Method and apparatus for enhancing PDCP duplication

Abstract

The present disclosure relates to methods and apparatus for wireless communications, including devices such as UEs and / or base stations. In one aspect, the device may send a list of multiple CCs for transmission of at least one PDCP PDU, the multiple CCs corresponding to multiple indicated CCs. The device may also send at least one PDCP PDU on one or more CCs among the multiple CCs. In addition, the device may determine whether to retransmit at least one PDCP PDU, the retransmission of at least one PDCP PDU being associated with a PDCP duplication process. The device may also select one or more CCs among the multiple CCs for retransmission of at least one PDCP PDU.

Description

Technical Field

[0001] The present disclosure relates generally to communication systems and, more particularly, to transmissions in wireless communication systems. Background Art

[0002] Wireless communication systems are widely deployed to provide a variety of telecommunication services, such as telephony, video, data, messaging, and broadcasting. Typical wireless communication systems may employ multiple access technologies capable of supporting communications with multiple users by sharing available system resources. Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

[0003] These multiple access technologies have been adopted in a variety of telecommunication standards to provide a common protocol that enables different wireless devices to communicate at a city, country, region, or even global level. An example telecommunication standard is 5G New Radio (NR). 5GNR is a part of the continuous mobile broadband evolution released by the Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with the Internet of Things (IoT)) and other requirements. 5G NR includes services associated with enhanced (pc) mobile broadband (eMBB), massive machine type communication (mMTC), and ultra-reliable low-latency communication (URLLC). Some aspects of 5G NR may be based on 4G Long Term Evolution (LTE) standards. There is a need to further improve 5G NR technology. These improvements may also be applicable to other multiple access technologies and telecommunication standards that employ these technologies. Summary of the invention

[0004] A brief summary of one or more aspects is given below to provide a basic understanding of such aspects. This summary is not an exhaustive overview of all contemplated aspects, and is neither intended to identify the key or important elements of all aspects, nor to describe the scope of any or all aspects. Its sole purpose is to give some concepts of one or more aspects in a simple form as a prelude to a more detailed description given later.

[0005] In one aspect of the present disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a user equipment (UE). The apparatus may receive a configuration of one or more uplink resources for transmission of at least one PDCP PDU, wherein the configuration may be associated with a configured grant. The apparatus may also send a list of multiple component carriers (CCs) for transmission of at least one packet data convergence protocol (PDCP) protocol data unit (PDU), the multiple CCs corresponding to multiple indicated CCs. The apparatus may also receive an indication of multiple CCs for transmission of at least one PDCP PDU. In addition, the apparatus may send at least one PDCP PDU on one or more CCs of the multiple CCs. The apparatus may also determine whether to retransmit at least one PDCP PDU, the retransmission of at least one PDCP PDU being associated with a PDCP duplication process. The apparatus may also select one or more CCs of the multiple CCs for retransmission of at least one PDCP PDU. In addition, the apparatus may receive an indication of whether to retransmit at least one PDCP PDU. The apparatus may also determine whether to activate one or more uplink resources for retransmission of at least one PDCP PDU. The apparatus may also send a scheduling request (SR) for retransmission of at least one PDCP PDU. Additionally, the apparatus may receive a configuration of one or more uplink resources for retransmission of the at least one PDCP PDU, wherein the configuration may be associated with a dynamic grant.The apparatus may also retransmit the at least one PDCP PDU based on the determination of whether to retransmit the at least one PDCP PDU.

[0006] In another aspect of the present disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a base station. The apparatus may send a configuration of one or more uplink resources for transmission of at least one PDCP PDU, wherein the configuration may be associated with a configured grant. The apparatus may also receive a list of multiple component carriers (CCs) for transmission of at least one packet data convergence protocol (PDCP) protocol data unit (PDU), the multiple CCs corresponding to multiple indicated CCs. The apparatus may also send an indication of multiple CCs for transmission of at least one PDCP PDU. In addition, the apparatus may determine whether at least one PDCP PDU is retransmitted, the retransmission of at least one PDCP PDU being associated with a PDCP duplication process. The apparatus may also send an indication of whether to retransmit at least one PDCP PDU. The apparatus may also determine whether one or more uplink resources are activated for retransmission of at least one PDCP PDU. In addition, the apparatus may receive a scheduling request (SR) for retransmission of at least one PDCP PDU. The apparatus may also send a configuration of one or more uplink resources for retransmission of at least one PDCP PDU, wherein the configuration may be associated with a dynamic grant. The apparatus may also receive a retransmission of the at least one PDCP PDU based on the determination of whether the at least one PDCP PDU is retransmitted.

[0007] To achieve the foregoing and related ends, one or more aspects include features fully described below and particularly pointed out in the claims. The following description and the accompanying drawings set forth in detail certain illustrative features of one or more aspects. However, these features are indicative of only a few of the various ways in which the basic principles of the various aspects may be employed, and this specification is intended to include all such aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a diagram showing an example of a wireless communication system and an access network.

[0009] Figure 2A is a diagram illustrating an example of a first frame according to various aspects of the present disclosure.

[0010] Figure 2B is a diagram illustrating an example of DL channels within a subframe according to various aspects of the present disclosure.

[0011] Figure 2C is a diagram illustrating an example of a second frame according to various aspects of the present disclosure.

[0012] Figure 2D is a diagram illustrating an example of UL channels within a subframe according to various aspects of the present disclosure.

[0013] Figure 3is a diagram showing an example of a base station and a user equipment (UE) in an access network.

[0014] Figure 4A is a diagram illustrating an example PDCP duplication process in accordance with one or more techniques of this disclosure.

[0015] Figure 4B is a diagram illustrating an example PDCP duplication process in accordance with one or more techniques of this disclosure.

[0016] Figure 5 is a diagram illustrating an example PDCP duplication process in accordance with one or more techniques of this disclosure.

[0017] Figure 6 is a diagram illustrating an example PDCP duplication process in accordance with one or more techniques of this disclosure.

[0018] Figure 7 is a diagram illustrating an example PDCP duplication process in accordance with one or more techniques of this disclosure.

[0019] Figures 8A-8D is a diagram illustrating example resource allocation for PDCP duplication in accordance with one or more techniques of this disclosure.

[0020] Fig. 9 is a diagram illustrating example communications between a UE and a base station in accordance with one or more techniques of this disclosure.

[0021] Fig.10 is a flow chart of a wireless communication method.

[0022] Fig.11 is a flow chart of a wireless communication method.

[0023] Fig.12 is a diagram illustrating an example of a hardware implementation for an example apparatus.

[0024] Fig.13 is a diagram illustrating an example of a hardware implementation for an example apparatus. DETAILED DESCRIPTION

[0025] The specific embodiments described below in conjunction with the accompanying drawings are intended to be a description of various configurations and are not intended to represent the only configurations that can practice the concepts described herein. In order to provide a thorough understanding of the various concepts, the specific embodiments include specific details. However, it will be apparent to those skilled in the art that these concepts can be practiced without these specific details. In some instances, in order to avoid ambiguity to these concepts, known structures and components are shown in block diagram form.

[0026] Several aspects of telecommunication systems will now be presented with reference to various devices and methods. These devices and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as "elements"). These elements can be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0027] For example, an element or any part of an element or any combination of elements can be implemented as a "processing system" including one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, systems on chip (SoCs), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gate logic, separate hardware circuits, and other suitable hardware configured to perform various functions described throughout the present disclosure. One or more processors in a processing system can execute software. Whether referred to as software, firmware, middleware, microcode, hardware description language, or other terms, software should be broadly interpreted as meaning instructions, instruction sets, codes, code segments, program codes, programs, subroutines, software components, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, processes, functions, etc.

[0028] Therefore, in one or more example embodiments, the functions described herein can be implemented with hardware, software, or any combination thereof. When implemented with software, these functions can be stored or encoded into one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media. Storage media can be any available media that can be accessed by a computer. By way of example and not limitation, such computer-readable media can include random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, a combination of computer-readable media of the aforementioned types, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer.

[0029] Figure 11 is a diagram showing an example of a wireless communication system and access network 100. The wireless communication system (also referred to as a wireless wide area network (WWAN)) includes a base station 102, a UE 104, an evolved packet core (EPC) 160, and another core network 190 (e.g., a 5G core (5GC)). The base station 102 may include a macro cell (a high-power cellular base station) and / or a small cell (a low-power cellular base station). A macro cell includes a base station. A small cell includes a femto cell, a pico cell, and a micro cell.

[0030] The base station 102 configured for 4G LTE (collectively referred to as the Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) can interface with the EPC 160 via a first backhaul link 132 (e.g., an S1 interface). The base station 102 configured for 5GNR (collectively referred to as the Next Generation RAN (NG-RAN)) can interface with the core network 190 via a second backhaul link 184. Among other functions, the base station 102 can perform one or more of the following functions: transmission of user data, wireless channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), user and device tracking, RAN information management (RIM), paging, positioning, and transmission of warning messages. The base stations 102 may communicate with each other directly or indirectly (eg, via the EPC 160 or the core network 190) via the third backhaul link 134 (eg, an X2 interface). The first backhaul link 132, the second backhaul link 184, and the third backhaul link 134 may be wired or wireless.

[0031] Base station 102 can communicate wirelessly with UE 104. Each of base stations 102 can provide communication coverage for a corresponding geographic coverage area 110. There may be overlapping geographic coverage areas 110. For example, a small cell 102' can have a coverage area 110' that overlaps with the coverage area 110 of one or more macro base stations 102. A network including small cells and macro cells can be referred to as a heterogeneous network. A heterogeneous network can also include a home evolved node B (eNB) (HeNB), which can provide services to a restricted group called a closed user group (CSG). The communication link 120 between base station 102 and UE 104 can include an uplink (UL) (also referred to as a reverse link) transmission from UE 104 to base station 102 and / or a downlink (DL) (also referred to as a forward link) transmission from base station 102 to UE 104. The communication link 120 can use multiple input multiple output (MIMO) antenna technology, including spatial multiplexing, beamforming and / or transmit diversity. These communication links can be through one or more carriers. The base station 102 / UE 104 may use up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) of bandwidth for each carrier allocated in a carrier aggregation for a total of up to Yx MHz (x component carriers) for transmission in each direction. The carriers may or may not be adjacent to each other. The allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL ​​compared to UL). The component carriers may include a primary component carrier and one or more secondary component carriers. The primary component carrier may be referred to as a primary cell (PCell), and the secondary component carrier may be referred to as a secondary cell (SCell).

[0032] Some UEs 104 may communicate with each other using a device-to-device (D2D) communication link 158. The D2D communication link 158 may use DL / UL WWAN spectrum. The D2D communication link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). D2D communication may be performed through various wireless D2D communication systems, such as WiMedia, Bluetooth, ZigBee, Wi-Fi based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, LTE, or NR.

[0033] The wireless communication system may also include a Wi-Fi access point (AP) 150 that communicates with a Wi-Fi station (STA) 152 via a communication link 154 (e.g., in a 5 GHz unlicensed spectrum, etc.). When communicating in the unlicensed spectrum, the STA 152 / AP 150 may perform a clear channel assessment (CCA) prior to communicating to determine whether a channel is available.

[0034] The small cell 102' can operate in a licensed and / or unlicensed spectrum. When operating in an unlicensed spectrum, the small cell 102' can adopt NR and use the same unlicensed spectrum (e.g., 5 GHz, etc.) used by the Wi-Fi AP 150. The small cell 102' adopting NR in the unlicensed spectrum can improve the coverage of the access network and / or increase the capacity of the access network.

[0035] The electromagnetic spectrum is subdivided into various categories, bands, channels, etc. based on frequency / wavelength. In 5G NR, two initial operating bands have been identified with the frequency range names FR1 (410MHz-7.125GHz) and FR2 (24.25GHz-52.6GHz). The frequencies between FR1 and FR2 are often referred to as mid-band frequencies. Although a portion of FR1 is greater than 6GHz, FR1 is often (interchangeably) referred to as the "sub-6GHz" band in various documents and articles. Similar naming issues sometimes arise regarding FR2, which is often (interchangeably) referred to as the "millimeter wave" band in various documents and articles, although it is different from the extremely high frequency (EHF) band (30GHz-300 GHz), which is defined as the "millimeter wave" band by the International Telecommunication Union (ITU).

[0036] In view of the above, unless otherwise explicitly stated, it should be understood that the term "sub-6 GHz" and the like (if used herein) can broadly refer to frequencies less than 6 GHz, frequencies that can be within FR1, or frequencies that can include mid-band frequencies. In addition, unless otherwise explicitly stated, it should be understood that the term "millimeter wave" and the like (if used herein) can broadly refer to frequencies that can include mid-band frequencies, frequencies that can be within FR2, or frequencies that can be within the EHF band.

[0037] The base station 102 (whether a small cell 102' or a large cell (e.g., a macro base station)) may include and / or may be referred to as an eNB, a gNodeB (gNB), or another type of base station. Some base stations (such as gNB 180) may operate in traditional sub-6 GHz spectrum, at millimeter wave frequencies, and / or near millimeter wave frequencies to communicate with UE 104. When gNB 180 operates at millimeter wave or near millimeter wave frequencies, gNB 180 may be referred to as a millimeter wave base station. The millimeter wave base station 180 may utilize beamforming 182 with the UE 104 to compensate for path loss and short distance. Both the base station 180 and the UE 104 may include multiple antennas (such as antenna elements, antenna panels, and / or antenna arrays) to facilitate beamforming.

[0038] The base station 180 may send beamformed signals in one or more transmit directions 182' to the UE 104. The UE 104 may receive beamformed signals from the base station 180 in one or more receive directions 182". The UE 104 may also send beamformed signals to the base station 180 in one or more transmit directions. The base station 180 may receive beamformed signals from the UE 104 in one or more receive directions. The base station 180 / UE 104 may perform beam training to determine the best receive and transmit directions for each of the base station 180 / UE 104. The transmit and receive directions of the base station 180 may be the same or may be different. The transmit and receive directions of the UE 104 may be the same or may be different.

[0039] The EPC 160 may include a mobile management entity (MME) 162, other MMEs 164, a serving gateway 166, a multimedia broadcast multicast service (MBMS) gateway 168, a broadcast multicast service center (BM-SC) 170, and a packet data network (PDN) gateway 172. The MME 162 may communicate with a home subscriber server (HSS) 174. The MME 162 is a control node that handles signaling between the UE 104 and the EPC 160. Typically, the MME 162 provides bearer and connection management. All user Internet Protocol (IP) packets are transmitted through the serving gateway 166, which itself is connected to the PDN gateway 172. The PDN gateway 172 provides UE IP address allocation and other functions. The PDN gateway 172 and the BM-SC 170 are connected to IP services 176. The IP services 176 may include the Internet, the intranet, the IP multimedia subsystem (IMS), and the PS streaming services and / or other IP services. The BM-SC 170 may provide functionality for MBMS user service provisioning and delivery. The BM-SC 170 may serve as an entry point for content provider MBMS transmissions, may be used to authorize and initiate MBMS bearer services within a public land mobile network (PLMN), and may be used to schedule MBMS transmissions. The MBMS Gateway 168 may be used to distribute MBMS services to base stations 102 belonging to a multicast broadcast single frequency network (MBSFN) area that broadcasts a specific service, and may be responsible for session management (start / stop) and collecting eMBMS-related charging information.

[0040] The core network 190 may include an access and mobility management function (AMF) 192, other AMFs 193, a session management function (SMF) 194, and a user plane function (UPF) 195. The AMF 192 may communicate with a unified data management (UDM) 196. The AMF 192 is a control node that handles signaling between the UE 104 and the core network 190. Typically, the AMF 192 provides QoS flow and session management. All user Internet Protocol (IP) packets are transmitted through the UPF 195. The UPF 195 provides UE IP address allocation and other functions. The UPF 195 is connected to an IP service 197. The IP service 197 may include the Internet, an intranet, an IP multimedia subsystem (IMS), a packet switched (PS) stream (PSS) service, and / or other IP services.

[0041] A base station may include and / or be referred to as a gNB, a Node B, an eNB, an access point, a base transceiver, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), a transmission reception point (TRP), or some other appropriate term. Base station 102 provides an access point to EPC 160 or core network 190 for UE 104. Examples of UE 104 include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio unit, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., an MP3 player), a camera, a game console, a tablet device, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a medical device, an implant, a sensor / actuator, a display, or any other similar functional device. Some of UE 104 may be referred to as IoT devices (e.g., a parking meter, a gas pump, a toaster, a vehicle, a heart monitor, etc.). UE 104 may also be referred to as a station, a mobile station, a user station, a mobile unit, a user unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile user station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.

[0042] Reference again Figure 1In certain aspects, the UE 104 may include a receiving component 198 configured to receive a configuration of one or more uplink resources for transmission of at least one PDCP PDU, wherein the configuration may be associated with a configured grant. The receiving component 198 may also be configured to send a list of multiple component carriers (CCs) for transmission of at least one packet data convergence protocol (PDCP) protocol data unit (PDU), the multiple CCs corresponding to the multiple indicated CCs. The receiving component 198 may also be configured to receive an indication of multiple CCs for transmission of at least one PDCP PDU. The receiving component 198 may also be configured to send at least one PDCP PDU on one or more CCs of the multiple CCs. The receiving component 198 may also be configured to determine whether to retransmit at least one PDCP PDU, the retransmission of at least one PDCP PDU being associated with a PDCP duplication procedure. The receiving component 198 may also be configured to select one or more CCs of the multiple CCs for retransmission of at least one PDCP PDU. The receiving component 198 may also be configured to receive an indication of whether to retransmit the at least one PDCP PDU. The receiving component 198 may also be configured to determine whether to activate one or more uplink resources for retransmission of at least one PDCP PDU. The receiving component 198 may also be configured to send a scheduling request (SR) for retransmission of at least one PDCP PDU. The receiving component 198 may also be configured to receive a configuration of one or more uplink resources for retransmission of at least one PDCP PDU, wherein the configuration may be associated with a dynamic grant. The receiving component 198 may also be configured to retransmit at least one PDCP PDU based on the determination of whether to retransmit at least one PDCP PDU.

[0043] Reference again Figure 1In certain aspects, the base station 180 may include a transmission component 199 configured to transmit a configuration of one or more uplink resources for transmission of at least one PDCP PDU, wherein the configuration may be associated with a configured grant. The transmission component 199 may also be configured to receive a list of multiple component carriers (CCs) for transmission of at least one packet data convergence protocol (PDCP) protocol data unit (PDU), the multiple CCs corresponding to multiple indicated CCs. The transmission component 199 may also be configured to transmit an indication of multiple CCs for transmission of at least one PDCP PDU. The transmission component 199 may also be configured to determine whether at least one PDCP PDU is retransmitted, the retransmission of at least one PDCP PDU being associated with a PDCP duplication procedure. The transmission component 199 may also be configured to transmit an indication of whether to retransmit the at least one PDCP PDU. The transmission component 199 may also be configured to determine whether one or more uplink resources are activated for retransmission of at least one PDCP PDU. The transmission component 199 may also be configured to receive a scheduling request (SR) for retransmission of at least one PDCP PDU. The transmission component 199 may also be configured to send a configuration of one or more uplink resources for retransmission of at least one PDCP PDU, wherein the configuration may be associated with a dynamic grant. The transmission component 199 may also be configured to receive a retransmission of at least one PDCP PDU based on a determination of whether the at least one PDCP PDU is to be retransmitted.

[0044] Although the following description may focus on 5G NR, the concepts described herein may be applicable to other similar areas such as LTE, LTE-A, CDMA, GSM, and other wireless technologies.

[0045] Figure 2A FIG200 is a diagram showing an example of a first subframe within a 5G NR frame structure. Figure 2B FIG230 is a diagram showing an example of DL channels within a 5G NR subframe. Figure 2C Figure 250 shows an example of a second subframe within a 5G NR frame structure. Figure 2D FIG280 is a diagram showing an example of UL channels within a 5G NR subframe. The 5G NR frame structure may be frequency division duplex (FDD), where for a particular set of subcarriers (carrier system bandwidth), a subframe within a subcarrier set is dedicated to either DL or UL, or may be time division duplex (TDD), where for a particular set of subcarriers (carrier system bandwidth), a subframe within a subcarrier set is dedicated to both DL and UL. Figure 2A , 2CIn the example provided, it is assumed that the 5G NR frame structure is TDD, where subframe 4 is configured with slot format 28 (mainly DL), where D is DL, U is UL, and F is flexibly used between DL / UL, and subframe 3 is configured with slot format 1 (all UL). Although subframes 3 and 4 are shown using slot formats 1 and 28, respectively, any particular subframe can be configured with any of the various available slot formats 0-61. Slot formats 0 and 1 are full DL and full UL, respectively. Other slot formats 2-61 include a mix of DL, UL and flexible symbols. The UE is configured with the slot format (dynamically configured through DL control information (DCI) or semi-statically / statically configured through radio resource control (RRC) signaling) through the received slot format indicator (SFI). Note that the following description also applies to the 5G NR frame structure of TDD.

[0046] Other wireless communication technologies may have different frame structures and / or different channels. A frame (10ms) may be divided into 10 subframes (1ms) of equal size. Each subframe may include one or more time slots. A subframe may also include a microslot, which may include 7, 4 or 2 symbols. Depending on the time slot configuration, each time slot may include 7 or 14 symbols. For time slot configuration 0, each time slot may include 14 symbols, and for time slot configuration 1, each time slot may include 7 symbols. The symbol on the DL may be a cyclic prefix (CP) OFDM (CP-OFDM) symbol. The symbol on the UL may be a CP-OFDM symbol (for high throughput scenarios) or a discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbol (also known as a single carrier frequency division multiple access (SC-FDMA) symbol) (for power-limited scenarios; limited to single-stream transmission). The number of time slots in a subframe is based on the time slot configuration and numerology. For slot configuration 0, different digital schemes μ0 to 4 allow 1, 2, 4, 8, and 16 slots per subframe, respectively. For slot configuration 1, different digital schemes 0 to 2 allow 2, 4, and 8 slots per subframe, respectively. Therefore, for slot configuration 0 and digital scheme μ, there are 14 symbols / slot and 2 μ time slots / subframe. The subcarrier spacing and symbol length / duration are based on the digital scheme. The subcarrier spacing can be equal to 2 μ *15kHz, where μ is digital scheme 0 to 4. Thus, digital scheme μ=0 has a subcarrier spacing of 15kHz, and digital scheme μ=4 has a subcarrier spacing of 240kHz. The symbol length / duration is inversely related to the subcarrier spacing. Figures 2A-2DAn example of a slot configuration 0 with 14 symbols per slot and a digital scheme μ=2 with 4 slots per subframe is provided. The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 μs. Within a frame set, there may be one or more different bandwidth parts (BWPs) of frequency division multiplexing (see Figure 2B ). Each BWP can have a specific numbering scheme.

[0047] A resource grid may be used to represent the frame structure. Each slot includes a resource block (RB) (also referred to as a physical RB (PRB)) having 12 consecutive subcarriers. The resource grid is divided into a plurality of resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

[0048] like Figure 2A As shown in , some of the REs carry reference (pilot) signals (RS) for the UE. The RS may include a demodulation RS (DM-RS) (indicated as R for a particular configuration, but other DM-RS configurations are possible) and a channel state information reference signal (CSI-RS) for channel estimation at the UE. The RS may also include a beam measurement RS (BRS), a beam refinement (BRRS), and a phase tracking RS (PT-RS).

[0049] Figure 2BExamples of various DL channels within a subframe of a frame are shown. The physical downlink control channel (PDCCH) carries DCI in one or more control channel elements (CCEs) (e.g., 1, 2, 4, 8, or 16 CCEs), each CCE including six RE groups (REGs), each REG including 12 consecutive REs in an OFDM symbol of an RB. The PDCCH within a BWP may be referred to as a control resource set (CORESET). The UE is configured to monitor PDCCH candidates in a PDCCH search space (e.g., a common search space, a UE-specific search space) during a PDCCH monitoring opportunity on the CORESET, wherein the PDCCH candidates have different DCI formats and different aggregation levels. Additional BWPs may be located at higher and / or lower frequencies across the channel bandwidth. The primary synchronization signal (PSS) may be within symbol 2 of a particular subframe of a frame. The UE 104 uses the PSS to determine subframe / symbol timing and physical layer identification. The secondary synchronization signal (SSS) may be within symbol 4 of a particular subframe of a frame. The UE uses the SSS to determine the physical layer cell identification group number and the radio frame timing. Based on the physical layer identification and the physical layer cell identification group number, the UE can determine the physical cell identifier (PCI). Based on the PCI, the UE can determine the position of the aforementioned DM-RS. The physical broadcast channel (PBCH) carrying the master information block (MIB) can be logically grouped with the PSS and SSS to form a synchronization signal (SS) / PBCH block (also referred to as an SS block (SSB)). The MIB provides the number of RBs in the system bandwidth and the system frame number (SFN). The physical downlink shared channel (PDSCH) carries user data, broadcast system information not sent via the PBCH (such as a system information block (SIB)), and paging messages.

[0050] like Figure 2C As shown in , some of the REs carry DM-RS for channel estimation at the base station (indicated as R for one specific configuration, but other DMRS configurations are possible). The UE may send DM-RS for a physical uplink control channel (PUCCH) and DM-RS for a physical uplink shared channel (PUSCH). The PUSCH DM-RS may be sent in the first one or two symbols of the PUSCH. The PUCCH DM-RS may be sent in different configurations depending on whether a short PUCCH or a long PUCCH is sent and depending on the specific PUCCH format used. The UE may send a sounding reference signal (SRS). The SRS may be sent in the last symbol of a subframe. The SRS may have a comb structure, and the UE may send the SRS on one of these comb structures. The SRS may be used by the base station for channel quality estimation to enable frequency-dependent scheduling on the UL.

[0051] Figure 2D Examples of various UL channels within a subframe of a frame are shown. The PUCCH may be located as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, channel quality indicator (CQI), precoding matrix indicator (PMI), rank indicator (RI), and hybrid automatic repeat request (HARQ) ACK / NACK feedback. The PUSCH carries data and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), and / or UCI.

[0052] Figure 3 3 is a block diagram of a base station 310 communicating with a UE 350 in an access network. In the DL, IP packets from the EPC 160 are provided to the controller / processor 375. The controller / processor 375 implements layer 3 and layer 2 functions. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller / processor 375 provides: RRC layer functions associated with broadcasting of system information (e.g., MIB, SIB), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), mobility between radio access technologies (RATs), and measurement configuration for UE measurement reporting; PDCP layer functions associated with header compression / decompression, security (encryption, decryption, integrity protection, integrity verification), and switching support functions; RLC layer functions associated with transmission of upper layer packet data units (PDUs), error correction through ARQ, concatenation, segmentation and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority processing, and logical channel prioritization.

[0053] The transmit (TX) processor 316 and the receive (RX) processor 370 implement layer 1 functions associated with various signal processing functions. Layer 1, including the physical (PHY) layer, may include error detection on the transmission channel, forward error correction (FEC) encoding / decoding of the transmission channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. The TX processor 316 processes the mapping to the signal constellation based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-phase phase shift keying (M-PSK), M-order quadrature amplitude modulation (M-QAM)). Subsequently, the coded and modulated symbols can be split into parallel streams. Each stream can then be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., a pilot) in the time domain and / or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT) to generate a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to generate multiple spatial streams. Channel estimates from a channel estimator 374 may be used to determine coding and modulation schemes and for spatial processing. Channel estimates may be derived based on reference signals and / or channel condition feedback sent by the UE 350. The spatial streams may then be provided to different antennas 320 via separate transmitters 318TX. Each transmitter 318TX may modulate an RF carrier with a corresponding spatial stream for transmission.

[0054] At the UE 350, each receiver 354RX receives a signal through its corresponding antenna 352. Each receiver 354RX recovers the information modulated onto the RF carrier and provides the information to a receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functions associated with various signal processing functions. The RX processor 356 can perform spatial processing on the information to recover any spatial streams destined for the UE 350. If multiple spatial streams are destined for the UE 350, the RX processor 356 can combine them into a single OFDM symbol stream. The RX processor 356 then uses a fast Fourier transform (FFT) to transform the OFDM symbol stream from the time domain to the frequency domain. The frequency domain signal includes a separate OFDMA symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier and the reference signal are recovered and demodulated by determining the most likely signal constellation point sent by the base station 310. These soft decisions can be based on the channel estimates calculated by the channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals originally sent on the physical channel by the base station 310. The data and control signals are then provided to the controller / processor 359 which implements layer 3 and layer 2 functions.

[0055] The controller / processor 359 may be associated with a memory 360 that stores program codes and data. The memory 360 may be referred to as a computer readable medium. In the UL, the controller / processor 359 provides demultiplexing between transport and logical channels, packet reassembly, decryption, header decompression, and control signal processing to recover IP packets from the EPC 160. The controller / processor 359 is also responsible for error detection using an ACK and / or NACK protocol to support HARQ operations.

[0056] Similar to the functions described in conjunction with DL transmission performed by the base station 310, the controller / processor 359 provides: RRC layer functions associated with system information (e.g., MIB, SIB) acquisition, RRC connection, and measurement reporting; PDCP layer functions associated with header compression / decompression and security (encryption, decryption, integrity protection, integrity verification); RLC layer functions associated with transmission of upper layer PDUs, error correction through ARQ, concatenation, segmentation and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority processing, and logical channel prioritization.

[0057] Channel estimates derived by the channel estimator 358 based on a reference signal or feedback transmitted by the base station 310 may be used by the TX processor 368 to select appropriate coding and modulation schemes and to facilitate spatial processing. The spatial streams generated by the TX processor 368 may be provided to different antennas 352 via separate transmitters 354TX. Each transmitter 354TX may modulate an RF carrier with a corresponding spatial stream for transmission.

[0058] UL transmissions are processed at the base station 310 in a manner similar to that described in conjunction with the receiver functionality at the UE 350. Each receiver 318RX receives a signal through its respective antenna 320. Each receiver 318RX recovers information modulated onto an RF carrier and provides the information to a RX processor 370.

[0059] The controller / processor 375 may be associated with a memory 376 that stores program codes and data. The memory 376 may be referred to as a computer readable medium. In the UL, the controller / processor 375 provides demultiplexing between transport and logical channels, packet reassembly, decryption, header decompression, control signal processing to recover IP packets from the UE 350. The IP packets from the controller / processor 375 may be provided to the EPC 160. The controller / processor 375 is also responsible for error detection using an ACK and / or NACK protocol to support HARQ operations.

[0060] At least one of the TX processor 368, the RX processor 356, and the controller / processor 359 may be configured to perform Figure 1 198 related aspects.

[0061] At least one of the TX processor 316, the RX processor 370, and the controller / processor 375 may be configured to perform Figure 1 199 related aspects.

[0062] Some aspects of wireless communications include Packet Data Convergence Protocol (PDCP) duplication, which involves sending multiple copies of the same PDCP protocol data unit (PDU) without waiting for radio link control (RLC) error detection. Downlink PDCP duplication can be achieved via a base station implementation and can include multiple different aspects. For example, downlink PDCP duplication can include: configuring a UE with multiple downlink (DL) RLC entities mapped to the same PDCP entity. In some instances, the UE may not know which component carriers (CCs) are being used for duplication and whether the base station is actually performing duplication or sending a single copy.

[0063] Uplink PDCP duplication may involve more configuration on the UE side. In some aspects, the RLC entity may be mapped to a carrier set via a radio resource control (RRC) configuration, where the two replicated RLC entities utilize non-overlapping carrier sets. In addition, a medium access control (MAC) control element (MAC-CE) may be used to turn duplication on or off, i.e., turning off may deactivate the secondary RLC.

[0064] Figure 4A 4 is a diagram illustrating an example PDCP duplication procedure. Figure 4A As shown in FIG. 400 , the diagram 400 includes a service data adaptation protocol (SDAP) 410, a PDCP 412, an RLC 414, and a MAC 416, which are part of a master node (MN) stack in a UE. The diagram 400 also includes an RLC 424 and a MAC 426, which are part of a secondary node (SN) stack in a UE. Figure 4AThe PDCP duplication procedure is shown in the dual connectivity (DC) case using split bearers.

[0065] Figure 4B 450 is a diagram illustrating an example PDCP duplication procedure. Figure 4B As shown in FIG. 450 , FIG. 450 includes SDAP 460, PDCP 462, RLC 464, RLC 474, and MAC 466. Figure 4B As shown in FIG. 4 , MAC 466 includes scheduler 480 , HARQ 482 , and HARQ 484 . Figure 4B The PDCP duplication process in the case of carrier aggregation (CA) is shown.

[0066] In addition, some aspects of wireless communication include PDCP duplication procedures to support ultra-reliable low-latency communication (URLLC) (i.e., higher reliability and low-latency communication). For example, these types of PDCP duplication can be used when radio link control (RLC) retransmissions may not meet latency specifications.

[0067] Some aspects of wireless communications may specify PDCP replication with up to a certain number of RLC entities (e.g., four (4) RLC entities), which may be configured via RRC signaling in an architecture combination (including CA and new radio (NR) dual connectivity (NR-DC) combined with CA). In addition, some aspects of wireless communications may specify mechanisms related to how a set or subset of configured RLC entities or legs are used for dynamic control of PDCP replication. Some aspects of wireless communications may also allow branch configurations to be changed via RRC signaling, for example, where replication may be changed from one CC (e.g., CC1 or CC2) to another CC (e.g., CC1 or CC3). In addition, some aspects of wireless communications may provide MAC-CE based UL replication branch configuration to the UE. In addition, in some aspects of wireless communications, work items (WIs) may be introduced to enhance PDCP replication.

[0068] In some aspects of wireless communications, PDCP duplication may be based on link conditions without considering different applications or services. However, it may be beneficial to consider duplication based on a combination of link conditions and applications or services, for example, to ensure that data is sent or received correctly. Among a range of URLLC applications and services, some applications or services may have strict reliability and latency specifications. However, another set of URLLC and industrial applications may allow some relaxation of latency and / or reliability specifications. PDCP duplication may also be based on base station detection, which may use MAC-CE to implement duplication. UE-assisted branch selection or autonomous activation or deactivation may be considered to reduce latency and improve reliability.

[0069] Some aspects of PDCP duplication may include UE-assisted branch selection or autonomous activation or deactivation. For example, if the number of replicas is less than the number of active RLC entities, the UE may select the active RLC entity to send the replicas. When doing so, the UE may consider listen-before-talk (LBT) results to allow faster adaptation to New Radio (NR) unlicensed spectrum (NR-U). The UE may also consider fast adaptation to degraded channels or beams. In addition, the UE may consider fast reaction to power headroom changes when sharing across carriers with limited headroom.

[0070] Figure 5 5 is a diagram illustrating an example PDCP duplication procedure. Figure 5 As shown in FIG. 5 , diagram 500 includes PDCP PDU 501, PDCP PDU 502, PDCP PDU 503, base station 510, PDCP 520, RLC 531, RLC 532, and RLC 533. Figure 5 UE-assisted branch selection is shown with two PDCP PDU repetitions and three active RLC entities. Figure 5 As shown in , since the number of PDCP PDU repetitions is less than the number of active RLC entities, the UE can select the active RLC entity to send the repetitions.

[0071] Some aspects of PDCP duplication may include selective duplication. For example, for each PDCP PDU, a PDCP PDU duplicate may be sent to one RLC entity and a timer may be started. If the timer expires, another PDCP PDU duplicate may be sent to another RLC entity. In addition, if the RLC entity receives an acknowledgment (ACK) for the first PDCP PDU duplicate and no further PDCP PDU duplicates are sent, the timer may be stopped. In addition, various aspects of wireless communication may decide to perform duplication based on packet type (e.g., Transmission Control Protocol (TCP) ACK).

[0072] Figure 6 600 is a diagram illustrating an example PDCP duplication procedure. Figure 6 As shown in FIG. 6 , diagram 600 includes PDCP PDU 601, PDCP PDU 602, PDCP PDU 603, base station 610, PDCP 620, RLC 631, RLC 632, and RLC 633. Figure 6 2 shows selective PDCP duplication with a specific number of copies (e.g., up to three (3) PDCP PDU copies). Figure 6As shown in , for each PDCP PDU, a PDCP PDU copy may be sent to one RLC entity and a timer may be started. If the timer expires, another PDCP PDU copy may be sent to another RLC entity.

[0073] Based on the above, there is a need for an enhanced PDCP duplication process. For example, there is a need for a PDCP duplication process that can reduce the amount of delay. There is also a need for a PDCP duplication process that can be dynamically scheduled.

[0074] Various aspects of the present disclosure may include enhanced PDCP duplication procedures and methods. For example, various aspects of the present disclosure may include PDCP duplication procedures and methods with reduced latency. In addition, various aspects of the present disclosure may include PDCP duplication procedures and methods that can be dynamically scheduled. Various aspects of the present disclosure may utilize physical layer feedback to reduce latency, for example, rather than based on upper layer feedback.

[0075] Various aspects of the present disclosure may include a PDCP duplication procedure for uplink communications. In some aspects, the UE may report the indicated component carriers (CCs) to the base station, and the base station may indicate the CCs on which the UE may send the PDCP PDU. The number of CCs may depend on the latency specification of the data packet, i.e., if the survival time for the data packet is shorter, more CCs may be indicated to the UE.

[0076] Figure 7 700 is a diagram illustrating an example PDCP duplication process in accordance with one or more techniques of this disclosure. Figure 7 As shown in FIG. 700 , FIG. 700 includes UE 702, base station 704, PDCP 720, RLC 731, RLC 732, and RLC 733. Figure 7 As shown in , UE 702 may report the number of indicated CCs to base station 704, and report power headroom report (PHR), reference signal received power (RSRP), reference signal received quality (RSRQ), and / or measured energy to base station 704. Base station 704 may then indicate one or more CCs to UE 702.

[0077] In some aspects, if a PDCP PDU is retransmitted, the UE may determine a CC on which to send a duplicate PDCP PDU. The action may depend on a power headroom (PH). For example, if the PH indicates that the transmitted power is greater than the allowed transmit power, the base station may not configure a CC for the UE. If the first PDCP PDU transmission fails, one or more CCs may be added, and these added CCs may be used to send duplicate PDCP PDUs, where the CCs used during the first transmission may be used for subsequent transmissions. The process may be repeated until the PDCP PDU is successfully received, or the maximum number of repetitions is reached, or the PHR is non-positive.

[0078] In addition, some CCs may be used for certain types of wireless communications (e.g., LTE), while other CCs may be used for other types of wireless communications (e.g., NR). In addition, some CCs may be within a specific frequency range (e.g., a first frequency range (FR1)), while other CCs may be within another frequency range (e.g., a second frequency range (FR2)). In addition, some CCs may be in an unlicensed band, while other CCs may be in a licensed band.

[0079] In some aspects, if the PDCP PDU is successfully received, or the maximum number of PDCP PDU repetitions is reached, or the additional CC does not allow PHR, the UE may not send any new copies of the PDCP PDU. However, if any of these steps is not reached (e.g., the PDCP PDU is not successfully received, or the maximum number of PDCP PDU repetitions is not reached, or the additional CC allows PHR), the UE may return to the CC determined on which to send the PDCP PDU copy if the PDCP PDU is to be retransmitted.

[0080] Various aspects of the present disclosure may include CC selection for PDCP PDU transmission. In some aspects, the UE may indicate one or more emphasized or indicated CCs to the base station based on the PH and / or measured energy. The instantaneous PH may promptly indicate whether there is some space for additional PDCP PDU replication at maximum power. In addition, whether the indicated CC is used may depend on the base station. The UE may also indicate the priority of the indicated CC to the base station. For example, the UE may indicate multiple indicated CCs to the base station.

[0081] In addition, the base station may select a CC based on reported PHR, RSRP, RSRQ and / or measured energy. For example, the base station may select a CC based on reported measured energy. The measured energy may be an energy used for comparison with an energy detection (ED) threshold. In addition, the energy may be measured by the base station or measured by the UE and reported to the base station. If the currently measured energy is not available, the base station may use the latest available measured energy to select a CC.

[0082] The base station may also select a CC based on the reported PHR, RSRP, or RSRQ. The CC may be selected based on the latest reported PHR, RSRP, or RSRQ. The base station may also average RSRP or RSRQ in the time domain, or select a CC based on the average RSRP or RSRQ. In addition, the base station may select a CC based on a combination of the above options.

[0083] Aspects of the present disclosure may also include PDCP PDU retransmission determination. In some aspects, the present disclosure may determine whether to retransmit the PDCP PDU based on the physical layer. If any data packet corresponding to the PDCP PDU results in a negative ACK (NACK), the PDCP PDU may be retransmitted. In some instances, the UE may determine the PDCP PDU retransmission based on the configured permission. The UE may determine which CC or how many CCs may be used for PDCP PDU retransmission. During data transmission, if the feedback of some CCs results in NACK, these CCs may be withdrawn and the CC with ACK may be used for the next transmission. In addition, when there is a smaller delivery time frame, UE triggering PDCP PDU retransmission may be more suitable for introducing PDCP duplication. For unlicensed bands, if no downlink feedback information (DFI) is received or the retransmission timer expires, the UE may trigger PDCP PDU retransmission. For licensed bands, if an uplink retransmission permission is received or the retransmission timer expires, the UE may trigger PDCP PDU retransmission.

[0084] Additionally, in some aspects, the base station may determine a PDCP PDU retransmission. If the received data results in a NACK or the retransmission timer expires, the base station may indicate to the UE to retransmit the PDCP PDU. In some instances, if the base station does not receive data, it may be difficult to determine a PDCP PDU retransmission. For NR-U, the base station may determine which TB size to use for transmission.

[0085] In some aspects, PDCP PDU retransmission may be determined based on a MAC-CE from a base station. For example, a MAC-CE may be introduced to indicate whether a PDCP PDU retransmission may be required. In addition, a MAC-CE may be introduced to indicate which CC and / or how many CCs may be used for PDCP PDU transmission.

[0086] Aspects of the present disclosure may also include resource allocation for PDCP PDU retransmissions. In some aspects, the PDCP PDU may be retransmitted based on a configured grant. For example, the base station may configure each available resource for the UE prior to the first transmission of each PDCP PDU. If the number of repetitions of the PDCP PDU is a certain number (e.g., two (2)), the base station may configure the number of resources (e.g., two (2) resources) for the UE prior to the first transmission of the PDCP PDU. Each resource may be released once the current PDCP PDU process is completed.

[0087] Various aspects of the present disclosure may also include multiple options for activating resources. In some instances, the base station may send an activation indication to the UE at each transmission. In addition, the base station may predefine the activation order of resources before the first transmission of the PDCP PDU. At each transmission of the PDCP PDU, the UE may autonomously activate and add one of these resources to send a copy of the PDCP PDU based on the predefined order. Before activating the resources, the base station may schedule other UEs to use these resources. In addition, the UE may autonomously activate resources for retransmission of the PDCP PDU. During the PDCP duplication process, other UEs may not use the activated resources.

[0088] Aspects of the present disclosure may also retransmit the PDCP PDU based on a dynamic grant. In some instances, the base station may indicate resources via a UL grant for the UE at each transmission of the PDCP PDU. The base station may first indicate a resource via a UL grant for the UE to send the PDCP PDU. If the first transmission fails, the base station may add resources and indicate the resources to the UE via a UL grant. The UE may use these indicated resources to send a copy of the PDCP PDU. The process may be repeated until the PDCP PDU is successfully received or the maximum number of copies is reached. In addition, the UE may send a scheduling request (SR) to the base station, and the base station may indicate the resources used for the PDCP PDU transmission.

[0089] Fig. 8A 800 is a diagram illustrating an example resource allocation for a PDCP duplication procedure. Fig. 8AAs shown in , diagram 800 includes UE 802 and base station 804. At 810, base station 804 may configure all resources and indicate the CC for the first PDCP PDU transmission. At 812, UE 802 may send data. At 814, if there is a NACK, base station 804 may indicate the CC for the PDCP PDU retransmission.

[0090] Figure 8B 8 is a diagram 820 showing an example resource allocation for a PDCP duplication procedure. Figure 8B As shown in , diagram 820 includes UE 822 and base station 824. At 830, base station 824 may configure all resources. At 832, UE 822 may send data. At 834, base station 824 may provide feedback if feedback is available. At 836, UE 822 may activate resources for PDCP PDU transmission.

[0091] Figure 8C 840 is a diagram illustrating an example resource allocation for a PDCP duplication procedure. Figure 8C As shown in , diagram 840 includes UE 842 and base station 844. At 850, base station 844 may configure resources for a first PDCP PDU transmission. At 852, UE 842 may send data. At 854, if there is a NACK, base station 844 may configure resources (e.g., CC) for a next PDCP PDU transmission.

[0092] Fig.8D 860 is a diagram illustrating an example resource allocation for a PDCP duplication procedure. Fig.8D As shown in , diagram 860 includes UE 862 and base station 864. At 870, base station 864 may configure resources for a first PDCP PDU transmission. At 872, UE 862 may send data. At 874, base station 864 may provide feedback if feedback is available. At 876, UE 862 may send an SR. At 878, base station 864 may configure resources (e.g., CCs).

[0093] Fig. 9 900 is a diagram illustrating example communications between a UE 902 and a base station 904.

[0094] At 910, the base station 904 may send a configuration of one or more uplink resources for transmission of at least one PDCP PDU (e.g., configuration 914), wherein the configuration may be associated with a configured grant. At 912, the UE 902 may receive a configuration of one or more uplink resources for transmission of at least one PDCP PDU (e.g., configuration 914), wherein the configuration may be associated with a configured grant.

[0095] At 920, the UE 902 may transmit a list of multiple CCs (e.g., list 924) for transmission of at least one PDCP PDU, the multiple CCs corresponding to the multiple indicated CCs. At 922, the base station 904 may receive a list of multiple CCs (e.g., list 924) for transmission of at least one PDCP PDU, the multiple CCs corresponding to the multiple indicated CCs.

[0096] At 930, the base station 904 may send an indication of a plurality of CCs used for transmission of at least one PDCP PDU (e.g., indication 934). At 932, the UE 902 may receive an indication of a plurality of CCs used for transmission of at least one PDCP PDU (e.g., indication 934).

[0097] At 934, the UE 902 may transmit at least one PDCP PDU (e.g., PDCP PDU 936) on one or more CCs of the plurality of CCs.

[0098] At 940, the UE 902 may determine whether to retransmit at least one PDCP PDU, the retransmission of the at least one PDCP PDU being associated with a PDCP duplication procedure. At 942, the base station 904 may determine whether at least one PDCP PDU is retransmitted, the retransmission of the at least one PDCP PDU being associated with a PDCP duplication procedure. In some instances, the determination of whether to retransmit at least one PDCP PDU may be associated with feedback from at least one physical layer. In addition, the determination of whether to retransmit at least one PDCP PDU may be based on at least one of a power headroom or a time period expiration.

[0099] At 944, the UE 902 may select one or more CCs of the plurality of CCs for retransmission of the at least one PDCP PDU. In some aspects, when at least one CC of the one or more CCs corresponds to an acknowledgement (ACK), the at least one CC may be associated with the retransmission of the at least one PDCP PDU. Additionally, when the at least one CC corresponds to a negative ACK (NACK), the at least one CC may be de-associated with the retransmission of the at least one PDCP PDU.

[0100] At 950, the base station 904 may send an indication (e.g., indication 954) of whether to retransmit at least one PDCP PDU. At 952, the UE 902 may receive an indication (e.g., indication 954) of whether to retransmit at least one PDCP PDU. In some instances, the indication may identify one or more additional CCs in a plurality of CCs for retransmission of the at least one PDCP PDU. In addition, the indication may be associated with an acknowledgement (ACK) or a negative ACK (NACK). In addition, the indication may be received or sent via a medium access control (MAC) control element (MAC-CE).

[0101] At 960, the UE 902 may determine whether to activate one or more uplink resources for retransmission of at least one PDCP PDU. At 962, the base station 904 may determine whether one or more uplink resources are activated for retransmission of at least one PDCP PDU.

[0102] At 970, UE 902 may send a scheduling request (SR) for retransmission of at least one PDCP PDU (eg, SR 974). At 972, base station 904 may receive a scheduling request (SR) for retransmission of at least one PDCP PDU (eg, SR 974).

[0103] At 980, the base station 904 may send a configuration of one or more uplink resources for retransmission of at least one PDCP PDU (e.g., configuration 984), wherein the configuration may be associated with a dynamic grant. At 982, the UE 902 may receive a configuration of one or more uplink resources for retransmission of at least one PDCP PDU (e.g., configuration 984), wherein the configuration may be associated with a dynamic grant.

[0104] At 990, the UE 902 may retransmit the at least one PDCP PDU (e.g., PDCP PDU 994) based on the determination of whether to retransmit the at least one PDCP PDU. At 992, the base station 904 may receive a retransmission of the at least one PDCP PDU (e.g., PDCP PDU 994) based on the determination of whether the at least one PDCP PDU is retransmitted. In some aspects, the at least one PDCP PDU may be retransmitted when the number of PDCP PDU repetitions is less than a maximum threshold, or the retransmission of the at least one PDCP PDU may be based on a power headroom report (PHR).

[0105] Fig.101000 is a flow chart of a wireless communication method. The method may be performed by a UE or a component of a UE (e.g., UE 104, 350, 902; apparatus 1202; a processing system, which may include a memory 360 and may be the entire UE or a component of a UE, such as a TX processor 368, a controller / processor 359, a transmitter 354TX, an antenna 352, etc.). Optional aspects are shown with dashed lines. The methods described herein may provide multiple benefits, such as improved communication signaling, resource utilization, and / or power savings.

[0106] At 1002, an apparatus may receive a configuration of one or more uplink resources for transmission of at least one PDCP PDU, wherein the configuration may be associated with a configured grant, such as in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 For example, 1002 can be performed by the determination component 1240.

[0107] At 1004, the apparatus may send a list of multiple CCs for transmission of at least one PDCP PDU, the multiple CCs corresponding to the multiple indicated CCs, such as in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 For example, 1004 can be performed by the determination component 1240.

[0108] At 1006, the apparatus may receive an indication of a plurality of CCs for transmission of at least one PDCP PDU, such as in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 For example, 1006 can be performed by the determination component 1240.

[0109] At 1008, the apparatus may transmit at least one PDCP PDU on one or more CCs of the plurality of CCs, such as in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 For example, 1008 can be performed by the determination component 1240.

[0110] At 1010, the apparatus may determine whether to retransmit at least one PDCP PDU, the retransmission of at least one PDCP PDU being associated with a PDCP duplication process, such as in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9For example, 1010 may be performed by the determining component 1240. In some instances, the determination of whether to retransmit at least one PDCP PDU may be associated with feedback from at least one physical layer, such as in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 In addition, the determination of whether to retransmit at least one PDCP PDU may be based on at least one of a power headroom or a time period expiration, as described in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 As described in the examples.

[0111] At 1012, the apparatus may select one or more CCs from a plurality of CCs for retransmission of at least one PDCP PDU, such as in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 For example, 1012 may be performed by determining component 1240. In some aspects, when at least one CC of the one or more CCs corresponds to an acknowledgment (ACK), the at least one CC may be associated with a retransmission of at least one PDCP PDU, such as in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 In addition, when at least one CC corresponds to a negative ACK (NACK), the at least one CC may be associated with the retransmission of at least one PDCP PDU, as described in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 As described in the examples.

[0112] At 1014, the apparatus may receive an indication of whether to retransmit at least one PDCP PDU, such as in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 For example, 1014 may be performed by determining component 1240. In some instances, the indication may identify one or more additional CCs in a plurality of CCs for retransmission of at least one PDCP PDU, such as in combination with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 In addition, the indication may be associated with an acknowledgement (ACK) or a negative ACK (NACK), such as in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9In addition, the indication may be received or sent via a medium access control (MAC) control element (MAC-CE), such as in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 As described in the examples.

[0113] At 1016, the device may determine whether to activate one or more uplink resources for retransmission of at least one PDCP PDU, such as in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 For example, 1016 can be performed by determining component 1240.

[0114] At 1018, the apparatus may send a scheduling request (SR) for retransmission of at least one PDCP PDU, such as in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 For example, 1018 can be performed by determining component 1240.

[0115] At 1020, the apparatus may receive a configuration of one or more uplink resources for retransmission of at least one PDCP PDU, wherein the configuration may be associated with a dynamic grant, such as in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 For example, 1020 can be performed by the determination component 1240.

[0116] At 1022, the apparatus may retransmit at least one PDCP PDU based on the determination of whether to retransmit at least one PDCP PDU, such as in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 For example, 1022 may be performed by the determining component 1240. In some aspects, when the number of PDCP PDU repetitions is less than the maximum threshold, at least one PDCP PDU may be retransmitted, or the retransmission of at least one PDCP PDU may be based on a power headroom report (PHR), such as in combination with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 As described in the examples.

[0117] Fig.111100 is a flow chart of a wireless communication method. The method may be performed by a base station or a component of a base station (e.g., base station 102, 180, 310, 904; device 1302; processing system, which may include memory 376 and may be the entire base station or a component of a base station, such as antenna 320, receiver 318RX, RX processor 370, controller / processor 375, etc.). Optional aspects are shown using dashed lines. The methods described herein may provide multiple benefits, such as improved communication signaling, resource utilization, and / or power savings.

[0118] At 1102, an apparatus may send a configuration of one or more uplink resources for transmission of at least one PDCP PDU, wherein the configuration may be associated with a configured grant, such as in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 For example, 1102 can be performed by the determination component 1340.

[0119] At 1104, the apparatus may receive a list of a plurality of component carriers (CCs) for transmission of at least one packet data convergence protocol (PDCP) protocol data unit (PDU), the plurality of CCs corresponding to a plurality of indicated CCs, such as in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 For example, 1104 can be performed by the determination component 1340.

[0120] At 1106, the apparatus may send an indication of a plurality of CCs for transmission of at least one PDCP PDU, such as in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 For example, 1106 can be performed by the determination component 1340.

[0121] At 1108, the apparatus may determine whether at least one PDCP PDU is retransmitted, the retransmission of at least one PDCP PDU being associated with a PDCP duplication procedure, such as in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 For example, 1108 may be performed by determining component 1340. In some instances, the determination of whether at least one PDCP PDU is retransmitted may be associated with feedback from at least one physical layer, such as in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9In addition, the determination of whether at least one PDCP PDU is retransmitted may be based on at least one of a power headroom or a time period expiration, as described in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 As described in the examples.

[0122] In some aspects, one or more CCs among the plurality of CCs may be selected for retransmission of at least one PDCP PDU, such as in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 In addition, when at least one CC of the one or more CCs corresponds to an ACK, the at least one CC may be associated with a retransmission of at least one PDCP PDU, as described in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 In addition, when at least one CC corresponds to a negative ACK (NACK), the at least one CC may be associated with a retransmission of at least one PDCP PDU, as described in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 As described in the examples.

[0123] At 1110, the apparatus may send an indication of whether to retransmit at least one PDCP PDU, such as in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 For example, 1110 may be performed by determining component 1340. In some instances, the indication may identify one or more additional CCs in a plurality of CCs for retransmission of at least one PDCP PDU, such as in combination with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 In addition, the indication may be associated with an acknowledgement (ACK) or a negative ACK (NACK). The indication may be sent via a medium access control (MAC) control element (MAC-CE), such as in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 As described in the examples.

[0124] At 1112, the apparatus may determine whether one or more uplink resources are activated for retransmission of at least one PDCP PDU, such as in conjunction with Figure 4A , 4B, 5, 6, 7, 8A-8D and Fig. 9 For example, 1112 can be performed by the determination component 1340.

[0125] At 1114, the apparatus may receive a scheduling request (SR) for retransmission of at least one PDCP PDU, such as in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 For example, 1114 can be performed by determining component 1340.

[0126] At 1116, the apparatus may send a configuration of one or more uplink resources for retransmission of at least one PDCP PDU, wherein the configuration may be associated with a dynamic grant, such as in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 For example, 1116 can be performed by determining component 1340.

[0127] At 1118, the apparatus may receive a retransmission of at least one PDCP PDU based on the determination of whether the at least one PDCP PDU is retransmitted, such as in conjunction with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 For example, 1118 may be performed by the determining component 1340. In some examples, when the number of PDCP PDU repetitions is less than a maximum threshold or the retransmission of at least one PDCP PDU is based on a power headroom report (PHR), a retransmission of at least one PDCP PDU may be received, such as in combination with Figure 4A , 4B , 5, 6, 7, 8A-8D and Fig. 9 As described in the examples.

[0128] Fig.1212 is a diagram 1200 showing an example of a hardware implementation for an apparatus 1202. The apparatus 1202 is a UE and includes a cellular baseband processor 1204 (also referred to as a modem) coupled to a cellular RF transceiver 1222 and one or more subscriber identity modules (SIM) cards 1220, an application processor 1206 coupled to a secure digital (SD) card 1208 and a screen 1210, a Bluetooth module 1212, a wireless local area network (WLAN) module 1214, a global positioning system (GPS) module 1216, and a power supply 1218. The cellular baseband processor 1204 communicates with the UE 104 and / or the BS 102 / 180 via the cellular RF transceiver 1222. The cellular baseband processor 1204 may include a computer-readable medium / memory. The computer-readable medium / memory may be non-transitory. The cellular baseband processor 1204 is responsible for general processing, including executing software stored on the computer-readable medium / memory. The software, when executed by the cellular baseband processor 1204, causes the cellular baseband processor 1204 to perform the various functions described above. The computer-readable medium / memory may also be used to store data manipulated by the cellular baseband processor 1204 when executing the software. The cellular baseband processor 1204 also includes a receiving component 1230, a communication manager 1232, and a transmission component 1234. The communication manager 1232 includes one or more of the components shown. The components within the communication manager 1232 may be stored in a computer-readable medium / memory, and / or configured as hardware within the cellular baseband processor 1204. The cellular baseband processor 1204 may be a component of the UE 350, and may include at least one of the TX processor 368, the RX processor 356, and the controller / processor 359, and / or the memory 360. In one configuration, the device 1202 may be a modem chip and include only the baseband processor 1204, and in another configuration, the device 1202 may be the entire UE (e.g., see Figure 3 350) and includes the aforementioned additional modules of device 1202.

[0129] The communication manager 1232 includes a determining component 1240 configured to send a list of a plurality of component carriers (CCs) for transmission of at least one packet data convergence protocol (PDCP) protocol data unit (PDU), the plurality of CCs corresponding to the plurality of indicated CCs, e.g., as described in connection with step 1004 above. The determining component 1240 may also be configured to send at least one PDCP PDU on one or more CCs of the plurality of CCs, e.g., as described in connection with step 1008 above. The determining component 1240 may also be configured to determine whether to retransmit the at least one PDCP PDU, the retransmission of the at least one PDCP PDU being associated with a PDCP duplication procedure, e.g., as described in connection with step 1010 above.

[0130] The apparatus may include executing Fig. 9 and Fig.10 The additional components of each block in the algorithm in the preceding flowchart. Therefore, Fig. 9 and Fig.10 Each block in the aforementioned flow chart can be performed by a component and the apparatus may include one or more of these components. The component may be one or more hardware components specifically configured to perform the stated process / algorithm, implemented by a processor configured to perform the stated process / algorithm, stored in a computer-readable medium to be implemented by a processor, or some combination thereof.

[0131] In one configuration, the apparatus 1202 (and in particular the cellular baseband unit 1204) includes: a unit for sending a list of multiple component carriers (CCs) for transmission of at least one packet data convergence protocol (PDCP) protocol data unit (PDU), the multiple CCs corresponding to the multiple indicated CCs. The apparatus 1202 may also include: a unit for sending at least one PDCP PDU on one or more CCs of the multiple CCs. The apparatus 1202 may also include: a unit for determining whether to retransmit at least one PDCP PDU, the retransmission of at least one PDCP PDU being associated with a PDCP duplication process. The aforementioned units may be one or more of the aforementioned components of the apparatus 1202 configured to perform the functions recited by the aforementioned units. As described above, the apparatus 1202 may include a TX processor 368, an RX processor 356, and a controller / processor 359. Therefore, in one configuration, the aforementioned units may be the TX processor 368, the RX processor 356, and the controller / processor 359 configured to perform the functions recited by the aforementioned units.

[0132] Fig.131300 is a diagram illustrating an example of a hardware implementation for an apparatus 1302. The apparatus 1302 is a base station and includes a baseband unit 1304. The baseband unit 1304 may communicate with the UE 104 via a cellular RF transceiver. The baseband unit 1304 may include a computer-readable medium / memory. The baseband unit 1304 is responsible for general processing, including executing software stored on a computer-readable medium / memory. The software, when executed by the baseband unit 1304, causes the baseband unit 1304 to perform the various functions described above. The computer-readable medium / memory may also be used to store data manipulated by the baseband unit 1304 when executing the software. The baseband unit 1304 also includes a receiving component 1330, a communication manager 1332, and a transmission component 1334. The communication manager 1332 includes one or more of the components shown. The components within the communication manager 1332 may be stored in a computer-readable medium / memory and / or configured as hardware within the baseband unit 1304. The baseband unit 1304 may be a component of the BS 310 , and may include at least one of the TX processor 316 , the RX processor 370 , and the controller / processor 375 , and / or the memory 376 .

[0133] The communication manager 1332 includes a determining component 1340 configured to receive a list of multiple component carriers (CCs) for transmission of at least one packet data convergence protocol (PDCP) protocol data unit (PDU), the multiple CCs corresponding to the multiple indicated CCs, for example, as described in conjunction with step 1104 above. The determining component 1340 can be configured to determine whether the at least one PDCP PDU is retransmitted, the retransmission of the at least one PDCP PDU being associated with a PDCP duplication procedure, for example, as described in conjunction with step 1108 above.

[0134] The apparatus may include executing Fig. 9 and Fig.11 The additional components of each block in the algorithm in the preceding flowchart. Therefore, Fig. 9 and Fig.11 Each block in the aforementioned flow chart can be performed by a component, and the apparatus may include one or more of these components. The component may be one or more hardware components specifically configured to perform the stated process / algorithm, implemented by a processor configured to perform the stated process / algorithm, stored in a computer-readable medium to be implemented by a processor, or some combination thereof.

[0135] In one configuration, the apparatus 1302 (and in particular the baseband unit 1304) includes: a unit for receiving a list of multiple component carriers (CCs) for transmission of at least one packet data convergence protocol (PDCP) protocol data unit (PDU), the multiple CCs corresponding to the multiple indicated CCs. The apparatus 1302 may also include: a unit for determining whether at least one PDCP PDU is retransmitted, the retransmission of at least one PDCP PDU being associated with a PDCP duplication process. The aforementioned units may be one or more of the aforementioned components of the apparatus 1302 configured to perform the functions recited by the aforementioned units. As described above, the apparatus 1302 may include a TX processor 316, an RX processor 370, and a controller / processor 375. Therefore, in one configuration, the aforementioned units may be the TX processor 316, the RX processor 370, and the controller / processor 375 configured to perform the functions recited by the aforementioned units.

[0136] Further disclosures are included in the appendix.

[0137] It is to be understood that the specific order or hierarchy of the blocks in the disclosed process / flowchart is an illustration of an exemplary method. It is to be understood that the specific order or hierarchy of the blocks in the process / flowchart may be rearranged based on design preferences. In addition, some blocks may be combined or omitted. The attached method claims present the elements of the various blocks in an exemplary order and are not intended to be limited to the specific order or hierarchy presented.

[0138] Provide the previous description so that those skilled in the art can practice the various aspects described in this article. Various modifications to these aspects will be apparent to those skilled in the art, and the overall principles defined herein may be applicable to other aspects. Therefore, the claims are not limited to the various aspects shown herein, but are to be given the full scope consistent with the language claims, wherein, unless otherwise specified, the reference to the singular element is not intended to mean "one and only one", but "one or more". The word "exemplary" is used herein to mean "used as an example, illustration or explanation". Any aspect described as "exemplary" herein is not necessarily interpreted as preferred or more advantageous than other aspects. Unless otherwise specified, the term "some" refers to one or more. Such as "at least one of A, B or C", "one or more of A, B or C", "at least one of A, B and C", "one or more of A, B and C" and "A, B, C or any combination thereof" and the like combination, including any combination of A, B and / or C, and may include multiple A, multiple B or multiple C. Specifically, combinations such as "at least one of A, B, or C", "one or more of A, B, or C", "at least one of A, B and C", "one or more of A, B, and C", and "A, B, C, or any combination thereof" may be only A, only B, only C, A and B, A and C, B and C, or A and B and C, wherein any such combination may include one or more members of A, B, or C. All structural and functional equivalents of the elements of various aspects described throughout the present disclosure are expressly incorporated herein by reference and are intended to be covered by the claims, and these structural and functional equivalents are or will become known to those skilled in the art. In addition, the content disclosed herein is not intended to be dedicated to the public, regardless of whether such disclosure is explicitly recorded in the claims. The words "module", "device", "element", "equipment", etc. may not be substitutes for the word "unit". Therefore, no claim element is to be interpreted as a functional module unless the element is explicitly recorded using the phrase "unit for..."

[0139] appendix

[0140] Enhancements for PDCP duplication

[0141] introduce

[0142] Motivation: To support Ultra-Reliable Low Latency Communications (URLCC) (i.e., higher reliability and low latency)

[0143] o Used when Radio Link Control (RLC) retransmissions may not meet latency requirements

[0144] In some aspects of wireless communications,

[0145] o Packet Data Convergence Protocol (PDCP) duplication design sends two copies of the same PDCP Protocol Data Unit (PDU) without waiting for RLC error detection

[0146] Downlink PDCP duplication is primarily implemented by gNB and only requires

[0147] o Configuring a UE with multiple downlink (DL) RLC entities mapped to the same PDCP entity

[0148] οUE has no knowledge of which component carriers are being used for duplication and whether the gNB is actually performing duplication or just sending one copy

[0149] Uplink PDCP duplication involves more configuration at the UE

[0150] o RLC entities are mapped to carrier sets via radio resource control (RRC) configuration, where two replicated RLC entities utilize non-overlapping carrier sets

[0151] o Medium Access Control (MAC) Control Element (MAC-CE) can be used to turn replication on / off (“off” deactivates the secondary RLC)

[0152] ο

[0153] PDCP duplication in case of DC with split bearer

[0154]

[0155] PDCP duplication in case of CA

[0156]

[0157] introduce

[0158] In some aspects of wireless communications

[0159] o Specifies PDCP duplication with up to 4 RLC entities configured via RRC in architecture combinations including CA only and NR-DC combined with CA

[0160] o Specify mechanisms related to dynamic control of how a set or subset of configured RLC entities or branches are used for PDCP duplication

[0161] Release 15 only allows branch configuration changes via RRC, e.g. if replication needs to change from (CC1, CC2) to (CC1, CC3)

[0162] Release 16 provides UE with UL duplication branch based on MAC CE

[0163] In some aspects of wireless communications

[0164] o Work Items (WI) may be introduced for enhancements for PCDP replication

[0165] question

[0166] In some aspects of wireless communications

[0167] o PDCP duplication based only on link conditions without considering different applications / services

[0168] It is best to consider duplication based on link conditions and application / service combination

[0169] o Within the range of URLLC applications and services, some of these applications and services may have strict reliability and latency requirements. However, another set of URLLC and industrial applications may allow for some relaxation of latency and / or reliability requirements.

[0170] oPDCP duplication is based on gNB detection only and then uses MAC CE to implement duplication

[0171] UE-assisted branch selection or autonomous activation / deactivation can be considered to reduce latency and increase reliability

[0172] Some suggestions for PDCP duplication enhancement

[0173] UE-assisted branch selection or autonomous activation / deactivation

[0174] o If the number of duplicates < the number of active RLC entities, the UE picks the active RLC entity to send the duplicates taking into account:

[0175] LBT output allows faster adaptation for NR-U

[0176] Fast adaptation to degraded channels / beams

[0177] Fast response to power headroom changes when sharing across carriers in headroom-limited scenarios

[0178] Selective copying

[0179] οExample suggestions

[0180] For each PDCP PDU, send one copy to one RLC entity and start a timer

[0181] If the timer expires, send another copy to another RLC entity

[0182] If an (RLC) ACK is received for the first copy, stop the timer (and do not send further copies)

[0183] Example suggestion: Determine whether to perform replication based on packet type (e.g., TCP ACK)

[0184] Example UE-assisted branch selection: two replicas, three active RLC entities

[0185]

[0186] Example: Selective replication with up to 3 replicas

[0187] suggestion

[0188] Instead of being based on upper layer feedback, physical layer feedback can be used to reduce latency, and PDCP duplication will be scheduled dynamically

[0189] PDCP duplication process

[0190] ο Consider uplink

[0191] Step 1: UE reports the preferred component carrier (CC) to gNB, and gNB indicates the CC for UE to send PDCP PDU

[0192] The number of CCs depends on the latency requirement of the packet, i.e. if the lifetime of the packet is shorter, more CCs will be indicated to the UE

[0193]

[0194] suggestion

[0195] Step 2: If retransmission of the PDCP PDU is required, determine the CC to be used to send the copy of the PDCP PDU. This action may need to be based on the power headroom (PH).

[0196] If the PH indicates that the transmitted power is higher than the allowed transmit power, the gNB will not configure CC for the UE.

[0197] If the first transmission fails, more CCs will be added and these added CCs will be used to send duplicate PDCP packets, where the CCs used during the first transmission are used for the second transmission, and the process is repeated until the PDCP PDU is successfully received or the maximum number of duplicates is reached or the PHR is not positive.

[0198] For CC

[0199] o Some may be in LTE and others in NR

[0200] o Some may be in FR1 and others in FR2

[0201] o Some may be in unlicensed bands and others in licensed bands

[0202] Step 3: If the PDCP PDU is successfully received, or the maximum number of PDCP PDU copies is reached, or PHR is not allowed for additional CCs, no new copy of the PDCP PDU is sent; otherwise, go to step 2

[0203] Suggestion A

[0204] CC selection for PDCP transmission

[0205] Option A.1: The UE indicates to the gNB its preferred CC based on PH and / or measured energy

[0206] The instantaneous PH can indicate in time whether there is some room for additional PDCP PDU duplication at maximum power

[0207] Whether the indicated CC will be used depends on the gNB

[0208] The UE can also indicate the priority of the preferred CC to the gNB

[0209] oUE indicates two preferred CCs to the gNB and numbers the CCs in order of preference as CC 0 and CC 1. If the gNB selects only one CC, the UE prefers CC 0.

[0210] Option A.2: gNB selects CC based on reported PHR / RSRP / RSRQ / measured energy

[0211] Option A.2.1 Select CC based on reported measured energy

[0212] οThe measured energy is the energy used for comparison with the ED threshold

[0213] It can be measured by the gNB or measured by the UE and reported to the gNB

[0214] If the currently measured energy is not available, the gNB may use the latest available measured energy to select the CC

[0215] Option A.2.2 Select CC based on reported PHR / RSRP / RSRQ

[0216] ο Option A.2.2.1: Based on the latest reported PHR / RSRP / RSRQ

[0217] Option A.2.2.2: Average RSRP / RSRQ in the time domain and select CC based on average RSRP / RSRQ

[0218] Option A.2.3: Select CC based on a combination of Option A.2.1 and Option A.2.2

[0219] Recommendation B

[0220] PDCP PDU retransmission confirmation

[0221] οOption B.1: Physical layer based

[0222] If any data packet corresponding to the PDCP PDU is NACK, the PDCP PDU is required to be retransmitted

[0223] Option B.1.1 UE determines PDCP PDU retransmission

[0224] This option only works if the configuration allows it.

[0225] oUE can determine which and how many CCs will be used for PDCP PDU retransmission

[0226] During data transmission, if the feedback of some CCs is NACK, these CCs will be withdrawn and only CCs with ACK will be used for the next transmission

[0227] o UE triggered PDCP PDU is more suitable for the main use case of introducing PDCP duplication when there is a tight delivery time budget

[0228] For unlicensed bands

[0229] If no DFI is received or the retransmission timer is reached, the UE triggers PDCP PDU retransmission

[0230] For licensed frequency bands

[0231] If an uplink retransmission grant is received or the retransmission timer is reached, the UE triggers PDCP PDU retransmission

[0232] Option B.1.2 gNB determines PDCP PDU retransmission

[0233] o If the received data is NACK or the retransmission timer is reached, the gNB instructs the UE to retransmit the PDCP PDU

[0234] o If the gNB does not receive the data, it will be difficult to determine the PDCP PDU retransmission

[0235] For NR-U, which TB should be used for transmission

[0236] Option B.2: Based on MAC CE from gNB

[0237] A new MAC CE will be introduced to

[0238] o Indicates whether PDCP PDU retransmission is required

[0239] ο Which CC and how many CCs will be used for PDCP PDU transmission

[0240] Recommendation C

[0241] Resource allocation

[0242] οOption C.1: Configuration Permission

[0243] The gNB configures all available resources for the UE before the first transmission of each PDCP PDU

[0244] o If the number of repetitions of a PDCP PDU is 2, the gNB shall configure two resources for the UE before the first transmission of the PDCP PDU

[0245] Once the current PDCP PDU process is completed, all resources are released

[0246] Three options for activating resources

[0247] Option C.1.1 gNB sends activity indication to UE at each transmission

[0248] Option C.1.2 Before the first transmission of a PDCP PDU, the gNB predefines the order of activities of the resources

[0249] At each transmission of a PDCP PDU, the UE autonomously activates and adds one of the resources to send a copy of the PDCP PDU based on a predefined order

[0250] Before the resources are activated, the gNB can schedule other UEs to use them

[0251] Option C.1.3 UE autonomously activates resources for PDCP PDU retransmission

[0252] During the PDCP PDU duplication process, other UEs cannot use this resource

[0253] οOption C.2: Dynamic Grant

[0254] Option C.2.1 The gNB indicates the resources via the UL grant to the UE at each transmission of a PDCP PDU

[0255] o The gNB will first indicate a resource via UL grant for the UE to send the PDCP PDU; if the first transmission fails, the gNB will add a resource and indicate the resource to the UE via UL grant, and the UE will use the two indicated resources to send a copy of the PDCP PDU; repeat the process until the PDCP PDU is successfully received or the maximum number of copies is reached

[0256] Option C.2.2 Example where UE sends SR and gNB indicates resources for PDCP PDU transmission for resource allocation

Claims

1. A method for wireless communication of a user equipment (UE), comprising: transmitting a list of a plurality of component carriers (CCs) for transmission of at least one packet data convergence protocol (PDCP) protocol data unit (PDU), the plurality of CCs corresponding to the plurality of indicated CCs; Sending the at least one PDCP PDU on one or more CCs among the plurality of CCs; determining whether to retransmit the at least one PDCP PDU, the retransmission of the at least one PDCP PDU being associated with a PDCP duplication procedure; as well as One or more CCs among the plurality of CCs are selected for the retransmission of the at least one PDCP PDU.

2. The method according to claim 1, wherein: When at least one CC among the one or more CCs corresponds to an acknowledgment (ACK), the at least one CC is associated with the retransmission of the at least one PDCP PDU; or when the at least one CC corresponds to a negative ACK (NACK), the at least one CC is de-associated with the retransmission of the at least one PDCP PDU.

3. The method according to claim 1, further comprising: An indication of whether to retransmit the at least one PDCP PDU is received.

4. The method according to claim 3, wherein: The indication identifies one or more additional CCs among the plurality of CCs to be used for the retransmission of the at least one PDCP PDU.

5. The method according to claim 3, wherein: The indication is associated with an acknowledgement (ACK) or a negative ACK (NACK).

6. The method according to claim 3, wherein: The indication is received via a Medium Access Control (MAC) Control Element (MAC-CE).

7. The method according to claim 1, further comprising: The at least one PDCP PDU is retransmitted based on the determination of whether to retransmit the at least one PDCP PDU.

8. The method according to claim 7, wherein: When the number of PDCP PDU repetitions is less than a maximum threshold or the retransmission of the at least one PDCP PDU is based on a power headroom report (PHR), the at least one PDCP PDU is retransmitted.

9. The method according to claim 1, further comprising: A configuration of one or more uplink resources for the transmission of the at least one PDCP PDU is received, wherein the configuration is associated with a configured grant.

10. The method according to claim 1, further comprising: A configuration of one or more uplink resources for the retransmission of the at least one PDCP PDU is received, wherein the configuration is associated with a dynamic grant.

11. The method according to claim 1, further comprising: Determining whether to activate one or more uplink resources for the retransmission of the at least one PDCP PDU.

12. The method according to claim 1, further comprising: A scheduling request (SR) is sent for the retransmission of the at least one PDCP PDU.

13. The method according to claim 1, further comprising: An indication of the plurality of CCs used for the transmission of the at least one PDCP PDU is received.

14. The method according to claim 1, wherein: The determination of whether to retransmit the at least one PDCP PDU is associated with at least one physical layer feedback.

15. The method according to claim 1, wherein: The determination of whether to retransmit the at least one PDCP PDU is based on at least one of a power headroom or an expiration of a time period.

16. An apparatus for wireless communication of a user equipment (UE), comprising: Memory; as well as at least one processor coupled to the memory and configured to: transmitting a list of a plurality of component carriers (CCs) for transmission of at least one packet data convergence protocol (PDCP) protocol data unit (PDU), the plurality of CCs corresponding to the plurality of indicated CCs; Sending the at least one PDCP PDU on one or more CCs among the plurality of CCs; determining whether to retransmit the at least one PDCP PDU, the retransmission of the at least one PDCP PDU being associated with a PDCP duplication procedure; as well as One or more CCs among the plurality of CCs are selected for the retransmission of the at least one PDCP PDU.

17. The device according to claim 16, wherein: When at least one CC among the one or more CCs corresponds to an acknowledgment (ACK), the at least one CC is associated with the retransmission of the at least one PDCP PDU; or when the at least one CC corresponds to a negative ACK (NACK), the at least one CC is de-associated with the retransmission of the at least one PDCP PDU.

18. The device according to claim 16, wherein: The at least one processor is further configured to: An indication of whether to retransmit the at least one PDCP PDU is received.

19. The device according to claim 18, wherein: The indication identifies one or more additional CCs among the plurality of CCs to be used for the retransmission of the at least one PDCP PDU.

20. The device according to claim 18, wherein The indication is associated with an acknowledgement (ACK) or a negative ACK (NACK).

21. The device according to claim 18, wherein The indication is received via a Medium Access Control (MAC) Control Element (MAC-CE).

22. The device according to claim 16, wherein: The at least one processor is further configured to: The at least one PDCP PDU is retransmitted based on the determination of whether to retransmit the at least one PDCP PDU.

23. The device according to claim 22, wherein: When the number of PDCP PDU repetitions is less than a maximum threshold or the retransmission of the at least one PDCP PDU is based on a power headroom report (PHR), the at least one PDCP PDU is retransmitted.

24. The device according to claim 16, wherein: The at least one processor is further configured to: A configuration of one or more uplink resources for the transmission of the at least one PDCP PDU is received, wherein the configuration is associated with a configured grant.

25. The device according to claim 16, wherein: The at least one processor is further configured to: A configuration of one or more uplink resources for the retransmission of the at least one PDCP PDU is received, wherein the configuration is associated with a dynamic grant.

26. The device according to claim 16, wherein: The at least one processor is further configured to: Determining whether to activate one or more uplink resources for the retransmission of the at least one PDCP PDU.

27. The device according to claim 16, wherein: The at least one processor is further configured to: A scheduling request (SR) is sent for the retransmission of the at least one PDCP PDU.

28. The apparatus of claim 16, wherein: The at least one processor is further configured to: An indication of the plurality of CCs used for the transmission of the at least one PDCP PDU is received.

29. The device according to claim 16, wherein: The determination of whether to retransmit the at least one PDCP PDU is associated with at least one physical layer feedback.

30. The device according to claim 16, wherein: The determination of whether to retransmit the at least one PDCP PDU is based on at least one of a power headroom or an expiration of a time period.

31. An apparatus for wireless communication of a user equipment (UE), comprising: means for transmitting a list of a plurality of component carriers (CCs) for transmission of at least one packet data convergence protocol (PDCP) protocol data unit (PDU), the plurality of CCs corresponding to the plurality of indicated CCs; means for transmitting the at least one PDCP PDU on one or more CCs among the plurality of CCs; means for determining whether to retransmit the at least one PDCP PDU, the retransmission of the at least one PDCP PDU being associated with a PDCP duplication procedure; as well as means for selecting one or more CCs among the plurality of CCs for the retransmission of the at least one PDCP PDU.

32. The device according to claim 31, wherein When at least one CC among the one or more CCs corresponds to an acknowledgment (ACK), the at least one CC is associated with the retransmission of the at least one PDCP PDU; or when the at least one CC corresponds to a negative ACK (NACK), the at least one CC is de-associated with the retransmission of the at least one PDCP PDU.

33. The apparatus of claim 31 , further comprising: Means for receiving an indication of whether to retransmit the at least one PDCP PDU.

34. The device according to claim 33, wherein The indication identifies one or more additional CCs among the plurality of CCs to be used for the retransmission of the at least one PDCP PDU.

35. The device according to claim 33, wherein The indication is associated with an acknowledgement (ACK) or a negative ACK (NACK).

36. The device according to claim 33, wherein The indication is received via a Medium Access Control (MAC) Control Element (MAC-CE).

37. The apparatus of claim 31 , further comprising: means for retransmitting the at least one PDCP PDU based on the determination of whether to retransmit the at least one PDCP PDU.

38. The device according to claim 37, wherein When the number of PDCP PDU repetitions is less than a maximum threshold or the retransmission of the at least one PDCP PDU is based on a power headroom report (PHR), the at least one PDCP PDU is retransmitted.

39. The apparatus of claim 31 , further comprising: Means for receiving a configuration of one or more uplink resources for the transmission of the at least one PDCP PDU, wherein the configuration is associated with a configured grant.

40. The apparatus of claim 31 , further comprising: Means for receiving a configuration of one or more uplink resources for the retransmission of the at least one PDCP PDU, wherein the configuration is associated with a dynamic grant.

41. The apparatus of claim 31 , further comprising: means for determining whether to activate one or more uplink resources for the retransmission of the at least one PDCP PDU.

42. The apparatus of claim 31 , further comprising: means for sending a scheduling request (SR) for the retransmission of the at least one PDCP PDU.

43. The apparatus of claim 31 , further comprising: Means for receiving an indication of the plurality of CCs used for the transmission of the at least one PDCP PDU.

44. The apparatus of claim 31, wherein: The determination of whether to retransmit the at least one PDCP PDU is associated with at least one physical layer feedback.

45. The apparatus of claim 31, wherein: The determination of whether to retransmit the at least one PDCP PDU is based on at least one of a power headroom or an expiration of a time period.

46. ​​A computer readable medium storing computer executable code for wireless communication of a user equipment (UE), the code, when executed by a processor, causing the processor to: transmitting a list of a plurality of component carriers (CCs) for transmission of at least one packet data convergence protocol (PDCP) protocol data unit (PDU), the plurality of CCs corresponding to the plurality of indicated CCs; Sending the at least one PDCP PDU on one or more CCs among the plurality of CCs; determining whether to retransmit the at least one PDCP PDU, the retransmission of the at least one PDCP PDU being associated with a PDCP duplication procedure; as well as One or more CCs among the plurality of CCs are selected for the retransmission of the at least one PDCP PDU.

47. A wireless communication method of a base station, comprising: receiving a list of a plurality of component carriers (CCs) for transmission of at least one packet data convergence protocol (PDCP) protocol data unit (PDU), the plurality of CCs corresponding to the plurality of indicated CCs; as well as determining whether the at least one PDCP PDU is retransmitted, the retransmission of the at least one PDCP PDU being associated with a PDCP duplication procedure; One or more CCs among the multiple CCs are selected for the retransmission of the at least one PDCP PDU.

48. The method of claim 47, wherein: When at least one CC among the one or more CCs corresponds to an acknowledgment (ACK), the at least one CC is associated with the retransmission of the at least one PDCP PDU; or when the at least one CC corresponds to a negative ACK (NACK), the at least one CC is de-associated with the retransmission of the at least one PDCP PDU.

49. The method of claim 47, further comprising: An indication is sent as to whether to retransmit the at least one PDCP PDU.

50. The method of claim 49, wherein: The indication identifies one or more additional CCs among the plurality of CCs to be used for the retransmission of the at least one PDCP PDU.

51. The method of claim 49, wherein: The indication is associated with an acknowledgement (ACK) or a negative ACK (NACK).

52. The method of claim 49, wherein: The indication is sent via a Medium Access Control (MAC) Control Element (MAC-CE).

53. The method of claim 47, further comprising: Based on the determination of whether the at least one PDCP PDU is retransmitted, a retransmission of the at least one PDCP PDU is received.

54. The method of claim 53, wherein: When the number of PDCP PDU repetitions is less than a maximum threshold or the retransmission of the at least one PDCP PDU is based on a power headroom report (PHR), the retransmission of the at least one PDCP PDU is received.

55. The method of claim 47, further comprising: A configuration of one or more uplink resources for the transmission of the at least one PDCP PDU is transmitted, wherein the configuration is associated with a configured grant.

56. The method of claim 47, further comprising: A configuration of one or more uplink resources for the retransmission of the at least one PDCP PDU is transmitted, wherein the configuration is associated with a dynamic grant.

57. The method of claim 47, further comprising: A determination is made as to whether one or more uplink resources are activated for the retransmission of the at least one PDCP PDU.

58. The method of claim 47, further comprising: A scheduling request (SR) is received for the retransmission of the at least one PDCP PDU.

59. The method of claim 47, further comprising: An indication of the plurality of CCs used for the transmission of the at least one PDCP PDU is sent.

60. The method of claim 47, wherein: The determination of whether the at least one PDCP PDU is retransmitted is associated with at least one physical layer feedback.

61. The method of claim 47, wherein: The determination of whether the at least one PDCP PDU is retransmitted is based on at least one of a power headroom or an expiration of a time period.

62. An apparatus for wireless communication of a base station, comprising: Memory; as well as at least one processor coupled to the memory and configured to: receiving a list of a plurality of component carriers (CCs) for transmission of at least one packet data convergence protocol (PDCP) protocol data unit (PDU), the plurality of CCs corresponding to the plurality of indicated CCs; as well as determining whether the at least one PDCP PDU is retransmitted, the retransmission of the at least one PDCP PDU being associated with a PDCP duplication procedure; One or more CCs among the multiple CCs are selected for the retransmission of the at least one PDCP PDU.

63. The device according to claim 62, wherein When at least one CC among the one or more CCs corresponds to an acknowledgment (ACK), the at least one CC is associated with the retransmission of the at least one PDCP PDU; or when the at least one CC corresponds to a negative ACK (NACK), the at least one CC is de-associated with the retransmission of the at least one PDCP PDU.

64. The apparatus of claim 62, wherein: The at least one processor is further configured to: An indication is sent as to whether to retransmit the at least one PDCP PDU.

65. The apparatus of claim 64, wherein: The indication identifies one or more additional CCs among the plurality of CCs to be used for the retransmission of the at least one PDCP PDU.

66. The apparatus of claim 64, wherein: The indication is associated with an acknowledgement (ACK) or a negative ACK (NACK).

67. The apparatus of claim 64, wherein: The indication is sent via a Medium Access Control (MAC) Control Element (MAC-CE).

68. The apparatus of claim 62, wherein: The at least one processor is further configured to: Based on the determination of whether the at least one PDCP PDU is retransmitted, a retransmission of the at least one PDCP PDU is received.

69. The apparatus of claim 68, wherein: When the number of PDCP PDU repetitions is less than a maximum threshold or the retransmission of the at least one PDCP PDU is based on a power headroom report (PHR), the retransmission of the at least one PDCP PDU is received.

70. The apparatus of claim 62, wherein: The at least one processor is further configured to: A configuration of one or more uplink resources for the transmission of the at least one PDCP PDU is transmitted, wherein the configuration is associated with a configured grant.

71. The apparatus of claim 62, wherein: The at least one processor is further configured to: A configuration of one or more uplink resources for the retransmission of the at least one PDCP PDU is transmitted, wherein the configuration is associated with a dynamic grant.

72. The apparatus of claim 62, wherein: The at least one processor is further configured to: A determination is made as to whether one or more uplink resources are activated for the retransmission of the at least one PDCP PDU.

73. The apparatus of claim 62, wherein: The at least one processor is further configured to: A scheduling request (SR) is received for the retransmission of the at least one PDCP PDU.

74. The apparatus of claim 62, wherein: The at least one processor is further configured to: An indication of the plurality of CCs used for the transmission of the at least one PDCP PDU is sent.

75. The apparatus of claim 62, wherein: The determination of whether the at least one PDCP PDU is retransmitted is associated with at least one physical layer feedback.

76. The apparatus of claim 62, wherein: The determination of whether the at least one PDCP PDU is retransmitted is based on at least one of a power headroom or an expiration of a time period.

77. An apparatus for wireless communication of a base station, comprising: means for receiving a list of a plurality of component carriers (CCs) for transmission of at least one packet data convergence protocol (PDCP) protocol data unit (PDU), the plurality of CCs corresponding to the plurality of indicated CCs; as well as means for determining whether the at least one PDCP PDU is retransmitted, the retransmission of the at least one PDCP PDU being associated with a PDCP duplication procedure; One or more CCs among the multiple CCs are selected for the retransmission of the at least one PDCP PDU.

78. The apparatus of claim 77, wherein: When at least one CC among the one or more CCs corresponds to an acknowledgment (ACK), the at least one CC is associated with the retransmission of the at least one PDCP PDU; or when the at least one CC corresponds to a negative ACK (NACK), the at least one CC is de-associated with the retransmission of the at least one PDCP PDU.

79. The apparatus of claim 77, further comprising: Means for sending an indication of whether to retransmit the at least one PDCP PDU.

80. The apparatus of claim 79, wherein: The indication identifies one or more additional CCs among the plurality of CCs to be used for the retransmission of the at least one PDCP PDU.

81. The apparatus of claim 79, wherein: The indication is associated with an acknowledgement (ACK) or a negative ACK (NACK).

82. The apparatus of claim 79, wherein: The indication is sent via a Medium Access Control (MAC) Control Element (MAC-CE).

83. The apparatus of claim 77, further comprising: means for receiving a retransmission of the at least one PDCP PDU based on the determination whether the at least one PDCP PDU is retransmitted.

84. The apparatus of claim 83, wherein: When the number of PDCP PDU repetitions is less than a maximum threshold or the retransmission of the at least one PDCP PDU is based on a power headroom report (PHR), the retransmission of the at least one PDCP PDU is received.

85. The apparatus of claim 77, further comprising: Means for sending a configuration of one or more uplink resources for the transmission of the at least one PDCP PDU, wherein the configuration is associated with a configured grant.

86. The apparatus of claim 77, further comprising: Means for sending a configuration of one or more uplink resources for the retransmission of the at least one PDCP PDU, wherein the configuration is associated with a dynamic grant.

87. The apparatus of claim 77, further comprising: means for determining whether one or more uplink resources are activated for the retransmission of the at least one PDCP PDU.

88. The apparatus of claim 77, further comprising: Means for receiving a scheduling request (SR) for the retransmission of the at least one PDCP PDU.

89. The apparatus of claim 77, further comprising: Means for sending an indication of the plurality of CCs used for the transmission of the at least one PDCP PDU.

90. The apparatus of claim 77, wherein: The determination of whether the at least one PDCP PDU is retransmitted is associated with at least one physical layer feedback.

91. The apparatus of claim 77, wherein: The determination of whether the at least one PDCP PDU is retransmitted is based on at least one of a power headroom or an expiration of a time period.

92. A computer readable medium storing computer executable code for wireless communication of a base station, the code when executed by a processor causes the processor to perform the following operations: receiving a list of a plurality of component carriers (CCs) for transmission of at least one packet data convergence protocol (PDCP) protocol data unit (PDU), the plurality of CCs corresponding to the plurality of indicated CCs; and determining whether the at least one PDCP PDU is retransmitted, the retransmission of the at least one PDCP PDU being associated with a PDCP duplication procedure; in, One or more CCs among the plurality of CCs are selected for the retransmission of the at least one PDCP PDU.

Images