Patent Description:
<CIT> relates to handover methods for reducing a handover interruption time in a mobile communication system. <CIT> relates to downlink transmission beam configuration techniques for wireless communications.

As the demand for mobile broadband access continues to increase, there exists a need for further improvements in NR and LTE technology.

In the following, each of the described methods, apparatuses, examples and aspects which does not fully correspond to the invention as defined in the claims is thus not according to the invention and is, as well as the whole following description, present for illustration purposes only or to highlight specific aspects of features of the claims.

Aspects of the present disclosure provide apparatus, methods, processing systems, and computer readable mediums for prioritizing a transmit beam of multiple transmit beams transmitted by at least two different cells, and selecting a receive beam for receiving the prioritized transmit beam.

The following description provides examples of receive-beam selection in communication systems, and is not limiting of the scope, applicability, or examples set forth in the claims.

In certain aspects, the UE 120a may be configured for determining signaling priority and beam selection based on the priority. For example, the beam manager <NUM> may be configured to establish a first cell connection with a target base station (e.g., BS 110a) while maintaining an existing second cell connection with a source BS (e.g., BS 110b). The beam manager <NUM> may also be configured to determine that a first transmission time of a first signal transmitted by the target BS is less than a threshold time duration from a second transmission time of a second signal transmitted by the source BS, wherein the UE 120a is configured to use a first receive beam to receive the first signal and a second receive beam to receive the second signal, wherein the first receive beam is different than the second receive beam, and wherein the first signal is associated with one or more first communication metrics and the second signal is associated with one or more second communication metrics.

Based on a determination that the first transmission time is less than the threshold time duration from the second transmission time, the beam manager <NUM> may be configured to determine which one of the one or more first communication metrics and the one or more second communication metrics has priority over the other. If the one or more first communication metrics have priority over the one or more second communication metrics, the beam manager <NUM> may be configured to receive the first signal using the first receive beam instead of the second signal using the second receive beam. Alternatively, if the one or more second communication metrics have priority over the one or more first communication metrics, the beam manager <NUM> may be configured to receive the second signal using the second receive beam instead of the first signal using the first receive beam, in accordance with aspects of the present disclosure.

<FIG> illustrates an example architecture of a distributed radio access network (RAN) <NUM>, which may be implemented in the wireless communication network <NUM> illustrated in <FIG>. As shown in <FIG>, the distributed RAN includes core network (CN) <NUM> and access node (AN) <NUM>.

The CN <NUM> may host core network functions. CN <NUM> may be centrally deployed. CN <NUM> functionality may be offloaded (e.g., to advanced wireless services (AWS)), in an effort to handle peak capacity. The CN <NUM> may include the access and mobility management function (AMF) <NUM> and user plane function (UPF) <NUM>. The AMF <NUM> and UPF <NUM> may perform one or more of the core network functions.

The AN <NUM> may communicate with the CN <NUM> (e.g., via a backhaul interface). The AN <NUM> may communicate with the AMF <NUM> via an N2 (e.g., NG-C) interface. The AN <NUM> may communicate with the UPF <NUM> via an N3 (e.g., NG-U) interface. The AN <NUM> may include a central unit-control plane (CU-CP) <NUM>, one or more central unit-user plane (CU-UPs) <NUM>, one or more distributed units (DUs) <NUM>-<NUM>, and one or more Antenna/Remote Radio Units (AU/RRUs) <NUM>-<NUM>. The CUs and DUs may also be referred to as gNB-CU and gNB-DU, respectively. One or more components of the AN <NUM> may be implemented in a gNB <NUM>. The AN <NUM> may communicate with one or more neighboring gNBs.

The CU-CP <NUM> may be connected to one or more of the DUs <NUM>-<NUM>. The CU-CP <NUM> and DUs <NUM>-<NUM> may be connected via a F1-C interface. As shown in <FIG>, the CU-CP <NUM> may be connected to multiple DUs, but the DUs may be connected to only one CU-CP. Although <FIG> only illustrates one CU-UP <NUM>, the AN <NUM> may include multiple CU-UPs. The CU-CP <NUM> selects the appropriate CU-UP(s) for requested services (e.g., for a UE). The CU-UP(s) <NUM> may be connected to the CU-CP <NUM>. For example, the DU-UP(s) <NUM> and the CU-CP <NUM> may be connected via an E1 interface. The CU-CP(s) <NUM> may be connected to one or more of the DUs <NUM>-<NUM>. The CU-UP(s) <NUM> and DUs <NUM>-<NUM> may be connected via a F1-U interface. As shown in <FIG>, the CU-CP <NUM> may be connected to multiple CU-UPs, but the CU-UPs may be connected to only one CU-CP.

A DU, such as DUs <NUM>, <NUM>, and/or <NUM>, may host one or more TRP(s) (transmit/receive points, which may include an Edge Node (EN), an Edge Unit (EU), a Radio Head (RH), a Smart Radio Head (SRH), or the like). A DU may be located at edges of the network with radio frequency (RF) functionality. A DU may be connected to multiple CU-UPs that are connected to (e.g., under the control of) the same CU-CP (e.g., for RAN sharing, radio as a service (RaaS), and service specific deployments). DUs may be configured to individually (e.g., dynamic selection) or jointly (e.g., joint transmission) serve traffic to a UE. Each DU <NUM>-<NUM> may be connected with one of AU/RRUs <NUM>-<NUM>.

The CU-CP <NUM> may be connected to multiple DU(s) that are connected to (e.g., under control of) the same CU-UP <NUM>. Connectivity between a CU-UP <NUM> and a DU may be established by the CU-CP <NUM>. For example, the connectivity between the CU-UP <NUM> and a DU may be established using Bearer Context Management functions. Data forwarding between CU-UP(s) <NUM> may be via a Xn-U interface.

The distributed RAN <NUM> may support front-hauling solutions across different deployment types. For example, the RAN <NUM> architecture may be based on transmit network capabilities (e.g., bandwidth, latency, and/or jitter). The distributed RAN <NUM> may share features and/or components with LTE. For example, AN <NUM> may support dual connectivity with NR and may share a common front-haul for LTE and NR. The distributed RAN <NUM> may enable cooperation between and among DUs <NUM>-<NUM>, for example, via the CU-CP <NUM>. An inter-DU interface may not be used.

Logical functions may be dynamically distributed in the distributed RAN <NUM>. As will be described in more detail with reference to <FIG>, the Radio Resource Control (RRC) layer, Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer, Medium Access Control (MAC) layer, Physical (PHY) layers, and/or Radio Frequency (RF) layers may be adaptably placed, in the AN and/or UE.

<FIG> illustrates a diagram showing examples for implementing a communications protocol stack <NUM> in a RAN (e.g., such as the RAN <NUM>), according to aspects of the present disclosure. The illustrated communications protocol stack <NUM> may be implemented by devices operating in a wireless communication system, such as a <NUM> NR system (e.g., the wireless communication network <NUM>). In various examples, the layers of the protocol stack <NUM> may be implemented as separate modules of software, portions of a processor or ASIC, portions of non-collocated devices connected by a communications link, or various combinations thereof. Collocated and non-collocated implementations may be used, for example, in a protocol stack for a network access device or a UE. As shown in <FIG>, the system may support various services over one or more protocols. One or more protocol layers of the protocol stack <NUM> may be implemented by the AN and/or the UE.

As shown in <FIG>, the protocol stack <NUM> is split in the AN (e.g., AN <NUM> in <FIG>). The radio resource control (RRC) layer <NUM>, packet data convergence protocol (PDCP) layer <NUM>, radio link control (RLC) layer <NUM>, medium access control (MAC) layer <NUM>, physical (PHY) layer <NUM>, and radio frequency (RF) layer <NUM> may be implemented by the AN. For example, the CU-CP (e.g., CU-CP <NUM> in <FIG>) and the CU-UP e.g., CU-UP <NUM> in <FIG>) each may implement the RRC layer <NUM> and the PDCP layer <NUM>. A DU (e.g., DUs <NUM>-<NUM> in <FIG>) may implement the RLC layer <NUM> and MAC layer <NUM>. The AU/RRU (e.g., AU/RRUs <NUM>-<NUM> in <FIG>) may implement the PHY layer(s) <NUM> and the RF layer(s) <NUM>. The PHY layers <NUM> may include a high PHY layer and a low PHY layer.

The UE may implement the entire protocol stack <NUM> (e.g., the RRC layer <NUM>, the PDCP layer <NUM>, the RLC layer <NUM>, the MAC layer <NUM>, the PHY layer(s) <NUM>, and the RF layer(s) <NUM>).

<FIG> is a block diagram illustrating example components <NUM> of UE 120a and one of BS 110a or BS 110b (e.g., in the wireless communication network <NUM> of <FIG>), which may be used to implement aspects of the present disclosure.

At the BS 110a, a transmit processor <NUM> may receive data from a data source <NUM> and control information from a controller/processor <NUM>. The control information may be for the physical broadcast channel (PBCH), physical control format indicator channel (PCFICH), physical hybrid automatic repeat request (HARQ) indicator channel (PHICH), physical downlink control channel (PDCCH), group common PDCCH (GC PDCCH), etc. The data may be for the physical downlink shared channel (PDSCH), etc. The processor <NUM> may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. The transmit processor <NUM> may also generate reference symbols, such as for the primary synchronization signal (PSS), secondary synchronization signal (SSS), and cell-specific reference signal (CRS). A transmit (TX) multiple-input multiple-output (MIMO) processor <NUM> may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, and/or the reference symbols, if applicable, and may provide output symbol streams to the modulators (MODs) 432a-432t. Each modulator may further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. Downlink signals from modulators 432a-432t may be transmitted via the antennas 434a-434t, respectively.

At the UE 120a, the antennas 452a-452r may receive the downlink signals from the BS 110a and may provide received signals to the demodulators (DEMODs) in transceivers 454a-454r, respectively. Each demodulator <NUM> may condition (e.g., filter, amplify, down-convert, and digitize) a respective received signal to obtain input samples. A MIMO detector <NUM> may obtain received symbols from all the demodulators 454a-454r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor <NUM> may process (e.g., demodulate, de-interleave, and decode) the detected symbols, provide decoded data for the UE 120a to a data sink <NUM>, and provide decoded control information to a controller/processor <NUM>.

On the uplink, at UE 120a, a transmit processor <NUM> may receive and process data (e.g., for the physical uplink shared channel (PUSCH)) from a data source <NUM> and control information (e.g., for the physical uplink control channel (PUCCH) from the controller/processor <NUM>. The symbols from the transmit processor <NUM> may be precoded by a TX MIMO processor <NUM> if applicable, further processed by the demodulators in transceivers 454a-454r (e.g., for SC-FDM, etc.), and transmitted to the BS 110a. At the BS 110a, the uplink signals from the UE 120a may be received by the antennas <NUM>, processed by the modulators <NUM>, detected by a MIMO detector <NUM> if applicable, and further processed by a receive processor <NUM> to obtain decoded data and control information sent by the UE 120a.

The controller/processor <NUM> and/or other processors and modules at the UE 120a may perform or direct the execution of processes for the techniques described herein. For example, as shown in <FIG>, the controller/processor <NUM> of the UE 120a has beam manager <NUM> that may be configured for determining signaling priority and beam selection based on the priority. For example, the beam manager <NUM> may be configured to establish a first cell connection with a target base station (e.g., BS 110a) while maintaining an existing second cell connection with a source BS (e.g., BS 110b). The beam manager <NUM> may also be configured to determine that a first transmission time of a first signal transmitted by the target BS is less than a threshold time duration from a second transmission time of a second signal transmitted by the source BS, wherein the UE 120a is configured to use a first receive beam to receive the first signal and a second receive beam to receive the second signal, wherein the first receive beam is different than the second receive beam, and wherein the first signal is associated with one or more first communication metrics and the second signal is associated with one or more second communication metrics.

The transmission timeline for each of a downlink and an uplink may be partitioned into units of radio frames. Each radio frame may have a predetermined duration (e.g., <NUM> milliseconds (ms)) and may be partitioned into <NUM> subframes, each of <NUM>, with indices of <NUM> through <NUM>. A mini-slot is a subslot structure (e.g., <NUM>, <NUM>, or <NUM> symbols).

In NR, a synchronization signal (SS) block (SSB) is transmitted. The PSS may provide half-frame timing, and the SS may provide the CP length and frame timing.

As described in more detail below with reference to <FIG>, each symbol in a slot may indicate a link direction (e.g., DL, UL, or flexible) for data transmission and the link direction for each subframe may be dynamically switched.

<FIG> is a diagram 600A showing an example of a DL-centric subframe. The DL-centric subframe may include a control portion 602A. The control portion 602A may exist in the initial or beginning portion of the DL-centric subframe. The control portion 602A may include various scheduling information and/or control information corresponding to various portions of the DL-centric subframe. In some configurations, the control portion 602A may be a physical DL control channel (PDCCH), as indicated in <FIG>. The DL-centric subframe may also include a DL data portion 604A. The DL data portion 604A may sometimes be referred to as the payload of the DL-centric subframe. The DL data portion 604A may include the communication resources utilized to communicate DL data from the scheduling entity (e.g., UE or BS) to the subordinate entity (e.g., UE). In some configurations, the DL data portion 604A may be a physical DL shared channel (PDSCH).

The DL-centric subframe may also include a common UL portion 606A. The common UL portion 606A may sometimes be referred to as an UL burst, a common UL burst, and/or various other suitable terms. The common UL portion 606A may include feedback information corresponding to various other portions of the DL-centric subframe. For example, the common UL portion 606A may include feedback information corresponding to the control portion 602A. Non-limiting examples of feedback information may include an acknowledgement (ACK) signal, a negative-acknowledgment (NACK) signal, a HARQ indicator, and/or various other suitable types of information. The common UL portion 606A may include additional or alternative information, such as information pertaining to random access channel (RACH) procedures, scheduling requests (SRs), and various other suitable types of information. As illustrated in <FIG>, the end of the DL data portion 604A may be separated in time from the beginning of the common UL portion 606A. One of ordinary skill in the art will understand that the foregoing is merely one example of a DL-centric subframe and alternative structures having similar features may exist without necessarily deviating from the aspects described herein.

<FIG> is a diagram 600B showing an example of an UL-centric subframe. The UL-centric subframe may include a control portion 602B. The control portion 602B may exist in the initial or beginning portion of the UL-centric subframe. The control portion 602B in <FIG> may be similar to the control portion 602A described above with reference to <FIG>. The UL-centric subframe may also include an UL data portion 604B. The UL data portion 604B may sometimes be referred to as the payload of the UL-centric subframe. The UL portion may refer to the communication resources utilized to communicate UL data from the subordinate entity (e.g., UE) to the scheduling entity (e.g., UE or BS).

As illustrated in <FIG>, the end of the control portion 602B may be separated in time from the beginning of the UL data portion 604B. The UL-centric subframe may also include a common UL portion 606B. The common UL portion 606B in <FIG> may be similar to the common UL portion 606A described above with reference to <FIG>. The common UL portion 606B may additionally or alternatively include information pertaining to channel quality indicator (CQI), sounding reference signals (SRSs), and various other suitable types of information. One of ordinary skill in the art will understand that the foregoing is merely one example of an UL-centric subframe and alternative structures having similar features may exist without necessarily deviating from the aspects described herein.

<FIG> is a call-flow diagram <NUM> illustrating an example process for a make-before-break (MBB) handover (also referred to herein as a dual active protocol stack (DAPS) handover) between a UE 120a and at least a source cell (e.g., such as cell 102a or cell 102b of the wireless communication network <NUM> of <FIG>) corresponding to a source gNB (e.g., such as BS 110a or BS 110b of the wireless communication network <NUM> of <FIG>), and target cell (e.g., such as the other of cell 102a or cell 102b of the wireless communication network <NUM> of <FIG>) corresponding to a target gNB (e.g., such as BS 110a or BS 110b of the wireless communication network <NUM> of <FIG>). <FIG> also includes a gNB central unit (CU) <NUM> and a core network (CN) user plane function (UPF) <NUM>.

In certain aspects, at a first step <NUM>, an event trigger may occur at the UE 120a causing the UE 120a to communicate a measurement report with the gNB-CU <NUM>. For example, the measurement report may indicate to the gNB-CU <NUM> that the UE 120a initiated an MBB handover. Accordingly, gNB-CU can make an MBB handover decision in response to receiving the measurement report. The measurement report may be triggered by a determination by the UE 120a that relative value(s) of one or more criteria (e.g., received power, received quality, path loss, etc.) associated with signaling received from the source gNB 110a are less than a threshold value.

At a second step <NUM>, gNB-CU <NUM> and target gNB-DU 110b may generate a UE context setup request/response. At a third step <NUM>, the gNB-CU <NUM> may transmit a radio resource control (RRC) reconfiguration message to the UE 120a. In some examples, the RRC reconfiguration message includes a "make-before-break-HO" indication requesting the UE 120a to perform MBB handover procedures. For example, the RRC Reconfiguration message may include CellGroupConfig (Reconfigwithsync) information. On receiving the RRC reconfiguration message, UE 120a maintains the connection to the source gNB-DU 110a cell even while establishing the connection to the target gNB-DU 110b cell. That is, the UE 120a can transmit and receive data via the source cell during handover.

At a fourth step <NUM>, the UE 120a may continue data transmission and reception with the source gNB-DU 110a. The UE 120a may also connect to the target cell via synchronization and RACH procedures with the gNB-DU 110b. Upon connection with the target gNB-DU, at a fifth step <NUM>, the UE 120a may transmit an "RRC Connection Reconfiguration Complete" message to the gNB-CU <NUM>. Upon reception of the RRC Connection Reconfiguration Complete message, the gNB-CU may determine a release decision.

At a sixth step <NUM>, source gNB-DU 110a, target gNB-DU 110b, and gNB-CU <NUM> may determine a UE Context Modification Request/Response with the source gNB-DU 110a. At a seventh step <NUM>, the gNB-CU <NUM> may transmit an RRC Reconfiguration message that releases the source gNB-DU 110a cell. Upon reception of the RRC Reconfiguration message, the UE 120a may release connection to the source gNB.

At an eighth step <NUM>, the UE 120a may transmit a RRC Reconfiguration Complete message to gNB-CU <NUM>. At a ninth step <NUM>, gNB-CU <NUM> and target gNB-DU 110b determine a UE Context Release with the source gNB-DU 110a.

During a make-before-break (MBB) handover process or a dual active protocol stack (DAPS) handover process, a UE (e.g., UE 120a of the wireless communication network <NUM> of <FIG>) may be connected to both a source BS (e.g., such as BS 110a or BS 110b of the wireless communication network <NUM> of <FIG>) and a target BS (e.g., such as the other of BS 110a or BS 110b of the wireless communication network <NUM> of <FIG>), wherein the source BS is part of a first cell (e.g., such as cell 102a or cell 102b of the wireless communication network <NUM> of <FIG>), and the target BS is part of a second cell (e.g., such as the other of cell 102a or cell 102b of the wireless communication network <NUM> of <FIG>).

In certain aspects, the UE 120a may establish a first cell connection with the target BS 110b while maintaining the existing second cell connection with the source BS 110a. For example, due to mobility, if the UE 120a determines that path loss between the UE 120a and the source BS 110a has increased to a threshold value, the UE 120a may initiate a handover to the target BS 110b based on measurements of signaling (e.g., broadcast) from the target BS 110b. Thus, once the UE 120a has established a first cell connection with the target BS 110b, and maintained second cell connection with the source BS 110a, the UE 120a may use a first receive beam to receive a first signal from the target BS 110b, and a second receive beam to receive a second signal from the source BS 110a during the MBB handover, wherein the first receive beam is different than the second receive beam.

During the MBB handover, the target BS 110b may transmit a first signal to the UE 120a, and the source BS 110a may transmit a second signal to the UE 120a. However, in some cases, the source BS 110a and the target BS 110b may not communicate with each other to coordinate the timing of signal transmissions from each BS such that the UE 120a may receive both the first signal and the second signal. As such, the first signal and the second signal may be transmitted using the same time resources (overlapping), or transmitted relatively close to each other in terms of time. In one example, if the transmission timing of the first signal is relatively close to the transmission timing of the second signal, the UE 120a may not have enough time to receive the first signal, and then switch from the first cell connection to the second cell connection to receive the second signal. Thus, in some examples, the UE 120a will have to determine which signal to receive.

In certain aspects, the first signal is associated with one or more first communication metrics and the second signal is associated with one or more second communication metrics. For example, each of the one or more first communication metrics and the one or more second communication metrics may include one or more quality of service (QoS) metrics which include one or more of: a QoS class identifier (QCI), a resource type (e.g., guaranteed bit rate (GBR), a delay critical GBR, or non-GBR), a packet delay budget (PDB), a packet error rate (PER), an averaging window, a maximum data burst volume, a reliability requirement, a priority requirement, or a latency requirement.

In some examples, the GBR metric represents a bit rate expected to be provided to the UE 120a in a wireless communication. When a transmission rate of a communication is greater than or equal to the GBR, the QoS metric for that communication is satisfied; however, when the transmission rate of the communication is less than the GBR, the QoS metric of the service is not acceptable.

In some examples, the PDB can represent how a scheduler in the MAC layer (e.g., such as the MAC layer <NUM> of <FIG>) handles data to be communicated. For example, data with a higher priority can be expected to be scheduled before data with a lower priority. In some examples, the PER (or bit error rate (BER)) represents a number of erroneous data packets communicated with respect to the total number of data packets communicated. In some examples, the averaging window represents the duration over which a guaranteed flow bit rate (GFBR) shall be calculated (e.g., in the BS, UPF, or UE). In some examples, the maximum data burst volume relates to the largest amount of data that the BS is required to serve.

In some configurations, the first signal or the second signal may include data having a relatively low or ultra-low latency requirement. For example, the latency requirement of data in the first signal may be lower than the latency requirement of data in the second signal. Generally, latency refers to the delay associated with receipt of data at its intended destination. In some configurations, the first signal or the second signal may include data having a relatively high priority requirement. For example, the priority requirement of the first signal may be higher than the priority requirement of second signal. In some examples, the priority level may be determined and provided by network operators (e.g., network providers) based on a subscriber (e.g., user) profile. For example, certain subscribers may be provided with a higher level of priority than other subscribers. In another example, priority level may be associated with certain data (e.g., emergency related messages). Generally, priority refers to the importance or time-sensitivity of the data. Data having relatively higher importance and/or relatively greater time-sensitivity should be received before other data having relatively lesser importance and/or relatively lesser time-sensitivity. In some configurations, the first signal or the second signal may include data having a relatively high reliability requirement. For example, the reliability requirement of the first signal may be greater than the reliability requirement of the second signal. Generally, reliability refers to how consistently data is successfully received by the intended destination without errors.

In some examples, a transmission time of the first signal overlaps a transmission time of the second signal (e.g., the first signal and the second signal are transmitted using the same time resources). In the invention, a difference in time between the transmission time of the first signal and the transmission time of the second signal is below a threshold and the UE 120a needs to determine a priority associated with each of the first signal and the second signal in order to determine which signal to receive. In the invention, the threshold is a minimum amount of time required by the UE 120a to switch from one receive beam for receiving signaling from one of the source BS 110a or target BS 110b, to a second receive beam for receiving signaling from the other of the source BS 110a or target BS 110b. Based on a comparison of the priority of the first beam with the priority of the second beam, the UE 120a determines to receive the signal having the highest priority, and proceeds to select a receive beam for receiving the signal having the highest priority, instead of receiving the other signal via another receive beam.

It should be noted that switching from the first cell connection to the second cell connection may include switching from a first transmit beam to a second transmit beam, where the first transmit beam is transmitted by one of the source BS 110a or the target BS 110b, and where the second transmit beam is transmitted by the other of the source BS 110a or the target BS 110b. Switching from the first cell connection to the second cell connection may also include switching from a first set of radio-frequency (RF) parameters associated with the first cell to a second set of RF parameters associated with the second cell. In some examples, the RF parameters include one or more of a bandwidth, a transmit power, a channel frequency, or a center frequency associated with the first cell and the second cell.

For example, <FIG>, and <FIG> are block diagrams (800A, 800B, 800C) illustrating examples of an overlapping scenario and non-overlapping scenarios during MBB handover.

Here, <FIG> illustrates an overlapping scenario in which the PDSCH or PDCCH for a target cell (e.g., such as cell 102a or cell 102b of the wireless communication network <NUM> of <FIG>) overlaps (e.g., wherein at least a portion of a transmission beam transmitting the first signal may overlap in time with another transmission beam transmitting the second signal) a PDSCH or PDCCH for a source cell (e.g., such as the other of cell 102a or cell 102b of the wireless communication network <NUM> of <FIG>).

In certain aspects, for the overlapping scenario, determining which of the first signal or the second signal to receive may be based on which signal has priority over the other. For example, if the priority is based on quality of service (QoS), and assuming that the overlap channels are both PDSCHs but associated with different applications (e.g., enhanced mobile broadband (eMBB) and ultra-reliable low-latency communication (URLLC)), the QoS of the applications may be determined and a higher priority may be given to applications with higher QoS, (e.g., URLLC).

<FIG> illustrates a non-overlapping scenario where, if the duration D (represented by arrows) in time between the physical channels from both cells is large enough for switching between cells by the UE 120a (i.e., a configured threshold), then the UE 120a may switch between the first cell and the second cell to receive both of the first signal and the second signal. However, in an example where the duration between the physical channels from both cells is not large enough for switching between cells, the UE 120a may determine which one of the one or more first communication metrics and the one or more second communication metrics has priority over the other.

<FIG> illustrates another non-overlapping scenario, where the duration D in time between a physical channel of the target cell and a physical channel of the source cell is not large enough to permit the UE 120a to switch between the first cell and the second cell to receive both of the first signal and the second signal. Thus, in one example, the UE 120a may determine which one of the one or more first communication metrics associated with the physical channel of the target cell and the one or more second communication metrics associated with the physical channel of the source cell has priority over the other.

Accordingly, the UE 120a may be configured to determine a difference in timing between a transmission of the first signal and a transmission of the second signal to determine whether the UE 120a can receive both the first signal and the second signal, or if the UE 120a can only receive one. For example, the UE 120a may determine that a first transmission time of the first signal transmitted by the target BS 110b is less than a threshold time duration from a second transmission time of the second signal transmitted by the source BS 110a. Thus, in this example, the UE 120a can receive only one of the first signal or the second signal.

Based on determining that the first transmission time is less than the threshold time duration from the second transmission time, the UE 120a may determine which one of the one or more first communication metrics and the one or more second communication metrics has priority over the other. If the one or more first communication metrics have priority over the one or more second communication metrics, the UE 120a may determine to receive the first signal using the first receive beam instead of the second signal using the second receive beam. Alternatively, if the one or more second communication metrics have priority over the one or more first communication metrics, the UE 120a may determine to receive the second signal using the second receive beam instead of the first signal using the first receive beam.

In certain aspects, the one or more first communication metrics associated with the first signal, and the one or more second communication metrics associated with the second signal can be ranked by the UE 120a according to a QoS type and/or value. For example, the first signal may be an enhanced mobile broadband (eMBB) signal having a PER requirement of <NUM>-<NUM> with no PDB, while the second signal may be an ultra-reliable low-latency communication (URLLC) having a PER requirement of <NUM>-<NUM> and a PDB requirement. In some examples, the UE 120a may rank the first and second communication metrics according to which has the relatively highest latency, reliability, and/or priority requirements. Thus, in determining which one of the one or more first communication metrics and the one or more second communication metrics have priority over the other, the UE 120a may determine which of the one or more first communication metrics and the one or more second communication metrics has a relatively highest ranked communication metric over the other. For example, the UE 120a may determine to receive the second signal associated with the URLLC because the QoS type (e.g., URLLC signal with a PDB requirement ranks higher than the eMBB with no PDB requirement), and the QoS value (e.g., a PER of <NUM>-<NUM> associated with the URLLC is ranked higher than the PER of <NUM>-<NUM> associated with the eMBB).

In some examples, the UE 120a may rank the first signal and the second signal based on a hierarchy of QoS types and/or values. For example, the hierarchy of values may start with a QoS metric such as PER. Accordingly, the UE 120a may compare the PER requirement of the first signal with the second signal to determine which has a highest priority. If the first signal and the second signal have different PER requirements, then the UE 120a may select the signal having the lower PER requirement. However, if both the first signal and the second signal have the same PER, then the UE 120a may consider the next QoS metric in the hierarchy; for example, PDB. For example, if only one signal has a PDB, then the UE 120a may select to receive that signal. However, if both the first signal and the second signal have the same PDB, then the UE 120a may consider the next QoS metric in the hierarchy. Accordingly, the UE 120a may continue to rank each of the first signal and the second signal according to a hierarchy of QoS types and/or values until the UE 120a determines which signal has the higher priority. At that point, the UE 120a will determine to receive that signal.

In some examples, each of the first communication metric and the second communication metric are associated with different time durations within a time period. In some examples, the time period may relate to the start of the MBB handover to its completion. For example, the time period may relate to a duration where the UE 120a can communicate (transmit and receive) over both the first cell connection and the second cell connection during the handover. Thus, within that time period, there may be one or more contiguous time durations that are associated with a different QoS metric.

For example, <FIG> is a diagram <NUM> illustrating an example of contiguous time durations (e.g., T1-T2, T2-T3, and T3-T4) associated with different communication metrics (e.g., QoS metrics) throughout the duration of time that the UE 120a can communicate over both the first cell connection and the second cell connection during an MBB handover.

In this example, the period of time between T1 and T4 may relate to the period of time where the UE 120a can communicate over both the first cell connection and the second cell connection. Each of the contiguous durations of time within the period of time may correspond to one or more communication metrics (e.g., QoS metrics). Thus, if signaling is transmitted to the UE 120a via both of the first cell connection and the second cell connection, the UE 120a may determine to receive one of a first signal from the first cell or a second signal for the second cell based on which of the first signal and the second signal has the highest priority based on the communication metric(s) associated with the applicable time duration (e.g., T1-T2, T2-T3, and T3-T4).

For example, a first time duration (e.g., T1-T2) may be associated with a priority level of a signal transmitted to the UE 120a. Thus, if a first signal is transmitted to the UE 120a via the first cell connection, and a second signal is transmitted to the UE 120a via the second cell connection during the first time duration, the UE 120a may compare the priority of the first signal to the priority of the second signal to determine which has the highest priority. In one example, the first signal may be an eMBB signal with a low priority relative to the second signal (e.g., a URLLC signal). Thus, the UE 120a may determine to receive the second signal via a second receive beam instead of the first signal via a first receive beam.

In another example, a second time duration (e.g., T2-T3) may be associated with a PDB metric of a signal. Thus, if the first signal is transmitted to the UE 120a via the first cell connection, and the second signal is transmitted to the UE 120a via the second cell connection during the second time duration, the UE 120a may compare a PDB of the first signal to a PDB of the second signal to determine which signal has a PDB, and if both signals have a PDB, which signal has the lowest PDB. Thus, the UE 120a may determine to receive the signal having the lowest PDB instead of the other signal.

In another example, a third time duration (e.g., T3-T4) may be associated with a PER metric of a signal. Thus, if the first signal is transmitted to the UE 120a via the first cell connection, and the second signal is transmitted to the UE 120a via the second cell connection during the third time duration, the UE 120a may compare a PER of the first signal to a PER of the second signal to determine which signal has a PER, and if both signals have a PER, which signal has the lowest PDB. Thus, the UE 120a may determine to receive the signal having the lowest PDB instead of the other signal.

Accordingly, in some examples, when the UE 120a determines which one of the one or more first communication metrics and the one or more second communication metrics have priority over the other, the UE 120a may also determine a first communication metric of the one or more first communication metrics associated with the first transmission time, and a second communication metric of the one or more second communication metrics associated with the second transmission time. The UE 120a may then determine which one of the first communication metric and the second communication metric has priority over the other.

<FIG> is a flow diagram illustrating example operations <NUM> for wireless communication, in accordance with certain aspects of the present disclosure. The operations <NUM> may be performed, for example, by UE (e.g., such as a UE 120a in the wireless communication network <NUM>). Operations <NUM> may be implemented as software components that are executed and run on one or more processors (e.g., controller/processor <NUM> of <FIG>). Further, the transmission and reception of signals by the UE 120a in operations <NUM> may be enabled, for example, by one or more antennas (e.g., antennas <NUM> of <FIG>). In certain aspects, the transmission and/or reception of signals by the UE 120a may be implemented via a bus interface of one or more processors (e.g., controller/processor <NUM>) obtaining and/or outputting signals.

The operations <NUM> may begin, at a first step <NUM>, by establishing a first cell connection with a first base station (BS) while maintaining an existing second cell connection with a second BS 110a. In some examples, the first BS is one of a target BS or a source BS, while the second BS is the other of the target BS or the source BS.

The operations <NUM> may proceed to a second step <NUM>, by determining that a first transmission time of a first signal transmitted by the first BS 110b is less than a threshold time duration from a second transmission time of a second signal transmitted by the second BS 110a, wherein the UE 120a is configured to use a first receive beam to receive the first signal and a second receive beam to receive the second signal, wherein the first receive beam is different than the second receive beam, and wherein the first signal is associated with one or more first communication metrics and the second signal is associated with one or more second communication metrics.

The operations <NUM> may proceed to a third step <NUM>, wherein, based on determining that the first transmission time is less than the threshold time duration from the second transmission time, the operations <NUM> may proceed to a first sub-step <NUM> by determining which one of the one or more first communication metrics and the one or more second communication metrics has priority over the other. The operations <NUM> may then proceed to one of a second sub-step <NUM> or a third sub-step <NUM>, where, if the one or more first communication metrics have priority over the one or more second communication metrics, the operations <NUM> proceed by receiving the first signal using the first receive beam instead of the second signal using the second receive beam. Alternatively, if the one or more second communication metrics have priority over the one or more first communication metrics, the operations <NUM> proceed by receiving the second signal using the second receive beam instead of the first signal using the first receive beam.

In certain aspects, each of the one or more first communication metrics and the one or more second communication metrics comprise one or more quality of service (QoS) metrics, wherein the one or more QoS metrics comprise one or more of: a guaranteed bit rate, a priority level, a packet delay budget, a packet error rate, an averaging window, and a maximum data burst volume.

In certain aspects, the one or more first communication metrics and the one or more second communication metrics are ranked by type, and wherein determining which one of the one or more first communication metrics and the one or more second communication metrics have priority over the other comprises determining which of the one or more first communication metrics and the one or more second communication metrics has a highest ranked communication metric with priority over the other.

In certain aspects, each of the one or more first communication metrics and the one or more second communication metrics are associated with a different time period, and wherein determining which one of the one or more first communication metrics and the one or more second communication metrics have priority over the other comprises determining a first communication metric of the one or more first communication metrics associated with the first transmission time. In certain aspects, determining which one of the one or more first communication metrics and the one or more second communication metrics have priority over the other comprises determining a second communication metric of the one or more second communication metrics associated with the second transmission time. In certain aspects, determining which one of the one or more first communication metrics and the one or more second communication metrics have priority over the other comprises determining which one of the first communication metric and the second communication metric has priority over the other.

In certain aspects, the handover operation comprises a make-before-break (MBB) handover and wherein the first cell connection and the second cell connection are both maintained for a time period during the handover, and wherein each of the different time periods occur during the time period during the handover.

In certain aspects, the first transmission time overlaps with the second transmission time.

In certain aspects, the threshold time duration is a minimum time required by the UE 120a for switching from the first cell connection to the second cell connection.

In certain aspects, switching from the first cell connection to the second cell connection comprises switching from a first transmit beam to a second transmit beam, wherein the first transmit beam is transmitted by one of the second BS 110a or the first BS 110b, and wherein the second transmit beam is transmitted by the other of the second BS 110a or the first BS 110b. In certain aspects, switching from the first cell connection to the second cell connection comprises switching from a first set of radio-frequency (RF) parameters associated with the first cell to a second set of RF parameters associated with the second cell, wherein the RF parameters include one or more of a bandwidth, a transmit power, a channel frequency, or a center frequency.

In certain aspects, the first signal comprises one of a first physical downlink shared channel or a first physical downlink control channel, and wherein the second signal comprises one of a second physical downlink shared channel or a second physical downlink control channel.

The processing system <NUM> includes a processor <NUM> coupled to a computer-readable medium/memory <NUM> via a bus <NUM>. In certain aspects, the computer-readable medium/memory <NUM> is configured to store instructions (e.g., computer-executable code) that when executed by the processor <NUM>, cause the processor <NUM> to perform the operations illustrated in <FIG>, or other operations for performing the various techniques discussed herein for selecting signaling to receive during MBB handover. In certain aspects, computer-readable medium/memory <NUM> stores code <NUM> for establishing a first cell connection; code <NUM> for determining that transmission time of a first signal is less than a threshold time duration from a second transmission time of a second signal; code <NUM> for determining which communication metric has priority; and code <NUM> for receiving a first signal and a second signal.

In certain aspects, the processor <NUM> has circuitry configured to implement the code stored in the computer-readable medium/memory <NUM>. The processor <NUM> includes circuitry <NUM> for establishing a first cell connection; circuitry <NUM> for determining that transmission time of a first signal is less than a threshold time duration from a second transmission time of a second signal; circuitry <NUM> for determining which communication metric has priority; and circuitry <NUM> for receiving a first signal and a second signal.

A CDMA network may implement a radio technology such as Universal Terrestrial Radio Access (UTRA), CDMA2000, etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. CDMA2000 covers IS-<NUM>, IS-<NUM> and IS-<NUM> standards. An OFDMA network may implement a radio technology such as NR (e.g., <NUM> RA), Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE <NUM> (Wi-Fi), IEEE <NUM> (WiMAX), IEEE <NUM>, Flash-OFDMA, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunication System (UMTS).

A UE may also be referred to as a mobile station, a terminal, an access terminal, a subscriber unit, a station, a Customer Premises Equipment (CPE), a cellular phone, 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 computer, a camera, a gaming device, a netbook, a smartbook, an ultrabook, an appliance, a medical device or medical equipment, a biometric sensor/device, a wearable device such as a smart watch, smart clothing, smart glasses, a smart wrist band, smart j ewelry (e.g., a smart ring, a smart bracelet, etc.), an entertainment device (e.g., a music device, a video device, a satellite radio, etc.), a vehicular component or sensor, a smart meter/sensor, industrial manufacturing equipment, a global positioning system device, or any other suitable device that is configured to communicate via a wireless or wired medium.

Claim 1:
A method (<NUM>), performed by a user equipment, UE, the method (<NUM>) comprising:
establishing (<NUM>) a first cell connection with a first base station, BS, while maintaining an existing second cell connection with a second BS;
determining (<NUM>) that a first transmission time of a first signal transmitted by the first BS is less than a threshold time duration from a second transmission time of a second signal transmitted by the second BS, wherein the threshold time duration is a minimum time required by the UE for switching from the first cell connection to the second cell connection, wherein the UE is configured to use a first receive beam to receive the first signal and a second receive beam to receive the second signal, wherein the first receive beam is different than the second receive beam, and wherein the first signal is associated with one or more first communication metrics and the second signal is associated with one or more second communication metrics;
based on determining that the first transmission time is less than the threshold time duration from the second transmission time:
determining (<NUM>) which one of the one or more first communication metrics and the one or more second communication metrics has priority over the other;
if the one or more first communication metrics have priority over the one or more second communication metrics (<NUM>), receiving the first signal using the first receive beam instead of the second signal using the second receive beam; and
if the one or more second communication metrics have priority over the one or more first communication metrics (<NUM>), receiving the second signal using the second receive beam instead of the first signal using the first receive beam.