Apparatus and method for communication

Abstract

Embodiments of the present disclosure provide an importance-based packet data convergence protocol (PDCP) replication enhancement solution. In the solution, a terminal device receives replication information indicating an active state of PDCP replication for a plurality of importance levels, the replication information also indicating a quality of service (QoS) flow associated with the plurality of importance levels; determining whether to activate the PDCP replication for a first importance level based at least on the replication information; and if the PDCP replication is activated for the first importance level, replication, by a PDCP entity of the terminal device, a first packet within the QoS flow for submission to a plurality of Radio Link Control (RLC) entities of the terminal device, the first packet having the first importance level.

Description

TECHNICAL FIELD

[0001] Example embodiments of the present disclosure generally relate to the field of communications technology, and in particular, to devices and methods for packet data convergence protocol (PDCP) duplication enhancement based on importance of packets. BACKGROUND

[0002] In Release 18 (Rel-18), a work item on eXtended Reality (XR) enhancement is ongoing. XR awareness of terminal devices and network devices will improve user experience, increase the capacity of New Radio (NR) systems supporting XR services, and reduce the power consumption of terminal devices.

[0003] Due to Internet Protocol (IP) fragmentation or other reasons, a video frame in XR traffic can arrive at a Radio Access Network (RAN) as a set of Protocol Data Units (PDUs) (e.g., multiple IP packets). For XR / media services, a set of packets is used to carry the payload of a PDU collection (e.g., a frame, a video slice / tile). The packets in such a PDU collection can be decoded / processed as a whole. PDU collection based Quality of Service (QoS) handling is studied, and this handling will impact the design of RAN protocols.

[0004] In downlink, PDU collection importance is provided by a Core Node (CN) to identify the importance of a PDU collection within a QoS flow. Similarly, in uplink, PDU collection importance should also be provided to the Access Stratum (AS) layer. According to this importance, PDU collections with high importance can be duplicated to improve reliability. SUMMARY

[0005] Generally, embodiments of the present disclosure provide methods, devices, and computer storage media for PDCP duplication enhancement based on importance of packets.

[0006] In a first aspect, a terminal device is provided. The terminal device includes a processor configured to cause the terminal device to receive, from a network device, duplication information indicating activation status of packet data convergence protocol (PDCP) duplication for a plurality of importance levels, the duplication information further indicating quality of service (QoS) flows associated with the plurality of importance levels; determine, based at least on the duplication information, whether to activate the PDCP duplication for a first importance level of the plurality of importance levels; and in accordance with a determination that the PDCP duplication is activated for the first importance level, duplicate, by a PDCP entity of the terminal device, a first packet within the QoS flow for submission to a plurality of radio link control (RLC) entities of the terminal device, the first packet having the first importance level.

[0007] In a second aspect, a network device is provided. The network device includes a processor configured to cause the network device to send, to a terminal device, duplication information indicating activation status of packet data convergence protocol (PDCP) duplication for a plurality of importance levels, the duplication information further indicating quality of service (QoS) flows associated with the plurality of importance levels.

[0008] In a third aspect, a terminal device is provided. The terminal device includes a processor configured to cause the terminal device to, in response to an event or packet discard indication from a network device, discard a first duplicated packet generated by packet data convergence protocol (PDCP) duplication of a first packet based on at least one of: an importance level of the first packet, a radio bearer associated with the first packet, or a radio link control (RLC) entity associated with the first duplicated packet.

[0009] In a fourth aspect, a network device is provided. The network device includes a processor configured to cause the network device to send, to a terminal device, at least one of: a packet discard indication to discard at least one duplicated packet generated by packet data convergence protocol (PDCP) duplication of a packet, or discard information indicating an order in which different duplicated packets are to be discarded.

[0010] In a fifth aspect, a communication method performed by a terminal device is provided. The method includes receiving, from a network device, duplication information indicating activation status of packet data convergence protocol (PDCP) duplication for a plurality of importance levels, the duplication information further indicating quality of service (QoS) flows associated with the plurality of importance levels; determining, based at least on the duplication information, whether to activate the PDCP duplication for a first importance level of the plurality of importance levels; and in accordance with a determination that the PDCP duplication is activated for the first importance level, duplicating, by a PDCP entity of the terminal device, a first packet within the QoS flow for submission to a plurality of radio link control (RLC) entities of the terminal device, the first packet having the first importance level.

[0011] In a sixth aspect, a communication method performed by a network device is provided. The method includes transmitting, to a terminal device, duplication information indicating activation status of packet data convergence protocol (PDCP) duplication for a plurality of importance levels, the duplication information further indicating quality of service (QoS) flows associated with the plurality of importance levels.

[0012] In a seventh aspect, a communication method performed by a terminal device is provided. The method includes, in response to an event or packet discard indication from a network device, discarding, based on at least one of: an importance level of a first packet, a radio bearer associated with the first packet, or a radio link control (RLC) entity associated with a first duplicated packet, a first duplicated packet generated by PDCP duplication of the first packet.

[0013] In an eighth aspect, a communication method performed by a network device is provided. The method includes transmitting, to a terminal device, at least one of: a packet discard indication for discarding at least one duplicated packet generated by PDCP duplication of a packet, or discard information indicating an order in which different duplicated packets are to be discarded.

[0014] In a ninth aspect, a computer-readable medium having instructions stored thereon, which when executed on at least one processor, cause the at least one processor to perform the method according to any one of the fifth aspect to the eighth aspect.

[0015] Other features of the present disclosure will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0016] The above and other objects, features and advantages of the present disclosure will become more apparent from the following description when taken in conjunction with the accompanying drawings, in which: Figure 1An exemplary communication environment in which exemplary embodiments of the present disclosure can be implemented is illustrated; Figure 2 A signaling flow for packet duplication according to some embodiments of the present disclosure is illustrated; Figure 3 An exemplary schematic diagram of packet paths according to some embodiments of the present disclosure is illustrated; Figure 4A A schematic diagram illustrating an exemplary format of duplication information via a medium access control (MAC) control element (CE) according to some embodiments of the present disclosure is illustrated; Figure 4B A schematic diagram illustrating another exemplary format of duplication information via a MAC CE according to some embodiments of the present disclosure is illustrated; Figure 4C A schematic diagram illustrating another exemplary format of duplication information format via a MAC CE according to some embodiments of the present disclosure is illustrated; Figure 5A A schematic diagram illustrating an exemplary format of duplication information via a PDCP control PDU according to some embodiments of the present disclosure is illustrated; Figure 5B A schematic diagram illustrating another exemplary format of duplication information via a PDCP control PDU according to some embodiments of the present disclosure is illustrated; Figure 6A A schematic diagram illustrating an exemplary format of duplication information via a SDAP control PDU according to some embodiments of the present disclosure is illustrated; Figure 6B A schematic diagram illustrating another exemplary format of duplication information via a SDAP control PDU according to some embodiments of the present disclosure is illustrated; Figure 7 A schematic diagram illustrating another exemplary format of duplication information associated with a QoS flow according to some embodiments of the present disclosure is illustrated; Figure 8 Another signaling flow for packet duplication according to some embodiments of the present disclosure is illustrated; Figure 9 A flowchart of a method implemented at a terminal device according to some embodiments of the present disclosure is illustrated; Figure 10 A flowchart of a method implemented at a network device according to some embodiments of the present disclosure is illustrated; Figure 11 A flowchart of a method implemented at a terminal device according to some embodiments of the present disclosure is illustrated; Figure 12A flow diagram illustrating a method implemented at a network device, in accordance with some embodiments of the disclosure, is shown in FIG. 1. Figure 13 A simplified block diagram of a device suitable for implementing exemplary embodiments of the disclosure is shown in FIG. 2.

[0017] Throughout the drawings, identical or similar reference numerals can designate identical or similar elements. DETAILED DESCRIPTION

[0018] The principles of the present disclosure will now be described with reference to some example embodiments. It should be understood that these embodiments are described for illustrative purposes only and are helpful in understanding and implementing the present disclosure, but are not meant to limit the scope of the present disclosure in any way. The embodiments described herein can be implemented in various ways other than those described below.

[0019] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0020] As used herein, the term “terminal device” refers to any device that has wireless or wired communication capabilities. Examples of terminal devices include, but are not limited to: a user equipment (UE); a personal computer; a desktop computer; a mobile computer; a cellular phone; a smart phone; a personal digital assistant (PDA); a portable computer; a tablet; a wearable device; an internet of things (IoT) device; an Ultra-reliable and Low Latency Communication (URLLC) device; an Internet of Everything (IoE) device; a machine type communication (MTC) device; a device for V2X communication on a vehicle, where X refers to a pedestrian, a vehicle, or infrastructure / network; a device for Integrated Access and Backhaul (IAB); a spaceborne or an airborne vehicle in a Non-terrestrial network (NTN) that includes satellites and High Altitude Platforms (HAPs) covering Unmanned Aircraft Systems (UAS); an eXtended Reality (XR) device including different types of realities such as Augmented Reality (AR), Mixed Reality (MR), and Virtual Reality (VR); an unmanned aerial vehicle (UAV), which is commonly known as a drone, that is an aircraft without any human pilot onboard; a device on a high speed train (HST); or an image-capturing device such as a digital camera, a sensor; a gaming device; a music storage and playback appliance; or an Internet device, etc. that enables wireless or wired Internet access and browsing, etc. A “terminal device” can also have “multicast / broadcast” functionality to support public safety and mission critical, V2X applications, transparent IPv4 / IPv6 multicast delivery, IPTV, smart energy, wireless backhaul, and so on. A “terminal device” can also incorporate one or more Subscriber Identity Modules (SIMs), in which case the latter is referred to as a multi-SIM.The term “terminal device” can be used interchangeably with “UE,” “mobile station,” “subscriber station,” “mobile terminal,” “user terminal,” or “wireless device.”

[0021] The term “network device” refers to a device capable of providing or hosting a cell or coverage in which a terminal device can communicate. Examples of network devices include, but are not limited to, NodeB (NodeB or NB), evolved NodeB (eNodeB (evolved NodeB) or eNB), next generation NodeB (gNB, generation NodeB), transmission reception point (TRP), remote radio unit (RRU), radio head (RH), remote radio head (RRH), IAB node, low power node (such as femto node, pico node), reconfigurable intelligent surface (RIS), and the like.

[0022] A terminal device or a network device can have Artificial Intelligence (AI) or machine learning capability. A terminal device or a network device typically includes a model that has been trained for a specific function according to a large amount of collected data and can be used to predict some information.

[0023] A terminal device or a network device can operate in several frequency ranges, such as FR1 (e.g., 450-6000 MHz), FR2 (e.g., 24.25-52.6 GHz), bands greater than 100 GHz, and terahertz (THz). A terminal device or a network device can also operate on licensed / unlicensed / shared spectrum. In a multi-radio dual connectivity (MR-DC) application scenario, a terminal device can have more than one connection with a network device. A terminal device or a network device can operate in full duplex, flexible duplex, and cross-split duplex modes.

[0024] Embodiments of the present disclosure can be implemented in test equipment (e.g., signal generator, signal analyzer, spectrum analyzer, network analyzer, test terminal device, test network device, channel emulator). In some embodiments, a terminal device can connect with a first network device and a second network device. One of the first network device and the second network device can be a master node, and the other can be a secondary node. The first network device and the second network device can use different radio access technologies (RAT). In some embodiments, the first network device can be a first RAT device, and the second network device can 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 different RATs can be sent from at least one of the first network device or the second network device to the terminal device. In some embodiments, first information can be sent from the first network device to the terminal device, and second information can be sent from the second network device to the terminal device directly or via the first network device. In some embodiments, information related to configuration for the terminal device configured by the second network device can be sent from the second network device via the first network device. Information related to reconfiguration for the terminal device configured by the second network device can be sent from the second network device to the terminal device directly or via the first network device.

[0025] As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term “including” and variations thereof are to be construed as open-ended terms meaning that other functions, devices, or items not specifically named are also encompassed. The term “based on” is to be construed as “based at least in part on.” The term “one embodiment” and “an embodiment” are to be construed as “at least one embodiment.” The term “another embodiment” is to be construed as “at least one other embodiment.” The terms “first,” “second,” etc. can refer to different or the same objects. Other explicit or implicit definitions can be given below.

[0026] In some examples, values, programs, or devices are described as “best,” “lowest,” “highest,” “smallest,” “greatest,” etc. It will be understood that such descriptions indicate that a selection can be made among many used functional alternatives, and that such selection need not be better, smaller, higher, or otherwise better than other selections.

[0027] As used herein, the term “resource,” “transmission resource,” “uplink resource,” or “downlink resource” can refer to any resource used to perform communication, such as a resource in time domain, a resource in frequency domain, a resource in space domain, a resource in code domain, or any other resource that enables communication, etc. Hereinafter, unless explicitly stated, resources in frequency domain and time domain will be used as examples of transmission resources for describing some example embodiments of the present disclosure. Note that example embodiments of the present disclosure are equally applicable to other resources in other domains.

[0028] As used herein, the term “PDU set” can include one or more PDUs that carry a payload of one information unit generated at an application layer (e.g., a frame or a video slice for an eXtended Reality Multimedia (XRM) service). In some implementations, all PDUs in a PDU set are needed by the application layer to use the corresponding information unit. In other implementations, the application layer can recover part or all of the information unit when some PDUs are lost.

[0029] As used herein, the term “packet” can refer to a PDU, one or more PDUs, a service data unit (SDU), one or more SDUs, a PDU set, etc. Hereinafter, some embodiments can be described with respect to a PDU or a PDU set. However, this is an example and not a limitation.

[0030] As used herein, the term “data burst” can refer to a group of PDUs generated and transmitted by an application in a short period of time. A data burst can include one or more PDU sets.

[0031] As used herein, the term “radio bearer (RB)” as used herein can refer to a tunnel that can fetch and carry information from one end to another. The term “data radio bearer (DRB)” as used herein can refer to an RB that is established for transmission of data plane packets. The term “signaling radio bearer (SRB)” as used herein can refer to an RB used for transmission of signaling messages (e.g., radio resource control (RRC) messages, non-access stratum (NAS) messages). In the present disclosure, the terms "importance" and "importance level" are used interchangeably. As one example, a value of importance can be used to indicate an importance level. Further, embodiments described in relation to "importance" or "importance level" can apply to "priority" or "priority level". Thus, the terms "importance", "importance level", "priority", and "priority level" are used interchangeably.

[0032] The principles and specific embodiments of the present disclosure will be described in detail below with reference to the attached drawings.

[0033] Figure 1 A schematic diagram of an exemplary communication environment 100 in which exemplary embodiments of the present disclosure can be implemented is illustrated. In the communication environment 100, a plurality of communication devices, including terminal devices 110 and network devices 120, can communicate with each other.

[0034] In Figure 1 In an example, the terminal devices 110 can be UEs, and the network devices 120 can be base stations serving the UEs. A service area of the network devices 120 can be referred to as a cell 102. In the present disclosure, the terms "terminal device" and "UE" are used interchangeably, and the terms "network device", "base station", and "network (NW)" are used interchangeably.

[0035] It should be understood that Figure 1 The number of devices and their connections shown are for illustrative purposes only and are not intended to be limiting. The communication environment 100 can include any suitable number of devices configured to implement exemplary embodiments of the present disclosure. Although not shown, it should be appreciated that one or more additional devices can be located in the cell 102, and one or more additional cells can be deployed in the communication environment 100.

[0036] In some exemplary embodiments, a link from a network device 120 to a terminal device 110 is referred to as a DL (downlink), and a link from a terminal device 110 to a network device 120 is referred to as a UL (uplink). In the DL, the network device 120 is a TX (transmit) device (or transmitter), and the terminal device 110 is an RX (receive) device (or receiver). In the UL, the terminal device 110 is a TX device (or transmitter), and the network device 120 is an RX device (or receiver).

[0037] Communications in the communication environment 100 can conform to any suitable standards, including but not limited to Global System for Mobile Communication (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 can be performed according to any generation of communication protocol that is currently known or that will be developed in the future. 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), 5.5G, 5G-Advanced networks, or sixth generation (6G) networks.

[0038] In Figure 1 In an example, the terminal device 110 can include one PDCP entity 130 and one or more Radio Link Control (RLC) entities. If duplication is configured for an RB through RRC signaling, the terminal device 110 can include at least two RLC entities to handle duplicated packets, such as RLC entity 140-1 and RLC entity 140-2 (which are also referred to as a primary RLC and a secondary RLC, or individually as RLC entity 140). A logical channel (LCH) corresponding to RLC entity 140-1 is referred to as a primary LCH, and an LCH corresponding to RLC entity 140-2 is referred to as a secondary LCH.

[0039] In some embodiments, all RLC entities have the same RLC mode. Therefore, the duplication at PDCP includes multiple submissions of the same packet: one to each activated RLC entity of the RB. Thus, by means of multiple independent transmission paths, packet duplication increases reliability, reduces latency, and is particularly beneficial for Ultra Reliable and Low Latency Communication (URLLC) services.

[0040] When duplication is configured for a DRB, RRC also sets the state of PDCP duplication (activated or deactivated) at (re)configuration. After (re)configuration, the PDCP duplication state can be dynamically controlled later by Medium Access Control (MAC) Control Elements (CEs) and Dual Connectivity (DC). The terminal device applies the MAC CE commands regardless of their origin (Master Cell Group, MCG, or Secondary Cell Group, SCG).

[0041] When duplication is configured for a SRB, the state is always active and cannot be dynamically controlled. When duplication is configured for a DRB with more than one secondary RLC entity, RRC also sets the state of each of these entities (i.e., activated or deactivated). Later, MAC CEs can be used to dynamically control whether each configured secondary RLC entity for a DRB should be activated or deactivated, i.e., which RLC entities should be used for duplicated transmission.

[0042] In some embodiments, the primary RLC entity cannot be deactivated. When duplication for a DRB is deactivated, all secondary RLC entities associated with that DRB are deactivated. When a secondary RLC entity is deactivated, the secondary RLC entity is not re-established, the Hybrid Automatic Repeat Quest (HARQ) buffer is not flushed, and the transmitting PDCP entity should instruct the secondary RLC entity to discard all duplicated PDCP PDUs.

[0043] PDCP Control PDUs are required not to be duplicated and are always submitted to the primary RLC entity.

[0044] When duplication for a DRB is activated, the Radio Access Network (RAN) can ensure that at least one serving cell is activated for each LCH associated with the activated RLC entity of the DRB. When the deactivation of an SCell leaves and there is no serving cell activated for a LCH of the DRB, the NG-RAN can ensure that duplication is also deactivated for the RLC entity associated with the LCH.

[0045] When duplication is activated, the original PDCP PDU and the corresponding duplicate can not be transmitted on the same carrier. The LCHs of the RBs configured with duplication can belong to the same MAC entity (referred to as Carrier Aggregation (CA) duplication) or belong to different MAC entities (referred to as DC duplication). When duplication on more than two RLC entities is configured for a RB, CA duplication can also be configured in either or both of the MAC entities together with DC duplication. In CA duplication, LCH mapping restrictions are used in the MAC entity to ensure that different LCHs of a RB in the MAC entity are not transmitted on the same carrier. When CA duplication is configured for an SRB, one of the LCHs associated with the SRB is mapped to a Special Cell (SpCell), such as a Primary Cell (PCell) and a Primary Secondary Cell (PSCell).

[0046] When CA duplication is deactivated for a DRB in a MAC entity (i.e., none or only one of the RLC entities of the DRB in the MAC entity is activated), the logical channel mapping restrictions for the logical channels of the DRB are released as long as CA duplication remains deactivated for the DRB in the MAC entity.

[0047] When an RLC entity acknowledges the transmission of a PDCP PDU, the PDCP entity can instruct other RLC entities to discard the PDCP PDU. In addition, in the case of CA duplication, when an RLC entity restricted to SCells reaches the maximum number of retransmissions for a PDCP PDU, the terminal device 110 notifies the network device 120 without triggering RLF (Radio Link Failure).

[0048] A one-octet copy activation / deactivation MAC CE is identified by a MAC subheader with a logical channel identity (LCID). The MAC CE has a fixed size and consists of a single octet containing eight D-fields (e.g., D0-D7). The copy activation / deactivation MAC CE is defined for the MAC entity. The Di field indicates the activation / deactivation status of PDCP duplication for DRB i, where i is the ascending order number of DRB ID in the DRBs configured with PDCP duplication and RLC entities associated with the MAC entity. The Di field set to 1 indicates that PDCP duplication for DRB i shall be activated. The Di field set to 0 indicates that PDCP duplication for DRB i shall be deactivated. Note that if a DRB is configured with more than two RLC entities, i.e., has more than two RLC-DRBs, the copy activation / deactivation MAC CE is not used.

[0049] A copy RLC activation / deactivation MAC CE is identified by a MAC subheader with an extended logical channel identity (eLCID). The MAC CE has a fixed size and consists of a single octet. The DRB ID field indicates the identity of the DRB for which the MAC CE applies. The length of this field can be 5 bits. The RLCi (e.g., RLC0-RLC2) field indicates the activation / deactivation status of PDCP duplication for RLC entity i of the DRB, where i is arranged in ascending order of secondary RLC entity LCH ID in the order of MCG and SCG. The RLCi field set to 1 indicates that PDCP duplication for RLC entity i shall be activated. The RLCi field set to 0 indicates that PDCP duplication for RLC entity i shall be deactivated.

[0050] The following PDU set related information is identified by the user plane function (UPF) to support PDU set based handling: PDU set sequence number (SN), end PDU of the PDU set, PDU SN within the PDU set, PDU set size in bytes. In some cases, it is up to the application to decide whether to transfer the PDU set size in bytes.

[0051] The PDU set importance parameter can be used to identify the importance of the PDU set in a QoS flow. In case of congestion, the RAN can use this parameter for packet discard at PDU set level.

[0052] The following PDU set QoS parameters are defined to support PDU set handling: PDU set error rate (PSER), PDU set delay budget (PSDB), and whether all PDUs in a PDU set are required by the application layer (PDU set integrity indication).

[0053] PSER defines an upper bound on the rate of PDU sets that have been processed by the link layer protocol transmitting end (e.g., RLC in 3GPP access RAN) but have not been successfully delivered to the upper layer (e.g., PDCP in 3GPP access RAN) by the corresponding receiving end. Thus, PSER defines an upper bound on the non-congestion related packet loss rate. The purpose of PSER is to allow proper link layer protocol configuration (e.g., RLC and HARQ in 3GPP access RAN). The value of PSER is the same in UL and DL for each 5G QoS identifier (5QI). A PDU set is considered to be in error if any of the PDUs in the PDU set is not successfully transmitted. Note that the definition of PSER can be revisited.

[0054] PSDB defines an upper bound on the delay that a PDU set can encounter when transmitted between a UE and an N6 termination point at the UPF, i.e., the time between the reception of the first PDU of a PDU set and the successful delivery of the last arrived PDU. PSDB applies to DL PDU sets received by the UPF over the N6 interface and to UL PDU sets transmitted by the terminal device 110. The value of PSDB is the same in UL and DL for a certain 5QI. Note that the definition of PSDB can be revisited. Note also that a PDU set is considered to be successfully delivered if all PDUs of the PDU set are successfully delivered.

[0055] In order to enable support of PSDB, it is assumed that there is a maximum duration threshold on the inter-arrival time between the PDUs within a PDU set and the first arrived PDU according to a service level agreement (SLA) or pre-configuration. It needs to be discussed how to handle the case where the maximum duration threshold is not met. PSDB is an optional parameter. If the policy control function (PCF) has enough information to determine PSDB, PSDB is used to support the configuration of scheduling and link layer functions.

[0056] New 5G QoS parameters can be defined for PDU set concept. A PDU set consists of one or more PDUs, the following PDU set QoS parameters apply: PDU set delay budget (PSDB), PDU set error rate (PSER), PDU set integrated handling indication (PSIHI).

[0057] PDU set importance can be defined for delivery in units of each PDU set. All PDU sets within one QoS flow shall apply the same PSER, PSDB and PSIHI. PDU set importance can be different for different PDU sets within one QoS flow.

[0058] If PDU set QoS parameters (and other QoS characteristics like 5QI, ARP) are the same for different types of PDU sets, they can be mapped to the same QoS flow. One QoS flow is associated with one PSER and one PSDB at any time. In addition, different PDU sets within one QoS flow can be associated with different "PDU set importance" information.

[0059] In some cases, PDU set information "PDU set importance" can be provided by the UPF to the Next Generation Radio Access Network (NG-RAN) via the user plane header General Packet Radio Services (GPRS) Tunnelling Protocol for the User Plane (GTP-U) for user plane packets. It can be used by the NG-RAN for packet discard at PDU set level in case of congestion.

[0060] The current PDCP duplication mechanism includes: i) PDCP duplication is configured per RB granularity. Once a RB is configured with PDCP duplication function, all packets in this RB shall be duplicated when the PDCP duplication function is activated. ii) For XR traffic, different PDU sets within one QoS flow (which can be mapped to the same DRB) can be associated with different "PDU set importance" information. The reliability requirement of PDU sets with different importance can be different, therefore, PDU sets with high importance can apply PDCP duplication, while PDU sets with low importance do not apply PDCP duplication, thus improving the reliability of PDU sets with high importance, and improving resource utilization. iii) If congestion or other problems occur, PDCP duplication (for DRB, RLC, or importance) can be deactivated, or duplicated packets can be discarded with higher priority.

[0061] Based on the above, there are some issues to be solved. These issues include at least: i) how to perform importance-based PDCP duplication, ii) how to configure / activate / deactivate importance-based PDCP duplication, iii) how to calculate data volume when activating / deactivating importance-based PDCP duplication, iv) how to discard duplicated packets when congestion or other situations occur.

[0062] Reference is made to Figure 2 The figure illustrates a signaling flow 200 of packet duplication, according to some embodiments of the present disclosure. For the purpose of discussion, reference will be made to Figure 1 The signaling flow 200 is discussed, for example, by using the terminal device 110 and the network device 120.

[0063] As shown, the network device 120 sends (202) duplication information to the terminal device 110, the duplication information indicating activation status of PDCP duplication for a plurality of importance levels. In one embodiment, the duplication information can indicate activation status of PDCP duplication for a plurality of values. The duplication information further indicates QoS flows to which the plurality of importance levels are associated. For example, the plurality of importance levels can be associated with special QoS flows. The duplication information can be included in an activation / deactivation command. A plurality of QoS flows can be mapped to the same DRB. When the activation / deactivation command is transmitted to the terminal device 110, the terminal device 110 can be indicated a QoS flow ID (QFI, QoS Flow ID).

[0064] The terminal device 110 accordingly receives (204) the duplication information from the network device 120. Based at least on the duplication information, the terminal device 110 determines (206) whether to activate or deactivate PDCP duplication for an importance level in the plurality of importance levels.

[0065] If PDCP duplication is activated for the first importance level, the terminal device 110 duplicates (208) the first packet within the QoS flow for submission to the plurality of RLC entities of the terminal device 110. The first packet is set / configured with the first importance level. For example, the PDCP entity 130 of the terminal device 110 duplicates the first packet for submission to the RLC entity 140.

[0066] A packet (such as an SDU, a PDU, or a set of PDUs) can have different importance levels (which are also referred to as priorities). In one example, if PDCP duplication for a certain importance level is activated, the terminal device 110 (or the PDCP entity 130) can submit the same PDCP PDU (having that importance level) multiple times: once for each activated RLC entity 140 of the RB.

[0067] In some embodiments, the terminal device 110 can determine whether the duplication information indicates activation of PDCP duplication for the first importance level. Further, the terminal device 110 can determine whether PDCP duplication is activated for the RB associated with the QoS flow. If the duplication information indicates activation of PDCP duplication for the first importance level and / or PDCP duplication is activated for the RB, the terminal device 110 determines that PDCP duplication is activated for the first importance level.

[0068] For example, the activation / deactivation can be performed per DRB or per QoS flow. If duplication is deactivated for a DRB, all importance-based PDCP duplication associated with that DRB is deactivated.

[0069] In some embodiments, if PDCP duplication is deactivated for the first importance level, the terminal device 110 (or the PDCP entity 130) can instruct the secondary RLC entities of the plurality of RLC entities to discard duplicated packets corresponding to the first packet. In one example, if a certain importance level is deactivated, the transmitting PDCP entity can instruct the associated secondary RLC entities to discard all duplicated PDCP PDUs.

[0070] In some embodiments, based at least on the duplication information, the terminal device 110 can determine whether to deactivate PDCP duplication for a second importance level of the plurality of importance levels. If PDCP duplication is deactivated for the second importance level, the terminal device 110 (or the PDCP entity 130) can submit a second packet within the QoS flow to the primary RLC entity without duplicating the second packet. The second packet can be configured or set with the second importance level.

[0071] In one example, if PDCP duplication is deactivated for a certain importance level, the PDCP PDU (with the importance level) can be submitted to the RLC entity 140, e.g., the primary RLC entity. In this case, bearer split can not be considered.

[0072] Reference is now made to Figure 3 The figure illustrates an exemplary schematic diagram 300 of packet paths according to some embodiments of the disclosure. Packets 310 for which the importance level PDCP duplication is activated are submitted by the PDCP entity 130 to the primary RLC entity and the secondary RLC entity. Packets 320 for which the importance level PDCP duplication is deactivated are submitted by the PDCP entity 130 to the primary RLC entity, and not to the secondary RLC entity.

[0073] In one example, for the PDCP layer, the transmitting PDCP entity is associated with at least two RLC entities, e.g., RLC entity 140-1 and RLC entity 140-2. If PDCP duplication is activated for the importance level and the PDCP PDU is a PDCP data PDU, the terminal device 110 can duplicate the PDCP data PDU with the importance level and submit the PDCP data PDU to the associated RLC entity for which PDCP duplication is activated. Otherwise, the terminal device 110 can submit the PDCP control PDU to the primary RLC entity, i.e., RLC entity 140-1.

[0074] The procedure of importance-based PDCP duplication is associated with the MAC layer and the PDCP layer. In the MAC layer, PDCP duplication is activated and deactivated for all associated importance levels or a subset of associated importance levels by receiving a MAC CE (e.g., duplication importance activation / deactivation MAC CE) and / or an indication by RRC.

[0075] In one example, if a MAC CE (e.g., duplication importance activation / deactivation MAC CE) activating PDCP duplication for an associated importance level (e.g., importance level of a DRB or a QoS flow) is received, the terminal device 110 can indicate to the upper layer (e.g., PDCP or SDAP layer) the activation of PDCP duplication for the indicated importance level.

[0076] In one example, if a MAC CE (e.g., duplication importance activation / deactivation MAC CE) deactivating PDCP duplication for an associated importance level (e.g., importance level of a DRB or a QoS flow) is received, the terminal device 110 can indicate to the upper layer (e.g., PDCP or SDAP layer) the deactivation of PDCP duplication for the indicated importance level.

[0077] In one example, for the PDCP layer, if an indication of activation of importance based PDCP duplication has been received from lower layers (e.g., MAC layer), or a PDCP / SDAP control PDU indicates that activation of importance based PDCP duplication has been received, the PDCP entity 130 can activate PDCP duplication for the indicated associated importance level.

[0078] In one example, if an indication of deactivation of importance based PDCP duplication has been received from lower layers (e.g., MAC layer), or a PDCP / SDAP control PDU indicates that deactivation of importance based PDCP duplication has been received, the PDCP entity 130 can deactivate PDCP duplication for the indicated associated importance level.

[0079] In some embodiments, the terminal device 110 can send assistance information to the network device 120. The assistance information includes at least one of: a number of the plurality of importance levels, or a suggestion of one or more importance levels for which PDCP duplication is activated.

[0080] In one example, the terminal device 110 can assist the network device 120 to configure / activate / deactivate importance based PDCP duplication. The terminal device 110 can indicate to the network device 120 (e.g., via UE assistance information) at least one of the following information: a suggestion of importance level for which PDCP duplication is activated, a number of importance levels.

[0081] To indicate importance based duplication, in some embodiments, the duplication information includes a plurality of fields corresponding to a plurality of importance levels. A field of the plurality of fields indicates an activation status of a corresponding importance level. For example, a bitmap can be used, as described below. In one embodiment, the duplication information includes an indication of a reference level for partitioning the plurality of importance levels according to whether PDCP duplication is activated or not. For example, the terminal device 110 can be indicated an importance level to serve as a reference criterion, as described below.

[0082] The duplication information can be included in any suitable signaling. In some embodiments, the duplication information can be received in RRC signaling. When duplication is configured for a certain importance level, the RRC can set the status of PDCP duplication (activated or deactivated) for each importance level at (re)configuration.

[0083] In one example, each importance level can correspond to one bit (e.g., one bit in importanceDuplicationState). If the bit for a certain importance level is set to 1 (or true), PDCP duplication for that importance level is activated. If the bit for a certain importance level is set to 0 (or false), PDCP duplication for that importance level is deactivated.

[0084] The importance value or level can be configured as a reference standard. For importance levels equal to or higher than the configured importance value, PDCP duplication can be activated. In one example, 4 importance levels (0~3) are defined, where 0 refers to the highest importance level and 3 refers to the lowest importance level. If the configured value is 1, PDCP duplication for importance levels with values 0 and 1 should be activated, and PDCP duplication for importance levels with values 2 and 3 should be deactivated.

[0085] In some embodiments, QFIs associated with importance levels can also be configured. For example, a list of ImportanceDuplication can be configured by the network device 120.

[0086] In some embodiments, duplication information can be received in a MAC CE. After duplication configuration, a MAC CE can be utilized to dynamically control the PDCP duplication state for a certain importance level. The relevant MAC CE (e.g., duplication importance activation / deactivation MAC CE, which can be newly introduced) can include at least one of the following fields: a DRB ID field, an importance i (or IMPi) field, an importance level field (or importance field), a QFI field.

[0087] The DRB ID field can indicate the identity of the DRB to which the MAC CE applies.

[0088] The IMPi field can indicate the activation / deactivation state of PDCP duplication for importance i of the DRB (or for the PDU set / QoS flow), where i is the ascending order number of importance value or importance level. The IMPi field set to 1 indicates that PDCP duplication for IMPi can be activated. The IMPi field set to 0 indicates that PDCP duplication for IMPi can be deactivated.

[0089] The importance level field can indicate that PDCP duplication for importance levels equal to or higher than the value of this field can be activated. For example, if 4 importance levels (0~3) are defined, where 0 refers to the highest importance level and 3 refers to the lowest importance level. If the importance level field value is 1, PDCP duplication for importance levels with values 0 and 1 should be activated, and PDCP duplication for importance levels with values 2 and 3 should be deactivated.

[0090] The field QFI can indicate the ID of the QoS flow associated with the importance level. In some embodiments, the MAC CE further includes an identification of the RB associated with the QoS flow.

[0091] Reference is now made to Figure 4A which illustrates a schematic diagram of an exemplary format 400A of the duplication information via MAC CE, according to some embodiments of the present disclosure. The format 400A includes fields for configuring three importance levels. In one embodiment, the format 400A includes an IMP0 field 408, an IMP1 field 406, and an IMP2 field 404, a DRB ID field 402 (and / or a QFI field), wherein the DRB ID field 402 contains five bits.

[0092] In one example, the activation / deactivation status of PDCP duplication for RLC entity i and importance i can be mixed together in the same MAC CE. Reference is now made to Figure 4B which illustrates a schematic diagram of another exemplary format 400B of the duplication information via MAC CE, according to some embodiments of the present disclosure. The format 400B can represent a duplication RLC and importance activation / deactivation MAC CE for four (as an example) importance levels. In one embodiment, the format 400B includes a DRB ID field 410 (and / or a QFI field), an RLC0 field 416, an RLC1 field 414, an RLC2 field 412, an IMP0 field 424, an IMP1 field 422, an IMP2 field 420, an IMP3 field 418, and a reserved field (R field), wherein the DRB ID field 402 contains five bits.

[0093] Reference is now made to Figure 4C which illustrates a schematic diagram of another exemplary format 400C of the duplication information via MAC CE, according to some embodiments of the present disclosure. The format 400C includes a DRB ID field 426 (and / or a QFI field) and an importance field 428, wherein the DRB Id field 402 contains five bits and the importance field contains three bits.

[0094] In some embodiments, the duplication information can be received in a PDCP control PDU. After duplication configuration, a PDCP control PDU can be utilized to dynamically control the PDCP duplication status for a certain importance level. The new PDCP control PDU can include at least one of the following fields: a new PDU type field, an importance i (or IMPi) field, an importance level field (or importance field), a QFI field.

[0095] In one example, the PDU type field can include a bit value of "000" for PDCP status report, a bit value of "001" for interspersed robust header compression (ROHC) feedback, a bit value of "010" for Ethernet header compression (EHC) feedback, and a bit value of "011" for uplink data compression (UDC) feedback. The PDU type field can also include a new value, e.g., a bit value of "100" for importance-based PDCP duplication activation / deactivation.

[0096] The IMPi field can indicate an activation / deactivation status of PDCP duplication for importance i of a DRB (or for a set of PDUs / QoS flow), where i is an ascending order number of importance value or importance level. The IMPi field set to 1 indicates that PDCP duplication for importance i can be activated. The IMPi field set to 0 indicates that PDCP duplication for importance i can be deactivated.

[0097] The importance level field can indicate that PDCP duplication of importance levels equal to or higher than the value of the field can be activated. For example, if 4 importance levels (0~3) are defined, where 0 refers to the highest importance level and 3 refers to the lowest importance level. If the field value is 1, PDCP duplication of importance levels with values 0 and 1 should be activated, and PDCP duplication of importance levels with values 2 and 3 should be deactivated.

[0098] In one example, the QFI field can indicate an ID of a QoS flow associated with an importance level. In addition, the QFI field can be optional.

[0099] Referring now to Figure 5A the figure illustrates a schematic diagram of an exemplary format 500A of duplication information via PDCP control PDU, according to some embodiments of the present disclosure. The format 500A includes a D / C field 502, a PDU type field 504, an IMP0 field 512, an IMP1 field 510, an IMP2 field 508, and an IMP3 field 506, where the PDU type field 504 contains three bits.

[0100] Referring now to Figure 5B the figure illustrates a schematic diagram of another exemplary format 500B of duplication information via PDCP control PDU, according to some embodiments of the present disclosure. The format 500B includes a D / C field 502, a PDU type field 504, and an importance field 514, where the PDU type field 504 contains three bits and the importance field 514 contains four bits.

[0101] In one embodiment, the duplication information can be received in a SDAP control PDU. After duplication configuration, a SDAP control PDU can be utilized to dynamically control the PDCP duplication status for a certain importance level. The (new) SDAP control PDU can include at least one of the following fields: (new) PDU type field, QFI field, importance i (or IMPi) field, importance level field (or importance field).

[0102] The PDU type field with a certain value can indicate that the PDU is used to activate / deactivate importance-based PDCP duplication.

[0103] The QFI field can indicate the ID of the QoS flow associated with the importance level. Note that the SDAP layer can indicate the QFI to lower layers (e.g., PDCP layer) for PDCP duplication handling.

[0104] The IMPi field can indicate the activation / deactivation status of PDCP duplication for importance i for a QoS flow (or for a set of PDUs), where i is the importance value or the ascending order number of importance level. The IMPi field set to 1 indicates that PDCP duplication for IMPi should be activated. The IMPi field set to 0 indicates that PDCP duplication for IMPi should be deactivated.

[0105] The importance field can indicate that PDCP duplication for importance levels equal to or higher than the field value should be activated. For example, if 4 importance levels (0~3) are defined, 0 is the highest importance level and 3 is the lowest importance level. If the field value is 1, PDCP duplication for importance levels with values 0 and 1 should be activated, and PDCP duplication for importance levels with values 2 and 3 should be deactivated.

[0106] Referring now to Figure 6A , this figure illustrates a schematic diagram of an exemplary format 600A of duplication information via a SDAP control PDU, according to some embodiments of the present disclosure. The format 600A for four (as an example) importance levels includes a D / C field 602, a QFI field 604, a PDU type field 606, an IMP0 field 614, an IMP1 field 612, an IMP2 field 610, and an IMP3 field 608, as well as a reserved field (R field), where the QFI field 604 contains six bits and the PDU type field 606 contains four bits.

[0107] Referring now to Figure 6BFIG. 6B illustrates a diagram of another exemplary format 600B of replicating information via SDAP control PDU, according to some embodiments of the present disclosure. Format 600B includes a D / C field 602, a QFI field 604, a PDU type field 606, an importance field 616, and a reserved field (R field), where the QFI field 604 contains six bits, and the PDU type field 606 contains four bits.

[0108] In some embodiments, for each importance level in the plurality of importance levels, the replicating information further indicates whether PDCP duplication is activated for each secondary RLC entity. In some embodiments, the plurality of RLC entities can include a primary RLC entity and at least one RLC entity for which PDCP duplication is activated for a first importance level.

[0109] If packets (e.g., SDUs / PDUs / PDU sets) with different importance levels are mapped to different LCHs, the network device 120 can instruct the terminal device 110 to activate / deactivate importance-based PDCP duplication (e.g., via RRC / MAC CE / PDCP control PDU / SDAP control PDU). At least one of the following fields can be configured or transmitted to the terminal device 110: a DRB ID or QFI field, an importance i (or IMPi) field, an importance level field (or importance field), an RLCi field.

[0110] In one example, the DRB ID or QFI field can indicate an ID of a QoS flow or DRB associated with an importance level.

[0111] In one example, the IMPi field can indicate an activation / deactivation status of PDCP duplication for importance i for a QoS flow (or for a PDU set), where i is an importance value or an ascending order number of importance levels. The IMPi field set to 1 indicates that PDCP duplication for importance i should be activated. The IMPi field set to 0 indicates that PDCP duplication for importance i should be deactivated.

[0112] In one example, for importance levels equal to or higher than the value of the field, PDCP duplication should be activated. For example, if 4 importance levels (0~3) are defined, 0 is the highest importance level and 3 is the lowest importance level. If the field value is 1, PDCP duplication for importance levels with values 0 and 1 should be activated, and PDCP duplication for importance levels with values 2 and 3 should be deactivated.

[0113] In one example, the RLCi field can indicate the activation / deactivation status of PDCP duplication for RLC entity i of DRB or importance, where i is arranged in ascending order of secondary RLC entity logical channel ID in the order of MCG and SCG. The RLCi field set to 1 indicates that PDCP duplication for RLC entity i should be activated. The RLCi field set to 0 indicates that PDCP duplication for RLC entity i should be deactivated. Note that one or more secondary RLC entities can be associated with a particular importance.

[0114] Reference is now made to Figure 7 which illustrates a schematic diagram of another example format 700 of duplication associated with QoS flows, according to some embodiments of the present disclosure. Format 700 for four importance levels can indicate duplicated RLCs. For example, format 700 includes a DRB ID field 702 (and / or QFI field) and a reserved field (R field) in a first octet 704, two IMPi (e.g., IMP0, IMP1) fields and six RLCi fields (i.e., two RLC0, two RLC1, and two RLC2) in a second octet 706, and two IMPi (e.g., IMP2, IMP3) fields and six RLCi fields (i.e., two RLC0, two RLC1, and two RLC2) in a third octet 708, where the DRB ID field 702 contains five bits.

[0115] Generally, different PDUs / PDU sets within one QoS flow / DRB can be associated with different “PDU set importance” information, according to some embodiments of the present disclosure. For PDUs / PDU sets of higher importance, PDCP duplication can be employed to improve reliability of PDUs / PDU sets of higher importance. When congestion or other situations occur, PDCP duplication can be deactivated (for a DRB, RLC entity, or importance level). Thus, reliability of PDUs / PDU sets of higher importance can be improved, and resource utilization can be improved.

[0116] It should be understood that the length of any of the above-mentioned fields is for illustration purposes only and without any limitation. In embodiments of the present disclosure, the fields can have any suitable length. Furthermore, the order of the different fields mentioned above is for illustration purposes only and without any limitation. In embodiments of the present disclosure, the different fields can be arranged in any suitable manner.

[0117] Considering that PDCP duplication can be activated for one importance level but deactivated for another importance level, PDCP data volume calculation can be performed by considering importance-based PDCP duplication.

[0118] Referring again to flow 200, in some embodiments, the plurality of RLC entities includes a primary RLC entity and at least a first RLC entity other than the primary RLC entity, and the PDCP entity 130 can indicate to a first MAC entity a first PDCP data amount corresponding to a first importance level. The first MAC entity is associated with the first RLC entity, and the first PDCP data amount excludes an amount of data for control packets.

[0119] In some embodiments, the PDCP entity 130 can indicate to a second MAC entity a second PDCP data amount corresponding to the first importance level as a predetermined value (e.g., 0). The second MAC entity is associated with a second RLC entity for which PDCP duplication is deactivated.

[0120] The amount of data can be calculated in the PDCP entity 130. In one example, if PDCP duplication is activated for a certain importance, the PDCP entity 130 can indicate to a MAC entity associated with a primary RLC entity a PDCP data amount. The PDCP entity 130 can indicate to a MAC entity associated with an RLC entity other than the primary RLC entity for which PDCP duplication is activated a PDCP data amount corresponding to the importance (excluding PDCP control PDUs). The PDCP entity 130 can indicate to a MAC entity associated with an RLC entity for which PDCP duplication is deactivated a PDCP data amount corresponding to an importance of 0.

[0121] In some embodiments, PDCP duplication is deactivated for a second importance level, and the PDCP entity 130 can indicate to a third MAC entity a third PDCP data amount corresponding to the second importance level as a predetermined value (e.g., 0). The third MAC entity is associated with a third RLC entity other than the primary RLC entity. In some embodiments, the PDCP entity 130 can indicate to a fourth MAC entity a fourth PDCP data amount corresponding to the second importance level as a predetermined value. The fourth MAC entity is associated with a fourth RLC entity for which PDCP duplication is deactivated.

[0122] In one example, if PDCP duplication is deactivated for a certain importance, the PDCP entity can indicate to a MAC entity associated with a primary RLC entity a PDCP data amount. Further, the PDCP entity can indicate to a MAC entity associated with an RLC entity other than the primary RLC entity for which PDCP duplication is activated a PDCP data amount corresponding to an importance of 0. The PDCP entity can indicate to a MAC entity associated with an RLC entity for which PDCP duplication is deactivated a PDCP data amount corresponding to an importance of 0.

[0123] In general, according to some embodiments of the present disclosure, when performing PDCP data volume calculations, if PDCP duplication is activated for a certain importance level, packets having that importance level should be included in the PDCP data volume associated with the activated RLC entity. If PDCP duplication is deactivated for a certain importance level, packets having that importance level should be excluded from the PDCP data volume associated with the activated secondary RLC entity. Thus, PDCP data volume can be calculated as intended.

[0124] In some scenarios, congestion or other issues can occur, and it can be desirable to discard one or more packets. Referring to Figure 8 the figure illustrates a signaling flow 800 of packet discard according to some embodiments of the present disclosure. For purposes of discussion, reference will be made to Figure 1 Signaling flow 800 will be discussed, for example, by using terminal device 110 and network device 120.

[0125] In some embodiments, terminal device 110 can receive (804) an event indication or packet discard indication sent (802) from network device 120. The event can be congestion occurring in communication environment 100 or any other event requiring packets to be discarded. In some embodiments, terminal device 110 can detect (806) the event occurrence.

[0126] In response to detecting the event or packet discard indication, terminal device 110 can discard (808) a first duplicate packet generated by PDCP duplication of a first packet. The first duplicate packet can be discarded based on at least one of: an importance level of the first packet, a radio bearer associated with the first packet, or an RLC entity associated with the first duplicate packet.

[0127] For example, when congestion or other issues occur, network device 120 can instruct terminal device 110 to perform packet discard (e.g., importance-based discard via RRC / SDAP control PDU / PDCP control PDU / MCA CE), or terminal device 110 can determine that packet discard (e.g., importance-based discard) should be performed.

[0128] In some embodiments, the first duplicate packet can be discarded before a second duplicate packet generated by PDCP duplication of a second packet, and the importance level of the second packet is higher than the importance level of the first packet. That is, lower importance packets (e.g., SDUs, PDUs, or sets of PDUs) should be discarded first.

[0129] In some embodiments, the first packet can be associated with a primary RLC entity, and the first duplicate packet is associated with an RLC entity different from the primary RLC entity, and the first duplicate packet is discarded before the first packet. If PDCP duplication is activated (e.g., for a DRB / RLC entity / importance), duplicate packets (e.g., duplicate PDUs or PDU sets) associated with RLC entities other than the primary RLC entity for which PDCP duplication is activated should be discarded before packets (e.g., PDUs or PDU sets) associated with the primary RLC entity.

[0130] In some embodiments, the terminal device 110 can receive, from the network device 120, discard information indicating an order in which different duplicate packets are to be discarded. In such embodiments, the first duplicate packet is discarded further based on the discard information. For example, the network device 120 can indicate to the terminal device 110 which DRB / RLC entity / importance should be discarded before other DRB / RLC entities / importance. In some embodiments, the discard information is received in, for example, an RRC, an SDAP control PDU, a PDCP control PDU, or an MCA CE. For example, the network device 120 can indicate to the terminal device 110 which DRB / RLC entity / importance should be discarded before other DRB / RLC entities / importance via an RRC, an SDAP control PDU, a PDCP control PDU, or an MCA CE.

[0131] Generally, according to some embodiments of the present disclosure, if congestion or other problems occur, duplicate packets with higher priority can be discarded. If congestion or other problems occur, PDCP duplication for lower importance can be deactivated. Thus, when congestion occurs, duplicate packets can be discarded first.

[0132] Figure 9 A flowchart of a communication method 900 implemented at a terminal device according to some embodiments of the present disclosure is illustrated. For purposes of discussion, the method 900 will be described from the perspective of a terminal device (e.g., the terminal device 110).

[0133] At block 910, the terminal device receives, from a network device, duplication information indicating an activation status of packet data convergence protocol (PDCP) duplication for a plurality of importance levels, the duplication information further indicating quality of service (QoS) flows associated with the plurality of importance levels.

[0134] At block 920, the terminal device determines whether to activate PDCP duplication for a first importance level of the plurality of importance levels based at least on the duplication information.

[0135] At block 930, the terminal device activates PDCP duplication for the first importance level in accordance with the determination, the first packet within the QoS flow being duplicated by a PDCP entity of the terminal device for submission to a plurality of radio link control (RLC) entities of the terminal device, the first packet having the first importance level.

[0136] In some example embodiments, the terminal device can determine whether the duplication information indicates activation of PDCP duplication for the first importance level; determine whether PDCP duplication is activated for a radio bearer associated with the QoS flow; and determine to activate PDCP duplication for the first importance level in accordance with the determination that the duplication information indicates activation of PDCP duplication for the first importance level and / or PDCP duplication is activated for the radio bearer.

[0137] In some example embodiments, in accordance with the determination to deactivate PDCP duplication for the first importance level, the terminal device can instruct, by the PDCP entity, a secondary RLC entity of the plurality of RLC entities to discard a duplicate packet corresponding to the first packet.

[0138] In some example embodiments, the terminal device can determine whether to deactivate PDCP duplication for a second importance level of the plurality of importance levels based at least on the duplication information; and in accordance with the determination to deactivate PDCP duplication for the second importance level, submit, by the PDCP entity to a primary RLC entity, a second packet within the QoS flow without duplicating the second packet, the second packet having the second importance level.

[0139] In some example embodiments, the terminal device can send, to the network device, assistance information including at least one of: a number of the plurality of importance levels, or a suggestion regarding one or more importance levels for which PDCP duplication is activated.

[0140] In some example embodiments, the duplication information includes at least one of: a plurality of fields corresponding to the plurality of importance levels, wherein a field of the plurality of fields indicates an activation status of a corresponding importance level; or an indication of a reference level that divides the plurality of importance levels in accordance with whether PDCP duplication is activated.

[0141] In some example embodiments, the duplication information can be received in at least one of: a radio resource control (RRC) message, a medium access control (MAC) control element (CE), a PDCP control protocol data unit (PDU), or a service data adaptation protocol (SDAP) control PDU.

[0142] In some example embodiments, the MAC CE can further include an identification of a radio bearer associated with the QoS flow.

[0143] In some example embodiments, the PDCP control PDU can further include an indication of a type of the PDCP control PDU for PDCP duplication.

[0144] In some example embodiments, the SDAP control PDU can further include an indication of a type of the PDCP control PDU for PDCP duplication.

[0145] In some example embodiments, for each importance level of the plurality of importance levels, the duplication information can further indicate whether PDCP duplication is activated for each secondary RLC entity, and the plurality of RLC entities include a primary RLC entity and at least one RLC entity for which PDCP duplication is activated for the first importance level.

[0146] In some example embodiments, the plurality of RLC entities can include a primary RLC entity and at least a first RLC entity other than the primary RLC entity, and the terminal device performs at least one of: indicating, by the PDCP entity, a first PDCP data volume corresponding to the first importance level to a first medium access control (MAC) entity, where the first MAC entity is associated with the first RLC entity, and the first PDCP data volume excludes a data volume of control packets; or indicating, by the PDCP entity, a second PDCP data volume corresponding to the first importance level to a second MAC entity as a predetermined value, where the second MAC entity is associated with a second RLC entity for which PDCP duplication is deactivated.

[0147] In some example embodiments, PDCP duplication can be deactivated for a second importance level, and the terminal device can perform at least one of: indicating, by the PDCP entity, a third PDCP data volume corresponding to the second importance level to a third MAC entity as a predetermined value, where the third MAC entity is associated with a third RLC entity other than the primary RLC entity; or indicating, by the PDCP entity, a fourth PDCP data volume corresponding to the second importance level to a fourth MAC entity as a predetermined value, where the fourth MAC entity is associated with a fourth RLC entity for which PDCP duplication is deactivated.

[0148] Figure 10 A flowchart of a communication method 1000 implemented at a network device according to some embodiments of the present disclosure is illustrated. For purposes of discussion, the method 1000 will be described from the perspective of a network device (e.g., the network device 120 in FIG. 1). Figure 1

[0149] ​At block 1010, the network device transmits, to the terminal device, replication information indicating activation status of packet data convergence protocol (PDCP) replication for a plurality of importance levels, the replication information further indicating quality of service (QoS) flows associated with the plurality of importance levels.

[0150] In some example embodiments, the network device can receive, from the terminal device, assistance information including at least one of: a number of the plurality of importance levels, or a suggestion regarding one or more importance levels for which PDCP replication is activated.

[0151] In some example embodiments, the replication information can include at least one of: a plurality of fields corresponding to the plurality of importance levels, wherein a field of the plurality of fields indicates the activation status of a corresponding importance level; or an indication of a reference level that divides the plurality of importance levels depending on whether PDCP replication is activated.

[0152] In some example embodiments, the replication information can be received in at least one of: a radio resource control (RRC) message, a medium access control (MAC) control element (CE), a PDCP control protocol data unit (PDU), or a service data adaptation protocol (SDAP) control PDU.

[0153] In some example embodiments, the MAC CE can further include an identification of a radio bearer associated with the QoS flow.

[0154] In some example embodiments, the PDCP control PDU can further include a type indication of the PDCP control PDU for PDCP replication.

[0155] In some example embodiments, the SDAP control PDU can further include a type indication of the PDCP control PDU for PDCP replication.

[0156] In some example embodiments, for each importance level of the plurality of importance levels, the replication information can further indicate whether PDCP replication is activated for each secondary RLC entity.

[0157] Figure 11 A flowchart of a communication method 1100 implemented at a terminal device according to some embodiments of the present disclosure is illustrated. For purposes of discussion, the method 1100 will be described from the perspective of a terminal device 110 (e.g., in FIG. 1). Figure 1

[0158] ​At block 1110, in response to the event or packet discard indication from the network device, the terminal device discards a first duplicate packet generated by packet data convergence protocol (PDCP) duplication of a first packet based on at least one of: an importance level of the first packet, a radio bearer associated with the first packet, or a radio link control (RLC) entity associated with the first duplicate packet.

[0159] In some example embodiments, the first duplicate packet can be discarded before a second duplicate packet generated by PDCP duplication of a second packet, and the importance level of the second packet is higher than the importance level of the first packet.

[0160] In some example embodiments, the first packet can be associated with a primary RLC entity, and the first duplicate packet is associated with an RLC entity different from the primary RLC entity, and the first duplicate packet is discarded before the first packet.

[0161] In some example embodiments, the terminal device can receive, from the network device, discard information indicating an order in which different duplicate packets are to be discarded, and wherein the first duplicate packet is discarded further based on the discard information.

[0162] In some example embodiments, the discard information can be received in at least one of: a radio resource control (RRC) message, a medium access control (MAC) control element (CE), a PDCP control protocol data unit (PDU), or a service data adaptation protocol (SDAP) control PDU.

[0163] Figure 12 A flow chart of a communication method 1200 implemented at a network device is illustrated in accordance with some embodiments of the present disclosure. For purposes of discussion, the method 1200 will be described from the perspective of a network device 120 (e.g., a network device in a network device 120 in FIG. 1). Figure 1

[0164] At block 1210, the network device sends, to a terminal device, at least one of: a packet discard indication to discard at least one duplicate packet generated by packet data convergence protocol (PDCP) duplication of a packet, or discard information indicating an order in which different duplicate packets are to be discarded.

[0165] In some example embodiments, the discard information can be sent in at least one of: a radio resource control (RRC) message, a medium access control (MAC) control element (CE), a PDCP control protocol data unit (PDU), or a service data adaptation protocol (SDAP) control PDU.

[0166] Figure 13 ​is a simplified block diagram of a device 1300 suitable for implementing embodiments of the present disclosure. The device 1300 can be considered another exemplary implementation of any of the devices as shown in Figure 1 FIG. 1. Thus, the device 1300 can be implemented at or as at least a portion of the terminal device 110 or the network device 120.

[0167] As shown, the device 1300 includes a processor 1310, a memory 1320 coupled to the processor 1310, a suitable transceiver 1340 coupled to the processor 1310, and a communication interface coupled to the transceiver 1340. The memory 1310 stores at least a portion of a program 1330. The transceiver 1340 can be used for bi-directional communication or unidirectional communication, as desired. The transceiver 1340 can include at least one of a transmitter 1342 and a receiver 1344. The transmitter 1342 and the receiver 1344 can be functional modules or physical entities. The transceiver 1340 has at least one antenna to facilitate communication, although in practice a node mentioned in the present application can have several antennas. The communication interface can represent any interface necessary to communicate with other network elements, such as an X2 / Xn interface for bi-directional 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 eNBs / gNBs, an Un interface for communication between eNBs / gNBs and relay nodes (RNs), or a Uu interface for communication between eNBs / gNBs and terminal devices.

[0168] It is assumed that the program 1330 includes program instructions that, when executed by the associated processor 1310, enable the device 1300 to operate in accordance with the embodiments of the present disclosure, as discussed herein with reference to Figures 1 to 12 The embodiments herein can be realized by computer software, firmware, or hardware, or combinations thereof, executable by the processor 1310 of the device 1300. The processor 1310 can be configured to implement various embodiments of the present disclosure. Further, the combination of the processor 1310 and the memory 1320 can be considered to be a processing unit 1350 adapted to implement various embodiments of the present disclosure.

[0169] The memory 1320 can be of any type suitable to the local technical network, and can be implemented using any suitable data storage technology, such as nonvolatile computer-readable storage media, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory, as non-limiting examples. While only one memory 1320 is shown in the device 1300, there can be several physically distinct memory modules in the device 1300. The processor 1310 can be of any type suitable to the local technical network, and can include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), and processors based on multi-core processor architectures, as non-limiting examples. The device 1300 can have multiple processors such as a special-purpose integrated circuit chip that is subject to a clock that synchronizes the main processor.

[0170] According to embodiments of the present disclosure, a terminal device including circuitry is provided. The circuitry is configured to receive, from a network device, duplication information indicating activation status of packet data convergence protocol (PDCP) duplication for a plurality of importance levels, the duplication information further indicating quality of service (QoS) flows associated with the plurality of importance levels; determine, based at least on the duplication information, whether to activate PDCP duplication for a first importance level of the plurality of importance levels; and in accordance with a determination to activate PDCP duplication for the first importance level, duplicate, by a PDCP entity of the terminal device, a first packet within a QoS flow for submission to a plurality of radio link control (RLC) entities of the terminal device, the first packet having the first importance level. According to embodiments of the present disclosure, the circuitry can be configured to perform any of the methods implemented by a terminal device as discussed above.

[0171] According to embodiments of the present disclosure, a network device including circuitry is provided. The circuitry is configured to transmit, to a terminal device, duplication information indicating activation status of packet data convergence protocol (PDCP) duplication for a plurality of importance levels, the duplication information further indicating quality of service (QoS) flows associated with the plurality of importance levels. According to embodiments of the present disclosure, the circuitry can be configured to perform any of the methods implemented by a network device as discussed above.

[0172] According to embodiments of the present disclosure, a terminal device including circuitry is provided. The circuitry is configured to, in response to an event or a packet discard indication from a network device, discard a first duplicate packet generated by packet data convergence protocol (PDCP) duplication of a first packet based on at least one of: an importance level of the first packet, a radio bearer associated with the first packet, or a radio link control (RLC) entity associated with the first duplicate packet. According to embodiments of the present disclosure, the circuitry can be configured to perform any of the methods implemented by the terminal device as discussed above.

[0173] According to embodiments of the present disclosure, a network device including circuitry is provided. The circuitry is configured to: a packet discard indication for discarding at least one duplicate packet generated by packet data convergence protocol (PDCP) duplication of a packet, or discard information indicating an order in which different duplicate packets are to be discarded. According to embodiments of the present disclosure, the circuitry can be configured to perform any of the methods implemented by the network device as discussed above.

[0174] As used herein, the term “circuitry” can refer to hardware and / or a combination of hardware and software. For example, circuitry can be a combination of analog and / or digital hardware circuitry with software / firmware. As another example, circuitry can be any portion of hardware processor with software, including a digital signal processor, software, and memory that work together to cause an apparatus, such as a terminal device or a network device, to perform various functions. In yet another example, circuitry can be a hardware circuitry and / or processor, such as a microprocessor or a portion of a microprocessor, that requires software / firmware to operate but the software can not be present when it is not needed to operate. As used herein, the term “circuitry” also encompasses implementation in only hardware circuitry or a processor, or a portion of hardware circuitry or a processor, and its (or their) accompanying software and / or firmware.

[0175] In summary, embodiments of the present disclosure provide the following aspects.

[0176] In an aspect, a terminal device is presented, the terminal device comprising: a processor configured to cause the terminal device to: receive, from a network device, duplication information indicating activation states for packet data convergence protocol (PDCP) duplication for a plurality of importance levels, the duplication information further indicating quality of service (QoS) flows associated with the plurality of importance levels; determine, based at least on the duplication information, whether to activate PDCP duplication for a first importance level of the plurality of importance levels; and in accordance with a determination that PDCP duplication is activated for the first importance level, duplicate, by a PDCP entity of the terminal device, a first packet within a QoS flow for submission to a plurality of radio link control (RLC) entities of the terminal device, the first packet having the first importance level.

[0177] In some embodiments, the terminal device is further caused to: determine whether the duplication information indicates activation of PDCP duplication for the first importance level; determine whether PDCP duplication is activated for a radio bearer associated with the QoS flow; and determine to activate PDCP duplication for the first importance level according to the determination that the duplication information indicates activation of PDCP duplication for the first importance level and / or PDCP duplication is activated for the radio bearer.

[0178] In some embodiments, the terminal device is further caused to: according to the determination to deactivate PDCP duplication for the first importance level, instruct, by the PDCP entity, a secondary RLC entity of the plurality of RLC entities to discard duplicated packets corresponding to the first packet.

[0179] In some embodiments, the terminal device is further caused to: determine, based at least on the duplication information, whether to deactivate PDCP duplication for a second importance level of the plurality of importance levels; and according to the determination to deactivate PDCP duplication for the second importance level, submit, by the PDCP entity to a primary RLC entity, a second packet within the QoS flow without duplicating the second packet, the second packet having the second importance level.

[0180] In some embodiments, the terminal device is further caused to: send, to the network device, assistance information including at least one of: a number of the plurality of importance levels, or a suggestion regarding one or more importance levels for which PDCP duplication is activated.

[0181] In some embodiments, the duplication information includes at least one of: a plurality of fields corresponding to the plurality of importance levels, wherein a field of the plurality of fields indicates an activation status of a corresponding importance level; or an indication of a reference level that divides the plurality of importance levels according to whether PDCP duplication is activated.

[0182] In some embodiments, the duplication information is received in at least one of: a radio resource control (RRC) message, a medium access control (MAC) control element (CE), a PDCP control protocol data unit (PDU), or a service data adaptation protocol (SDAP) control PDU.

[0183] In some embodiments, the MAC CE further includes an identification of a radio bearer associated with the QoS flow.

[0184] In some embodiments, the PDCP control PDU further includes a type indication of the PDCP control PDU for PDCP duplication.

[0185] In some embodiments, the SDAP control PDU further includes a type indication of the PDCP control PDU for PDCP duplication.

[0186] In some embodiments, for each importance level of the plurality of importance levels, the duplication information further indicates whether PDCP duplication is activated for each secondary RLC entity, and the plurality of RLC entities includes a primary RLC entity and at least one RLC entity for which PDCP duplication is activated for the first importance level.

[0187] In some embodiments, the plurality of RLC entities can include a primary RLC entity and at least a first RLC entity other than the primary RLC entity, and further causing the terminal device to perform at least one of: indicating, by the PDCP entity, a first PDCP data volume corresponding to the first importance level to a first medium access control (MAC) entity, where the first MAC entity is associated with the first RLC entity, and the first PDCP data volume excludes a data volume of control packets; or indicating, by the PDCP entity, a second PDCP data volume corresponding to the first importance level to a second MAC entity as a predetermined value, where the second MAC entity is associated with a second RLC entity for which PDCP duplication is deactivated.

[0188] In some embodiments, PDCP duplication is deactivated for a second importance level, and further causing the terminal device to perform at least one of: indicating, by the PDCP entity, a third PDCP data volume corresponding to the second importance level to a third MAC entity as a predetermined value, where the third MAC entity is associated with a third RLC entity other than the primary RLC entity; or indicating, by the PDCP entity, a fourth PDCP data volume corresponding to the second importance level to a fourth MAC entity as a predetermined value, where the fourth MAC entity is associated with a fourth RLC entity for which PDCP duplication is deactivated.

[0189] In an aspect, a network device is presented. The network device includes a processor configured to cause the network device to: transmit, to a terminal device, duplication information indicating an activation status of packet data convergence protocol (PDCP) duplication for a plurality of importance levels, the duplication information further indicating quality of service (QoS) flows associated with the plurality of importance levels.

[0190] In some embodiments, further causing the network device to: receive, from the terminal device, assistance information including at least one of: a number of the plurality of importance levels, or a suggestion regarding one or more importance levels for which PDCP duplication is activated.

[0191] In some embodiments, the replication information comprises at least one of: a plurality of fields corresponding to the plurality of importance levels, wherein a field of the plurality of fields indicates an activation status of a corresponding importance level; or an indication of a reference level that partitions the plurality of importance levels according to whether PDCP replication is activated.

[0192] In some embodiments, the replication information is received in at least one of: a radio resource control (RRC) message, a medium access control (MAC) control element (CE), a PDCP control protocol data unit (PDU), or a service data adaptation protocol (SDAP) control PDU.

[0193] In some embodiments, the MAC CE further comprises an identification of a radio bearer associated with the QoS flow.

[0194] In some embodiments, the PDCP control PDU further comprises a type indication of the PDCP control PDU for PDCP replication.

[0195] In some embodiments, the SDAP control PDU further comprises a type indication of the PDCP control PDU for PDCP replication.

[0196] In some embodiments, for each importance level of the plurality of importance levels, the replication information further indicates whether PDCP replication is activated for each secondary RLC entity.

[0197] In an aspect, a terminal device is presented. The terminal device comprises a processor configured to cause the terminal device to, in response to an event or packet discard indication from a network device, discard a first replicated packet generated by packet data convergence protocol (PDCP) replication of a first packet based on at least one of: an importance level of the first packet, a radio bearer associated with the first packet, or a radio link control (RLC) entity associated with the first replicated packet.

[0198] In some embodiments, the first replicated packet is discarded before a second replicated packet generated by PDCP replication of a second packet, and the importance level of the second packet is higher than the importance level of the first packet.

[0199] In some embodiments, the first packet is associated with a primary RLC entity, and the first replicated packet is associated with an RLC entity different from the primary RLC entity, and the first replicated packet is discarded before the first packet.

[0200] In some embodiments, the terminal device is further caused to: receive, from the network device, discard information indicating an order in which different replicated packets are to be discarded, and wherein the first replicated packet is discarded further based on the discard information.

[0201] In some embodiments, the discard information is received in at least one of a radio resource control (RRC) message, a medium access control (MAC) control element (CE), a PDCP control protocol data unit (PDU), or a service data adaptation protocol (SDAP) control PDU.

[0202] In an aspect, a network device is presented. The network device includes a processor configured to cause the network device to transmit, to a terminal device, at least one of a packet discard indication for discarding at least one duplicated packet generated by packet data convergence protocol (PDCP) duplication of a packet, or discard information indicating an order in which different duplicated packets are to be discarded.

[0203] In some embodiments, the discard information is transmitted in at least one of a radio resource control (RRC) message, a medium access control (MAC) control element (CE), a PDCP control protocol data unit (PDU), or a service data adaptation protocol (SDAP) control PDU.

[0204] In an aspect, a terminal device includes at least one processor and at least one memory coupled to the at least one processor and storing instructions thereon, which when executed by the at least one processor, cause the device to perform the method implemented by a terminal device discussed above.

[0205] In an aspect, a network device includes at least one processor and at least one memory coupled to the at least one processor and storing instructions thereon, which when executed by the at least one processor, cause the device to perform the method implemented by a network device discussed above.

[0206] In an aspect, a terminal device includes at least one processor and at least one memory coupled to the at least one processor and storing instructions thereon, which when executed by the at least one processor, cause the device to perform the method implemented by a terminal device discussed above.

[0207] In an aspect, a network device includes at least one processor and at least one memory coupled to the at least one processor and storing instructions thereon, which when executed by the at least one processor, cause the device to perform the method implemented by a network device discussed above.

[0208] In an aspect, a computer program including instructions, which when executed by at least one processor, causes the at least one processor to perform the method discussed above with respect to the network device is provided.

[0209] In an aspect, a computer program including instructions, which when executed by at least one processor, causes the at least one processor to perform the method discussed above with respect to the network device is provided.

[0210] In an aspect, a computer program including instructions, which when executed by at least one processor, causes the at least one processor to perform the method discussed above with respect to the terminal device is provided.

[0211] In an aspect, a computer program including instructions, which when executed by at least one processor, causes the at least one processor to perform the method discussed above with respect to the network device is provided.

[0212] In an aspect, a computer program including instructions, which when executed by at least one processor, causes the at least one processor to perform the method discussed above with respect to the terminal device is provided.

[0213] In an aspect, a computer program including instructions, which when executed by at least one processor, causes the at least one processor to perform the method discussed above with respect to the network device is provided.

[0214] In an aspect, a computer program including instructions, which when executed by at least one processor, causes the at least one processor to perform the method discussed above with respect to the terminal device is provided.

[0215] In an aspect, a computer program including instructions, which when executed by at least one processor, causes the at least one processor to perform the method discussed above with respect to the network device is provided.

[0216] In general, the various embodiments of the disclosure can be implemented in hardware or special-purpose circuits, software, logic or any combination thereof. Some aspects can be implemented in hardware, while other aspects can be implemented in firmware or software which can be executed by a controller, microprocessor or other computing device. While various aspects of the embodiments of the disclosure are illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein can be implemented in hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controler or other computing devices, or some combination thereof.

[0217] The present disclosure also provides at least one computer program product which is tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, which execute on a target real or virtual processor in an apparatus to perform the processes or methods described above, according to Figures 1 to 13 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 can be combined or split between program modules as desired in various embodiments. Machine executable instructions for program modules can be executed within a local or distributed device. In a distributed device, program modules can be located in both local and remote memory storage media.

[0218] Program code for carrying out methods of the present disclosure can be written in any combination of one or more programming languages. This program code can be provided to a processor or controller of a general or special purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the code, which executes on the processor or controller, produces a computer implementing the functions / acts specified in the flowcharts and / or block diagrams. The program code can be entirely on the machine, partially on the machine, as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0219] The program code described above can be embodied on a machine readable medium, which can be any tangible medium that contains or stores the program for use by or in connection with an instruction execution system, apparatus, or device. The machine readable medium can be a machine readable signal medium or a machine readable storage medium. The machine readable medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the machine readable storage medium will include an electrical connection having one or more wires, a portable computer diskette, 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.

[0220] Moreover, while operations are depicted in a particular order, this should not be understood as requiring such an order nor infringing on performing all illustrated operations to achieve desirable results. In certain circumstances, multitasking and parallel processing can be advantageous. While various embodiments are described in this specification in terms of a number of specific aspects, features, and / or method actions, those skilled in the art will recognize that the embodiments described herein are not a limitation on the scope or spirit of the present disclosure. It is contemplated that various aspects and features described herein can be implemented independently of one another and that various implementations of these aspects and features can be derived from the description, which is to be regarded as illustrative only, rather than restrictive. Further, where a particular feature or aspect is indicated as being optional, the scope of the disclosure is intended to encompass both alternatives (the particular feature is included) and the alternatives (the particular feature is not included).

[0221] While the present disclosure has been described with reference to specific implementations thereof, it should be understood that various other alternatives, modifications, and equivalents can be used. Therefore, the embodiments described are to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.

Claims

1. A terminal device, the terminal device comprising: Processor, the processor being configured to cause the terminal device to: Replication information is received from network devices, the replication information indicating the activation status of Packet Data Convergence Protocol (PDCP) replication for multiple importance levels, and the replication information also indicating the Quality of Service (QoS) flow associated with the multiple importance levels; Based at least on the replication information, determine whether to activate PDCP replication for the first importance level among the plurality of importance levels; as well as Based on the determination that the PDCP replication is activated for the first importance level, the PDCP entity of the terminal device replicates the first packet within the QoS flow for submission to multiple radio link control (RLC) entities of the terminal device, the first packet having the first importance level.

2. The terminal device according to claim 1, further comprising the terminal device: Determine whether the replication information indicates activation of PDCP replication for the first importance level; Determine whether to activate PDCP replication for the radio bearer associated with the QoS flow; and Based on the determination of the replication information indicating the activation of PDCP replication for the first importance level and / or the activation of PDCP replication for the radio bearer, it is determined that PDCP replication is activated for the first importance level.

3. The terminal device according to claim 1, further comprising the terminal device: Based on the determination to activate the PDCP replication for the first importance level, the PDCP entity instructs the secondary RLC entity among the plurality of RLC entities to discard the replication group corresponding to the first group.

4. The terminal device according to claim 1, further comprising the terminal device: Based at least on the replication information, determine whether to activate PDCP replication for the second importance level among the plurality of importance levels; and Based on the determination to deactivate PDCP replication for the second importance level, the PDCP entity submits a second packet within the QoS flow to the primary RLC entity without replicating the second packet, which has the second importance level.

5. The terminal device according to claim 1, further comprising the terminal device: Sending auxiliary information to the network device, the auxiliary information including at least one of the following: The number of the multiple importance levels, or Recommendations regarding the activation of one or more importance levels of the PDCP replication.

6. The terminal device according to claim 1, wherein the copied information includes at least one of the following: Multiple fields corresponding to the multiple importance levels, wherein a field among the multiple fields indicates the activation state corresponding to the importance level, or Indicators for reference levels used to classify the multiple importance levels based on whether PDCP replication is activated.

7. The terminal device of claim 6, wherein the copying information is received in at least one of the following: Radio resource control (RRC) messages, Media access control (MAC) control element (CE). PDCP control protocol data unit (PDU, Protocol Data Unit), or The Service Data Adaptation Protocol (SDAP) controls the PDU.

8. The terminal device of claim 7, wherein the MAC CE further includes an identifier of a radio bearer associated with the QoS flow. The PDCP control PDU also includes a type indication for PDCP replication, or The SDAP control PDU also includes the PDCP control PDU for a type indication of PDCP replication.

9. The terminal device of claim 1, wherein for each of the plurality of importance levels, the replication information further indicates whether to activate the PDCP replication for each secondary RLC entity, and The plurality of RLC entities include a master RLC entity and at least one RLC entity for which PDCP replication for the first importance level has been activated.

10. The terminal device of claim 1, wherein the plurality of RLC entities includes a main RLC entity and at least a first RLC entity other than the main RLC entity, and further causes the terminal device to perform at least one of the following: The PDCP entity indicates a first PDCP data volume corresponding to the first importance level to a first Media Access Control (MAC) entity, wherein the first MAC entity is associated with the first RLC entity, and the first PDCP data volume excludes the data volume of control packets, or The PDCP entity indicates to the second MAC entity a second PDCP data volume corresponding to the first importance level as a predetermined value, wherein the second MAC entity is associated with a second RLC entity whose PDCP replication is deactivated.

11. The terminal device of claim 4, wherein the PDCP replication is deactivated for the second importance level, and further causes the terminal device to: The PDCP entity indicates to the third MAC entity the amount of third PDCP data corresponding to the second importance level as a predetermined value, wherein the third MAC entity is associated with a third RLC entity other than the main RLC entity, or The PDCP entity indicates to the fourth MAC entity the fourth PDCP data amount corresponding to the second importance level as the predetermined value, wherein the fourth MAC entity is associated with the fourth RLC entity where the PDCP replication is deactivated.

12. A network device, the network device comprising: Processor, the processor being configured to cause the network device to: Replication information is sent to the terminal device, the replication information indicating the activation status of Packet Data Convergence Protocol (PDCP) replication for multiple importance levels, and the replication information also indicating the Quality of Service (QoS) flow associated with the multiple importance levels.

13. The network device of claim 12, wherein the copied information includes at least one of the following: Multiple fields corresponding to the multiple importance levels, wherein a field among the multiple fields indicates the activation state corresponding to the importance level, or Indicators for reference levels used to classify the multiple importance levels based on whether PDCP replication is activated.

14. A terminal device, the terminal device comprising: Processor, the processor being configured to cause the terminal device to: In response to an event or packet drop indication from a network device, the first replicated packet generated by the Packet Data Convergence Protocol (PDCP) replication of the first packet is dropped based on at least one of the following: The importance level of the first group, The radio bearer associated with the first packet, or The radio link control (RLC) entity associated with the first replicated packet.

15. The terminal device of claim 14, wherein the first replicated packet is discarded before a second replicated packet is generated by PDCP replication of the second packet, and the importance level of the second packet is higher than the importance level of the first packet, and / or The first packet is associated with the primary RLC entity, and the first copy packet is associated with an RLC entity different from the primary RLC entity, and the first copy packet is discarded before the first packet.

16. The terminal device according to claim 14, further comprising the terminal device: Receive discard information from the network device indicating the order in which different replicated packets will be discarded, and The first replicated packet is further discarded based on the discard information.

17. A network device, the network device comprising: A processor, configured to cause the network device to send at least one of the following to the terminal device: A packet discard instruction used to discard at least one replicated packet generated by the Packet Data Convergence Protocol (PDCP) replication of packets, or Discard information indicating the order in which different copy groups will be discarded.

18. A communication method implemented at a terminal device, the communication method comprising: Replication information is received from network devices, the replication information indicating the activation status of Packet Data Convergence Protocol (PDCP) replication for multiple importance levels, and the replication information also indicating the Quality of Service (QoS) flows associated with the multiple importance levels; Based at least on the replication information, determine whether to activate PDCP replication for the first importance level among the plurality of importance levels; as well as Based on the determination that the PDCP replication is activated for the first importance level, the PDCP entity of the terminal device replicates the first packet within the QoS flow for submission to multiple Radio Link Control (RLC) entities of the terminal device, the first packet having the first importance level.

19. A communication method implemented at a network device, the communication method comprising: Replication information is sent to the terminal device, the replication information indicating the activation status of Packet Data Convergence Protocol (PDCP) replication for multiple importance levels, and the replication information also indicating the Quality of Service (QoS) flow associated with the multiple importance levels.

20. A communication method implemented at a terminal device, the communication method comprising: In response to an event or packet drop indication from a network device, the first replicated packet generated by the Packet Data Convergence Protocol (PDCP) replication of the first packet is dropped based on at least one of the following: The importance level of the first group, The radio bearer associated with the first packet, or The radio link control (RLC) entity associated with the first replicated packet.

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