Patent Description:
Aspects of the present disclosure generally relate to wireless communication and specifically, to methods and apparatuses for coordination between multicast/broadcast communication and unicast communication.

Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (for example, bandwidth, or transmit power among other examples, or a combination thereof).

The above multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different user equipments (UEs) to communicate on a municipal, national, regional, and even global level. New Radio (NR), which may also be referred to as <NUM>, is a set of enhancements to the LTE mobile standard promulgated by the 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 downlink (DL), using CP-OFDM or SC-FDMA (for example, also known as discrete Fourier transform spread OFDM (DFT-s-OFDM)) on the uplink (UL), as well as supporting beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation.

A base station in an LTE network may send transmissions to a UE over a physical radio channel, such as a physical downlink shared channel (PDSCH). This one-to-one communication may be considered a unicast transmission. The LTE network may also use single cell point to multipoint (SC-PTM) to improve efficiency and to reduce latency. That is, an eNB may multicast or broadcast a transmission to multiple UEs. While an LTE network may only have unicast communications on the PDSCH, an NR network may have multicast/broadcast (MB) communications that share the same PDSCH as unicast communications. Because MB and unicast communications may share the same PDSCH, it is possible for the NR network to have coordination between an MB radio bearer (MRB) and a unicast dedicated radio bearer (DRB). However, this coordination may involve inefficiencies, some of which may be due to inflexible configurations. These inefficiencies may cause a gNB and UEs to waste channel, signaling and processing resources. <NPL>), discusses Broadcast and Multicast Communication Enablers for the Fifth-Generation of Wireless Systems Deliverable D3. <NUM> Air Interface. <NPL>, discusses <NUM> New Radio for Terrestrial Broadcast: A Forward-Looking Approach for NR-MBMS. <NPL>), discusses Broadcast and Multicast Communication Enablers for the Fifth-Generation of Wireless Systems Deliverable D3. <NUM> RAT Protocols and Radio Resource Management in <NUM>-Xcast.

The invention is defined in independent claims <NUM>, <NUM>, <NUM> and <NUM>. Further features are defined in dependent claims. In the following description the subject-matter of <FIG> and <FIG>-<NUM> and their descriptions in combination with <FIG> and its description is according to the invention as defined in the claims. The rest of the following description and figures (even if named embodiment(s), example(s), aspect(s), disclosure(s) etc.) does not or does not fully correspond to the invention as defined in the claims (e.g. due to one or more features present in and required by the independent claims which are missing in the embodiment(s), example(s), aspect(s), disclosure(s) etc., for example due to the use of expressions like "or", "alternative", "alternatively, "may", "preferably", "optional(ly)", "can", "could", "as an/for example" etc. replacing one or more features present in and required by the independent claims and/or rendering one or more features present in and required by the independent claims as optional) and is therefore not according to the invention as defined in the claims but is considered as useful for understanding the invention.

The foregoing has outlined rather broadly the features and technical advantages of examples in accordance with the disclosure in order that the detailed description that follows may be better understood.

It is to be noted, however, that the appended drawings illustrate only some typical aspects of this disclosure and are therefore not to be considered limiting of its scope, for the description may admit to other equally effective aspects.

This disclosure may, however, be embodied in many different forms and are not to be construed as limited to any specific structure or function presented throughout this disclosure.

These apparatuses and techniques will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, or algorithms among other examples, or combinations thereof (collectively referred to as "elements").

A base station in a Long Term Evolution (LTE) network, such as an eNB, may send transmissions to a user equipment (UE) over a physical radio channel, such as a physical downlink shared channel (PDSCH). The LTE network may use a radio network temporary identifier (RNTI) to identify the radio channel from among other radio channels. For example, an eNB may schedule a unicast (one-to-one) transmission to a UE using a cell RNTI (C-RNTI). The eNB may also multicast or broadcast a transmission to multiple UEs, using a shared PDSCH. The eNB may schedule a multicast/broadcast (MB) transmission using a common RNTI, which may be a group RNTI (G-RNTI).

An NR network will support cooperation between MB communications and unicast communications. For example, MB communications and unicast communications in an NR network may share the same PDSCH, while an LTE network may only have unicast communications on the PDSCH. Because MB communications and unicast communications may share the same PDSCH in an NR network, it is possible to have coordination between an MB radio bearer (MRB) and a unicast dedicated radio bearer (DRB). However, this coordination may have inefficiencies, some of which may be due to an inflexible configuration of the MRB and the DRB. These inefficiencies may cause a gNB and UEs to waste channel, signaling, and processing resources. For example, some UEs on a cell edge may not be receiving successful transmissions via the MRB, and a gNB may not be able to switch from an MRB to a DRB. The gNB may expend extra processing and signaling resources to send additional transmissions at a later time to UEs that are not successfully receiving the transmissions via the MRB. Additionally or alternatively, a gNB may overuse a DRB during MRB/DRB coordination, which may lead to a gNB and corresponding UEs wasting channel, signaling, and processing resources. For example, the gNB may be transmitting to UEs using a DRB more frequently than necessary when an MRB may be more efficient.

In some aspects, as described herein, a base station, such as a gNB, may coordinate between MB communication and unicast communication. The base station may transmit, to a UE, a configuration for a mixed mode that uses a shared PDSCH for MB traffic and for unicast traffic, and that permits switching between a DRB and an MRB. The base station may transmit a first communication via a first bearer, the first bearer being the DRB or the MRB. The base station may identify a second bearer based at least in part on the configuration, the second bearer being the other of the DRB or the MRB. The base station may transmit a second communication via the second bearer. The UE may receive the first communication via the first bearer, identify the second bearer based at least in part on the configuration, and receive the second communication via the second bearer.

In this way, the base station and the UE are not limited to a fixed mixed mode configuration that may be inefficient. The base station may determine the configuration and signal it to the UE. The UE may provide feedback to aid the base station in selecting the configuration. The base station and the UE may thus avoid wasting channel, signaling, and processing resources that would be spent accounting for inefficiencies in the coordination. For example, when a maximum bit rate is sufficient, a base station may determine that transmissions to UEs are using a DRB more than necessary. In such instances, the base station and the UE may be able to switch from a DRB to an MRB. Additionally or alternatively, the base station may save processing and signaling resources that would otherwise be spent sending additional transmissions at a later time to UEs that are not successfully receiving the transmissions via broadcast.

<FIG> is a block diagram illustrating an example wireless network in accordance with various aspects of the present disclosure. The wireless network may be a Long Term Evolution (LTE) network or some other wireless network, such as a <NUM> or NR network. The wireless network may include a quantity of base stations (BSs) <NUM> (shown as BS 110a, BS 110b, BS 110c, and BS 110d) and other network entities. A BS is an entity that communicates with user equipment (UE(s)) and may also be referred to as a Node B, an eNodeB, an eNB, a gNB, a NR BS, a <NUM> node B (NB), an access point (AP), or a transmit receive point (TRP) among other examples, or combinations thereof (these terms are used interchangeably herein). In 3GPP, the term "cell" can refer to a coverage area of a BS or a BS subsystem serving this coverage area, 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, or another type of cell. 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.

The wireless network may be a heterogeneous network that includes BSs of different types, for example, macro BSs, pico BSs, femto BSs, or relay BSs among other examples, or combinations thereof. These different types of BSs may have different transmit power levels, different coverage areas, and different impacts on interference in the wireless network. 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). A network controller <NUM> may couple to the set of BSs 102a, 102b, 110a and 110b, and may provide coordination and control for these BSs. The BSs may also communicate with one another, for example, directly or indirectly via a wireless or wireline backhaul.

In some aspects, a cell may not be stationary, rather, the geographic area of the cell may move in accordance with the location of a mobile BS. In some aspects, the BSs may be interconnected to one another or to one or more other BSs or network nodes (not shown) in the wireless network through various types of backhaul interfaces such as a direct physical connection, or a virtual network among other examples, or combinations thereof using any suitable transport network.

The wireless network may also 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 may also be referred to as a relay BS, a relay base station, or a relay among other examples, or combinations thereof.

UEs <NUM> (for example, 120a, 120b, 120c) may be dispersed throughout the wireless network, and each UE may be stationary or mobile. A UE may also be referred to as an access terminal, a terminal, a mobile station, a subscriber unit, or a station among other examples, or combinations thereof. 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 medium.

MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, or location tags among other examples, or combinations thereof, 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, or memory components among other examples, or combinations thereof.

In general, any quantity of wireless networks may be deployed in a given geographic area. Each wireless network may support a particular radio access technology (RAT) and may operate on one or more frequencies or frequency channels. A frequency may also be referred to as a carrier or the like, or combinations thereof.

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

<FIG> is a block diagram illustrating an example base station (BS) in communication with a user equipment (UE) in a wireless network in accordance with various aspects of the present disclosure.

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 (MCSs) for each UE based at least in part on channel quality indicators (CQIs) received from the UE, process (for example, encode) 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. Transmit processor <NUM> may also process system information (for example, for semi-static resource partitioning information (SRPI) or the like, or combinations thereof) and control information (for example, CQI requests, grants, upper layer signaling among other examples, or combinations thereof) and provide overhead symbols and control symbols. Transmit processor <NUM> may also 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 MOD <NUM> may process a respective output symbol stream (for example, for OFDM or the like, or combinations thereof) to obtain an output sample stream. Each MOD <NUM> may further process (for example, convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. T downlink signals from MODs 232a through 232t may be transmitted via T antennas 234a through 234t, respectively. In accordance with various aspects described in more detail below, the synchronization signals can be generated with location encoding to convey additional information.

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 R demodulators (DEMODs) 254a through 254r, respectively. Each DEMOD <NUM> may condition (for example, filter, amplify, downconvert, and digitize) a received signal to obtain input samples. Each DEMOD <NUM> may further process the input samples (for example, for OFDM or the like, or combinations thereof) to obtain received symbols. A MIMO detector <NUM> may obtain received symbols from all R DEMODs 254a through 254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor <NUM> may process (for example, 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/processor <NUM>. A channel processor may determine a reference signal received power (RSRP), a received signal strength indicator (RSSI), a reference signal received quality (RSRQ), a channel quality indicator (CQI) among other examples, or combinations thereof.

On the uplink, at UE <NUM>, a transmit processor <NUM> may receive and process data from a data source <NUM> as well as control information (for example, for reports including RSRP, RSSI, RSRQ, CQI among other examples, or combinations thereof) from controller/processor <NUM>. The symbols from transmit processor <NUM> may be precoded by a TX MIMO processor <NUM> if applicable, further processed by MODs 254a through 254r (for example, for discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-s-OFDM), orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) (CP-OFDM) among other examples, or combinations thereof), and transmitted to base station <NUM>. At base station <NUM>, the uplink signals from UE <NUM> and other UEs may be received by antennas <NUM>, processed by DEMODs <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 UE <NUM>.

Controller/processor <NUM> of base station <NUM>, controller/processor <NUM> of UE <NUM>, or any other component(s) of <FIG> may perform one or more techniques associated with coordination between multicast/broadcast communication and unicast communication as described in more detail elsewhere herein. For example, controller/processor <NUM> of base station <NUM>, controller/processor <NUM> of UE <NUM>, or any other component(s) of <FIG> may perform or direct operations of, for example, process <NUM> of <FIG>, process <NUM> of <FIG>, or other processes as described herein. 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 or uplink.

In some aspects, the UE includes means for receiving a configuration for a shared physical downlink shared channel (PDSCH), wherein the configuration indicates a single packet data convergence protocol layer for both the multicast/broadcast communication and the unicast communication, a first radio link control layer associated with a first medium access control layer and a first physical layer for the multicast/broadcast communication, and a second radio link control layer associated with a second medium access control layer and a second physical layer for the unicast communication; means for receiving a first communication via the shared PDSCH and a first bearer based at least in part on the configuration, the first communication being one of a unicast communication or a multicast/broadcast communication; means for receiving a second communication via the shared PDSCH and the first bearer or a second bearer based at least in part on the configuration, the second communication being the other of the unicast communication or the multicast/broadcast communication. In some aspects, the UE includes means for transmitting uplink feedback, associated with at least one of the first communication or the second communication, using a cell radio network temporary identifier. The means for the UE to perform operations described herein may include, for example, antenna <NUM>, demodulator <NUM>, MIMO detector <NUM>, receive processor <NUM>, transmit processor <NUM>, TX MIMO processor <NUM>, modulator <NUM>, controller/processor <NUM>, memory <NUM>, or a combination thereof.

In some aspects, the base station includes means for transmitting a configuration for a shared PDSCH, wherein the configuration indicates a single packet data convergence protocol layer for both the multicast/broadcast communication and the unicast communication, a first radio link control layer associated with a first medium access control layer and a first physical layer for the multicast/broadcast communication, and a second radio link control layer associated with a second medium access control layer and a second physical layer for the unicast communication; means for transmitting a first communication via the shared PDSCH and a first bearer based at least in part on the configuration, the first communication being one of a unicast communication or a multicast/broadcast communication; means for transmitting a second communication via the shared PDSCH and the first bearer or a second bearer based at least in part on the configuration, the second communication being the other of the unicast communication or the multicast/broadcast communication. The means for the base station to perform operations described herein may include, for example, transmit processor <NUM>, TX MIMO processor <NUM>, modulator <NUM>, antenna <NUM>, demodulator <NUM>, MIMO detector <NUM>, receive processor <NUM>, controller/processor <NUM>, memory <NUM>, and/or scheduler <NUM>.

In some aspects, the base station includes means for dynamically scheduling packets over the first physical layer, the second physical layer, or both. In some aspects, the base station includes means for transmitting a different configuration based at least in part on the uplink feedback. In some aspects, the base station includes means for dynamically switching between the first bearer and the second bearer, wherein the first bearer is one of a multicast broadcast radio bearer (MRB) or a dedicated radio bearer (DRB), and wherein the second bearer is the other of the MRB or the DRB. In some aspects, the base station includes means for assigning a sequence number, to a communication transmitted after the switching, that continues from a sequence number used for a communication transmitted before the switching.

<FIG> is a block diagram illustrating a logical architecture of a distributed radio access network (RAN) in accordance with various aspects of the present disclosure. One or more entities of a <NUM> network may have a multicast/broadcast (MB) user plane function (MB-UPF) and an access and mobility function (AMF). The MB-UPF may have an N3 interface for delivering an MB-flow of packets (for example, in the form of protocol data units (PDUs)) to a <NUM> access node, such as a gNB. The AMF may control signaling for MB-flow setup and modification using an N2 interface to the gNB.

The gNB may include a central unit (CU), indicated as gNB-CU. The gNB may also include one or more distributed units (DUs), indicated as DU1 and DU2. DU1 and DU2 may be configured to individually (for example, via dynamic selection) or jointly (for example, via joint transmission) serve traffic to a UE. As shown, DU1 may serve traffic using MRB1 and DU2 may server traffic using MRB2.

<FIG> is a diagram illustrating coordination between MB communication and unicast communication. At a first operation <NUM>, a base station <NUM>, such as a gNB, may send a configuration for MB and unicast mixed mode to a UE <NUM>. The configuration may indicate a mixed mode of operation for MB and unicast. The mixed mode may use a shared PDSCH for MB traffic and for unicast traffic and permit switching between a DRB and an MRB. Additionally or alternatively, the mixed mode may permit intra-MRB switching, such as switching between unicast communications and multicast/broadcast communications on the same MRB. In some aspects, the configuration may enable or disable intra-MRB switching. Additionally or alternatively, the configuration may indicate a C-RNTI to be used for unicast communications on an MRB and a G-RNTI to be used for multicast/broadcast communications on the same MRB. The configuration may include information for a carrier aggregation (CA) mixed mode, a dual connectivity (DC) mixed mode, a dual bearer (MRB and DRB) mixed mode, information about DRB/MRB correspondence, information indicating whether intra-MRB switching is enabled or disabled, information indicating whether DRB/MRB switching is enabled or disabled, information indicating a C-RNTI for unicast communications, information indicating a G-RNTI for multicast/broadcast communications, or any combination thereof.

At a second operation <NUM>, UE <NUM> may identify a first bearer, a second bearer, or both, using the configuration. Base station <NUM> may send a first communication <NUM> via a DRB or an MRB and send a second communication <NUM> via the other of the DRB or the MRB. The first communication <NUM> may be one of a unicast communication or a multicast/broadcast communication, and the second communication <NUM> may be the other of the unicast communication or the multicast/broadcast communication. In some aspects, base station <NUM> may have flexibility to switch between a DRB and an MRB. Additionally or alternatively, for intra-MRB switching, the base station <NUM> may send the first communication <NUM> via an MRB and may also send the second communication <NUM> via the MRB. For example, the base station <NUM> may send a unicast communication (as the first communication <NUM>) via the MRB and may then send a multicast/broadcast communication (as the second communication <NUM>) via the same MRB. As another example, the base station <NUM> may send a multicast/broadcast communication (as the first communication <NUM>) via the MRB and may then send a unicast communication (as the second communication <NUM>) via the same MRB. A communication (the first communication <NUM> or the second communication <NUM>) may be scrambled and descrambled with a C-RNTI (for example, indicated in the configuration) when the communication is a unicast communication. A communication (the first communication <NUM> or the second communication <NUM>) may be scrambled and descrambled with a G-RNTI (for example, indicated in the configuration) when the communication is a multicast/broadcast communication.

As shown, the base station <NUM> may send the first communication <NUM> via a first bearer and may send the second communication <NUM> via the first bearer or a second bearer. For example, for DRB/MRB switching, the base station <NUM> transmits the first communication <NUM> via the first bearer (which is one of a DRB or an MRB) and transmits the second communication <NUM> via the second bearer (which is the other of the DRB or the MRB). For intra-MRB switching, the base station <NUM> transmits the first communication <NUM> via the first bearer (which is an MRB) and also transmits the second communication <NUM> via the first bearer (which is the same MRB). In either case, the first communication <NUM> and the second communication <NUM> may be scrambled and descrambled using different RNTIs. For example, the first communication <NUM> may be scrambled and descrambled using a first RNTI (one of a C-RNTI or a G-RNTI), and the second communication <NUM> may be scrambled and descrambled using a second RNTI (the other of the C-RNTI or the G-RNTI). The configuration may indicate the RNTIs to be used for scrambling the first communication <NUM> and the second communication <NUM>.

Base station <NUM> may use RNTIs to identify channels for transmissions. Base station <NUM> may send original data using a G-RNTI and send retransmissions using the G-RNTI and a C-RNTI. Additionally or alternatively, base station <NUM> may send data in parallel using a G-RNTI and a C-RNTI. Base station <NUM> may bi-cast original data using the G-RNTI and the C-RNTI. This is similar to duplication transmission involved with DC.

In some aspects, base station <NUM> may send a redundant transmission using a C-RNTI. For example, base station <NUM> may broadcast original data using a G-RNTI and send a redundant version using the C-RNTI. UE <NUM> may combine data using the G-RNTI and the C-RNTI, for example, using soft-combining that combines pieces of insufficient information together so that a total signal may be decoded. Such redundancy may be used for UEs at an edge of a cell, because a signal-to-noise ratio (SNR) may not be as high at an edge of a cell. This redundancy may be used without being triggered by UE feedback.

In some aspects, base station <NUM> may layer transmissions, such as for video. For example, base station <NUM> may use basic transmission layers using a G-RNTI and use enhancement layers using a C-RNTI. Alternatively, base station <NUM> may use basic transmission layers using a C-RNTI and use enhancement layers using a G-RNTI. A higher layer may have an indication of bits that base station <NUM> may use to differentiate between PDUs for a basic transmission layer and PDUs for an enhancement layer. Base station <NUM> may, for example, inspect a general packet radio service (GPRS) tunneling protocol (GTP) header to identify the bits. Additionally or alternatively, base station <NUM> may use basic transmissions with G-RNTI and add in enhancement layers using C-RNTI. Base station <NUM> may enforce a quality of service (QoS). A GTP header may include information for a QoS flow ID and thus base station <NUM> may know to which QoS-flow a layer belongs. In some aspects, base station <NUM> may determine an upper bound of a basic layer's data rate per guaranteed bit rate (GBR) IE in a QoS profile. Base station <NUM> may configure a maximum bitrate of a combined MB communication and unicast communication per a maximum bit rate (MBR) IE in the QoS profile.

<FIG> illustrates network protocol layers for an MB-flow in a CA mixed mode for coordination between MB communication and unicast communication in accordance with various aspects of the present disclosure. Protocol layers for an MRB in CA mixed mode may include a single packet data convergence protocol (PDCP) layer <NUM> for both MB traffic and unicast traffic, a single radio link control (RLC) layer <NUM> for both MB traffic and unicast traffic, a single medium access control (MAC) layer <NUM> for both MB traffic and unicast traffic, and two physical (PHY) layers <NUM> and <NUM>. One physical layer <NUM> may be for MB traffic and one physical layer <NUM> may be for unicast traffic. That is, a base station, such as base station <NUM>, may use dual RNTI (G-RNTI and C-RNTI) in a shared MAC protocol layer.

In some aspects, a base station may schedule data dynamically, using downlink control information (DCI), for example, on different carriers or on the same carrier with a different RNTI. The base station may dynamically schedule each MAC PDU using the G-RNTI, the C-RNTI, or both. The base station may dynamically schedule each MAC PDU based at least in part on channel state information (CSI) of a UE, a quantity of receiving UEs, QoS requirements (for example, delay or packet error rate (PER)), or a combination thereof.

Additionally or alternatively, UE <NUM> may provide feedback for unicast assistance. UE <NUM> may transmit feedback using a C-RNTI using, for example, CSI feedback, hybrid automatic repeat request (HARQ) ACK/NACK, an RLC status report, or a PDCP status report. UE <NUM> may include, in a status report, an MRB-ID, a G-RNTI, or a unique logical channel ID (LCID) for the base station to identify a corresponding MRB. A HARQ retransmission may be on either an MRB or a DRB.

<FIG> illustrates network protocol layers for an MB-flow in a DC mixed mode for coordination between MB communication and unicast communication in accordance with various aspects of the present disclosure. A base station, such as base station <NUM>, provides an MB-flow using dual RLCs that share a PDCP layer. According to the invention as claimed a configuration for DC mixed mode includes a single PDCP layer <NUM> for both the MB traffic and the unicast traffic, a first RLC layer <NUM> associated with a first MAC layer <NUM> and a first physical (PHY) layer <NUM> for the MB traffic, and a second RLC layer <NUM> associated with a second MAC layer <NUM> and a second physical layer <NUM> for the unicast traffic.

In a distributed RAN, a physical layer may be supported in a radio unit (RU) or a distributed unit (DU) by dedicated hardware in a base station, and it may be difficult to upgrade this hardware. PDCP is supported in a central unit (CU) of a base station, and the CU may use PDCP based unicast/broadcast selection and achieve considerable gain with unicast/broadcast coordination. A base station may use the PDCP layer with its general purpose hardware and unicast/broadcast cooperation may be implemented without upgrading hardware of the base station. Note that although the CA mixed mode may provide tighter MB and unicast coordination on a shared channel in a MAC layer than for the DC mixed mode, the base station dedicated hardware may not need to be upgraded to use the DC mixed mode with a shared PDCP channel, and so the DC mixed mode may be more useful in some examples.

In some aspects, a base station may determine to transmit duplicate PDUs on both RLC layers for duplication. The base station may configure a UE-specific unicast RLC layer for an MRB. For an incoming packet or PDU, the base station may dynamically select to transmit by a broadcast (G-RNTI) RLC layer only, by a unicast (C-RNTI) RLC layer only, or by both RLC layers (such as for duplication). In some aspects, a base station may decide whether to transmit by the broadcast RLC layer, the unicast RLC layer, or by both RLC layers based at least in part on, for example, a quantity of receiving UEs. If a quantity of UEs in communication with the base station does not satisfy a threshold quantity, the base station may use a unicast RLC layer. Additionally or alternatively, the base station may select which RLC layers to use based at least in part on channel state information (CSI) from UEs in communication with the base station. Broadcast coverage is generally smaller than unicast coverage so if a coverage area does not satisfy a threshold size, CSI may indicate, via UE feedback, a degradation at a cell edge. UEs at a cell center may receive broadcast transmissions, and UEs at a cell edge may receive an additional unicast transmission. Additionally or alternatively, a base station may select which RLC layers to use based at least in part on an RLC receiving status and link status. If a quantity of UEs reporting NACK satisfies a threshold, the base station may use MB for retransmission. If the quantity of UEs does not satisfy a threshold, the base station may use unicast for the UEs that are reporting NACK.

In some aspects, for either the CA mixed mode or the DC mixed mode, a base station may determine if a QoS or a data packet rate may be met using MB or unicast. For example, the base station may use a packet error rate (PER) requirement to determine whether to use MB or unicast. In some other aspects, a base station may decide to use MB or unicast based at least in part on communication conditions and a timeout period. For example, if the base station has spent <NUM> for transmission and retransmission, the base station may time out, even though some UEs may not receive the transmission correctly. In such examples, the base station may decide to use MB or unicast transmissions based at least in part on a determination of which configuration would be most efficient, given retransmission delays for either MB or unicast, so that the UEs that would otherwise not receive a transmission successfully might receive the transmission. For example, if a unicast retransmission would be faster than an MB retransmission, in light of a timeout threshold, the base station may decide to use unicast for retransmission to reach more UEs before a timeout occurs.

Additionally or alternatively, if RLC and PDCP are not in the same network entity or are different network entities or devices, and if a base station receives an RLC status report, the base station may send the report back to a PDCP entity. The base station may send the report via a dynamic delegation discovery service (DDDS) message if RLC feedback is enabled, so that the PDCP entity will make the decision as to whether to use MB or unicast for retransmission.

<FIG> illustrates network protocol layers for an MB-flow in a dual bearer mixed mode for coordination between MB communication and unicast communication in accordance with various aspects of the present disclosure. In examples with CA or DC mixed modes, a base station may use a single MRB. However, in dual bearer mixed mode, the base station may decide to use an MRB or a DRB that may each may have all network protocol layers. For example, the MRB and the DRB may have separate PDCP layers <NUM> and <NUM>, separate RLC layers <NUM> and <NUM>, separate MAC layers <NUM> and <NUM>, and separate physical layers <NUM> and <NUM> for the MB traffic and the unicast traffic. On a UE side, the MRB and the DRB may have separate physical layers <NUM> and <NUM>, separate MAC layers <NUM> and <NUM>, separate RLC layers <NUM> and <NUM>, and separate PDCP layers <NUM> and <NUM> for the MB traffic and the unicast traffic.

In the dual bearer mixed mode, switching between an MRB and a DRB may be less dynamic than the CA mixed mode and the DC mixed mode. For a packet MB-flow, a base station may select to use an MRB or a DRB, such as to switch from the MRB to the DRB. The base station may signal this switch to a UE using a message with a MAC command element (CE) or a radio resource control (RRC) message. In such examples, using a MAC CE may be less complicated than using an RRC message, due to the structure of RRC. By signaling the switch to a UE, the UE may determine whether to monitor G-RNTI.

An MRB may be associated with a DRB. A base station may associate an MB-flow or QoS-flow, to a DRB, in a PDU session setup or modification process, and provide information identifying this association to a UE. Therefore, the UE may receive and store information identifying the association between an MRB and a DRB.

In some aspects, an MRB and a DRB may share the same PDCP sequence number (SN) space. The base station may assign the PDCP SN continuously in MRB/DRB switching. For example, the base station may switch from MRB to DRB but the PDCP SN may be continuous so that a UE may track duplication based at least in part on the PDCP SN. In such examples, a UE may share a PDCP SN space but not necessarily share a common PDCP protocol layer. The base station may use RRC signaling to configure which PDCP SN space the UE is to use. Using a shared PDCP SN space, the base station may maintain a continuation of PDCP SNs, and a UE may detect packet loss and track duplication based at least in part on the continuation of PDCP SNs in the shared PDCP SN space. The base station may configure the UE to monitor for the continuation of PDCP SNs in the shared PDCP SN space. Alternatively, the UE may have a common PDCP that is shared between the MRB and the DRB.

In some aspects, a PDCP SN space may be shared on a UE side but not a base station side. If a PDCP SN space is shared, a UE may operate similar to the DC mixed mode. In the DC mixed mode, the UE and the base station share a PDCP layer. In the MRB and DRB dual bearer mixed mode, it is possible for a PDCP layer to be shared at the UE but not the base station.

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

In some aspects, the apparatus <NUM> may be configured to perform one or more operations described herein in connection with <FIG>. Additionally or alternatively, the apparatus <NUM> may be configured to perform one or more processes described herein, such as process <NUM> of <FIG>. In some aspects, the apparatus <NUM> may include one or more components of the UE described above in connection with <FIG>.

The reception component <NUM> receives communications, such as reference signals, control information, data communications, or a combination thereof, from the apparatus <NUM>. The reception component <NUM> may provide received communications to one or more other components of the apparatus <NUM>, such as the communication manager <NUM>. In some aspects, the reception component <NUM> may perform signal processing on the received communications (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, de-mapping, equalization, interference cancellation, or decoding, among other examples), and may provide the processed signals to the one or more other components.

In some aspects, the communication manager <NUM> may generate communications and may transmit the generated communications to the transmission component <NUM> for transmission to the apparatus <NUM>.

The communication manager <NUM> receives or causes the reception component <NUM> to receive a configuration for a shared PDSCH, wherein the configuration indicates a single packet data convergence protocol layer for both the multicast/broadcast communication and the unicast communication, a first radio link control layer associated with a first medium access control layer and a first physical layer for the multicast/broadcast communication, and a second radio link control layer associated with a second medium access control layer and a second physical layer for the unicast communication. The communication manager <NUM> receives or causes the reception component <NUM> to receive a first communication via the shared PDSCH and a first bearer based at least in part on the configuration. The first communication is one of a unicast communication or a multicast/broadcast communication. The communication manager <NUM> receives or causes the reception component <NUM> to receive a second communication via the shared PDSCH and the first bearer or a second bearer based at least in part on the configuration. The second communication is the other of the unicast communication or the multicast/broadcast communication. The communication manager <NUM> may transmit or may cause the transmission component <NUM> to transmit uplink feedback, associated with at least one of the first communication or the second communication, using a cell radio network temporary identifier. In some aspects, the communication manager <NUM> may include a controller/processor, a memory, or a combination thereof, of the UE described above in connection with <FIG>.

In some aspects, the communication manager <NUM> may include a set of components, such as a switching component <NUM>. Alternatively, the set of components may be separate and distinct from the communication manager <NUM>. In some aspects, one or more components of the set of components may include or may be implemented within a controller/processor, a memory, or a combination thereof, of the UE described above in connection with <FIG>. Additionally or alternatively, one or more components of the set of components may be implemented at least in part as software stored in a memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by a controller or a processor to perform the functions or operations of the component. The switching component <NUM> may switch between a unicast DRB and an MRB. Additionally or alternatively, the switching component <NUM> may switch between MRBs via intra-MRB switching.

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

In some aspects, the apparatus <NUM> may be configured to perform one or more operations described herein in connection with <FIG>. Additionally or alternatively, the apparatus <NUM> may be configured to perform one or more processes described herein, such as process <NUM> of <FIG>. In some aspects, the apparatus <NUM> may include one or more components of the base station described above in connection with <FIG>.

The reception component <NUM> may provide received communications to one or more other components of the apparatus <NUM>, such as the communication manager <NUM>. In some aspects, the reception component <NUM> may perform signal processing on the received communications (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, de-mapping, equalization, interference cancellation, or decoding, among other examples), and may provide the processed signals to the one or more other components. In some aspects, the reception component <NUM> may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a controller/processor, a memory, or a combination thereof, of the base station described above in connection with <FIG>.

The transmission component <NUM> transmits communications, such as reference signals, control information, data communications, or a combination thereof, to the apparatus <NUM>. In some aspects, the communication manager <NUM> may generate communications and may transmit the generated communications to the transmission component <NUM> for transmission to the apparatus <NUM>. In some aspects, the transmission component <NUM> may include one or more antennas, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the base station described above in connection with <FIG>.

The communication manager <NUM> transmits or causes the transmission component <NUM> to transmit a configuration for a shared PDSCH, wherein the configuration indicates a single packet data convergence protocol layer for both the multicast/broadcast communication and the unicast communication, a first radio link control layer associated with a first medium access control layer and a first physical layer for the multicast/broadcast communication, and a second radio link control layer associated with a second medium access control layer and a second physical layer for the unicast communication. The communication manager <NUM> transmits or causes the transmission component <NUM> to transmit a first communication via the shared PDSCH and a first bearer based at least in part on the configuration. The first communication is one of a unicast communication or a multicast/broadcast communication. The communication manager <NUM> transmits or causes the transmission component <NUM> to transmit a second communication via the shared PDSCH and the first bearer or a second bearer based at least in part on the configuration. The second communication may is other of the unicast communication or the multicast/broadcast communication. The communication manager <NUM> may receive or may cause the reception component <NUM> to receive uplink feedback, associated with at least one of the first communication or the second communication, using a cell radio network temporary identifier. The communication manager <NUM> may transmit or may cause the transmission component <NUM> to transmit a different configuration based at least in part on the uplink feedback. In some aspects, the communication manager <NUM> may include a controller/processor, a memory, a scheduler, a communication unit, or a combination thereof, of the base station described above in connection with <FIG>.

In some aspects, the communication manager <NUM> may schedule or may cause the scheduling component <NUM> to schedule packets (for example, on one or more layers, such as one or more physical layers or one or more radio link control layers). In some aspects, the communication manager <NUM> may switch or may cause the switching component <NUM> to switch between the first bearer and the second bearer. The first bearer may be one of an MRB or a DRB, and the second bearer may be the other of the MRB or the DRB. In some aspects, the communication manager <NUM> may assign or may cause the sequence number assignment component <NUM> to assign a sequence number, to a communication transmitted after the switching, that continues from a sequence number used for a communication transmitted before the switching.

In some aspects, the communication manager <NUM> may include a set of components, such as a scheduling component <NUM>, a switching component <NUM>, a sequence number assignment component <NUM>, or a combination thereof. Alternatively, the set of components may be separate and distinct from the communication manager <NUM>. In some aspects, one or more components of the set of components may include or may be implemented within a controller/processor, a memory, a scheduler, a communication unit, or a combination thereof, of the base station described above in connection with <FIG>. Additionally or alternatively, one or more components of the set of components may be implemented at least in part as software stored in a memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by a controller or a processor to perform the functions or operations of the component.

The scheduling component <NUM> may schedule packets (for example, on one or more layers, such as one or more physical layers or one or more radio link control layers). The switching component <NUM> may switch between the first bearer and the second bearer. The first bearer may be one of an MRB or a DRB, and the second bearer may be the other of the MRB or the DRB. The sequence number assignment component <NUM> may assign a sequence number, to a communication transmitted after the switching, that continues from a sequence number used for a communication transmitted before the switching.

<FIG> is a flowchart illustrating an example process <NUM> performed by a UE in accordance with various aspects of the present disclosure. Example process <NUM> is an example where the UE (for example, UE <NUM>) performs operations associated with coordination between multicast/broadcast communication and unicast communication.

As shown in <FIG>, process <NUM> includes receiving a configuration for a shared PDSCH (block <NUM>). The UE (such as by using reception component <NUM>, depicted in <FIG>) receives a configuration for a shared PDSCH, as described above, wherein the configuration indicates a single packet data convergence protocol layer for both the multicast/broadcast communication and the unicast communication, a first radio link control layer associated with a first medium access control layer and a first physical layer for the multicast/broadcast communication, and a second radio link control layer associated with a second medium access control layer and a second physical layer for the unicast communication.

As further shown in <FIG>, in some aspects, process <NUM> includes receiving a first communication via the shared PDSCH and a first bearer based at least in part on the configuration, the first communication being one of a unicast communication or a multicast/broadcast communication (block <NUM>). The UE (such as by using reception component <NUM>, depicted in <FIG>) receives a first communication via the shared PDSCH and a first bearer based at least in part on the configuration, as described above. The first communication is one of a unicast communication or a multicast/broadcast communication.

As further shown in <FIG>, process <NUM> includes receiving a second communication via the shared PDSCH and the first bearer or a second bearer based at least in part on the configuration, the second communication being the other of the unicast communication or the multicast/broadcast communication (block <NUM>). The UE (such as by using reception component <NUM>, depicted in <FIG>) receives a second communication via the shared PDSCH and the first bearer or a second bearer based at least in part on the configuration, as described above. The second communication is the other of the unicast communication or the multicast/broadcast communication.

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 additional aspect, the first bearer is an MRB and both the first communication and the second communication are received via the MRB.

In a second additional aspect, alone or in combination with the first aspect, the first bearer is one of an MRB or a dedicated radio bearer (DRB), the second bearer is the other of the MRB or the DRB, the first communication is received via the first bearer, and the second communication is received via the second bearer.

In a third additional aspect not being part of the invention as claimed, the configuration indicates a single packet data convergence protocol layer for both the multicast/broadcast communication and the unicast communication, a single radio link control layer for both the multicast/broadcast communication and the unicast communication, a single medium access control layer for both the multicast/broadcast communication and the unicast communication, a first physical layer for the multicast/broadcast communication, and a second physical layer for the unicast communication.

In a fourth additional aspect, alone or in combination with one or more of the first through third aspects, process <NUM> includes transmitting uplink feedback, associated with at least one of the first communication or the second communication, using a cell radio network temporary identifier.

In a fifth additional aspect, alone or in combination with one or more of the first through fourth aspects, the uplink feedback includes an identifier that identifies at least one of an MRB used for at least one of the first communication or the second communication, a group radio network temporary identifier associated with the MRB, a logical channel identifier associated with the MRB, or a combination thereof.

In a sixth additional aspect, according to the invention as claimed, the configuration indicates a single packet data convergence protocol layer for both the multicast/broadcast communication and the unicast communication, a first radio link control layer associated with a first medium access control layer and a first physical layer for the multicast/broadcast communication, and a second radio link control layer associated with a second medium access control layer and a second physical layer for the unicast communication.

In a seventh additional aspect not being part of the inveention as claimed, the configuration indicates separate packet data convergence protocol layers, separate radio link control layers, separate medium access control layers, and separate physical layers for the multicast/broadcast communication and the unicast communication.

In an eighth additional aspect, alone or in combination with one or more of the first through seventh aspects, a packet data convergence protocol sequence number space is shared between the first bearer and the second bearer, the first bearer is one of an MRB or a DRB, and the second bearer is the other of the MRB or the DRB.

In a ninth additional aspect, alone or in combination with one or more of the first through eighth aspects, the first communication is an initial transmission scrambled using a group radio network temporary identifier and the first bearer is an MRB, the second communication is a retransmission scrambled using a cell radio network temporary identifier and the second bearer is a DRB, and the retransmission has a different redundancy version than the initial transmission.

In a tenth additional aspect, alone or in combination with one or more of the first through ninth aspects, the first communication includes a base layer of a multi-layer video transmission and the second communication includes an enhancement layer of the multi-layer video transmission.

In an eleventh additional aspect, alone or in combination with one or more of the first through tenth aspects, a maximum data rate for the first bearer is based at least in part on a guaranteed bit rate associated with the first bearer.

In a twelfth additional aspect, alone or in combination with one or more of the first through eleventh aspects, a maximum combined data rate for the first bearer and the second bearer is based at least in part on a maximum bit rate associated with at least one of the first bearer or the second bearer.

Additionally or alternatively, two or more of the blocks of process <NUM> may be performed in parallel.

<FIG> is a flowchart illustrating an example process <NUM> performed by a base station in accordance with various aspects of the present disclosure. Example process <NUM> is an example where the base station (for example, base station <NUM>) performs operations associated with coordination between multicast/broadcast communication and unicast communication.

As shown in <FIG> process <NUM> includes transmitting a configuration for a shared PDSCH (block <NUM>). The base station (such as by using transmission component <NUM>, depicted in <FIG>) transmits a configuration for a shared PDSCH, as described above, wherein the configuration indicates a single packet data convergence protocol layer for both the multicast/broadcast communication and the unicast communication, a first radio link control layer associated with a first medium access control layer and a first physical layer for the multicast/ broadcast communication, and a second radio link control layer associated with a second medium access control layer and a second physical layer for the unicast communication.

As further shown in <FIG> process <NUM> includes transmitting a first communication via the shared PDSCH and a first bearer based at least in part on the configuration, the first communication being one of a unicast communication or a multicast/broadcast communication (block <NUM>). The base station (such as by using transmission component <NUM>, depicted in <FIG>) transmits a first communication via the shared PDSCH and a first bearer based at least in part on the configuration, as described above. The first communication is one of a unicast communication or a multicast/broadcast communication.

As further shown in <FIG>, process <NUM> includes transmitting a second communication via the shared PDSCH and the first bearer or a second bearer based at least in part on the configuration, the second communication being the other of the unicast communication or the multicast/broadcast communication (block <NUM>). The base station (such as by using transmission component <NUM>, depicted in <FIG>) transmits a second communication via the shared PDSCH and the first bearer or a second bearer based at least in part on the configuration, as described above. The second communication is the other of the unicast communication or the multicast/broadcast communication.

In a first additional aspect, the first bearer is an MRB and both the first communication and the second communication are transmitted via the MRB.

In a second additional aspect, alone or in combination with the first aspect, the first bearer is one of an MRB or a DRB, the second bearer is the other of the MRB or the DRB, the first communication is transmitted via the first bearer, and the second communication is transmitted via the second bearer.

In a fourth additional aspect, alone or in combination with one or more of the first through third aspects, process <NUM> includes dynamically scheduling packets over the first physical layer, the second physical layer, or both.

In a fifth additional aspect, alone or in combination with one or more of the first through fourth aspects, process <NUM> includes transmitting a different configuration based at least in part on the uplink feedback.

In a sixth additional aspect, alone or in combination with one or more of the first through fifth aspects, the uplink feedback includes an identifier that identifies at least one of an MRB used for at least one of the first communication or the second communication, a group radio network temporary identifier associated with the MRB, a logical channel identifier associated with the MRB, or a combination thereof.

In a seventh additional aspect, according to the invention as claimed, the configuration indicates a single packet data convergence protocol layer for both the multicast/broadcast communication and the unicast communication, a first radio link control layer associated with a first medium access control layer and a first physical layer for the multicast/broadcast communication, and a second radio link control layer associated with a second medium access control layer and a second physical layer for the unicast communication.

In an eighth additional aspect, alone or in combination with one or more of the first through seventh aspects, process <NUM> includes dynamically scheduling packets over the first radio link control layer, the second radio link control layer, or both.

In a ninth additional aspect not being part of the invention as claimed, the configuration indicates separate packet data convergence protocol layers, separate radio link control layers, separate medium access control layers, and separate physical layers for the multicast/broadcast communication and the unicast communication.

In a tenth additional aspect, alone or in combination with one or more of the first through ninth aspects, a packet data convergence protocol sequence number space is shared between the first bearer and the second bearer, the first bearer is one of an MRB or a DRB, and the second bearer is the other of the MRB or the DRB.

In an eleventh additional aspect, alone or in combination with one or more of the first through tenth aspects, process <NUM> includes dynamically switching between the first bearer and the second bearer, the first bearer is one of an MRB or a DRB, and the second bearer is the other of the MRB or the DRB.

In a twelfth additional aspect, alone or in combination with one or more of the first through eleventh aspects, process <NUM> includes assigning a sequence number, to a communication transmitted after the switching, that continues from a sequence number used for a communication transmitted before the switching.

In a thirteenth additional aspect, alone or in combination with one or more of the first through twelfth aspects, the first communication is an initial transmission scrambled using a group radio network temporary identifier and the first bearer is an MRB, the second communication is a retransmission scrambled using a cell radio network temporary identifier and the second bearer is a DRB, and the retransmission has a different redundancy version than the initial transmission.

In a fourteenth additional aspect, alone or in combination with one or more of the first through thirteenth aspects, the first communication includes a base layer of a multi-layer video transmission and the second communication includes an enhancement layer of the multi-layer video transmission.

Although <FIG> shows example blocks of process <NUM>, in some aspects, process <NUM> may include additional blocks. Blocks <NUM> and <NUM> process <NUM> may be performed in parallel.

It will be apparent that systems or methods described herein may be implemented in different forms of hardware, firmware, or a combination of hardware and software. The actual specialized control hardware or software code used to implement these systems or methods is not limiting of the aspects. Thus, the operation and behavior of the systems or methods were described herein without reference to specific software code-it being understood that software and hardware can be designed to implement the systems or methods based, at least in part, on the description herein.

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, or not equal to the threshold among other examples, or combinations thereof.

As an example, "at least one of: a, b, or c" is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination with multiples of the same element (for example, a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c).

Claim 1:
A method of wireless communication performed by a user equipment, UE, comprising:
receiving (<NUM>) a configuration for a physical downlink shared channel, PDSCH; wherein the configuration indicates a single packet data convergence protocol layer for both a multicast/broadcast communication and a unicast communication, a first radio link control layer associated with a first medium access control layer and a first physical layer for the multicast/broadcast communication, and a second radio link control layer associated with a second medium access control layer and a second physical layer for the unicast communication.
receiving (<NUM>) a first communication via the PDSCH and a first bearer based at least in part on the configuration, the first communication being one of the unicast communication or the multicast/broadcast communication; and
receiving (<NUM>) a second communication via the PDSCH and the first bearer or a second bearer based at least in part on the configuration, the second communication being the other of the unicast communication or the multicast/broadcast communication.