communication transmission to the UE <NUM>. Here, the indication that the source cell has ended the downlink communication transmission to the UE <NUM> may act as an implicit indication that the UE <NUM> is to cease SRS transmission to the source cell, or to release PUCCH resources associated with the source cell. Additionally, or alternatively, the indication may include an explicit indication to cease the SRS transmissions to the source cell or to release the PUCCH resources associated with the source cell.

In some aspects, the indication may indicate that the UE <NUM> is to both cease SRS transmissions to the source cell and release PUCCH resources associated with the source cell. That is, in some aspects, a single indication may be used. In some aspects, the indication may explicitly indicate that the UE <NUM> is to either cease SRS transmissions to the source cell or release PUCCH resources associated with the source cell. In such a case, the explicit indication to perform one operation may also operate as an implicit indication to perform the other operation. For example, an explicit indication to cease SRS transmissions to the source cell may operate as an implicit indication that the UE <NUM> is to release PUCCH resources associated with the source cell (such as such that the UE <NUM> autonomously releases the PUCCH resources associated with the source cell).

As shown by reference number <NUM>, the UE <NUM> may receive the indication that the UE <NUM> is to cease SRS transmissions to the source cell or release PUCCH resources associated with the source cell, and may cease SRS transmissions to the source cell or release PUCCH resources associated with the source cell based at least in part on the indication.

In some aspects, the UE <NUM> may switch from the limited capability mode to the full capability mode based at least in part on the indication that the UE <NUM> is to cease the SRS transmissions to the source cell, or to release the PUCCH resources associated with the source cell. For example, after ceasing the SRS transmission to the source cell or releasing the PUCCH resources associated with the source cell, the UE <NUM> may switch from the limited capability mode to the full capability mode. In some aspects, switching from the limited capability mode to the full capability mode may include, for example, moving all antennas from the source cell to the target cell, updating a number of monitored cells, updating a monitored bandwidth, or modifying one or more other configurations of the UE <NUM>. In some aspects, when the UE <NUM> switches to the full capability mode, an indicator (such as an indicator indicating that the UE <NUM> has switched to the full capability mode) may be provided to the target cell (such as via a MAC control element, an RRC message). In some aspects, based at least in part on this information, the target cell may begin scheduling the UE <NUM> at full capability.

In some aspects, the UE <NUM> may cease monitoring and reception of downlink transmissions from the source cell based at least in part on the indication that the UE <NUM> is to cease the SRS transmissions to the source cell, or to release the PUCCH resources associated with the source cell (such as since the source cell has determined that the source cell has ended transmissions of downlink communications to the UE <NUM>).

<FIG> is a diagram illustrating an example process <NUM> performed, for example, by a UE. The example process <NUM> shows where a UE, such as the UE <NUM>, performs operations associated with uplink switching for enhanced mobility.

As shown in <FIG>, in some aspects, the process <NUM> may include detecting a trigger to switch from a source cell to a target cell for transmitting PUSCH communications (block <NUM>). For example, the UE (such as by using receive processor <NUM>, transmit processor <NUM>, controller/processor <NUM>, memory <NUM>) may detect a trigger to switch from a source cell to a target cell for transmitting PUSCH communications, as described above. In some aspects, the trigger is detected in association with a handover from the source cell to the target cell. In some aspects, the UE is connected to the source cell and to the target cell during the handover.

As shown in <FIG>, in some aspects, the process <NUM> may include switching from the source cell to the target cell for transmitting PUSCH communications based at least in part on detecting the trigger (block <NUM>). For example, the UE (such as by using receive processor <NUM>, transmit processor <NUM>, controller/processor <NUM>, memory <NUM>) may switch from the source cell to the target cell for transmitting PUSCH communications based at least in part on detecting the trigger, as described above.

The process <NUM> may include additional aspects, such as any single aspect or any combination of aspects described below or in connection with one or more other processes described elsewhere herein.

In a first aspect, the trigger is associated with an RRC reconfiguration complete message provided to the target cell.

In a second aspect, alone or in combination with the first aspect, switching from the source cell to the target cell is based at least in part on upon receiving an ACK of the RRC reconfiguration complete message.

In a third aspect, alone or in combination with one or more of the first and second aspects, switching from the source cell to the target cell is based at least in part on upon receiving a PDCCH addressed to a C-RNTI associated with the UE.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the trigger is associated with the UE being scheduled for a transmission of a PUSCH communication.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, switching from the source cell to the target cell is based at least in part on upon receiving DCI including a PUSCH grant associated with the PUSCH communication.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, switching from the source cell to the target cell occurs at a time of a first configured grant occasion associated with the PUSCH communication.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, switching from the source cell to the target cell occurs at a time of a PUSCH grant associated with the PUSCH communication.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the trigger is associated with a configuration of the UE.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, switching from the source cell to the target cell is based at least in part on an assessment of channel conditions.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, switching from the source cell to the target cell for transmitting PUSCH communications occurs at substantially a same time that the UE switches from the source cell to the target cell for receiving downlink communications.

In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, the UE may transmit PUSCH communications, PUCCH communications, and SRS transmissions to the source cell until switching from the source cell to the target cell.

In a twelfth aspect, alone or in combination with one or more of the first through eleventh aspects, the UE is to continue to transmit PUCCH communications and SRS transmissions to the source cell for a period of time after the UE switches from the source cell to the target cell.

In a thirteenth aspect, alone or in combination with one or more of the first through twelfth aspects, information indicating that the UE has ended transmissions of uplink communications to the source cell is provided to the source cell.

In a fourteenth aspect, alone or in combination with one or more of the first through thirteenth aspects, the information indicating that the UE has ended transmissions of uplink communications to the source cell is provided by the UE via at least one of: RRC signaling, a MAC control element, or a PUCCH format.

In a fifteenth aspect, alone or in combination with one or more of the first through fourteenth aspects, the information indicating that the UE has ended transmissions of uplink communications to the source cell is provided by the target cell.

In a sixteenth aspect, alone or in combination with one or more of the first through fifteenth aspects, an uplink data packet is forwarded from the source cell to the target cell based at least in part on the information indicating that the UE has ended transmissions of uplink communications to the source cell.

In a seventeenth aspect, alone or in combination with one or more of the first through sixteenth aspects, the UE may switch from a limited capability mode to a full capability mode based at least in part on switching from the source cell to the target cell for transmitting PUSCH communications.

In an eighteenth aspect, alone or in combination with one or more of the first through seventeenth aspects, information indicating that the UE has switched to the full capability mode is provided to the target cell.

In a nineteenth aspect, alone or in combination with one or more of the first through eighteenth aspects, the UE switches from the source cell to the target cell for transmitting PUSCH communications carrying data to be processed for transmission after the switching from the source cell to the target cell.

In a twentieth aspect, alone or in combination with one or more of the first through nineteenth aspects, the trigger is associated with the transmission of a RRC reconfiguration complete message by the UE.

<FIG> is a diagram illustrating an example process <NUM> performed, for example, by a BS. The example process <NUM> shows where a base station, such as the base station <NUM>, performs operations associated with uplink switching for enhanced mobility.

As shown in <FIG>, in some aspects, the process <NUM> may include determining that a source cell has ended a downlink communication transmission to a UE (block <NUM>). For example, the base station (such as by using transmit processor <NUM>, receive processor <NUM>, controller/processor <NUM>, memory <NUM>) may determine that a source cell has ended a downlink communication transmission to a UE, such as the UE <NUM>, as described above. In some aspects, the downlink communication transmission to the UE ends in association with a handover from the source cell to a target cell. In some aspects, the UE is connected to the source cell and to the target cell during the handover.

As shown in <FIG>, in some aspects, the process <NUM> may include providing, based at least in part on determining that the source cell has ended the downlink communication transmission to the UE, an indication that the UE is cease SRS transmissions to the source cell, or release PUCCH resources associated with the source cell (block <NUM>). For example, the base station (such as by using transmit processor <NUM>, receive processor <NUM>, controller/processor <NUM>, memory <NUM>) may provide, based at least in part on determining that the source cell has ended the downlink communication transmission to the UE, an indication that the UE is to SRS transmissions to the source cell or and release PUCCH resources associated with the source cell, as described above.

In a first aspect, the indication is provided via at least one of: a MAC control element, a PDCCH, or RRC signaling.

In a second aspect, alone or in combination with the first aspect, the indication including information indicating that the source cell has ended the downlink communication transmission to the UE.

In a third aspect, alone or in combination with one or more of the first and second aspects, the indication is an explicit indication to cease the SRS transmissions to the source cell to release the PUCCH resources associated with the source cell.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the UE is to switch from a limited capability mode to a full capability mode based at least in part on the indication that the UE is to cease the SRS transmissions to the source cell, or to release the PUCCH resources associated with the source cell.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, when the UE switches to the full capability mode, an indicator is provided to the target cell.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the UE is to cease monitoring and reception of downlink transmissions from the source cell based at least in part on the indication that the UE is to cease the SRS transmissions to the source cell, or to release the PUCCH resources associated with the source cell.

As shown in <FIG>, in some aspects, the process <NUM> may include receiving an indication that the UE is to cease SRS transmissions to a source cell or release PUCCH resources associated with the source cell (block <NUM>). For example, the UE (such as by using receive processor <NUM>, controller/processor <NUM>, memory <NUM>) may receive an indication that the UE is to cease SRS transmissions to a source cell or release PUCCH resources associated with a source cell, as described above. In some aspects, the indication is received after the source cell has ended a downlink transmission to the UE in association with a handover from the source cell to a target cell. In some aspects, the UE is connected to the source cell and the target cell during the handover.

As shown in <FIG>, in some aspects, the process <NUM> may include ceasing, based at least in part on the indication, SRS transmissions to the source cell, or releasing PUCCH resources associated with the source cell (block <NUM>). For example, the UE (such as by using receive processor <NUM>, transmit processor <NUM>, controller/processor <NUM>, memory <NUM>) may cease, based at least in part on the indication, SRS transmissions to the source cell, or release PUCCH resources associated with the source cell, as described above.

In a first aspect, the indication is received via at least one of: a MAC control element, a PDCCH, or RRC signaling.

In a second aspect, alone or in combination with the first aspect, the indication includes information indicating that the source cell has ended the downlink transmission to the UE.

In a third aspect, alone or in combination with one or more of the first and second aspects, the indication is an explicit indication to cease the SRS transmissions to the source cell, or to release the PUCCH resources associated with the source cell.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the UE may switch from a limited capability mode to a full capability mode based at least in part on the indication that the UE is to cease the SRS transmissions to the source cell, or to release the PUCCH resources associated with the source cell.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the UE may cease monitoring and reception of downlink transmissions from the source cell based at least in part on the indication that the UE is to cease the SRS transmissions to the source cell, or to release the PUCCH resources associated with the source cell.

As used herein, the phrase "based on" is intended to be broadly construed to mean "based at least in part on.

As used herein, satisfying a threshold may refer to a value being greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold.

The various illustrative logics, logical blocks, modules, circuits and algorithm processes described in connection with the aspects disclosed herein may be implemented as electronic hardware, computer software, or combinations of both.

The hardware and data processing apparatus used to implement the various illustrative logics, logical blocks, modules and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose single- or multi-chip processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, or, any conventional processor, controller, microcontroller, or state machine. A processor also may be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In some aspects, particular processes and methods may be performed by circuitry that is specific to a given function.

Aspects of the subject matter described in this specification also can be implemented as one or more computer programs, i.e., one or more modules of computer program instructions, encoded on a computer storage media for execution by, or to control the operation of, data processing apparatus.

Various modifications to the aspects described in this disclosure may be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects without departing from the scope of this disclosure. Thus, the claims are not intended to be limited to the aspects shown herein, but are to be accorded the widest scope consistent with this disclosure, the principles and the novel features disclosed herein.

Certain features that are described in this specification in the context of separate aspects also can be implemented in combination in a single aspect. Conversely, various features that are described in the context of a single aspect also can be implemented in multiple aspects separately or in any suitable subcombination.

Claim 1:
A method of wireless communication performed by an apparatus of a user equipment, UE (<NUM>), comprising:
detecting a trigger to switch from a source cell to a target cell for transmitting physical uplink shared channel, PUSCH, communications,
wherein the trigger is detected in association with a handover from the source cell to the target cell,
wherein the UE (<NUM>) is connected to the source cell and to the target cell during the handover;
switching from the source cell to the target cell for transmitting the PUSCH communications, wherein switching from the source cell to the target cell is associated with detecting the trigger; and
releasing physical uplink control channel, PUCCH, resources associated with the source cell or ceasing sounding reference signal, SRS, transmissions to the source cell, wherein the releasing or the ceasing is associated with receiving an indication that the source cell has ended downlink communication transmission to the UE (<NUM>).