Remote user device and method

Abstract

An example embodiment of the present disclosure relates to an effective mechanism for dealing with discontinuous coverage scenarios. In the solution, a terminal device configured with multiple paths, including a first path that is an indirect path, determines, at a first entity of the terminal device, a successful transmission associated with a PDCP data packet data unit (PDU) on the first path, the first entity corresponding to the first path and at a layer lower than a Packet Data Convergence Protocol (PDCP) layer. Furthermore, the terminal device performs one of sending an acknowledgement indication indicating successful transmission to the PDCP entity of the terminal device and disabling sending acknowledgement indications to the PDCP entity. This allows the PDCP entity to recognize successful delivery of the PDCP data PDU via the indirect path and to timely discard or preserve duplicate PDCP data PDUs stored on other paths.

Description

[Technical Field]

[0001] FIELD Embodiments of the present disclosure relate generally to the field of telecommunications, and more particularly to methods, apparatus, and computer storage media for transmission management over multipath. [Background technology]

[0002] Recently, support for multipath technology has been proposed to improve reliability and throughput. Specifically, a user equipment (UE) can communicate with a network via both direct and indirect paths, and the UE can switch between or simultaneously use multiple paths. Furthermore, in the case of an indirect path, the UE can connect to the network equipment via a Layer 2 UE-to-network relay or via another UE (assuming that the UE-to-UE connection is ideal).

[0003] Furthermore, to improve reliability, a split bearer technique has also been proposed, which stores duplicates of packet data convergence protocol (PDCP) data packet data units (PDUs) in the lower entities for each path. Furthermore, when a PDCP data PDU is successfully transmitted to a network device via one of multiple paths, the duplicated PDCP data PDUs stored on the other paths are discarded.

[0004] However, the introduction of an indirect path, especially one that is assumed to be ideal, means that the UE's lower entities cannot indicate successful transmission on the indirect path to the UE's PDCP entity, and therefore cannot properly discard duplicate PDCP data PDUs stored on other paths. Summary of the Invention [Problem to be solved by the invention]

[0005] SUMMARY OF THE INVENTION Embodiments of the present disclosure generally provide a method, apparatus, and computer storage medium for multipath transmission management. [Means for solving the problem]

[0006] In a first aspect, a method of communication is provided, the method including, at a first entity of a terminal device configured with multiple paths, including a first path that is an indirect path, determining, at the first entity corresponding to the first path and at a layer lower than the PDCP layer, successful transmission associated with a PDCP data PDU on the first path, the method further including performing one of sending a confirmation indication indicating successful transmission to the PDCP entity of the terminal device and disabling sending of the confirmation indication to the PDCP entity.

[0007] In a second aspect, a method of communication is provided, the method including, in a PDCP entity of a terminal device configured with multiple paths including a first path that is an indirect path, determining successful transmission associated with a PDCP data packet data unit (PDU) on a second path of the multiple paths, the method further including sending a discard indication to a first entity corresponding to the first path, the first entity being at a layer lower than the PDCP layer, instructing the indirect path to discard a copy corresponding to the PDCP data PDU.

[0008] In a third aspect, there is provided a terminal apparatus comprising a processing unit and a memory, coupled to the processing unit, having instructions stored thereon, the instructions, when executed by the processing unit, causing the apparatus to perform a method according to the first aspect.

[0009] In a fourth aspect, there is provided a terminal device comprising a processing unit and a memory, coupled to the processing unit, on which instructions are stored, the instructions, when executed by the processing unit, causing the device to perform a method according to the first or second aspect.

[0010] In a fifth aspect, there is provided a computer-readable medium having stored thereon instructions which, when executed on at least one processor, cause the at least one processor to implement a method according to any of the first to second aspects.

[0011] Other features of the present disclosure will become readily apparent from the following description. [Brief explanation of the drawings]

[0012] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description of several embodiments of the present disclosure in the accompanying drawings.

[0013] [Figure 1A] FIG. 1 is a block diagram of an exemplary communication environment in which embodiments of the present disclosure may be implemented.

[0014] [Figure 1B] FIG. 1 is a diagram of an example protocol structure for a direct path according to some embodiments of the present disclosure.

[0015] [Figure 1C] FIG. 1 is a diagram of an example protocol structure for a standardized indirect path according to some embodiments of the present disclosure.

[0016] [Figure 1D] FIG. 1 is a diagram of an example protocol structure for a non-standardized indirect path according to some embodiments of the present disclosure.

[0017] [Figure 2A] FIG. 1 is a diagram of an example protocol structure of a terminal device according to some embodiments of the present disclosure. [Figure 2B] FIG. 1 is a diagram of an example protocol structure of a terminal device according to some embodiments of the present disclosure. [Figure 2C] FIG. 1 is a diagram of an example protocol structure of a terminal device according to some embodiments of the present disclosure.

[0018] [Figure 3A] FIG. 1 is a diagram of exemplary interactions between entities of a terminal device according to some embodiments of the present disclosure. [Figure 3B] FIG. 1 is a diagram of exemplary interactions between entities of a terminal device according to some embodiments of the present disclosure.

[0019] [Figure 4] FIG. 1 is a diagram of exemplary interactions between entities of a terminal device according to some embodiments of the present disclosure.

[0020] [Figure 5] FIG. 1 illustrates an exemplary method of communication implemented in a terminal device according to some embodiments of the present disclosure.

[0021] [Figure 6] FIG. 1 illustrates another exemplary method of communication implemented in a terminal device according to some embodiments of the present disclosure.

[0022] [Figure 7] FIG. 1 is a schematic block diagram of an apparatus suitable for practicing embodiments of the present disclosure.

[0023] Throughout the drawings, the same or similar reference numbers represent the same or similar elements. DETAILED DESCRIPTION OF THE INVENTION

[0024] The principles of the present disclosure will be described with reference to several embodiments. It should be understood that these embodiments are set forth for illustrative purposes only to aid those skilled in the art in understanding and practicing the present disclosure, and do not imply any limitations on the scope of the present disclosure. The present disclosure described herein can be embodied in various forms other than those described below.

[0025] In the following description and claims, unless defined otherwise, all technical and scientific terms used have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0026] In this disclosure, the term "terminal device" refers to any device with wireless or wired communication capabilities. Examples of terminal devices include user equipment (UE), personal computers, desktops, mobile phones, cellular phones, smartphones, personal digital assistants (PDAs), portable computers, tablets, wearable devices, Internet of Things (IoT) devices, Ultra-Reliable and Low Latency Communications (URLLC) devices, Any Internet of Things (IoE) devices, Machine Type Communications (MTC) devices, in-vehicle devices for V2X communications where X represents pedestrian, vehicle, or infrastructure / network, devices for Integrated Access and Backhaul (IAB), spacecraft or airborne vehicles in Non-Terrestrial Networks (NTN) including Satellites and High Altitude Platforms (HAPs) including Unmanned Aircraft Systems (UAS), and Extended Reality (XR) including different types of reality such as Augmented Reality (AR), Mixed Reality (MR), and Virtual Reality (VR). This includes, but is not limited to, Reality devices, unmanned aerial vehicles (UAVs), commonly known as drones, i.e., aircraft without a human pilot, devices on high-speed trains (HST), image capture devices such as digital cameras, sensors, and gaming devices, music storage and playback devices, and Internet appliances that enable wireless or wired Internet access and browsing. A "terminal device" may also have "multicast / broadcast" capabilities and support public safety and mission-critical applications, V2X applications, transparent IPV4 / IPV6 multicast delivery, IPTV, smart TV, wireless services, over-the-air software delivery, group communications, and IoT applications. It may also incorporate one or more subscriber identity modules (SIMs), known as multi-SIMs. The term "terminal device" may be used interchangeably with UE, mobile station, subscriber station, mobile terminal, user terminal, or wireless device.

[0027] The term "network device" refers to a device capable of providing or hosting a cell or coverage area over which terminal devices can communicate. Examples of network devices include, but are not limited to, a Node B (NodeB or NB), an evolved Node B (eNodeB or eNB), a next generation Node B (gNB), a transmission reception point (TRP), a remote radio unit (RRU), a radio head (RH), a remote radio head (RRH), a low-power node such as an IAB node, a femto node, a pico node, and a reconfigurable intelligent surface (RIS).

[0028] A terminal device or network device may have artificial intelligence (AI) or machine learning capabilities, which typically include models trained from a large amount of collected data for a specific function and can be used to predict some information.

[0029] A terminal device or network device may operate in multiple frequency ranges, such as FR1 (410 MHz to 7125 MHz), FR2 (24.25 GHz to 71 GHz), frequency bands greater than 100 GHz, and terahertz (THz). It can also operate in licensed, unlicensed, and shared spectrum. A terminal device may have multiple connections with network devices in Multi-Radio Dual Connectivity (MR-DC) application scenarios. A terminal device or network device can operate in full duplex, flexible duplex, and cross division duplex modes.

[0030] Embodiments of the present disclosure may be implemented in test equipment such as, for example, a signal generator, a signal analyzer, a spectrum analyzer, a network analyzer, a test terminal equipment, a test network equipment, a channel emulator, and the like.

[0031] In some embodiments, a terminal device may be connected to a first network device and a second network device. One of the first network device and the second network device may be a master node, and the other may be a secondary node. The first network device and the second network device may use different radio access technologies (RATs). In some embodiments, the first network device may be a first RAT device, and the second network device may be a second RAT device. In some embodiments, the first RAT device is an eNB, and the second RAT device is a gNB. Information related to the different RATs may be transmitted to the terminal device from at least one of the first network device and the second network device. In some embodiments, the first information may be transmitted from the first network device to the terminal device, and the second information may be transmitted from the second network device directly or via the first network device to the terminal device. In some embodiments, information related to the terminal device configuration configured by the second network device may be transmitted from the second network device via the first network device. The information regarding the reconfiguration of the terminal device configured by the second network device may be transmitted to the terminal device directly from the second network device or via the first network device.

[0032] In this disclosure, unless the context clearly indicates otherwise, the singular forms "a," "the," and "the" are intended to include the plural. The term "comprises" and variations thereof are interpreted as open-ended terms meaning "including, but not limited to." The term "based on" is interpreted as "based at least in part on." The terms "one embodiment" and "embodiment" are interpreted as "at least one embodiment." The term "another embodiment" is interpreted as "at least one other embodiment." Terms such as "first," "second," etc. may refer to different objects or the same object. The following content may include other definitions, both explicit and implicit.

[0033] In some instances, values, procedures, or devices are referred to as "optimal," "lowest," "highest," "minimum," "maximum," etc. It is understood that such descriptions are intended to indicate choices among multiple functional alternatives used, and that such choices are not necessarily better, smaller, higher, or more preferred than other choices.

[0034] As mentioned above, multipath and split bearer techniques have been proposed to improve reliability and throughput. Furthermore, a UE can communicate with the network via both direct and indirect paths, and the UE can switch between multiple paths or use multiple paths simultaneously.

[0035] Furthermore, in the case of an indirect path, a UE may be connected to the network device via a Layer 2 UE-to-network relay or via another UE (assuming the UE-to-UE connection is ideal). However, the introduction of an indirect path, especially an indirect path that is assumed to be ideal, means that the lower entities cannot indicate successful transmission on the indirect path to the PDCP entity in the UE and cannot properly discard duplicate PDCP data PDUs stored on other paths.

[0036] The embodiments of the present disclosure provide a solution for managing transmissions over multiple paths. In the present disclosure, when a lower entity (e.g., a first entity having a layer lower than the PDCP layer) determines a successful transmission associated with a PDCP data PDU over an indirect path, the lower entity may be configured to send an acknowledgement to the PDCP entity or to disable sending an acknowledgement to the PDCP entity. In this way, duplicate PDCP data PDUs stored over other paths can be appropriately discarded or kept.

[0037] For ease of discussion, some terms used in the following description are listed below. Direct network connection: Refers to a mode of network connection in which there is no relay terminal device / relay UE between the terminal device and the network device. Indirect network connection: This refers to a mode of network connection in which a relay terminal device / relay UE exists between a terminal device and a network device, and may also be referred to as a relay path. Indirect path / link / connection: refers to either a path between a network device and a remote terminal device that passes through an intermediate terminal device or multiple intermediate terminal devices, a path between a remote terminal device and an intermediate terminal device (i.e., a PC5 path / link / connection, or a sidelink path / link / connection, or a D2D path / link / connection, or a non-standardized path / link / connection, or a non-3GPP path / link / connection), or a path / link / connection between an intermediate terminal device and a network device. Non-standardized entity / path / link / connection: refers to an entity / path / link / connection that is not specified in a standard document (such as a 3GPP® specification) or is an ideal path / link / connection. Also referred to as a non-3GPP entity / path / link / connection. A non-standardized entity / path / link / connection is also referred to as an ideal path / link / connection. Examples of non-standardized entities / paths / links / connections include, but are not limited to, Wi-Fi entities / paths / links / connections, Bluetooth entities / paths / links / connections, Zigbee entities / paths / links / connections, etc. Standardized Entity / Path / Link / Connection: Refers to an entity / path / link / connection that is specified in a standard document (e.g., 3GPP specifications). First entity: Refers to an entity in a terminal device. The layer of the first entity is lower than the PDCP layer. In some embodiments, the first entity may be a radio link control (RLC) entity. In some other embodiments, the first entity may be an SRAP entity. Alternatively, in some other embodiments, the first entity may be a non-standardized entity.

[0038] In this disclosure, the terms path, link, and connection may be used interchangeably.

[0039] In this disclosure, the terms entity, layer, and sublayer are used interchangeably.

[0040] In this disclosure, descriptions of an entity corresponding to a (direct / indirect) path, an entity in a (direct / indirect) path, and an entity associated with a (direct / indirect) path may be used interchangeably.

[0041] Furthermore, it should be noted that the same data may be represented in different data formats. For example, the same data may be represented as a PDCP PDU, a SRAP SDU, a SRAP PDU, an RLC SDU, an RLC PDU, a non-standardized data unit / SDU / PDU, a non-3GPP data unit / SDU / PDU, etc. Thus, the terms PDCP PDU, SRAP SDU, SRAP PDU, an RLC SUC, an RLC PDU, a non-standardized data unit / SDU / PDU, and a non-3GPP data unit / SDU / PDU may be used interchangeably in some cases.

[0042] According to some embodiments of the present invention, a remote terminal device is configured to have multiple paths, including at least a first path and a second path. That is, the remote terminal device may be configured to have a first path, a second path, and optionally one or more other paths. Furthermore, in some embodiments, the first path is an indirect path, and any of the second path and one or more other paths may be either a direct path or an indirect path. In the following exemplary embodiments, the first path and the second path are used as exemplary paths. It should be understood that embodiments described with respect to a first path and a second path are also suitable for any other paths.

[0043] The principles and embodiments of the present disclosure will be described in detail below with reference to the drawings.

[0044] Communication Network Example 1A illustrates an exemplary communication environment 100 in which exemplary embodiments of the present disclosure can be implemented. The communication environment 100 includes a plurality of terminal devices and a network device. As shown in FIG. 1A, the communication environment 100 includes a network device 110 that provides a coverage area referred to as cell 110-2.

[0045] Furthermore, the communication environment 100 includes a terminal device 120-1 and a terminal device 120-2. For convenience of explanation, the terminal device 120-1 and the terminal device 120-2 will be collectively referred to as the terminal device 120.

[0046] Furthermore, terminal device 120-1 may communicate with network device 110 via multiple paths (also referred to as multipaths), each of which may be either a direct path or an indirect path. As shown in FIG. 1A, terminal device 120-1 (also referred to as remote UE or remote terminal device) may communicate with network device 110 via terminal device 120-2 (also referred to as relay UE or relay terminal device), while terminal device 120-1 may communicate directly with network device 110.

[0047] In some embodiments, with respect to terminal device 120-1, the following entities are configured for the direct path: a PDCP entity, a radio link control (RLC) entity, and a media access control (MAC) entity.

[0048] In some embodiments, with respect to terminal device 120-1, the following entities are configured for the standardized indirect path: a PDCP entity, a sidelink relay adaptation protocol (SRAP) entity, an RLC entity, and a MAC entity.

[0049] In some embodiments, with respect to terminal device 120-1, the following entities are configured for the standardized indirect path: a PDCP entity, a SRAP entity, an RLC entity, and a MAC entity.

[0050] In some embodiments, a SRAP entity and a non-standardized entity (also referred to as a non-3GPP device-to-device (D2D) entity) may be configured for a non-standardized indirect path with respect to terminal device 120-1. Alternatively, in some embodiments, a SRAP entity may not be present in the non-standardized indirect path.

[0051] In summary, terminal device 120-1 may communicate with network device 110 via any of the following paths: A direct path in which end device 120-1 is directly connected to network device 110. An exemplary protocol structure 150 for the direct path is shown in Figure 1B. A standardized indirect path in which terminal device 120-1 is connected to network device 110 via terminal device 120-2 and the path between terminal device 120-1 and terminal device 120-2 is a PC5 / sidelink (SL) path. An exemplary protocol structure 160 for the standardized indirect path is shown in FIG. 1C. An unstandardized indirect path in which terminal device 120-1 is connected to network device 110 via terminal device 120-2 and the path between terminal device 120-1 and terminal device 120-2 is an unstandardized path. An exemplary protocol structure 170 for an unstandardized indirect path in which the SRAP entity is optional is shown in FIG. 1D.

[0052] In some embodiments, terminal device 120-1 may connect to network device 110 using one direct path and one indirect path via Layer 2 UE-to-network relay (sometimes referred to as scenario #1). Alternatively, in some embodiments, terminal device 120-1 may connect to network device 110 using one direct path and one indirect path via terminal device 120-2 (assuming ideal UE-to-UE connectivity, sometimes referred to as scenario #2).

[0053] In some embodiments, it is expected that the following aspects will benefit from multipath: > Relay and direct multipath operation (including both scenarios #1 and #2) can provide efficient path switching between direct and indirect paths. The remote terminal 120-1 in multipath operation can provide improved user data throughput and reliability compared to a single link. The network device 110 can offload the congested direct connection of the remote terminal device 120-1 to an indirect path (eg, a different intra- / inter-frequency cell) via the terminal device 120-2.

[0054] In some embodiments, terminal device 120-1 supports direct bearers (i.e., bearers mapped to the direct path in Uu), indirect bearers (i.e., bearers mapped to the indirect path via a relay UE), and multi-path (MP) split bearers (i.e., bearers mapped to both paths based on the existing split bearer framework).

[0055] In some embodiments, the relationship between the terminal device 120-1 and the terminal device 120-2 involved in the unstandardized indirect path is pre-configured or static. As a specific example, the mapping between the terminal device 120-1 and the terminal device 120-2 is a 1:1 mapping.

[0056] In some embodiments, the duplicate PDU discard procedure may be triggered in the PDCP entity of terminal device 120-1. In a specific embodiment, terminal device 120-1 is configured with two acknowledged mode (AM) RLC entities, and the PDCP entity of terminal device 120-1 is configured with pdcp-Duplication. In this specific embodiment, upon receiving an acknowledgment for an RLC SDU with SN=x, the transmit side of the AM RLC entity should send an indication of successful delivery of the RLC SDU to upper layers and should set TX_Next_Ack equal to the SN of the RLC SDU with the smallest SN, where the SN of that RLC SDU is in the range TX_Next_Ack≦SN≦TX_Next, and an acknowledgment has not yet been received for that RLC SDU.

[0057] Furthermore, in this particular embodiment, if successful delivery of a PDCP data PDU is confirmed by one of the associated AM RLC entities, the transmitting PDCP entity may instruct the other AM RLC entities to discard the duplicate PDCP data PDU.

[0058] For an RLC entity, when an upper layer / entity (i.e., a PDCP layer / entity) indicates to discard a particular RLC service data unit (SDU) (e.g., an RLC SDU corresponding to a PDCP data PDU), the sender of an AM RLC entity or an unacknowledged mode (UM) RLC entity should discard the indicated RLC SDU if neither the RLC SDU nor its segments have been submitted to the lower layer. The sender of an AM RLC entity must not introduce an RLC SN gap when discarding an RLC SDU.

[0059] 1A-1D are for illustrative purposes only and are not intended to limit the present disclosure. Communication environment 100 may include any suitable number of network devices and / or terminal devices adapted to implement embodiments of the present disclosure. Furthermore, communication environment 100 may include any other devices other than network devices and terminal devices, such as core network elements, which are omitted herein to avoid obscuring the present disclosure.

[0060] In some embodiments, terminal device 120 and network device 110 may communicate with each other via channels, such as wireless communication channels over the air interface (e.g., the Uu interface). The wireless communication channels may include a physical uplink control channel (PUCCH), a physical uplink shared channel (PUSCH), a physical random access channel (PRACH), a physical downlink control channel (PDCCH), a physical downlink shared channel (PDSCH), and a physical broadcast channel (PBCH). Of course, any other suitable channels may also be used.

[0061] Communications in communication network 100 may conform to any suitable standard, including, but not limited to, Global System for Mobile Communications (GSM), Long Term Evolution (LTE), LTE-Evolution, LTE-Advanced (LTE-A), New Radio (NR), Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA), GSM EDGE Radio Access Network (GERAN), Machine Type Communication (MTC), etc. Embodiments of the present disclosure may be performed in accordance with any currently known or future-developed generation of communication protocols. Examples of communication protocols include, but are not limited to, first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G) communication protocols, 5.5G, 5G-Advanced networks, or sixth generation (6G) networks.

[0062] Exemplary Process for Managing Transmission Over Multipath Although features / operations are described individually in particular exemplary embodiments, it should be understood that these features / operations described in different exemplary embodiments can be used in any suitable combination unless expressly indicated to the contrary.

[0063] The principles and embodiments of the present disclosure will be described in detail below with reference to Figures 2A to 4. For convenience of explanation, Figures 2A to 4 will be described with reference to Figures 1A to 1D.

[0064] Furthermore, the following will refer to a specific embodiment for a better understanding. In this specific embodiment, the terminal device 120-1 is configured to have multiple paths, including a first path and a second path. For example, the first path may be an indirect path, and the second path may be a direct path or an indirect path. In this specific embodiment, the entities of the first path and the second path are associated with one PDCP entity (e.g., a split bearer is configured). Furthermore, a duplicate PDCP PDU may be transmitted via more than one path (e.g., both the first path and the second path).

[0065]

[0023] Reference is made to Figure 2A, which illustrates an exemplary protocol structure for terminal device 120-1 according to some embodiments of the present disclosure. In the specific embodiment of Figure 2A, the first path of terminal device 120-1 is a standardized indirect path. For example, terminal device 120-1 is connected to terminal device 120-2 via a PC5 interface or a sidelink connection. Additionally, in the specific embodiment of Figure 2A, an RLC entity and a MAC entity are configured for the first path.

[0066] 2B and 2C illustrate another example of a protocol structure of a terminal device 120-2 according to some embodiments of the present disclosure, where the first path is a non-standardized indirect path. In the specific embodiment of FIG. 2B, an SRAP entity and a non-standardized entity are configured for the first path. In the specific embodiment of FIG. 2C, a non-standardized entity is configured for the first path.

[0067] The following describes in detail an exemplary process of how to handle successful transmissions associated with PDCP PDUs (eg, PDCP Data PDUs) on an indirect path or how to handle discarding of duplicate PDCP Data PDUs.

[0068] Handles successful transmissions on indirect paths In some embodiments, terminal device 120-1 is configured to have a first entity corresponding to a first path (i.e., an indirect path), and the layer of the first entity is lower than the PDCP layer. As described above, terminal device 120-1 may be configured to have a different protocol structure (as shown in FIGS. 2A-2C) for the indirect path. Thus, the first entity may be a different entity corresponding to the different protocol structure. One example of a first entity is an RLC entity (as shown in FIG. 2A). Another example of a first entity is a non-standardized entity (as shown in FIGS. 2B and 2C).

[0069] According to some embodiments of the present invention, an indication of successful transmission (hereinafter also referred to as "acknowledgement indication") is sent to the PDCP entity. Based on the received acknowledgement indication, the PDCP entity may appropriately trigger the discarding of duplicate PDCP data PDUs, thereby allowing unnecessary resources to be released in a timely manner.

[0070] In some embodiments, the first entity of terminal device 120-1 determines a successful transmission associated with the PDCP data PDU on the first path, for example, the first entity receives an acknowledgment from terminal device 120-2.

[0071] In some embodiments, notification of successful transmission to the PDCP entity may be permitted, so that the first entity may send a confirmation indication to the PDCP entity indicating successful transmission.

[0072] In some embodiments, the confirmation indication may indicate some details regarding the successful transmission so that the PDCP entity can properly understand the transmission status of the associated PDCP data PDU.

[0073] In some embodiments, the confirmation indication may include a one-bit indication of successful transmission. Alternatively or additionally, in some embodiments, the confirmation indication may indicate a radio bearer (RB) identity, such as a signaling radio bearer (SRB) identity or a data radio bearer (DRB) identity. Alternatively or additionally, in some embodiments, the confirmation indication may indicate an RB type, such as an SRB or a DRB.

[0074] Alternatively, or additionally, in some embodiments, the confirmation indication may indicate a sequence number corresponding to a PDCP data PDU. It should be appreciated that the sequence number corresponding to a PDCP data PDU may be the sequence number of any suitable data unit, such as the sequence number of a non-standardized data unit / PDU / SDU, the sequence number of an RLC PDU / SDU, the sequence number of a PDCP PDU / SDU, or the sequence number of an SRAP PDU / SDU. The disclosure is not limited in this respect.

[0075] The details of the procedure for sending the confirmation instruction will be described with reference to FIG. 3A.

[0076] As shown in FIG. 3A, in some embodiments, the first entity transmits a first indication indicating successful transmission to an SRAP entity corresponding to the first path (310-1). In one specific embodiment, the first path is a standardized indirect path, and an SRAP entity, an RLC entity (e.g., a PC5 AM RLC entity), a MAC entity, and a PHY entity are configured for the first path. In this case, the RLC entity transmits the first indication to the SRAP entity. In another specific embodiment, the first path is a non-standardized indirect path, and an SRAP entity and a non-standardized entity are configured for the first path. In this case, the non-standardized entity may transmit the first indication to the SRAP entity. Then, in some embodiments, the SRAP entity may transmit a second indication corresponding to the first indication to the PDCP entity (310-2). Alternatively, in some embodiments, the SRAP entity may simply forward the second indication corresponding to the first indication to the PDCP entity.

[0077] It should be understood that the second indication and the first indication correspond to the same PDCP data PDU. At the same time, the second indication and the first indication may be expressed in different formats. For example, the first indication indicates successful transmission of an RLC SDU, and the second indication indicates successful transmission of an SRAP SDU.

[0078] Alternatively, in some embodiments, the transmission of the confirmation indication may be performed independently of the SRAP entity. Specifically, as shown in FIG. 3A, in some embodiments, the first entity may send a first indication indicating successful transmission directly to the PDCP entity (320).

[0079] In a specific embodiment, the first path is a standardized indirect path, and an SRAP entity, an RLC entity, a MAC entity, and a PHY entity are configured for the first path. In this case, even if an SRAP entity is configured, the RLC entity sends the first indication directly to the PDCP entity.

[0080] In another specific embodiment, the first path is a non-standardized indirect path, and an SRAP entity and a non-standardized entity are configured for the first path. In this case, even if an SRAP entity is configured, the non-standardized entity may send the first indication directly to the PDCP entity.

[0081] In another specific embodiment, the first path is a non-standardized indirect path, and a non-standardized entity is configured for the first path, in which case the non-standardized entity may send the first indication directly to the PDCP entity.

[0082] The acknowledgement enables the PDCP entity to trigger the discarding of the duplicated PDCP data PDUs on the other path (i.e., the second path). In this way, the PDCP entity can recognize the successful delivery of the PDCP data PDUs via the indirect path and trigger the discarding of the duplicated PDCP data PDUs in a timely manner.

[0083] As mentioned above, an indirect path refers to a scenario in which terminal device 120-1 communicates with network device 110 via terminal device 120-2. Preferably, the duplicate PDCP data PDU is discarded only if the PDCP data PDU is successfully transmitted to network device 110. However, an acknowledgment from terminal device 120-2 only indicates successful transmission from terminal device 120-1 to terminal device 120-2, and does not mean that the PDCP data PDU was successfully transmitted to network device 110.

[0084] With this in mind, successful transmission of the PDCP data PDU from terminal device 120-2 should not be indicated to the PDCP entity. Thus, in some embodiments, the first entity of terminal device 120-1 determines successful transmission associated with the PDCP data PDU on the first path. For example, the first entity receives an acknowledgment from terminal device 120-2. However, in some embodiments, transmission of the confirmation indication is disabled.

[0085] A detailed procedure for disabling the sending of confirmation instructions will be described with reference to FIG. 3B.

[0086] As shown in FIG. 3B , in some embodiments, the first entity disables (350) sending a first indication indicating successful transmission to an SRAP entity corresponding to the first path. In one specific embodiment, the first path is a standardized indirect path, and an SRAP entity, an RLC entity (e.g., a PC5 AM RLC entity), a MAC entity, and a PHY entity are configured for the first path. In this case, the RLC entity disables sending the first indication to the SRAP entity. In another specific embodiment, the first path is a non-standardized indirect path, and an SRAP entity and a non-standardized entity are configured for the first path. In this case, the non-standardized entity disables sending the first indication to the SRAP entity.

[0087] Alternatively, in some embodiments, the first entity disables (340) direct transmission of the first indication indicating successful transmission to the PDCP entity. In one specific embodiment, the first path is a standardized indirect path, and an SRAP entity, an RLC entity (e.g., a PC5 AM RLC entity), a MAC entity, and a PHY entity are configured for the first path. In this case, the RLC entity disables direct transmission of the first indication to the PDCP entity. In another specific embodiment, the first path is a non-standardized indirect path, and an SRAP entity and a non-standardized entity are configured for the first path. In this case, the non-standardized entity disables direct transmission of the first indication to the PDCP entity.

[0088] Alternatively, in some embodiments, the first entity may send a first indication to the SRAP entity indicating successful transmission (330-1), but disable transmission of a second indication corresponding to the first indication to the PDCP entity (330-2). In one specific embodiment, the first path is a standardized indirect path, and an SRAP entity, an RLC entity (e.g., a PC5 AM RLC entity), and a MAC entity are configured for the first path. In this case, the RLC entity sends the first indication to the SRAP entity, and the SRAP entity disables transmission of the second indication to the PDCP entity. In another specific embodiment, the first path is a non-standardized indirect path, and an SRAP entity and a non-standardized entity are configured for the first path. In this case, the non-standardized entity sends the first indication to the SRAP entity, and the SRAP entity disables transmission of the second indication to the PDCP entity.

[0089] In addition to disabling the sending of an acknowledgement indication, the PDCP entity may also disable instructing other paths to discard copies corresponding to the PDCP data PDUs in order to avoid improper discard procedures. Specifically, after receiving an acknowledgement indication, the PDCP entity disables instructing entities corresponding to the other paths to discard copies corresponding to the PDCP data PDUs. Since the other paths may be either a direct path, a non-standardized indirect path, or a standardized indirect path, the entities corresponding to the other paths may be the respective RLC entities, SRAP entities, or non-standardized entities.

[0090] In a specific embodiment, the other path is a direct path, and an RLC entity (e.g., a PC5 AM RLC entity), a MAC entity, and a PHY entity are configured for the other path, in which case the PDCP entity, after receiving the acknowledgement indication, disables instructing the RLC entity corresponding to the other path to discard the copies corresponding to the PDCP data PDUs.

[0091] In another specific embodiment, the other path is a standardized indirect path, and an SRAP entity, an RLC entity (e.g., a PC5 AM RLC entity), a MAC entity, and a PHY entity are configured for the other path. In some embodiments, even if an SRAP entity is configured, the PDCP entity, after receiving an acknowledgement indication, disables instructing the RLC entity corresponding to the other path to discard copies corresponding to the PDCP data PDUs. Alternatively or additionally, the PDCP entity disables instructing the SRAP entity corresponding to the other path to discard copies corresponding to the PDCP data PDUs.

[0092] In another specific embodiment, the other path is a non-standardized indirect path, and an SRAP entity and a non-standardized entity are configured for the other path. In this case, the PDCP entity disables instructing the SRAP entity corresponding to the other path to discard copies corresponding to PDCP data PDUs. Alternatively, the other path is a non-standardized indirect path, and a non-standardized entity is configured for the other path. In this case, the PDCP entity disables instructing the non-standardized entity corresponding to the other path to discard copies corresponding to PDCP data PDUs.

[0093] In this way, inappropriate discarding of PDCP data PDUs is avoided.

[0094] PDCP Data PDU Discards in Indirect Paths Generally, in the case of multipath, if a PDCP data PDU has already been successfully transmitted on one path (direct path or indirect path), the corresponding duplicate of the PDCP data PDU should be discarded. An exemplary process for discarding a PDCP data PDU on an indirect path is described below. For better understanding, the detailed discarding procedure is described with reference to Figure 4.

[0095] In some embodiments, the PDCP entity of terminal device 120-1 determines successful transmission associated with a PDCP data PDU on the direct path or the indirect path.

[0096] How successful transmission associated with a PDCP data PDU over the indirect path is determined has already been described in detail. For brevity, some of the details are omitted here. In the case of the direct path, the RLC entity (e.g., the AM RLC entity) of terminal device 120-1 may receive an acknowledgment from network device 110 and may indicate successful transmission to the PDCP entity.

[0097] As shown in FIG. 4, in some embodiments, the PDCP entity of terminal device 120-1 determines successful transmission associated with the PDCP data PDU on the second path by receiving (430) a confirmation indication from a first entity corresponding to the second path.

[0098] Upon determining successful transmission, the PDCP entity may trigger a discard procedure for the PDCP data PDU. In some embodiments, the PDCP entity sends a discard indication instructing the first path to discard the duplicate corresponding to the PDCP data PDU.

[0099] In some embodiments, the discard indication may indicate some details about the successful transmission so that the first entity can properly understand the transmission status of the associated PDCP data PDU.

[0100] In some embodiments, the discard indication may include a one-bit indication of successful transmission. Alternatively or additionally, in some embodiments, the discard indication may indicate an RB identity, such as an SRB identity or a DRB identity. Alternatively or additionally, in some embodiments, the confirmation indication indicates an RB type, such as an SRB or a DRB. Alternatively or additionally, in some embodiments, the discard indication indicates a sequence number corresponding to the PDCP data PDU.

[0101] The details of the procedure for transmitting the discard instruction will be described with reference to FIG.

[0102] As shown in FIG. 4, in some embodiments, the PDCP entity sends a third instruction to the SRAP entity corresponding to the first path, instructing the first path to discard the duplicate corresponding to the PDCP data PDU (410-1).

[0103] In one specific embodiment, the first path is a standardized indirect path, and an SRAP entity, an RLC entity (e.g., a PC5 AM RLC entity), a MAC entity, and a PHY entity are configured for the first path. In another specific embodiment, the first path is a non-standardized indirect path, and an SRAP entity and a non-standardized entity are configured for the first path. In these specific embodiments, the PDCP entity sends the third indication to the SRAP entity of the indirect path.

[0104] In some embodiments, after receiving the third indication, the SRAP entity determines whether an SRAP SDU corresponding to the PDCP data PDU has already been submitted to the first entity. If the SRAP SDU has already been submitted to the first entity as an SRAP PDU, the SRAP entity sends a fourth indication corresponding to the third indication to the first entity (410-2). Otherwise, the SRAP entity discards the SRAP SDU at the SRAP entity. In a specific embodiment, the first path is a standardized indirect path, and the SRAP entity may send the fourth indication to an RLC entity corresponding to the first path. In a specific embodiment, the first path is a non-standardized indirect path, and the SRAP entity may send the fourth indication to a non-standardized entity corresponding to the first path.

[0105] In some embodiments, when instructed by a higher layer / entity (i.e., a PDCP layer / entity) to discard a particular SRAP SDU, the transmitter of the SRAP entity should discard the instructed SRAP SDU if the SRAP SDU has not been submitted to a lower layer. Alternatively, if the SRAP SDU has already been submitted to a lower layer, the SRAP entity may instruct the associated AM RLC entity to discard the RLC SDU (SRAP PDU). Furthermore, the RLC SDU and the SRAP SDU contain the same PDCP data PDU.

[0106] In this way, even if a SRAP layer is introduced for the indirect path, PDCP can still be triggered to discard duplicate PDCP data PDUs appropriately.

[0107] Alternatively, the PDCP entity may instruct the first entity to directly discard the associated PDCP data PDU, regardless of whether an SRAP entity is configured in terminal device 120-1. Specifically, as shown in FIG. 4, in some embodiments, the PDCP entity may send a third instruction (420) to instruct the first path to directly discard the duplicate corresponding to the PDCP data PDU.

[0108] In a specific embodiment, the first path is a standardized indirect path, and an SRAP entity, an RLC entity, a MAC entity, and a PHY entity are configured for the first path. In this case, even if an SRAP entity is configured, the PDCP entity sends the third indication directly to the RLC entity.

[0109] In another specific embodiment, the first path is a non-standardized indirect path, and an SRAP entity and a non-standardized entity are configured for the first path. In this case, even if an SRAP entity is configured, the PDCP may send the third indication directly to the non-standardized entity.

[0110] In another specific embodiment, the first path is a non-standardized indirect path, and a non-standardized entity is configured for the first path, in which case the PDCP may send the third indication directly to the non-standardized entity.

[0111] In this way, unnecessary resources used to store copies of PDCP data PDUs that have already been successfully transmitted can be released in a timely manner.

[0112] Example method 5 illustrates a flowchart of an exemplary method 500 according to some embodiments of the present disclosure. For example, the method 500 may be implemented in the remote terminal 120-1 shown in FIG. 1A.

[0113] In block 510, the terminal device 120-1 configured to have multiple paths including a first path that is an indirect path determines, in a first entity of the terminal device 120-1 corresponding to the first path, a successful transmission associated with a PDCP PDU on the first path, the first entity being a layer lower than the PDCP layer.

[0114] In block 520, terminal device 120-1 performs one of sending a confirmation indication indicating successful transmission to the PDCP entity of terminal device 120-1 and disabling sending a confirmation indication to the PDCP entity.

[0115] In some embodiments, the confirmation indication indicates at least one of an RB identity, an RB type, a sequence number corresponding to the PDCP data PDU, and a successful transmission of the PDCP data PDU.

[0116] In some embodiments, the first entity is an RLC entity or a non-standardized entity.

[0117] In some embodiments, the terminal device 120-1 transmits, in a first entity, a first indication indicating successful transmission to an SRAP entity corresponding to the first path, and further transmits, in the SRAP entity, a second indication corresponding to the first indication to a PDCP entity.

[0118] In some embodiments, terminal device 120-1 transmits a first indication indicating successful transmission directly to the PDCP entity at the first entity.

[0119] In some embodiments, the terminal device 120-1 disables, in the first entity, the direct transmission of a first indication indicating successful transmission to the PDCP entity or the transmission of the first indication to the SRAP entity corresponding to the first path.

[0120] In some embodiments, the terminal device 120-1 transmits, in a first entity, a first indication indicating successful transmission to an SRAP entity corresponding to the first path, and further disables, in the SRAP entity, transmission of a second indication corresponding to the first indication to the PDCP entity.

[0121] In some embodiments, after receiving the confirmation indication, the terminal device 120-1 disables, in the PDCP entity, instructing an entity corresponding to a second path of the multiple paths to discard a copy corresponding to the PDCP data PDU, where the entity corresponding to the second path is one of an RLC entity, an SRAP entity, and a non-standardization entity.

[0122] In some embodiments, the second path is a direct path or another indirect path.

[0123] 6 illustrates a flowchart of an exemplary method 600 according to some embodiments of the present disclosure. For example, the method 600 may be implemented in the remote terminal 120-1 illustrated in FIG. 1A.

[0124] In block 610, the terminal device 120-1 determines, in a PDCP entity of the terminal device 120-1 configured to have multiple paths including a first path that is an indirect path, a successful transmission associated with a PDCP PDU on a second path of the multiple paths.

[0125] In block 620, the terminal device 120-1 sends a discard instruction to a first entity corresponding to the first path, the first entity being at a layer lower than the PDCP layer, instructing the first path to discard the copy corresponding to the PDCP data PDU.

[0126] In some embodiments, the second path is a direct path or another indirect path.

[0127] In some embodiments, the discard indication indicates at least one of an RB identity, an RB type, a sequence number corresponding to the PDCP data PDU, and a successful transmission of the PDCP data PDU.

[0128] In some embodiments, the first entity is an RLC entity or a non-standardized entity.

[0129] In some embodiments, the terminal device 120-1 sends a third instruction to the SRAP entity corresponding to the first path in the PDCP entity, the third instruction instructing the first path to discard the duplicate corresponding to the PDCP data PDU.

[0130] In some embodiments, after receiving the third indication, the terminal device 120-1 determines, at the SRAP entity, whether an SRAP SDU corresponding to the PDCP data PDU has already been submitted to the first entity. Further, in accordance with the determination that the SRAP SDU has already been submitted to the first entity as an SRAP PDU, the terminal device 120-1 sends, at the SRAP entity, a fourth indication corresponding to the third indication to the first entity, and in accordance with the determination that the SRAP SDU has not been submitted to the first entity, the terminal device 120-1 discards the SRAP SDU at the SRAP entity.

[0131] In some embodiments, terminal device 120-1 sends the third indication directly to the first entity in the PDCP entity.

[0132] Examples of equipment and devices 7 is a schematic block diagram of an apparatus 700 suitable for implementing embodiments of the present disclosure. Apparatus 700 can be considered another exemplary implementation of terminal apparatus 120 shown in FIG. 1A. Thus, apparatus 700 can be implemented in terminal apparatus 120, or at least as part of terminal apparatus 120.

[0133] As shown, the apparatus 700 comprises a processor 710, a memory 720 coupled to the processor 710, a suitable transmitter (TX) / receiver (RX) 740 coupled to the processor 710, and a communication interface coupled to the TX / RX 740. The memory 710 stores at least a portion of a program 730. The TX / RX 740 is for bidirectional communication. The TX / RX 740 has at least one antenna to facilitate communication, although in practice the access nodes referred to in this disclosure may have multiple antennas. The communication interface may represent any interface required for communication with other network elements, such as, for example, an X2 / Xn interface for bidirectional communication between eNBs / gNBs, an S1 / NG interface for communication between a Mobility Management Entity (MME) / Access and Mobility Management Function (AMF) / SGW / UPF and an eNB / gNB, an Un interface for communication between an eNB / gNB and a relay node (RN), or a Uu interface for communication between an eNB / gNB and a terminal device.

[0134] The program 730 is assumed to include program instructions that, when executed by the associated processor 710, cause the device 700 to operate in accordance with embodiments of the present disclosure, as described herein with reference to Figures 1A-6. Embodiments of the present disclosure may be implemented by computer software executable by the processor 710 of the device 700, by hardware, or by a combination of software and hardware. The processor 710 may be configured to implement various embodiments of the present disclosure. Furthermore, the combination of the processor 710 and the memory 720 may form a processing means 750 suitable for implementing various embodiments of the present disclosure.

[0135] Memory 720 may be of any type suitable for a local technology network and may be implemented using any suitable data storage technology, such as, by way of non-limiting example, non-transitory computer-readable storage media, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. While only one memory 720 is shown in device 700, device 700 may have multiple physically distinct memory modules. Processor 710 may be of any type suitable for a local technology network and may include, by way of non-limiting example, one or more of a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. Device 700 may have multiple processors, such as application-specific integrated circuit chips that are time-slaved to a clock that synchronizes the main processor.

[0136] In some embodiments, a terminal device 120-1 configured to have multiple paths including a first path that is an indirect path comprises circuitry configured to, at a first entity of the terminal device 120-1, the first entity corresponding to the first path and at a layer below the PDCP layer, perform one of: determining successful transmission associated with a PDCP PDU on the first path; sending an acknowledgement indication indicating successful transmission to the PDCP entity of the terminal device 120-1; and disabling sending of the acknowledgement indication to the PDCP entity.

[0137] In some embodiments, the confirmation indication indicates at least one of an RB identity, an RB type, a sequence number corresponding to the PDCP data PDU, and a successful transmission of the PDCP data PDU.

[0138] In some embodiments, the first entity is an RLC entity or a non-standardized entity.

[0139] In some embodiments, the circuitry is further configured to: send, at the first entity, a first indication indicating successful transmission to an SRAP entity corresponding to the first path; and, at the SRAP entity, send a second indication corresponding to the first indication to a PDCP entity.

[0140] In some embodiments, the circuitry is further configured to send a first indication indicating successful transmission directly to the PDCP entity at the first entity.

[0141] In some embodiments, the circuitry is further configured to disable, at the first entity, sending of a first indication indicating successful transmission directly to the PDCP entity or sending of the first indication to an SRAP entity corresponding to the first path.

[0142] In some embodiments, the circuitry is further configured to: send, at the first entity, a first indication indicating successful transmission to an SRAP entity corresponding to the first path; and disable, at the SRAP entity, transmission of a second indication corresponding to the first indication to the PDCP entity.

[0143] In some embodiments, the circuitry is further configured to, after receiving the confirmation indication, disable, in the PDCP entity, instructing an entity corresponding to a second path of the plurality of paths to discard a copy corresponding to the PDCP data PDU, wherein the entity corresponding to the second path is one of an RLC entity, an SRAP entity, and a non-standardization entity.

[0144] In some embodiments, the second path is a direct path or another indirect path.

[0145] In some embodiments, a terminal device 120-1 configured to have multiple paths, including a first path that is an indirect path, comprises circuitry configured to: determine, in a PDCP entity of the terminal device 120-1, a successful transmission associated with a PDCP PDU on a second path of the multiple paths; and send a discard instruction to a first entity corresponding to the first path, the first entity being at a layer lower than the PDCP layer, instructing the first path to discard a copy corresponding to the PDCP data PDU.

[0146] In some embodiments, the second path is a direct path or another indirect path.

[0147] In some embodiments, the discard indication indicates at least one of an RB identity, an RB type, a sequence number corresponding to the PDCP data PDU, and a successful transmission of the PDCP data PDU.

[0148] In some embodiments, the first entity is an RLC entity or a non-standardized entity.

[0149] In some embodiments, the circuitry is further configured to send, at the PDCP entity, a third instruction to an SRAP entity corresponding to the first path, instructing the first path to discard the duplicate corresponding to the PDCP data PDU.

[0150] In some embodiments, the circuitry is further configured to, after receiving the third indication, determine at the SRAP entity of terminal device 120-1 whether a SRAP SDU corresponding to the PDCP data PDU has already been submitted to the first entity, and, in accordance with a determination that the SRAP SDU has already been submitted to the first entity as a SRAP PDU, to send at the SRAP entity a fourth indication corresponding to the third indication to the first entity, and, in accordance with a determination that the SRAP SDU has not been submitted to the first entity, to discard the SRAP SDU at the SRAP entity.

[0151] In some embodiments, the circuitry is further configured to send the third indication directly to the first entity at the PDCP entity.

[0152] The term "circuitry" as used in this disclosure may refer to a hardware circuit and / or a combination of a hardware circuit and software. For example, a circuit may be a combination of analog and / or digital hardware circuitry and software / firmware. As another example, a circuit may be any portion of a hardware processor with software, where the hardware processor includes digital signal processor(s), software, and memory(s) that work together to cause a device, such as a terminal device or network device, to perform various functions. As yet another example, a circuit may be a hardware circuit and / or processor, such as a microprocessor or portion of a microprocessor, that requires software / firmware to operate, but the software may not be present when not necessary for operation. As used in this disclosure, the term circuitry also includes simply a hardware circuit or processor(s) or portion of a hardware circuit or processor(s) and its (or their) associated software and / or firmware implementation.

[0153] In summary, the embodiments of the present disclosure provide the following solutions:

[0154] In one solution, a communication method includes, in a first entity of a terminal device configured to have multiple paths including a first path that is an indirect path, the first entity corresponding to the first path and at a layer lower than a Packet Data Convergence Protocol (PDCP) layer, performing one of determining successful transmission associated with a PDCP data packet data unit (PDU) on the first path, sending a confirmation indication indicating successful transmission to the PDCP entity of the terminal device, and disabling sending of the confirmation indication to the PDCP entity.

[0155] In some embodiments, the confirmation indication indicates at least one of a radio bearer (RB) identity, an RB type, a sequence number corresponding to the PDCP data PDU, and successful transmission of the PDCP data PDU.

[0156] In some embodiments, the first entity is a radio link control (RLC) entity or a non-standardized entity.

[0157] In some embodiments, sending the confirmation indication to the PDCP entity includes: sending, at the first entity, a first indication indicating successful transmission to a sidelink relay adaptation protocol (SRAP) entity corresponding to the first path; and sending, at the SRAP entity, a second indication corresponding to the first indication to the PDCP entity.

[0158] In some embodiments, sending the confirmation indication to the PDCP entity includes, at the first entity, sending a first indication indicating successful transmission directly to the PDCP entity.

[0159] In some embodiments, disabling sending confirmation indications to the PDCP entity includes disabling, at the first entity, sending a first indication indicating successful transmission directly to the PDCP entity or sending the first indication to a sidelink relay adaptation protocol (SRAP) entity corresponding to the first path.

[0160] In some embodiments, disabling sending of confirmation indications to the PDCP entity includes: sending, at the first entity, a first indication indicating successful transmission to a sidelink relay adaptation protocol (SRAP) entity corresponding to the first path; and disabling, at the SRAP entity, sending of a second indication corresponding to the first indication to the PDCP entity.

[0161] In some embodiments, the method further includes, after receiving the confirmation indication, disabling, at the PDCP entity, instructing an entity corresponding to a second path of the plurality of paths to discard copies corresponding to the PDCP data PDU, wherein the entity corresponding to the second path is one of a Radio Link Control (RLC) entity, a Sidelink Relay Adaptation Protocol (SRAP) entity, and a non-standardization entity.

[0162] In some embodiments, the second path is a direct path or another indirect path.

[0163] In another solution, a communication method includes, in a Packet Data Convergence Protocol (PDCP) entity of a terminal device configured to have multiple paths including a first path that is an indirect path, determining successful transmission associated with a PDCP data packet data unit (PDU) on a second path of the multiple paths, and sending a discard instruction to a first entity corresponding to the first path, the first entity being at a layer lower than the PDCP layer, instructing the first path to discard a copy corresponding to the PDCP data PDU.

[0164] In some embodiments, the second path is a direct path or another indirect path.

[0165] In some embodiments, the discard indication indicates at least one of a radio bearer (RB) identity, an RB type, a sequence number corresponding to the PDCP data PDU, and successful transmission of the PDCP data PDU.

[0166] In some embodiments, the first entity is a radio link control (RLC) entity or a non-standardized entity.

[0167] In some embodiments, sending the discard instruction includes, at the PDCP entity, sending a third instruction to a Sidelink Relay Adaptation Protocol (SRAP) entity corresponding to the first path, the third instruction instructing the first path to discard the duplicate corresponding to the PDCP data PDU.

[0168] In some embodiments, the method further includes, after receiving the third indication, determining, at the SRAP entity, whether an SRAP SDU corresponding to the PDCP data PDU has already been submitted to the first entity; in accordance with the determination that the SRAP SDU has already been submitted to the first entity as an SRAP PDU, sending, at the SRAP entity, a fourth indication corresponding to the third indication to the first entity; and in accordance with the determination that the SRAP SDU has not been submitted to the first entity, discarding the SRAP SDU at the SRAP entity.

[0169] In some embodiments, sending the discard instruction includes, at the PDCP entity, sending a third instruction directly to the first entity.

[0170] In another solution, a communications device comprises a processor configured to cause the device to perform any of the above methods.

[0171] Another solution is a computer-readable medium having stored thereon instructions that, when executed on at least one processor, cause the at least one processor to perform a method according to any of the methods described above.

[0172] In general, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic, or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described using block diagrams, flowcharts, or some other pictorial representations, it should be understood that the blocks, devices, systems, techniques, or methods described in this disclosure may be implemented in, by way of non-limiting example, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller, or other computing device, or some combination thereof.

[0173] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions (e.g., computer-executable instructions included in program modules) that execute on a device by a target real or virtual processor to perform the processes or methods described above with reference to FIGS. 1-6. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split among program modules as desired in various embodiments. The machine-executable instructions for the program modules may be executed in local or distributed devices. In a distributed device, the program modules may be located in both local and remote storage media.

[0174] Program code for implementing the methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus, so that when executed by the processor or controller, the program code performs the functions / acts specified in the flowcharts and / or block diagrams. The program code may be executed entirely on a machine, partially on a machine, as a stand-alone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0175] The program code may be embodied in a machine-readable medium, which may be any tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. The machine-readable medium includes, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination thereof. More specific examples of machine-readable storage media include an electrical connection having one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0176] Furthermore, although operations are described in a particular order, this should not be understood as requiring such operations to be performed in the particular order shown, or sequentially, or that all of the operations shown be performed, to achieve desirable results. In certain situations, multitasking and parallel processing may be advantageous. Similarly, while several specific implementation details are included in the above description, these should not be construed as limiting the scope of the disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination.

[0177] Although the present disclosure has been described in language specific to structural features and / or methodological operations, it is to be understood that the present disclosure, which is limited to the appended claims, is not necessarily limited to the specific features or operations described above. Rather, the specific features and operations described above are disclosed as example forms of implementing the claims.

Claims

1. In a first entity of a terminal device configured to have a plurality of paths, including a first path that is an indirect path, the first entity corresponding to the first path and at a layer lower than a packet data convergence protocol (PDCP) layer determines successful transmission associated with a PDCP data packet data unit (PDU) on the first path; sending a confirmation indication to a PDCP entity of the terminal device indicating the successful transmission; and disabling sending the confirmation indication to the PDCP entity; and Methods of communication, including:

2. The confirmation instruction is Radio bearer (RB) identity, RB type, a sequence number corresponding to the PDCP data PDU; and Successful transmission of PDCP data PDUs, Indicating at least one of The method of claim 1.

3. the first entity is a radio link control (RLC) entity or a non-standardized entity; The method of claim 1.

4. sending the confirmation indication to the PDCP entity sending, at the first entity, a first indication indicating the successful transmission to a sidelink relay adaptation protocol (SRAP) entity corresponding to the first path; sending, at the SRAP entity, a second indication corresponding to the first indication to the PDCP entity; The method of claim 1.

5. sending the confirmation indication to the PDCP entity transmitting, at the first entity, a first indication indicating the successful transmission directly to the PDCP entity; The method of claim 1.

6. Disabling sending the confirmation indication to the PDCP entity includes: disabling, at the first entity, a direct transmission of a first indication indicating the successful transmission to the PDCP entity or a sidelink relay adaptation protocol (SRAP) entity corresponding to the first path. The method of claim 1.

7. Disabling sending the confirmation indication to the PDCP entity includes: sending, at the first entity, a first indication indicating the successful transmission to a sidelink relay adaptation protocol (SRAP) entity corresponding to the first path; and disabling, in the SRAP entity, transmission of a second indication corresponding to the first indication to a PDCP entity. The method of claim 1.

8. and after receiving the confirmation indication, disabling, in the PDCP entity, instructing an entity corresponding to a second path among the plurality of paths to discard a copy corresponding to the PDCP data PDU; The entity corresponding to the second path is a Radio Link Control (RLC) entity; a Sidelink Relay Adaptation Protocol (SRAP) entity; and A non-standardized entity is one of the The method of claim 1.

9. the second path is a direct path or another indirect path; The method of claim 8.

10. determining, in a Packet Data Convergence Protocol (PDCP) entity of a terminal device configured with a plurality of paths, including a first path being an indirect path, a successful transmission associated with a PDCP data packet data unit (PDU) on a second path of the plurality of paths; sending a discard instruction to a first entity corresponding to the first path, the first entity being at a layer lower than a PDCP layer, instructing the first path to discard a copy corresponding to the PDCP data PDU; Method of communication.

11. the second path is a direct path or another indirect path; The method of claim 10.

12. The discard instruction is Radio bearer (RB) identity, RB type, a sequence number corresponding to the PDCP data PDU; and Successful transmission of PDCP data PDUs, Indicating at least one of The method of claim 10.

13. the first entity is a radio link control (RLC) entity or a non-standardized entity; The method of claim 10.

14. The sending of the discard instruction includes: sending, in the PDCP entity, to a Sidelink Relay Adaptation Protocol (SRAP) entity corresponding to the first path, a third indication to instruct the first path to discard the duplicate corresponding to the PDCP data PDU. The method of claim 10.

15. determining, in the SRAP entity after receiving the third indication, whether an SRAP SDU corresponding to the PDCP data PDU has already been submitted to the first entity; sending, at the SRAP entity, a fourth indication corresponding to the third indication to the first entity according to determining that the SRAP SDU has already been submitted as an SRAP PDU to the first entity; discarding the SRAP SDU at the SRAP entity in accordance with a determination that the SRAP SDU has not been submitted to the first entity; further comprising:

15. The method of claim 14.

16. The sending of the discard instruction includes: and transmitting, at the PDCP entity, a third indication directly to the first entity. The method of claim 10.

17. a processor; a memory coupled to the processor and having instructions stored therein, The instructions, when executed by the processor, cause the first terminal device to perform a method according to any one of claims 1 to 9 or any one of claims 11 to 16. Terminal device.

18. - storing instructions which, when executed on at least one processor, cause the at least one processor to carry out the method of any one of claims 1 to 9 or any one of claims 11 to 16; Computer-readable medium.

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