Communication device and method for cascaded service data units

Abstract

This application relates to devices and components including apparatuses, systems, and methods for concatenation in a packet data convergence protocol sublayer or a service data adaptation sublayer in a wireless network.

Description

Background Technology

[0001] The 3rd Generation Partnership Project (3GPP) Technical Specifications (TS) define the standards for New Radio (NR) wireless networks. These TS describe aspects related to the operation of each layer of the protocol stack. Layer 2 (L2) of NR networks is divided into various sublayers, including: Media Access Control (MAC), Radio Link Control (RLC), Packet Data Convergence Protocol (PDCP), and Service Data Adaptation Protocol (SDAP). Attached Figure Description

[0002] Figure 1 A network environment according to some implementation schemes is shown.

[0003] Figure 2 The second-level processing according to some implementation schemes is shown.

[0004] Figure 3 A PDCP protocol data unit (PDU) according to some implementation schemes is shown.

[0005] Figure 4 Variations of PDCP cascades according to some implementation schemes are shown.

[0006] Figure 5 A first PDCP architecture according to some implementation schemes is shown.

[0007] Figure 6 A second PDCP architecture according to some implementation schemes is shown.

[0008] Figure 7 A PDCP PDU according to some implementation schemes is shown.

[0009] Figure 8 The retransmission operation is shown according to some implementation schemes.

[0010] Figure 9 SDAP cascading is shown according to some implementation schemes.

[0011] Figure 10 User equipment according to some implementation schemes is shown.

[0012] Figure 11 Network devices according to some implementation schemes are shown. Detailed Implementation

[0013] The following detailed description relates to the accompanying drawings. The same reference numerals may be used in different drawings to identify the same or similar elements. In the following description, specific details, such as particular structures, architectures, interfaces, and techniques, are set forth for illustrative and non-limiting purposes to provide a thorough understanding of various aspects of the various embodiments. However, it will be apparent to those skilled in the art that various aspects of the various embodiments may be practiced in other examples departing from these specific details. In some cases, descriptions of well-known devices, circuits, and methods have been omitted so as not to obscure the description of the various embodiments with unnecessary detail. For the purposes of this document, the phrases “A / B” and “A or B” refer to (A), (B), or (A and B).

[0014] The following is a glossary of terms that may be used in this disclosure.

[0015] As used herein, the term "circuit" refers to a portion of or includes said hardware component configured to provide the described functionality. Hardware components may include electronic circuitry, logic circuitry, processors (shared, dedicated, or grouped) or memories (shared, dedicated, or grouped), application-specific integrated circuits (ASICs), field-programmable devices (FPDs) (e.g., field-programmable gate arrays (FPGAs), programmable logic devices (PLDs), complex PLDs (CPLDs), high-capacity PLDs (HCPLDs), structured ASICs, or programmable system-on-a-chip (SoCs)), or digital signal processors (DSPs). In some embodiments, a circuit may execute one or more software or firmware programs to provide at least some of the said functionality. The term "circuit" may also refer to a combination of one or more hardware elements and program code for performing the functionality (or a combination of circuits used in an electrical or electronic system). In these embodiments, the combination of hardware elements and program code may be referred to as a particular type of circuit.

[0016] As used herein, the term "processor circuit" means, is part of, or includes the following: a circuit capable of sequentially and automatically performing a series of arithmetic or logical operations or recording, storing, or transmitting digital data. The term "processor circuit" may also refer to an application processor, baseband processor, central processing unit (CPU), graphics processing unit, single-core processor, dual-core processor, triple-core processor, quad-core processor, or any other device capable of executing or otherwise operating computer-executable instructions (such as program code, software modules, and / or functional procedures).

[0017] As used herein, the term "interface circuit" refers to, is part of, or includes a circuit that enables the exchange of information between two or more components or devices. The term "interface circuit" can refer to one or more hardware interfaces, such as buses, I / O interfaces, peripheral component interfaces, and network interface cards.

[0018] As used herein, the term "user equipment" or "UE" refers to equipment having radio communication capabilities that allow a user to access network resources within a communication network. The term "user equipment" or "UE" may be considered synonymous with and may be referred to as a client, mobile phone, mobile device, mobile terminal, user terminal, mobile unit, mobile station, mobile user, subscriber, user, remote station, access agent, user agent, receiver, radio equipment, reconfigurable radio equipment, or reconfigurable mobile device. Furthermore, the term "user equipment" or "UE" can include any type of wireless / wired equipment or any computing device that includes a wireless communication interface.

[0019] As used herein, the term "computer system" means any type of interconnected electronic device, computer device, or component thereof. Additionally, the term "computer system" or "system" may refer to the various components of a computer that are communicatively coupled to each other. Furthermore, the term "computer system" or "system" may refer to multiple computer devices or multiple computing systems that are communicatively coupled to each other and configured to share computing resources or network resources.

[0020] As used herein, the term "resource" refers to physical or virtual devices, physical or virtual components within a computing environment, or physical or virtual components within a particular device, such as computer equipment, mechanical equipment, memory space, processor / CPU time, processor / CPU utilization, processor and accelerator load, hardware time or utilization, power supply, input / output operations, port or network sockets, channel / link allocation, throughput, memory utilization, storage, network, database, and application or workload units. "Hardware resource" can refer to computing, storage, or networking resources provided by physical hardware components. "Virtualized resource" can refer to computing, storage, or networking resources provided by virtualized infrastructure to applications, devices, or systems. The terms "network resource" or "communication resource" can refer to resources accessible by a computer device / system via a communication network. The term "system resource" can refer to any kind of shared entity providing a service and can include computing or network resources. System resources can be considered as a coherent set of functions, network data objects, or services accessible through a server, wherein such system resources reside on a single host or multiple hosts and are clearly identifiable.

[0021] As used herein, the term "channel" refers to any tangible or intangible transmission medium used for transmitting data or data streams. The term "channel" may be synonymous or equivalent with "communication channel," "data communication channel," "transmission channel," "data transmission channel," "access channel," "data access channel," "link," "data link," "carrier," "radio frequency carrier," or any other similar term indicating a path or medium through which data is transmitted. Additionally, as used herein, the term "link" refers to a connection between two devices used for transmitting and receiving information.

[0022] As used in this article, the terms "instantiate" and "instantiate" refer to the creation of an instance. "Instance" also refers to the concrete occurrence of an object, which may occur, for example, during the execution of program code.

[0023] The term "connection" can mean that two or more elements at a common communication protocol layer have an established signaling relationship with each other through a communication channel, link, interface, or reference point.

[0024] As used herein, the term "network element" refers to physical or virtualized equipment or infrastructure used to provide wired or wireless communication network services. The term "network element" may be considered synonymous with or referred to as a networked computer, network hardware, network equipment, network node, or virtualized network function.

[0025] The term "information element" refers to a structural element that contains one or more fields. The term "field" refers to the individual content of an information element, or the data element that contains that content. An information element may include one or more additional information elements.

[0026] Figure 1 A network environment 100 according to some implementation schemes is illustrated. Network environment 100 may include a UE 104, which is communicatively coupled to a base station, such as base station 108. UE 104 and base station 108 can communicate via air interfaces compatible with 3GPP TS, such as those defining fifth-generation (5G) NR system standards. Base station 108 may be a next-generation node B (gNB) to provide one or more 5G New Radio (NR) cells, thereby providing NR user plane and control plane protocol terminals to UE 104.

[0027] In some implementations, base station 108 and one or more additional base stations may be arranged to provide services to UE 104 via a dual connectivity (DC) configuration such as Multiple Radio Access Technology-DC (MR-DC).

[0028] Network environment 100 may also include a core network (CN) 112. For example, CN 112 may include a 5th generation core network (5GC). CN 112 may be coupled to base station 108 via fiber optic or wireless backhaul. CN 112 may provide functionality to UE 104 via base station 108. These functions may include managing subscriber profile information, subscriber location, service authentication, or handover of voice and data sessions.

[0029] Base station 108 may have circuitry, such as BS L2 116, to implement L2 functionality including SDAP, PDCP, RLC, and MAC sublayer functions. Similarly, UE 104 may have circuitry, such as UE L2 120, to implement similar L2 functionality, enabling UE 104 and base station 108 to be communicatively coupled via transport channels, logical channels, RLC channels, radio bearers, and Quality of Service (QoS) streams.

[0030] In short, the MAC sublayer manages scheduling / priority handling, (de)multiplexing, and HARQ processes between logical and transport channels. The RLC sublayer manages (re)segmentation and error correction via Automatic Repeat Request (ARQ) between logical and RLC channels. The PDCP sublayer manages robust header (de)compression and security between radio bearers and RLC channels. Furthermore, the SDAP sublayer manages QoS flow processing between QoS flows and radio bearers. In the downlink, the sublayer converts Service Data Units (SDUs) into Protocol Data Units (PDUs) for use with lower sublayers. In the uplink, the sublayer converts PDUs into SDUs for use with upper sublayers.

[0031] In 3GPP Releases 15, 16, and 17, L2 NR concatenation of SDUs can occur at the MAC sublayer. Specifically, the MAC sublayer can generate MAC PDUs, such as transport blocks, that include multiple MAC SDUs. MAC SDUs can correspond to RLC PDUs from one or more resource blocks (RBs). For example, consider a MAC PDU comprising a first set of RLC PDUs from a first RB (RBx) and a single RLC PDU from a second RB (RBy). Each RLC PDU in the first set can correspond to an IP packet; for example, the first RLC PDU in the first set can correspond to IP packet n, and the second RLC PDU in the first set can correspond to IP packet n+1, while the RLC PDU from RBy corresponds to a segment of IP packet m.

[0032] Cascading at the MAC sublayer can be associated with the advantages of hardware processing at high data rates, but may come at the cost of additional L2 header processing overhead. L2 header processing overhead can include header processing portions for each SDU at multiple sublayers. The time required for payload processing may not be linearly proportional to the payload size. This cost can lead to a significant increase in central processing unit (CPU) load when there are a large number of small packets to be processed. Large numbers of packets can be generated by Transmission Control Protocol (TCP) Acknowledgments (ACKs), Extended Reality (XR) applications, and applications with many small packets, where latency is not critical.

[0033] To address the drawbacks of cascading at the MAC sublayer, embodiments of this disclosure describe cascading at higher sublayers, including cascading at the PDCP and SDAP sublayers.

[0034] The PDCP sublayer supports the following functions: user / control plane data transmission; maintenance of PDCP sequence numbers (SNs); header compression and decompression using the Robust Header Compression (RoHC) protocol; header compression and decompression using the Ethernet Header Compression (EHC) protocol; encryption and decryption; integrity protection and authentication; timer-based SDU dropping; routing first split bearers and dual active protocol stack (DAPS) bearers; replication; reordering and in-order delivery; out-of-order delivery; and duplicate dropping.

[0035] Based on the current PDCP design, the PDCP SDU to PDCP PDU mapping is one-to-one. Each PDCP SDU handles security, and each PDCP PDU adds a PDCP header. The current PDCP design cannot efficiently handle multiple small packets arriving in a short time and being transmitted together.

[0036] Some implementations describe PDCP concatenation when multiple small packets from a Data Radio Bearer (DRB) arrive within a short time and are assembled into a single PDCP PDU. This PDCP concatenation can improve the efficiency of L2 header processing and reduce PDCP processing time by reducing the number of secure processing runs to one. Some implementations may include multiple MAC / RLC / PDCP PDUs, each with one or more concatenated PDCP SDUs. Therefore, the implementation can be used with existing concatenations, such as at the MAC level.

[0037] Figure 2 An L2 processing 200 according to some implementation schemes is shown. L2 processing 200 may include receiving IP packets at the SDAP sublayer. Each IP packet may correspond to an SDAP SDU. The SDAP sublayer may add a header to the SDAP SDU to generate an SDAPPDU.

[0038] Each SDAP PDU can correspond to a PDCP SDU. The L2 processing 200 can also include a PDCP sublayer that cascades multiple PDCPSDUs into a virtual PDCP SDU, which can also be called a cascaded or pseudo-PDCP SDU. As shown in the figure, a virtual PDCP SDU can include three PDCP SDUs. The PDCP sublayer can add headers to the virtual PDCP SDU to generate a PDCPPDU.

[0039] By cascading multiple PDCP SDUs into a single PDCP PDU, L2 processing can be simplified. For example, the PDCP sublayer may only need to: perform one security procedure instead of three; add one Message Authentication Code Integrity (MAC-I) instead of three; and add one header instead of three. Furthermore, the RLC sublayer may also only need to add one header instead of three.

[0040] SDU-level operations performed by the PDCP layer can be performed on virtual PDCP SDUs instead of on individual PDCP SDUs. For example, the PDCP sublayer can encrypt the entire virtual PDCP SDU; and the COUNT used for encryption and integrity protection can increment based on virtual PDCP SDUs instead of individual PDCP SDUs (incrementing by 1 for each virtual PDCP SDU).

[0041] A PDCP PDU can correspond to an RLC SDU. L2 processing 200 can also include an RLC sublayer to generate an RLC PDU by adding a header to the RLC SDU.

[0042] An RLC PDU can correspond to a MAC SDU. L2 processing 200 can also include a MAC sublayer that generates a MAC PDU by adding a header to the MAC SDU. A MAC PDU can correspond to a transport block.

[0043] Assuming the cascading is performed by the PDCP sublayer, the MAC sublayer does not need to cascade more than one RLC PDU into the MACPDU.

[0044] Although the PDCP cascading shown in L2 processing 200 illustrates three PDCPSDUs combined into a single virtual PDCP SDU, other implementations may combine other numbers of PDCP SDUs. For example, some implementations may combine 10 or 100 PDCP SDUs into a single virtual PDCP SDU.

[0045] In some implementations, L2 processing 200 can resemble conventional L2 processing, except for the PDCP cascading at the PDCP sublayer.

[0046] In some implementations, PDCP processes that rely on PDCP SDUs may need to be based on virtual PDCP SDUs. Additionally / alternatively, intermediate SDU conversion steps may be introduced in the 3GPP TS.

[0047] PDCP concatenation can be configured based on several aspects. For example, PDCP concatenation can be enabled for specific DRBs, directions (UL or DL), or service types (such as XR, cloud gaming, TCP ACK, multicast broadcast service (MBS), small data transmission, etc.). In some implementations, UE capability signaling regarding PDCP or SDAP concatenation can be introduced.

[0048] The receiving entity can identify a PDCP PDU that includes a virtual PDCP SDU in various ways. For example, implementations include providing an indication in the PDCP header; relying on IP packet inspection, which is already required by RoHC, to identify the virtual PDCP SDU; or upper-layer packet detection, such as for Ethernet or unstructured non-IP PDU sessions. IP or non-IP packet detection can still benefit from including at least one bit in the PDCP header to indicate whether the PDCP PDU has been concatenated.

[0049] Figure 3 A PDCP PDU 300 according to some implementations is shown. The PDCP PDU 300 may include a header 304 that provides information that allows a receiving entity to determine that the PDCP PDU 300 includes cascaded PDCP SDUs.

[0050] Bit 0 of byte 1 is a bit that indicates whether the PDCP PDU 300 carries data (e.g., a PDCP data PDU) or control (e.g., a PDCP control PDU).

[0051] Bits 1 through 3 of byte 1 are reserved bits in the traditional PDCP header. Reserved bits can be used to define the concatenation type. For example, 000 can indicate that header 304 is a normal PDCP data PDU header, while 001 indicates that header 304 is a concatenated PDCP data PDU header. In other embodiments, bits 1 through 3 can be used as fields to identify various PDCP concatenation parameters as described elsewhere herein.

[0052] In some cases, there may be more than three reserved bits. For example, the PDCP data PDU format for a DRB with an 18-bit PDCP SN may have five reserved bits in octet 1. Therefore, the bit values ​​of the PDCP PDU 300 (for reserved bits, SN bits, or others) are shown as examples only and are not restrictive.

[0053] The header 304 shown in the figure can be a concatenated PDCP data PDU header with a group number field (#group) 308, which indicates the number of PDCP SDUs concatenated to the PDCP PDU 300. In some embodiments, the group number field 308 can be an octet, such as octet 3. The header 304 may also include a length indicator field (LI) 312 to indicate the size of each PDCP SDU. In some embodiments, the length indicator field 312 can be two octets, such as octet 4 and octet 5.

[0054] If all cascaded PDCP SDUs have the same length, a single length indication field 312 may suffice. Therefore, in this case, the group number field 308 may not be necessary. However, the group number field 308 can provide additional flexibility, for example, by allowing PDCP PDU 300 to include PDCP SDUs of different sizes.

[0055] In some implementations, the size of the PDCP SDU can be a pre-configured fixed size. In these implementations, the length indicator field 312 may not be required.

[0056] The length indicator field 312 can be followed by a data field that includes a virtual PDCP SDU with multiple cascaded PDCP SDUs.

[0057] In some implementations, the PDCP PDU 300 may include a second header portion, such as header 320, to define aspects of the second virtual PDCP SDU 324 of the PDCP PDU 300. Header 320 may include a length indication field 328 to indicate the size of each PDCP SDU in the virtual PDCP SDU 324.

[0058] The PDCP PDU 300 can include a MAC-I to perform integrity protection. As shown in the figure, the MAC-I is four bytes.

[0059] In some implementations, RRC configuration can be used to control various aspects of PDCP cascading; for example, RRC configuration can limit the applicability of PDCP SDU cascading to certain situations. In various implementations, the following RRC parameters can be transmitted via RRC configuration (e.g., RRC information elements).

[0060] The first parameter can indicate the maximum number of PDCP SDUs that can be cascaded within a single PDCP PDU. In some implementations, variations in this configuration parameter can provide more granularity. For example, the RRC parameter can indicate how many virtual PDCP SDUs can be included within a PDCP PDU, or how many PDCP SDUs can be included within a virtual PDCP SDU.

[0061] A second parameter, configurable by RRC, can indicate the maximum size of the cascaded PDCP PDU. This can correspond to the size of all virtual PDCP SDUs and headers included in the PDCP PDU. Additionally / optionally, the maximum size of the virtual PDCPSDU can be configured.

[0062] A third parameter, configurable by RRC, indicates the maximum size of a single PDCP SDU that can be cascaded. In some cases, this parameter can be derived from the first and second parameters, but it provides additional flexibility. The third parameter may be necessary when the PDCPPDU includes PDCP SDUs of different sizes.

[0063] The fourth parameter, which can be configured by RRC, can indicate the direction and enablement of PDCP SDU cascading. For example, the fourth parameter can indicate whether PDCP SDU cascading can be applied only in the downlink, only in the uplink, or in both the uplink and downlink.

[0064] In some aspects of this disclosure, the DRB can be configured with a threshold that can be used for PDCP cascading. For example, if the PDCP SDU is smaller than a typical Maximum Transmission Unit (MTU) by a threshold, the transmitter can apply cascading in the PDCP sublayer. The MTU can be configured by the network.

[0065] The configuration parameters described are optional and may not be used in all implementations. Furthermore, one or more of the configuration parameters may be used in conjunction with other configuration parameters or fixed, predefined configurations. For example, fixed rules may be added to the 3GPP TS defining PDCP or RRC operations that enable the device to recognize how to export the maximum size and number of cascaded PDCP SDUs, or whether to limit the maximum size of cascaded PDCP SDUs (e.g., limiting to a PDCP SDU size of 9,000 bytes or to one of a small set of predetermined values).

[0066] The location and method of applying cascading network configurations can be based on the UE capabilities used for SDU cascading. UE 104 can provide an indication of its capabilities for SDU cascading to base station 108 in UE capability signaling. Base station 108 can then determine and provide the appropriate cascading configuration for UE 104 via RRC.

[0067] Figure 4 Variations of PDCP cascades according to some implementation schemes are shown. Specifically, Figure 4 The first PDCP cascading variant 404 and the second PDCP cascading variant 408 are shown. Variants 404 / 408 reduce overhead in L2 processing by associating only one SDAP header with each cascaded PDCP SDU. This may mean that only PDCP SDUs with the same QFI are cascaded within a PDCP SDU. Each PDCP SDU may not require a separate SDAP header. If the SDAP sublayer generates a header, the PDCP sublayer may not need to include that header.

[0068] For variant 404, the PDCP sublayer can remove the SDAP header during cascading. For variant 408, the SDAP sublayer can generate only one SDAP header corresponding to all three SDAP payloads. In both variants, all SDAP headers can include the same content. Therefore, only one SDAP header may be needed for three SDAP payloads.

[0069] Reducing the number of SDAP headers can improve the efficiency of encryption and integrity protection operations at the PDCP sublayer. For example, as shown in PDCP PDU 412, which can be generated based on variant 404 or variant 408, integrity protection can be performed on the PDCP header, SDAP header, and SDAP content, while encryption can be based on the SDAP content and the corresponding MAC-I. Therefore, the complexity of encryption and integrity protection operations can be reduced by removing redundant SDAP headers. Consequently, it may be necessary to perform integrity protection only against a single SDAP header, and it may not be necessary to parse the SDU content on which encryption is based at the header / payload boundary.

[0070] In some options, PDCP SDUs that can be combined in cascaded PDCP PDUs can be based on a sequence of PDCP SDUs. For example, PDCP SDUs can be cascaded sequentially based on IP / non-IP (upper layer) packets. Sequential operation can be configured by RRC or assumed during RoHC activity.

[0071] Additionally / alternatively, a set of PDCP SDUs to be concatenated is defined based on reflection QoS settings, such as reflection Quality of Service (QoS) Indication (RQI) or reflection QoS Flow to Data Radio Bearer Mapping Indication (RDI). For example, for a PDCP SDU with a public QFI, the selection of PDCP SDUs to be concatenated to a PDCP PDU can be terminated if the SDAP header of the PDCP SDU has an RQI / RDI bit group indicating an update to QoS parameters (e.g., QoS rules, reflection QoS (RQ) timers, or QoS Flow to DRB mapping updates), regardless of whether the maximum number of PDCP SDUs that can be concatenated has been reached. A PDCP SDU with a header containing the RQI / RDI bit group can be concatenated with one or more additional PDCP SDUs in subsequent PDCP PDUs. In some implementations, selecting PDCP SDUs for concatenation in this manner can be optional and may depend on the specific network implementation.

[0072] In some implementations, to reduce overhead in L2 processing, concatenation options can be pre-configured in a fixed manner. This can allow for a reduction in the PDCP header, as it may not be necessary to transmit concatenation parameters in the header.

[0073] PDCP (or DRB) can be (pre-)configured with one or more of the following options.

[0074] In the first option, the PDCP (or DRB) can be (pre-)configured with multiple (same-sized) groups to be concatenated with the maximum length indicator; or a fixed set of concatenation conditions that may always be active.

[0075] In the second option, a flexible multidimensional lookup table can be (pre-configured). This table can include sets of parameters corresponding to unique values ​​or identifiers, which can be signaled in one or more bits of the PDCP header. The PDCP header can include values / identifiers pointing to a set of parameters in the lookup table. These parameters can include, for example, multiple PDCP SDUs that can be in a cascaded PDCP PDU; the size of each PDCP SDU; the size of the cascaded PDCP PDUs; the uplink / downlink direction enabling PDCP cascading, etc. In some implementations, a hash function can be used to link identifiers (e.g., hash values / tags) in the header to a set of parameters in the lookup table.

[0076] In the third option, RRC (or another layer) can define multiple cascading modes, where each mode can include, for example, a cascading PDCP PDU of a specific size and a specific number of PDCP SDUs or other cascading parameters. The PDCP header can have a field with a value identifying the mode number. The size of the header field can depend on the number of modes defined. For example, if three modes are defined, the header field can include two bits to provide an identifier for one of the three modes. In this example, a setting of 0b00 could indicate that PDCP cascading is not active.

[0077] In the fourth option, to accommodate a fixed set of concatenation parameters under different radio conditions, PDCP concatenation can be activated / deactivated via a new field in the downlink control signaling. Downlink control signaling can be transmitted from base station 108 to UE 104 via downlink control information (DCI) or MAC control element (CE).

[0078] Figure 5 A first PDCP architecture 500 for PDCP concatenation is illustrated according to some embodiments. The PDCP architecture 500 may include a transport PDCP sublayer 504 for performing PDCP concatenation and a receive PDCP sublayer 508 for performing PDCP demultiplexing. The transport PDCP sublayer 504 may be in UE 104 or base station 108. Similarly, the receive PDCP sublayer 508 may be in UE 104 or base station 108.

[0079] The transmit PDCP sublayer 504 and the receive PDCP sublayer 508 may have circuitry for performing a number of operations, some of which will be described herein. Unless otherwise described, the operations performed by the transmit PDCP sublayer 504 and the receive PDCP sublayer 508 may be similarly named operations as described in 3GPP TS 38.323v16.4.0 (2021-06).

[0080] The transmission PDCP sublayer 504 can provide a transmission (Tx) buffer 512 by storing packets received from higher sublayers (e.g., SDAP layers) in a transmission buffer.

[0081] The transport PDCP sublayer 504 can also provide PDCP concatenation 516 by assembling multiple PDCP SDUs corresponding to packets from the upper layer into a virtual PDCP SDU. PDCP concatenation can be performed when the various conditions described herein are met.

[0082] Following PDCP concatenation 516, the transport PDCP sublayer 504 can perform SN allocation 520 by assigning a PDCP SN to a virtual PDCP SDU. One SN can be provided for each virtual PDCP SDU.

[0083] After SN allocation 520, the transport PDCP sublayer 504 can perform integrity protection 524. Integrity protection 524 can be performed based on virtual PDCPSDU. For example, integrity protection 524 can be performed on the SDAP header and SDAP content included in the virtual PDCP SDU.

[0084] Following integrity protection 524, encryption 528 can be performed at the transport PDCP sublayer 504. Encryption 528 can also be performed based on a virtual PDCP SDU. For example, encryption 528 can be performed on SDAP content and MAC-I.

[0085] After encryption 528, the transport PDCP sublayer 504 can add a PDCP header 532 to the virtual PDCP SDU. The header may include information about the cascading of the virtual PDCP SDU.

[0086] After adding the PDCP header 532, the transport PDCP sublayer 504 can perform routing / replication 536. Routing can be performed on split bearers and DAPS bearers. When the transport PDCP sublayer 508 is configured with PDCP replication information elements (e.g., pdcp-Duplication), replication can be performed on DRBs.

[0087] PDCP PDUs can be provided to lower layers (e.g., RLC sublayer and below) and transmitted via a radio interface (Uu / PC5).

[0088] PDCP operations performed by the transport PDCP sublayer 504 may not include header compression, such as RoHC compression configuration that compresses IP, RTP, and TCP headers. Considering the need for concatenation of non-header-compressed packets and the possibility that compression profiles may not be suitable for multiple PDCP SDUs, header compression can be simply disabled.

[0089] At position 540, the receive PDCP sublayer 508 can remove the PDCP header. During PDCP header removal, the receive PDCP sublayer 508 can identify whether the PDCP PDU carries a virtual PDCP SDU or a traditional PDCP SDU. If the receive PDCP sublayer 508 receives a virtual PDCP SDU, it can also determine the concatenation parameters.

[0090] The receiving PDCP sublayer 508 can perform decryption 544 on the SDAP content and MAC-I of the virtual PDCP SDU, and can perform integrity verification 548 on the SDAP header and SDAP content.

[0091] After integrity verification 548, the receive PDCP sublayer 508 can perform reordering and deduplication 552. PDCP reordering can be done based on the SN associated with the virtual PDCP SDU. The reordered virtual PDCP SDU can be stored in the receive buffer.

[0092] The receive PDCP sublayer can perform PDCP demultiplexing 556 on the virtual PDCP SDU in the receive buffer to derive the PDCP SDU corresponding to the upper-layer packet. Information obtained from the PDCP header can help derive the PDCP SDU from the virtual PDCP SDU described herein.

[0093] After PDCP demultiplexing 556, the receiving PDCP sublayer 508 can provide PDCP SDU to the upper sublayer, such as the SDAP layer.

[0094] Figure 6 A second PDCP architecture 600 for PDCP concatenation is illustrated according to some embodiments. PDCP architecture 600 may include a transport PDCP sublayer 604 for performing PDCP concatenation and a receive PDCP sublayer 608 for performing PDCP demultiplexing. The transport PDCP sublayer 604 may be in UE 104 or base station 108. Similarly, the receive PDCP sublayer 608 may be in UE 104 or base station 108.

[0095] The transport PDCP sublayer 604 can perform operations similar to those described above for the transport PDC sublayer 504. Specifically, the transport PDCP sublayer 604 can perform operations similar to those described above for the transport PDCP sublayer 504, such as transport buffering 612, PDCP concatenation 616, SN allocation 620, integrity protection 624, encryption 628, adding PDCP headers 632, and routing / replication 636. However, in this embodiment, the transport PDCP sublayer 604 can also perform header compression 614 after the transport buffering 612. Header compression 614 can be performed on the PDCP SDU corresponding to the upper-layer packet. Header compression 614 can include RoHC based on RoHC compression configuration to compress the IP, RTP, and TCP headers within the PDCP SDU.

[0096] After header compression 614, PDCP cascading 616 can assemble PDCP SDUs with compressed headers into virtual PDCP SDUs.

[0097] The receive PDCP sublayer 608 can perform operations similar to those described above for the receive PDC sublayer 608. Specifically, the receive PDCP sublayer 608 can perform operations similar to those described above for the receive PDCP sublayer 508, including removing the PDCP header 640, decryption 644, integrity verification 648, reordering and deduplication 652, and PDCP demultiplexing 656. However, after recovering the PDCP SDU from PDCP demultiplexing 656, the receive PDCP sublayer 608 can perform header decompression 658 to decompress the IP, RTP, or TCP header compressed in header compression 614.

[0098] Information can be provided to the PDCP PDU header to help the receiving PDCP sublayer identify whether PDCP demultiplexing is performed. For example, fields in the header can indicate whether the PDCP PDU includes a virtual PDCP SDU (which has more than one PDCP SDU) or includes a single PDCP SDU.

[0099] When a PDCP PDU includes a virtual PDCP SDU, additional information can be provided in the header of the virtual PDCP SDU to assist the receiving PDCP sublayer in demultiplexing the virtual PDCP SDU to derive each PDCP SDU / upper-layer packet. In some implementations, the header of the virtual PDCP SDU may include multiple concatenated packets (which may correspond to a complete PDCP SDU, since segments may not be used as part of the concatenation process); and the length of each concatenated packet.

[0100] In some implementations, the network can impose certain restrictions on cascaded PDCP SDUs. This can improve the efficiency of signaling cascading information in the header.

[0101] Figure 7 A PDCP PDU 700 according to some embodiments is shown. The PDCP PDU 700 may include a PDCP PDU header 704, a virtual PDCP SDU header 708, a virtual PDCP SDU payload 712, and an optional MAC-I 716. The virtual PDCP SDU payload 712 may include n PDCP SDUs.

[0102] The PDCP PDU header may include a field that indicates that the PDCP PDU 700 includes a virtual PDCP SDU (e.g., C=1).

[0103] The virtual PDCP SDU header can include concatenation information in one or more fields to aid in the demultiplexing of the virtual PDCP SDU to export PDCP SDUs #1 to #n. The concatenation information can be transmitted according to option 1 720 or option 2 724.

[0104] In option 1 720, the cascading information can indicate the size of each PDCP SDU included in the virtual PDCP SDU. For example, the cascading information can include the length of PDCP SDU#1, the length of PDCP SDU#2, ..., the length of PDCP SDU#n.

[0105] In option 2 724, the concatenation information can indicate the number and size of PDCP SDUs included in the virtual PDCP SDU. Using this option, the PDCP SDU size can be applied to the PDCPSDU of the virtual PDCP SDU payload 712. In some implementations, the PDCP SDU size can be fixed by the network configuration; in this case, it may only be necessary to indicate the number of PDCP SDUs.

[0106] In the third option, explicit concatenation information can be omitted from the virtual PDCP SDU header. Instead, the network can be configured with a fixed PDCP SDU size and number.

[0107] In some implementations, various conditions can be defined to activate or deactivate PDCP concatenation. As mentioned above, one benefit of PDCP concatenation is reduced L2 overhead. However, this benefit may be diminished if the PDCP concatenation size is too large to be segmented in the RLC sublayer. Therefore, in some cases, this benefit is most suitable for transmitting multiple small data packets within a short time period. Infrequent data transmission or transmission of large packets may not benefit from PDCP concatenation. Options for activating PDCP concatenation are provided below.

[0108] In the first option, PDCP concatenation can be based on a timer. For example, only packets received from SDAP within a configured time period can be concatenated. For instance, the transport PDCP sublayer can start a timer when a packet is received from the SDAP sublayer. If additional packets are received before the timer expires, the transport PDCP sublayer can perform PDCP concatenation on the first packet and any additional packets received before the timer expires. PDCP concatenation can be limited by other conditions, such as the size or number of PDCP SDUs that can be concatenated.

[0109] In the second option, PDCP concatenation can be based on PDCP SDU / packet size. For example, only packets with a size equal to or smaller than the configured packet size can be considered for PDCP concatenation. If the transport PDCP sublayer determines that the packet size is larger than the configured packet size, the transport PDCP sublayer can perform conventional behavior (e.g., forming a PDCP PDU with one PDCP SDU).

[0110] In the third option, PDCP concatenation can be based on the virtual PDCP SDU size or the micro uplink grant size. For example, the virtual PDCP SDU size can be limited to no more than a configured threshold size. The transport PDCP sublayer can assemble PDCP SDUs into virtual PDCP SDUs, provided that the resulting virtual PDCP SDUs do not exceed the configured threshold size. In some implementations, the configured threshold size may correspond to a PDCP PDU that includes one or more virtual PDCP SDUs.

[0111] In the fourth option, PDCP concatenation can be based on radio quality. For example, PDCP concatenation can be disabled when radio quality is below a pre-configured threshold. Under poor radio conditions, the base station can add significant error protection and / or limit available power at the PHY level. Therefore, the number of bytes that can be accommodated in a MAC PDU is typically smaller in this case, as the network may not provide a large MAC PDU size for transmission. For example, the UE may experience a small license size at the cell edge (or under other conditions, such as congestion or when serving multiple other higher-priority transmissions). If the final PDCP PDU is too large to be segmented in the RLC, the benefits will be lost.

[0112] In some implementations, a PDCP SDU discarding mechanism can be defined for PDCP cascading.

[0113] In traditional operation, a PDCP SDU discard timer is maintained for each PDCP SDU to control the lifetime of each packet in the access layer. The transport PDCP sublayer can start the discard timer when a PDCP SDU is received from an upper layer. The transport PDCP sublayer can discard the PDCP SDU when its discard timer expires or when the PDCP SDU is confirmed as successfully delivered by a PDCP status report. The implementation describes two options for handling the discard timer of virtual PDCP SDUs.

[0114] In the first option, a drop timer can be maintained for each virtual PDCP SDU. The transport PDCP sublayer can start the PDCP drop timer when the virtual PDCP SDU is generated. When the drop timer expires, or if the virtual PDCP SDU is confirmed as successfully delivered by a PDCP status report, the transport PDCP sublayer can discard the virtual PDCP SDU and all associated packets.

[0115] In the second option, a discard timer can be maintained for each PDCP SDU, similar to the description of conventional operation above. For example, the transport PDCP sublayer can start a PDCP discard timer when a packet / PDCP SDU is received from an upper layer. If the discard timer for the first PDCP SDU expires after a virtual PDCP SDU carrying the first PDCP SDU is delivered by a lower layer, the transport PDCP sublayer may not discard the first PDCP SDU.

[0116] If, after generating a virtual PDCP SDU carrying the first PDCP SDU, the discard timer for the first PDCP SDU expires before the virtual PDCP SDU is confirmed as successfully delivered by the PDCP status report, the transport PDCP sublayer can discard the first PDCP SDU. This can be done by discarding the virtual PDCP SDU (along with all its PDCP SDUs) and regenerating a virtual PDCP SDU without the first PDCP SDU. Alternatively, the transport PDCP sublayer can retain the first PDCP SDU within the virtual PDCP SDU and mark it as discarded / invalid, or replace it with padding bits that are not interpreted as actual transmission by the receiving PDCP sublayer.

[0117] In some implementation schemes, PDCP SDU retransmission can be considered in conjunction with PDCP cascading.

[0118] During a mobility event, a UE may change its association with a first base station to a second base station. The UE may then need to re-establish the PDCP entity connection with the second base station. When re-establishing the PDCP Acknowledgment Mode (AM) entity, the transmission device may perform PDCP SDU retransmissions in certain situations. For example, the transmission device may (re)transmit all PDCP SDUs in ascending order of the COUNT value from the first PDCP SDU, for which there was no acknowledgment of successful delivery of the corresponding PDCP data PDU. The implementation describes how (re)transmissions are handled in the case of virtual PDCP SDUs.

[0119] In some implementations, when the PDCP AM entity is re-established, the transport entity can perform PDCP SDU retransmissions based on the new configuration (e.g., the configuration used when the PDCP AM entity was re-established) for all virtual PDCP SDUs that were not delivered (or delivered but not acknowledged). For example, if PDCP concatenation is not configured, the transport entity will perform traditional PDCPSDU retransmissions.

[0120] In one option, when a PDCP entity is configured for PDCP concatenation, the PDCP entity may not be configured with PDCP status reporting (statusReportRequired). If it is necessary to retransmit a virtual PDCP SDU transmitted using the first SN, the virtual PDCP SDU can be retransmitted using the new SN.

[0121] In the second option, when a PDCP entity is configured for PDCP concatenation, the PDCP entity can be configured with PDCP status reporting (statusReportRequired). A PDCP entity configured with PDCP status reporting allows receiving devices to receive packets out of order, and the PDCP transmitting device can retransmit only packets that were not successfully delivered. For a virtual PDCP SDU with PDCP SN#X, when indicating a fallback to a traditional PDCP SDU for retransmission in a new cell, all associated packets can use the same PDCP SN. However, the PDCP PDU header can include a sub-SN value to indicate the packet order in the previous virtual PDCP SDU.

[0122] Figure 8 The retransmission operation 800 according to some implementation schemes is shown.

[0123] In the first instance, PDCP PDU 804 is transmitted along with a PDCP header indicating SN=X. PDCP PDU 804 may also include a virtual PDCP SDU 808, which includes a header (V-SDU header) and three PDCP SDUs, namely PDCP SDU #1 to #3.

[0124] In cases where retransmission is required, where retransmission using a fallback to a traditional PDCP SDU is used, three PDCPPDUs can be generated: PDCP PDU 812, PDCP PDU 816, and PDCP PDU 820. Each of these PDCP PDUs may include a header with SN=X, but they may also include sequence information. Specifically, PDCP PDU 812 may have sequence=1 to indicate that its PDCP SDU is the first SDU in virtual PDCP SDU 808; PDCP PDU 816 may have sequence=2 to indicate that its PDCP SDU is the second SDU in virtual PDCP SDU 808; and PDCP PDU 820 may have sequence=3 to indicate that its PDCP SDU is the third SDU in virtual PDCP SDU 808.

[0125] In some implementations, data forwarding during handover between nodes can be handled for PDCP concatenation.

[0126] During handover, the source gNB can forward UE data to the target gNB at the DRB level. In the downlink, for all packets without PDCP SN reservation, the source gNB can forward QoS flows to the target gNB based on the QoS flow-to-DRB mapping in the source gNB. For DRBs where SN state preservation is applied, the source gNB can forward PDCP SDUs with SNs corresponding to PDCP PDUs that have not been acknowledged by the UE to the target gNB. In the uplink, PDCP PDUs received out of order in the source gNB may or may not be forwarded to the target gNB. This depends on whether out-of-order forwarding is enabled.

[0127] Various implementation schemes describe how virtual PDCP SDU data forwarding is handled during handover between base stations if PDCP concatenation is supported / configured.

[0128] In some implementations, a unified solution can be described for all possible PDCP cascading configuration changes (e.g., enabling / disabling or changing configuration parameters).

[0129] In the first option, out-of-order data forwarding can be disabled (e.g., PDCPSDUs with SN preservation can be discontinued). All data transmitted via the X2 / Xn interface is a PDCP SDU without SN allocation. Therefore, a virtual PDCP SDU transmitted with the first SN can be retransmitted with a new SN.

[0130] In the second option, out-of-order data forwarding can be supported (e.g., PDCPSDUs without SN forwarding in the X2 / Xn interface). If both the source gNB and the destination gNB support PDCP concatenation, then for the X2 / Xn interface, a virtual PDCP SDU flag can be added to the header of each packet to help the destination gNB identify whether the packet includes a virtual PDCP SDU or a traditional PDCPSDU.

[0131] If the source gNB enables PDCP concatenation and has a virtual PDCP SDU with an assigned SN for forwarding, but the destination gNB does not support PDCP concatenation, then as described above, the transmission device may not configure PDCP status reports (statusReportRequired) for PDCP entities configured with PDCP concatenation, and may not support out-of-order data forwarding.

[0132] While the above implementation describes concatenation at the PDCP sublayer, other implementations may include SDAP concatenation occurring directly at the SDAP sublayer level. The SDAP sublayer supports the following functions: mapping between QoS flows and data radio bearers; and marking QoS flow identifiers (QFIs) in downlink and uplink packets.

[0133] Similar to PDCP concatenation, SDAP SDUs eligible for concatenation can have a common QFI. The SDAP header may include one or more additional octet bytes of extension in the SDAP data PDU. Concatenation information enabling SDAP concatenation can be transmitted in SDAP header fields, such as those described above. Figure 3 The description of the PDCP header fields; or the (pre-configured) configuration as described elsewhere regarding PDCP cascading. In these implementations, SDAP instead of PDCP can be configured for DRB cascading; however, the principles of PDCP cascading described herein can be applied to SDAP cascading. All additional components, RRC configurations, and extra PDCP cascading options can be applied to SDAP cascading in a similar manner. Furthermore, RRC can be configured with a set of cascading options based on QFI. For example, different QFIs can have different cascading rules.

[0134] The presence of the SDAP header is optional in 3GPP and can depend on specific requirements for the DRB, such as the number of QoS flows in the uplink, 5GC-based network deployment, reflection QoS, etc. To illustrate the optional presence of the SDAP header, some implementations describe SDAP concatenation even when the SDAP header is not configured or present. In a first option, PDCP concatenation and SDAP concatenation can be used in combination. For example, SDAP concatenation can be used for a DRB in which the SDAP header is configured, while PDCP concatenation can be used for other DRBs. In a second option, the SDAP header can be included as long as concatenation is enabled at the SDAP level. For example, when SDAP concatenation is active, the use of the SDAP header can be forced.

[0135] The advantages of SDAP cascading can include not having to change the COUNT process and not having to change the PDCP process.

[0136] Figure 9 An SDAP cascade 900 is illustrated according to some implementation schemes. The IP sublayer can provide three packets, each with an IP header and a payload. Each packet can correspond to an SDAP SDU in the SDAP sublayer. The SDAP sublayer can generate virtual SDAP SDUs to include the three SDAP SDUs, all of which can include the same QFI.

[0137] The SDAP sublayer can generate SDAP PDUs by providing both a traditional SDAP header and a new SDAP header. The new SDAP header may include concatenation information that facilitates the receiving entity in processing the virtual SDAP SDU to recover the individual SDAP SDUs.

[0138] The PDCP sublayer can receive an SDAP PDU as a PDCP SDU, which includes the SDAP SDU content and SDAP header. The PDCP sublayer can generate a PDCP PDU based on a PDCP SDU consistent with conventional operations. The PDCP sublayer can perform encryption / integrity based on the received PDCP SDU.

[0139] Additional aspects regarding the RQI and RDI bits in the SDAP header can be considered. Given that RDI is applied to QoS flow-to-DRB mapping, the handling of the RQI bits may be more relevant than the RDI bits used for SDAP concatenation. For example, if the QoS flow-to-DRB mapping is changed via reflected QoS, there may be new PDCP PDUs in any case. However, the RQI bits may need to be kept associated with the exact corresponding upper-layer SDU used to update QoS rules or RQ timers. Furthermore, it may be desirable to avoid losing the relationship between the original SDU, QFI, and RDI / RQI bits.

[0140] In the first option, given a list of SDUs to be cascaded at the transmitter, SDUs can be cascaded as long as the legacy SDAP headers are the same (and the corresponding maximum number of SDUs has not been reached). The cascading boundary can be determined based on the legacy SDAP header content (e.g., QFI, RDI, or RQI) associated with the SDUs to be cascaded, which changes in a way that requires updating QoS flows to DRB mappings, RQ timers, or QoS rules. For example, if the legacy SDAP header content in SDU n changes as described above, then SDU n-1 could be the last SDU included in the first virtual SDAP SDU, and SDU n could be the first SDU in the second virtual SDAP SDU. In this case, the number of SDAP SDUs in the first virtual SDAP SDU can be less than the configured maximum number of SDAP SDUs that can be cascaded to the virtual SDAP SDUs.

[0141] In the second option, if the RQI bits associated with the SDU to be cascaded are set in a manner that triggers an update of the QoS rules or a restart of the RQ timer when the QFI is the same, the new / extended SDAP header may include a new field to identify the exact SDU to be associated with the RQI setting of such a cascaded PDU. The exact SDU can be identified by the SDU sequence number.

[0142] In the third option, the RQI or RDI bit can be set in a single traditional SDAP header, and this bit can be applied to all cascaded SDUs in the same way. In this way, the granularity of RQI / RDI can be at the level of the cascaded PDUs.

[0143] These three options can vary depending on the specific network implementation of RQI / RDI. In some implementations, these options can also be applied to PDCP cascading.

[0144] In some implementations, cascading may be limited to transmissions on certain interfaces between certain devices or network nodes.

[0145] In the first option, PDCP / SDAP cascading can be limited to the Uu interface between the UE and the base station, or in some implementations, it can be limited to Integrated Access and Backhaul-Mobile Terminal (IAB-MT) and Integrated Access and Backhaul-Distributed Unit (IAB-DU).

[0146] In the second option, PDCP / SDAP cascading can be used on the F1 interface (between the gNB Distributed Unit (DU) and the gNB Central Unit (CU),) the E1 interface (between the CU control plane and the CU data plane), the X2 interface (between base stations), and the Xn interface (between gNB CUs). Therefore, communication on these interfaces can be performed using the sequence number of the cascaded SDU from the UE.

[0147] In some implementations, if the terminating gNB also supports SDU concatenation, the concatenated F1 / E1 / X2 / Xn operations can be transparent. If one node does not support SDU concatenation while the other does (e.g., via the Uu interface), the base station may need to support the switching function.

[0148] During handover, if forwarding is used, it may be expected that the source gNB knows whether the target gNB supports concatenation. If the target gNB supports concatenation, the source gNB can forward the concatenated PDUs. If the target gNB does not support concatenation, the source gNB may only need to forward the non-concatenated (e.g., conventional) PDUs. For example, consider a source gNB initially transmitting multiple PDCPSDUs in a virtual PDCP SDU, and then determining that the UE is handing over to the target gNB before determining that the virtual PDCP SDU has been successfully delivered. If the target gNB supports concatenation, the source gNB can simply forward the virtual PDCP SDU to the target gNB. However, if the target gNB does not support concatenation, the source gNB may generate multiple PDCP PDUs that merge the multiple PDCP SDUs separately, and transmit the multiple PDCPPDUs to the target gNB according to conventional operation.

[0149] In some implementations, SDU concatenation can be applied or specified in such a way that it is only effective if it does not cause fragmentation at lower layers. However, other implementations may include full support for fragmentation. For example, if RLC retransmission within the granted size would lead to fragmentation because different transport block sizes are available for initial RLC transmission and RLC retransmission, then fragmentation may be allowed.

[0150] Figure 10 A UE 1000 according to some implementation schemes is shown. UE 1000 may be similar to Figure 1 The UE 106 is essentially interchangeable with it.

[0151] The UE 1000 can be any mobile or non-mobile computing device, such as, for example, a mobile phone, computer, tablet, XR device, glasses, industrial wireless sensors (e.g., microphone, carbon dioxide sensor, pressure sensor, humidity sensor, thermometer, motion sensor, accelerometer, laser scanner, fluid level sensor, stock sensor, voltmeter / ammeter, or actuator), video surveillance / monitoring device (e.g., camera or camcorder), wearable device (e.g., smartwatch), or Internet of Things device.

[0152] UE 1000 may include a processor 1004, RF interface circuitry 1008, memory / storage device 1012, user interface 1016, sensor 1020, drive circuitry 1022, power management integrated circuit (PMIC) 1024, antenna structure 1026, and battery 1028. The components of UE 1000 may be implemented as integrated circuits (ICs), portions of integrated circuits, discrete electronic devices or other modules, logic components, hardware, software, firmware, or combinations thereof. Figure 10 The block diagram is intended to show a high-level view of some of the components of the UE 1000. However, some of the components shown may be omitted, additional components may be present, and different arrangements of the components shown may occur in other specific implementations.

[0153] Components of UE 1000 can be coupled to various other components via one or more interconnects 1032, which can represent any type of interface, input / output, bus (local, system, or extension), transmission line, trace, or optical connector, allowing various circuit components (on common or different chips or chipsets) to interact with each other.

[0154] Processor 1004 may include processor circuitry such as baseband processor circuitry (BB) 1004A, central processing unit circuitry (CPU) 1004B, and graphics processing unit circuitry (GPU) 1004C. Processor 1004 may include any type of circuitry or processor circuitry that executes or otherwise operates computer-executable instructions (such as program code, software modules, or functional processes from memory / storage device 1012) to cause UE 1000 to perform the operations described herein.

[0155] In some implementations, the baseband processor circuit 1004A can access the communication protocol stack 1036 in the memory / storage device 1012 to communicate over a 3GPP-compliant network. Generally, the baseband processor circuit 1004A can access the communication protocol stack 1036 to perform the following operations: user plane functions at the PHY, MAC, RLC, PDCP, SDAP, and PDU layers; and control plane functions at the PHY, MAC, RLC, PDCP, RRC, and NAS layers. In some implementations, PHY layer operations may additionally / optionally be performed by components of the RF interface circuit 1008.

[0156] The baseband processor circuit 1004A can generate or process baseband signals or waveforms carrying information in a 3GPP-compliant network. In some implementations, the waveforms used for NR can be based on cyclic prefix OFDM (CP-OFDM) in the uplink or downlink, and Discrete Fourier Transform Extended OFDM (DFT-S-OFDM) in the uplink.

[0157] The memory / storage device 1012 may include one or more non-transitory computer-readable media, including instructions (e.g., a communication protocol stack 1036) that can be executed by one or more processors in processor 1004 to cause UE 1000 to perform the various operations described herein. The memory / storage device 1012 includes any type of volatile or non-volatile memory that can be distributed throughout UE 1000. In some embodiments, some of the memory / storage devices 1012 may be located on processor 1004 itself (e.g., L1 cache and L2 cache), while other memory / storage devices 1012 may be located external to processor 1004 but accessible via a memory interface. The memory / storage device 1012 may include any suitable volatile or non-volatile memory, such as, but not limited to, dynamic random access memory (DRAM), static random access memory (SRAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, solid-state memory, or any other type of memory device technology.

[0158] The RF interface circuit 1008 may include transceiver circuitry and a radio frequency front-end module (RFEM), which allows the UE 1000 to communicate with other devices via a radio access network. The RF interface circuit 1008 may include various components arranged in the transmit or receive path. These components may include, for example, switches, mixers, amplifiers, filters, synthesizer circuitry, and control circuitry.

[0159] In the receiving path, the RFEM can receive the radiated signal from the air interface via antenna structure 1026 and continue to filter and amplify the signal (using a low-noise amplifier). This signal can be provided to the receiver of the transceiver, which downconverts the RF signal into a baseband signal that is provided to the baseband processor of processor 1004.

[0160] In the transmission path, the transceiver's transmitter upconverts the baseband signal received from the baseband processor and provides the RF signal to the RFEM. The RFEM amplifies the RF signal using a power amplifier before it is radiated across the air interface via antenna 1026.

[0161] In various implementations, the RF interface circuit 1008 can be configured to transmit / receive signals in a manner compatible with NR access technology.

[0162] Antenna 1026 may include antenna elements to convert electrical signals into radio waves for propagation through the air and to convert received radio waves back into electrical signals. These antenna elements may be arranged in one or more antenna panels. Antenna 1026 may have omnidirectional, directional, or combinations thereof antenna panels to enable beamforming and multiple-input / multiple-output communication. Antenna 1026 may include a microstrip antenna; a printed antenna fabricated on the surface of one or more printed circuit boards; a patch antenna; or a phased array antenna. Antenna 1026 may have one or more panels designed for a specific frequency band, including those in FR1 or FR2.

[0163] User interface circuitry 1016 includes various input / output (I / O) devices designed to enable users to interact with UE 1000. User interface circuitry 1016 includes input device circuitry and output device circuitry. Input device circuitry includes any physical or virtual means for accepting input, particularly including one or more physical or virtual buttons (e.g., a reset button), a physical keyboard, a keypad, a mouse, a touchpad, a touchscreen, a microphone, a scanner, a headset, etc. Output device circuitry includes any physical or virtual means for displaying information or otherwise conveying information (such as sensor readings, actuator positions, or other similar information). Output device circuitry may include any number or combination of audio or visual displays, particularly including one or more simple visual outputs / indicators (e.g., binary status indicators such as light-emitting diodes (LEDs) and multi-character visual outputs), or more complex outputs such as display devices or touchscreens (e.g., liquid crystal displays (LCDs), LED displays, quantum dot displays, and projectors), wherein the output of characters, graphics, multimedia objects, etc., is generated or produced by the operation of UE 1000.

[0164] Sensor 1020 may include devices, modules, or subsystems designed to detect events or changes in their environment and transmit information about the detected events (sensor data) to other devices, modules, or subsystems. Examples of such sensors include: inertial measurement units including accelerometers, gyroscopes, or magnetometers; microelectromechanical systems (MEMS) or nanoelectromechanical systems (NEMS) including triaxial accelerometers, triaxial gyroscopes, or magnetometers; level sensors; flow sensors; temperature sensors (e.g., thermistors); pressure sensors; barometric pressure sensors; gravimeters; altimeters; image capture devices (e.g., cameras or lensless aperture sensors); light detection and ranging sensors; proximity sensors (e.g., infrared radiation detectors, etc.); depth sensors; ambient light sensors; ultrasonic transceivers; and microphones or other similar audio capture devices.

[0165] The driving circuit 1022 may include software and hardware elements for controlling specific devices embedded in, attached to, or otherwise communicatively coupled to the UE 1000. The driving circuit 1022 may include various drivers that allow other components to interact with or control various input / output (I / O) devices that may exist within or be connected to the UE 1000. For example, the driving circuit 1022 may include: a display driver for controlling and allowing access to a display device; a touchscreen driver for controlling and allowing access to a touchscreen interface; a sensor driver for acquiring sensor readings of the sensor circuit 1020 and controlling and allowing access to the sensor circuit 1020; a driver for acquiring actuator positions of electromechanical components or controlling and allowing access to electromechanical components; a camera driver for controlling and allowing access to an embedded image capture device; and an audio driver for controlling and allowing access to one or more audio devices.

[0166] The PMIC 1024 manages the power supplied to various components of the UE 1000. Specifically, relative to the processor 1004, the PMIC 1024 controls power selection, voltage scaling, battery charging, or DC-DC conversion.

[0167] In some implementations, the PMIC 1024 may control or otherwise become part of various power-saving mechanisms of the UE 1000, including DRX, as discussed herein.

[0168] Battery 1028 can power UE 1000, but in some examples, UE 1000 may be mounted in a fixed location and may have a power source coupled to the mains. Battery 1028 may be a lithium-ion battery, a metal-air battery such as a zinc-air battery, an aluminum-air battery, a lithium-air battery, etc. In some specific implementations, such as in vehicle-based applications, battery 1028 may be a typical lead-acid automotive battery.

[0169] Figure 11 A network device 1100 according to some embodiments is shown. The network device 1100 may be similar to... Figure 1 The equipment of base station 108 or core network 112 is basically interchangeable with it.

[0170] Network device 1100 may include processor 1104, RF interface circuitry 1108 (if implemented as a base station), core network (CN) interface circuitry 1112, memory / storage device circuitry 1116, and antenna structure 1126 (if implemented as a base station).

[0171] Components of network device 1100 can be coupled to various other components via one or more interconnects 1128.

[0172] The processor 1104, RF interface circuit 1108, memory / storage device circuit 1116 (including communication protocol stack 1110), antenna structure 1126, and interconnect 1128 are similar to those in the reference. Figure 10 Similar named components are shown and described. If device 1100 is implemented as a base station, then communication protocol stack 1110 may include an access layer. If network device 1100 is implemented as a device in core network 112, then communication protocol stack 1110 may include a NAS layer.

[0173] The CN interface circuit 1112 can provide connectivity to a core network (e.g., a 5th generation core network (5GC) using a 5GC-compatible network interface protocol (such as Carrier Ethernet) or some other suitable protocol). Network connectivity can be provided to / from base station 1100 via fiber optic or wireless backhaul. The CN interface circuit 1112 may include one or more dedicated processors or FPGAs for communicating using one or more of the aforementioned protocols. In some implementations, the CN controller circuit 1112 may include multiple controllers for providing connectivity to other networks using the same or different protocols.

[0174] In some implementations, base station 1100 may be coupled to transmit-receive point (TRP) using antenna structure 1126, CN interface circuitry or other interface circuitry.

[0175] As is widely recognized, the use of personally identifiable information should comply with privacy policies and practices that are generally accepted to meet or exceed industry or governmental requirements for protecting user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of authorized use should be clearly explained to users.

[0176] For one or more embodiments, at least one of the components shown in one or more of the foregoing figures may be configured to perform one or more operations, techniques, processes, or methods as described in the Examples section below. For example, the baseband circuitry described above in conjunction with one or more of the foregoing figures may be configured to operate according to one or more of the examples below. As another example, circuitry associated with the UE, base station, or network element described above in conjunction with one or more of the foregoing figures may be configured to operate according to one or more of the examples shown in the Examples section below.

[0177] Example

[0178] Further exemplary implementations are provided in the following sections.

[0179] Example 1 includes a method comprising: identifying a plurality of Packet Data Convergence Protocol (PDCP) Service Data Units (SDUs); generating PDCP Packet Data Units (PDUs) to include the plurality of PDCP SDUs and a header having a field having a value indicating that the PDCP PDUs are concatenated; and providing the PDCP PDUs to a Radio Link Control (RLC) sublayer for transmission.

[0180] Example 2 includes the method according to Example 1 or some other embodiment herein, wherein the header further includes: a group number field having a value indicating the number of PDCP SDUs in the PDCP PDU.

[0181] Example 3 includes the method according to Example 2 or some other embodiment herein, wherein the header further includes: a length field having a value indicating the length of each PDCP SDU in the number of PDCP SDUs.

[0182] Example 4 includes the method according to Example 1 or some other embodiment herein, wherein the plurality of PDCPSDUs includes a first group of one or more PDCP SDUs and a second group of one or more PDCP SDUs, and the header further includes: a first group number field having a value indicating the number of PDCP SDUs in the first group; a first length field having a value indicating the length of each PDCP SDU in the first group of one or more PDCP SDUs; and a second length field having a value indicating the length of each PDCP SDU in the second group of one or more PDCP SDUs.

[0183] Example 5 includes the method according to Example 4 or some other embodiment herein, wherein the header further includes: a second group number field having a value indicating the number of PDCP SDUs in the second group.

[0184] Example 6 includes the method according to Example 1 or some other embodiment herein, the method further comprising: identifying parameters pre-configured or signaled by a Radio Resource Control (RRC) message indicating the maximum number of PDCP SDUs that can be cascaded in a PDCP PDU; the maximum size of a PDCP PDU; the maximum size of a PDCP SDU that can be cascaded in a PDCP PDU; or the uplink or downlink direction that allows the cascading of PDCP SDUs.

[0185] Example 7 includes the method according to Example 1 or some other embodiment herein, the method further comprising: transmitting or receiving an indication of the PDCP cascading capability of the user equipment.

[0186] Example 8 includes the method according to Example 1 or some other embodiment herein, the method further comprising: identifying a plurality of Service Data Adaptation (SDAP) PDUs, each SDAP PDU having its own SDAP header and payload; determining that the plurality of SDAP headers have a common Quality of Service Flow Identifier; and generating the plurality of PDCP SDUs based on the determination to include an SDAP header and the plurality of payloads.

[0187] Example 9 includes the method according to Example 1 or some other embodiment herein, the method further comprising: identifying a plurality of Service Data Adaptation (SDAP) PDUs, each SDAP PDU having a common header and a respective payload; and generating the plurality of SDAP PDUs based on the determination to include the common header and the plurality of payloads.

[0188] Example 10 includes the method according to Example 1 or some other embodiment herein, wherein the value provides an identifier, and the method further includes: accessing a lookup table or a plurality of predefined patterns based on the identifier to determine one or more cascading parameters; and generating the PDCP PDU based on the one or more cascading parameters.

[0189] Example 11 includes the method according to Example 1 or some other embodiment herein, the method further comprising: receiving an indication that PDCP concatenation is activated in downlink control information or media access control control elements; and generating the PDCP PDU based on the indication.

[0190] Example 12 includes the method according to Example 1 or some other embodiment herein, wherein the PDCPPDU is a first PDCP PDU, the plurality of PDCP SDUs are a first plurality of PDCP SDUs, and the method further includes: identifying a second plurality of PDCP SDUs in a sequence, the second plurality of PDCP SDUs including the first plurality of PDCP SDUs; determining that the first PDCPPDU includes a reflected Quality of Service (QoS) Indicator (RQI) or a reflected QoS Flow to Data Radio Bearer Mapping Indicator (RDI) bit indicating an update of a Quality of Service parameter; based on the determination, setting a second PDCP SDU immediately preceding the first PDCP SDU in the sequence as the last PDCP SDU to be included in the first plurality of PDCP SDUs for concatenation to the first PDCP PDU; and generating a second PDCP PDU to include at least one additional PDCP SDU from the first PDCP SDU and the second plurality of PDCP SDUs.

[0191] Example 13 includes the method according to Example 1 or some other example herein, wherein the PDCPPDU will be transmitted via: a Uu interface between the user equipment and the base station; an F1 interface between the gNB distributed unit (DU) and the gNB central unit (CU); an E1 interface between the CU control plane and the CU data plane; an X2 interface between base stations or an Xn interface between gNB CUs.

[0192] Example 14 includes the method according to Example 1 or some other embodiment herein, wherein the method is performed by a source base station, the PDCP PDU is to be transmitted to a user equipment (UE), and the method further includes: determining that the UE is handing over to a target base station; determining whether the target base station supports concatenation; and based on the determination that the target base station supports concatenation, forwarding the plurality of PDCP SDUs in the PDCP PDU or in the plurality of corresponding PDCP PDUs.

[0193] Example 15 includes the method according to Example 1 or some other embodiment herein, the method further comprising: determining that the cascading of the plurality of PDCP SDUs will not result in lower-level segmentation; and generating the PDCP PDU to include the plurality of PDCP SDUs based on the determination.

[0194] Example 16 includes the method according to Example 1 or some other embodiment herein, the method further comprising: generating cascaded PDCP SDUs to include the plurality of PDCP SDUs; and performing encryption and integrity protection on the cascaded PDCP SDUs.

[0195] Example 17 includes a method comprising: identifying a plurality of Service Data Adaptation (SDAP) Service Data Units (SDUs); generating an SDAP PDU to include the plurality of SDAP SDUs and a header having a field having a value indicating that the SDAP PDUs are concatenated; and providing the SDAP PDUs to a Packet Data Convergence Protocol (PDCP) sublayer for transmission.

[0196] Example 18 includes the method according to Example 17 or some other embodiment herein, the method further comprising: determining that the plurality of SDAP SDUs have a common Quality of Service Flow Identifier (QFI); and generating the SDAP PDU to include the plurality of SDAP SDUs based on the determination.

[0197] Example 19 includes the method according to Example 17 or some other embodiment herein, wherein the header further includes: a group number field having a value indicating the number of SDAP SDUs in the SDAP PDU.

[0198] Example 20 includes the method according to Example 19 or some other embodiment herein, wherein the header further includes: a length field having a value indicating the length of each SDAP SDU in the number of SDAP SDUs.

[0199] Example 21 includes the method according to Example 17 or some other embodiment herein, the method further comprising: generating an SDAPPDU for a first data radio bearer (DRB) based on determining that the first DRB is configured with an SDAP header; and generating a cascaded PDCP PDU for a second DRB based on determining that the second DRB is configured without an SDAP header.

[0200] Example 22 includes the method according to Example 17 or some other embodiment herein, wherein identifying the plurality of SDAP SDUs is based on determining that the plurality of SDAP SDUs include a common header.

[0201] Example 23 includes the method according to Example 17 or some other embodiment herein, wherein the field is a first field and the header further includes a second field to identify the SDAP SDU associated with the Reflection Quality of Service (QoS) Indication (RQI) in the SDAP PDU among the plurality of SDAP SDUs.

[0202] Example 24 includes the method according to Example 17 or some other embodiment herein, wherein the header is an extended header, and the method further includes: generating an SDAP PDU to include a conventional header having a Reflection Quality of Service (QoS) Indication (RQI) or Reflection QoS Stream to Data Radio Bearer Mapping Indication (RDI) bit applied to the plurality of SDAP SDUs.

[0203] Example 25 includes a method comprising: storing a plurality of packets received from a Serving Data Adaptation (SDAP) sublayer in a transport buffer; identifying a plurality of PDCP Service Data Units (SDUs) corresponding to the plurality of packets respectively; generating a Virtual Packet Data Convergence Protocol (PDCP) SDU by concatenating the plurality of PDCP SDUs; assigning a sequence number (SN) to the virtual PDCP SDU; and generating a PDCP Protocol Data Unit (PDU) having the virtual PDCP SDU and a header including an indication of the SN.

[0204] Example 26 includes the method according to Example 25 or some other embodiment herein, the method further comprising: performing header compression on one or more of the plurality of PDCP SDUs; and generating the virtual PDCP SDU after performing the header compression.

[0205] Example 27 includes the method according to Example 25 or some other embodiment herein, wherein header compression is not performed on the plurality of PDCP SDUs.

[0206] Example 28 includes the method according to Example 25 or some other embodiment herein, the method comprising: performing integrity protection and encryption on the virtual PDCP SDU.

[0207] Example 29 includes the method according to Example 25 or some other embodiment herein, the method further comprising: generating the header to include an indication of the number of the plurality of PDCP SDUs or the length of a single PDCP SDU among the plurality of PDCP SDUs.

[0208] Example 30 includes the method according to Example 25 or some other embodiment herein, the method further comprising: generating the header to include an indication of the length of each of the plurality of PDCP SDUs.

[0209] Example 31 includes the method according to Example 25 or some other embodiment herein, the method further comprising: receiving a first packet of the plurality of packets; starting a timer based on receiving the first packet; and identifying the plurality of PDCP SDUs to include PDCP SDUs corresponding to packets received before the timer expires.

[0210] Example 32 includes the method according to Example 25 or some other embodiment herein, the method further comprising: receiving a configuration of a packet size; and identifying the plurality of PDCP SDUs to include PDCP SDUs having a size less than or equal to the packet size.

[0211] Example 33 includes the method according to Example 25 or some other embodiment herein, the method further comprising: receiving a configuration of a packet size; and identifying the plurality of PDCP SDUs in such a manner as to limit the size of the virtual PDCP SDU to no greater than the packet size.

[0212] Example 34 describes a method according to Example 25 or any other embodiment herein, the method further comprising: receiving a radio quality threshold; comparing the radio quality to the threshold; and generating the virtual PDCP SDU based on the comparison.

[0213] Example 35 includes the method according to Example 25 or some other embodiment herein, the method further comprising: initiating a PDCP discard timer based on the generation of the virtual PDCP SDU; and discarding the virtual PDCP SDU if no PDCP SDU has been provided to the Radio Link Control (RLC) sublayer when the PDCP discard timer expires.

[0214] Example 36 includes the method according to Example 25 or some other embodiment herein, wherein the virtual PDCP SDU is a first virtual PDCP SDU, the PDCP PDU is a first PDCP PDU, and the method further includes: starting a PDCP discard timer for the first PDCP SDU among the plurality of PDCP SDUs; discarding the first PDCP PDU when the expiration of the PDCP discard timer is detected, and determining that the first PDCP PDU has not been provided to the Radio Link Control (RLC) sublayer; generating a second virtual PDCP SDU to include the PDCP SDUs among the plurality of PDCP SDUs other than the first PDCP SDU; and generating a second PDCP PDU to include the second virtual PDCP SDU.

[0215] Example 37 includes the method according to Example 25 or some other embodiment herein, the method further comprising: determining that the successful delivery of the PDCP PDU was not acknowledged by a sublayer below the PDCP sublayer; determining whether PDCP concatenation is configured; and retransmitting the plurality of PDCP SDUs based on whether PDCP concatenation is configured.

[0216] Example 38 includes the method according to Example 37 or some other embodiment herein, wherein the PDCPPDU is a first PDCP PDU, the SN is a first SN, and the method further includes: determining that PDCP cascading is configured and PDCP status reporting is not configured; assigning a second SN to the virtual PDCP SDU; and generating a second PDCP PDU having the virtual PDCP SDU and a header including an indication of the second SN.

[0217] Example 39 includes the method according to Example 38 or some other embodiment herein, wherein out-of-order data forwarding is not enabled.

[0218] Example 40 includes the method according to Example 37 or some other embodiment herein, the method further comprising: determining that PDCP cascading is not configured and PDCP status reporting is configured; generating a plurality of PDCP PDUs to include the plurality of PDCP SDUs respectively, wherein each of the plurality of PDCP PDUs includes the SN and an indication of the order of the corresponding PDCP SDU in the virtual PDCP SDU.

[0219] Example 41 includes the method according to Example 40 or some other embodiment herein, wherein out-of-order data forwarding is enabled.

[0220] Example 42 includes a method comprising: receiving a Packet Data Convergence Protocol (PDCP) Packet Data Unit (PDU) from a Radio Link Control (RLC) sublayer; determining, based on the header of the PDCP PDU, that the PDCP PDU includes a virtual PDCP SDU having a plurality of PDCP Service Data Units (SDUs); demultiplexing the virtual PDCP SDU to obtain the plurality of PDCP SDUs; and providing the plurality of PDCP SDUs to a Service Data Adaptation Protocol (SDAP) sublayer.

[0221] Example 43 includes the method according to Example 42 or some other embodiment herein, the method further comprising: performing decryption and integrity verification on the virtual PDCP SDU.

[0222] Example 44 includes the method according to Example 42 or some other embodiment herein, the method further comprising: performing a reordering operation based on the sequence number in the header.

[0223] Example 45 includes the method according to Example 42 or some other embodiment herein, the method further comprising: performing header decompression on the plurality of PDCP SDUs after demultiplexing the virtual PDCP SD.

[0224] Example 46 may include an apparatus comprising one or more elements for performing the method described or associated with any of Examples 1 to 45 or any other method or process described herein.

[0225] Example 47 may include one or more non-transitory computer-readable media, the one or more non-transitory computer-readable media including instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform one or more elements of the method or any other method or process described herein according to any one of Examples 1 to 45.

[0226] Example 48 may include an apparatus comprising logic components, modules, or circuitry for performing one or more elements of the method described or associated with any of Examples 1 to 45 or any other method or process described herein.

[0227] Example 49 may include a method, technique, or process, or a part or component thereof, described or associated with any of Examples 1 to 45.

[0228] Embodiment 50 may include an apparatus comprising one or more processors and one or more computer-readable media, the one or more computer-readable media including instructions that, when executed by the one or more processors, cause the one or more processors to perform a method, technique, or process or part thereof as described or associated with any of Embodiments 1 to 45.

[0229] Example 51 may include a signal, or a portion thereof, described or associated with any of Examples 1 to 45.

[0230] Example 52 may include a datagram, information element, packet, frame, segment, PDU or message, or a portion or component thereof, as described or otherwise in accordance with any of Examples 1 to 45.

[0231] Example 53 may include a signal encoded with data, or a portion or component thereof, as described or associated with any of Examples 1 to 45, or otherwise described in this disclosure.

[0232] Example 54 may include a signal, or a portion or component thereof, encoded as a datagram, IE, packet, frame, segment, PDU, or message, as described or associated with any of Examples 1 to 45, or otherwise described in this disclosure.

[0233] Example 55 may include an electromagnetic signal carrying computer-readable instructions, wherein execution of the computer-readable instructions by one or more processors will cause the one or more processors to perform a method, technique, or process, or a portion thereof, as described or associated with any of Examples 1 to 45.

[0234] Example 56 may include a computer program comprising instructions, wherein execution of the program by a processing element will cause the processing element to perform any of the methods, techniques, or processes described or associated with any of Examples 1 to 45, or a portion thereof.

[0235] Example 57 may include signals in a wireless network as shown and described herein.

[0236] Example 58 may include a method for communicating in a wireless network as shown and described herein.

[0237] Example 59 may include a system for providing wireless communication as shown and described herein.

[0238] Example 60 may include a device for providing wireless communication as shown and described herein.

[0239] Unless otherwise expressly stated, any of the examples above may be combined with any other example (or combination of examples). The foregoing description of one or more specific embodiments provides illustration and description, but is not intended to be exhaustive or to limit the scope of the embodiments to the precise form disclosed. In light of the teachings above, modifications and variations are possible, or modifications and variations may be derived from practice of various embodiments.

[0240] Although the above embodiments have been described in considerable detail, many variations and modifications will become apparent to those skilled in the art once the disclosure is fully understood. This disclosure is intended to render the following claims as encompassing all such variations and modifications.

Claims

1. A method of communication, comprising: Identify multiple Packet Data Convergence Protocol (PDCP) Service Data Units (SDUs); Based on one or more concatenation parameters, a PDCP Packet Data Unit (PDU) is generated to include the plurality of PDCP SDUs and a header with a concatenation field having a concatenation value indicating that the PDCP PDUs are concatenated, wherein the concatenation value is an identifier for identifying the one or more concatenation parameters in a lookup table or for identifying a concatenation pattern including the one or more concatenation parameters from a plurality of concatenation patterns. as well as The PDCP PDU is provided to the Radio Link Control (RLC) sublayer for transmission.

2. The method according to claim 1, wherein the header further comprises: A group number field, the group number field having a group number value indicating the number of PDCP SDUs in the PDCP PDU; as well as The length field has a length value indicating the length of each PDCP SDU in the number of PDCP SDUs.

3. The method of claim 1, wherein the plurality of PDCP SDUs comprises a first group of one or more PDCPSDUs and a second group of one or more PDCP SDUs, and the header further comprises: A first group number field, wherein the first group number field has a first group number value indicating the number of PDCP SDUs in the first group; A first length field, the first length field having a first length value indicating the length of each PDCP SDU in the first group of one or more PDCP SDUs; and The second length field has a second length value indicating the length of each PDCP SDU in the second group of one or more PDCP SDUs.

4. The method according to any one of claims 1 to 3, further comprising: Identify parameters pre-configured by Radio Resource Control (RRC) messages or notified by signals, the RRC messages indicating the maximum number of PDCP SDUs that can be cascaded in a PDCP PDU; The maximum size of a PDCP PDU; the maximum size of a PDCP SDU that can be cascaded into a PDCP PDU; Alternatively, it allows cascading of PDCP SDUs in either the uplink or downlink direction.

5. The method according to any one of claims 1 to 3, further comprising: Indication of the PDCP cascading capability of transmitting or receiving user equipment.

6. The method according to any one of claims 1 to 3, further comprising: Identify multiple service data adaptation SDAP PDUs, each with a corresponding SDAP header and payload; The SDAP headers of the plurality of SDAP PDUs are determined to have a common Quality of Service Flow Identifier; as well as Based on the determination, the plurality of PDCP SDUs are generated to include an SDAP header and the payload of the plurality of SDAP PDUs.

7. The method according to any one of claims 1 to 3, further comprising: Identify multiple service data adaptation SDAP PDUs, each with a common header and a corresponding payload; as well as Based on the identification, the plurality of PDCP SDUs are generated to include the common header and the payload of the plurality of SDAP PDUs.

8. The method according to any one of claims 1 to 3, further comprising: Receive an indication that PDCP concatenation is activated in the downlink control information or media access control element; as well as The PDCP PDU is generated based on the instruction.

9. The method according to any one of claims 1 to 3, wherein the PDCP PDU is a first PDCP PDU, the plurality of PDCP SDUs are a first plurality of PDCP SDUs, and the method further comprises: Identify a second plurality of PDCP SDUs in the sequence, wherein the second plurality of PDCP SDUs includes the first plurality of PDCPSDUs; The first PDCP SDU is determined to include a reflected Quality of Service (QoS) Indicator (RQI) or a reflected QoS Stream to Data Radio Bearer Mapping Indicator (RDI) bit that indicates an update of the Quality of Service parameters. Based on the determination, the second PDCP SDU immediately preceding the first PDCP SDU in the sequence is set as the last PDCP SDU to be included in the first plurality of PDCP SDUs so as to be cascaded to the first PDCP SDU; as well as A second PDCP PDU is generated to include at least one additional PDCP SDU from the first PDCP SDU and the second plurality of PDCP SDUs.

10. The method according to any one of claims 1 to 3, wherein the PDCP PDU is transmitted via: a Uu interface between the user equipment and the base station; an F1 interface between the gNB distributed unit DU and the gNB central unit CU; an E1 interface between the CU control plane and the CU data plane; an X2 interface between base stations or an Xn interface between gNB CUs.

11. The method according to any one of claims 1 to 3, wherein the method is performed by a source base station, the PDCPPDU is transmitted to a user equipment (UE), and the method further comprises: It is determined that the UE is being handed over to the target base station; Determine whether the target base station supports cascading; as well as Based on the determination of whether the target base station supports cascading, the multiple PDCP SDUs are forwarded in the PDCP PDU or in the corresponding multiple PDCPPDUs.

12. The method according to any one of claims 1 to 3, further comprising: It is determined that the cascading of the multiple PDCP SDUs will not result in lower-level segmentation; as well as Based on the determination, the PDCP PDU is generated to include the plurality of PDCP SDUs.

13. The method according to any one of claims 1 to 3, further comprising: Generate cascaded PDCP SDUs to include the plurality of PDCP SDUs; as well as Encryption and integrity protection are performed on the cascaded PDCP SDUs.

14. An electronic device comprising: Receive buffer; and The processing circuit, coupled to the receiving buffer, is used to: Receive Packet Data Convergence Protocol (PDCP) Protocol Data Unit (PDU) from the Radio Link Control (RLC) sublayer, wherein the PDCP PDU includes a virtual PDCP SDU with multiple PDCP Service Data Units (SDUs); Access a lookup table or multiple predefined patterns based on the identifier in the header of the PDCP PDU to determine one or more cascade parameters; The PDCP PDU is processed based on one or more cascaded parameters; as well as The multiple virtual PDCP SDUs, including the virtual PDCP SDUs, are stored sequentially in the receive buffer based on multiple sequence numbers associated with the multiple virtual PDCP SDUs respectively.

15. The electronic device of claim 14, wherein the processing circuitry is further configured to: Decryption and integrity verification are performed on the virtual PDCP SDU.

Images