Notification of dropped PDCP SDU in wireless network device

Abstract

The invention relates to notification of a dropped PDCP SDU in a wireless network device. A method is disclosed, comprising: receiving, by a Packet Data Convergence Protocol (PDCP) entity, a plurality of PDCP SDUs for transmission; discarding at least one PDCP SDU from the plurality of PDCP SDUs used for transmission; and transmitting a discard notification indicating the discard of the PDCP SDU.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 665,684, filed on June 28, 2024, which is incorporated herein by reference in its entirety. Technical Field

[0003] The present application generally relates to discarding PDCP SDUs and providing discard notification in a wireless network device. Background Art

[0004] As wireless devices send and receive larger amounts of data, it becomes increasingly important to make the communication of data more efficient. In the PDCP layer, discarding PDCP SDUs becomes important in certain situations. However, discarding PDCP SDUs at the transmitting PDCP entity may result in inefficient operation of the receiving PDCP entity. Therefore, when PDCP SDUs are discarded at the transmitting PDCP entity, it is desirable to promote the efficiency of the receiving PDCP entity. Summary of the invention

[0005] Various aspects of examples of the invention are set out in the claims.

[0006] One or more embodiments may provide an apparatus, a computer-readable medium, a non-transitory computer-readable medium, a computer program product, and / or a method for receiving, through a Packet Data Convergence Protocol (PDCP) entity, a plurality of PDCP SDUs for transmission, discarding at least one PDCP SDU from the plurality of PDCP SDUs for transmission, and sending a discard notification indicating the discarding of the PDCP SDU.

[0007] One or more embodiments may provide an apparatus, a computer-readable medium, a computer program product, and / or a non-transitory computer-readable medium having means for receiving, through a Packet Data Convergence Protocol (PDCP) entity, a plurality of PDCP SDUs for transmission, discarding at least one PDCP SDU from the plurality of PDCP SDUs for transmission, and sending a discard notification indicating the discarding of the PDCP SDU.

[0008] In at least one example embodiment, the PDCP entity is comprised of user equipment.

[0009] In at least one example embodiment, the PDCP entity is comprised of a base station.

[0010] One or more example embodiments further perform receiving configuration information indicating that discard notification is enabled.

[0011] In at least one example embodiment, the configuration information indicates that a discard notification including a bitmap indication is enabled.

[0012] In at least one example embodiment, the configuration information indicates that a drop notification including a range indication is enabled.

[0013] In at least one example embodiment, the discard notification is a PDCP Control PDU.

[0014] One or more example embodiments further perform generating a discard notification.

[0015] In at least one example embodiment, the discard notification is generated based on discarding of at least one PDCP SDU.

[0016] In at least one example embodiment, the discard notification indicates the discard of the PDCP SDU by way of a bitmap indication.

[0017] In at least one example embodiment, the discard notification includes a bitmap indication and a first discarded PDCP SDU indication.

[0018] In at least one example embodiment, the first discarded PDCP SDU indication is a count.

[0019] In at least one example embodiment, the first discarded PDCP SDU indication is a sequence number (SN).

[0020] In at least one example embodiment, each bit position of the bitmap indication corresponds to a PDCP SDU that follows the PDCP SDU indicated by the first discarded PDCP SDU indication.

[0021] In at least one example embodiment, a first bit in the bitmap corresponds to a PDCP SDU that immediately follows the PDCP SDU indicated by the first discarded PDCP SDU indication.

[0022] In at least one example embodiment, the nth bit in the bitmap corresponds to a PDCP SDU that is n PDCP SDUs following the PDCP SDU indicated by the first discarded PDCP SDU indication.

[0023] In at least one example embodiment, each bit value in the bitmap indicates whether the corresponding PDCP SDU is discarded.

[0024] In at least one example embodiment, each bit value in the bitmap indicates whether the corresponding PDCP SDU is discarded or sent by the PDCP entity to lower layers for transmission.

[0025] One or more example embodiments further perform generating a bitmap indication.

[0026] In at least one example embodiment, generating the bitmap indication includes determining a size of the bitmap indication.

[0027] In at least one example embodiment, the size of the bitmap indication is an integer multiple of eight.

[0028] In at least one example embodiment, the size of the bitmap indication is determined such that the bitmap includes a bit corresponding to the last discarded PDCP SDU.

[0029] In at least one example embodiment, the discard notification includes a range indication, and the size of the bitmap indication is determined such that a last bit of the bitmap corresponds to a PDCP SDU that immediately precedes the PDCP SDU indicated by the range indication.

[0030] In at least one example embodiment, the discard notification indicates the discard of the PDCP SDU by way of a range indication.

[0031] In at least one example embodiment, the range indication comprises a first discarded PDCP SDU indication.

[0032] In at least one example embodiment, the first discarded PDCP SDU indication is a count.

[0033] In at least one example embodiment, the first discarded PDCP SDU indication is a SN.

[0034] In at least one example embodiment, the range indication includes a last discarded PDCP SDU indication.

[0035] In at least one example embodiment, the last discarded PDCP SDU indication indicates a last discarded PDCP SDU included by the range indication.

[0036] In at least one example embodiment, the last discarded PDCP SDU indication directly indicates the last discarded PDCP SDU included by the range indication.

[0037] In at least one example embodiment, the last discarded PDCP SDU indication is a count.

[0038] In at least one example embodiment, the last discarded PDCP SDU indication is the SN.

[0039] In at least one example embodiment, the last discarded PDCP SDU indication indirectly indicates a PDCP SDU.

[0040] In at least one example embodiment, the last discarded PDCP SDU indication indicates an offset from a first discarded PDCP SDU.

[0041] One or more example embodiments further perform generating a range indication.

[0042] In at least one example embodiment, discarding at least one PDCP SDU includes discarding a plurality of PDCP SDUs.

[0043] In at least one example embodiment, the discarded plurality of PDCP SDUs are consecutive.

[0044] In at least one example embodiment, the discard notification includes a scope indication.

[0045] One or more example embodiments further perform determining that the discarded plurality of PDCP SDUs are sufficiently consecutive.

[0046] One or more example embodiments further perform determining to include a range indication in the discard notification based on determining that the discarded plurality of PDCP SDUs are sufficiently contiguous.

[0047] In at least one example embodiment, a number of consecutive discarded PDCP SDUs exceeds a range threshold.

[0048] One or more example embodiments further perform determining that a number of consecutive discarded PDCP SDUs exceeds a range threshold.

[0049] In at least one example embodiment, determining to include a range indication in the discard notification is based on determining that a number of consecutive discarded PDCP SDUs exceeds a range threshold.

[0050] In at least one example embodiment, the discarded plurality of PDCP SDUs are non-contiguous.

[0051] In at least one example embodiment, the discard notification includes a bitmap indication and a corresponding first discarded PDCP SDU indication.

[0052] In at least one example embodiment, the discarded plurality of PDCP SDUs are substantially non-contiguous.

[0053] In at least one example embodiment, the discard notification includes a bitmap indication and a corresponding first discarded PDCP SDU indication.

[0054] One or more example embodiments further perform determining to include a bitmap indication and a corresponding first discarded PDCP SDU indication in the discard notification based on the discarded plurality of PDCP SDUs being sufficiently non-contiguous.

[0055] One or more example embodiments further perform determining that the discarded plurality of PDCP SDUs are sufficiently non-contiguous.

[0056] One or more example embodiments further perform determining to include a bitmap indication and a corresponding first discarded PDCP SDU indication in the discard notification based on determining that the discarded plurality of PDCP SDUs are sufficiently non-contiguous.

[0057] In at least one example embodiment, the number of consecutive discarded PDCP SDUs does not exceed a range threshold.

[0058] One or more example embodiments further perform determining that a number of consecutive discarded PDCP SDUs does not exceed a range threshold.

[0059] One or more example embodiments further perform determining to include a bitmap indication and a corresponding first discarded PDCP SDU indication in the discard notification based on determining that a number of consecutive discarded PDCP SDUs does not exceed a range threshold.

[0060] In at least one example embodiment, the discarded plurality of PDCP SDUs are PDCP SDUs belonging to the same PDCP PDU set. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] For a more complete understanding of embodiments of the present invention, reference is now made to the following description taken in conjunction with the accompanying drawings, in which:

[0062] Figure 1 is a block diagram illustrating an apparatus according to at least one example embodiment;

[0063] Figure 2 is a block diagram illustrating a wireless communication system according to at least one example embodiment;

[0064] Figure 3 is a diagram illustrating a protocol stack according to at least one example embodiment;

[0065] Figure 4 is a diagram illustrating a set of PDCP PDUs according to at least one example embodiment;

[0066] Figure 5 is a flow diagram illustrating activities associated with sending a drop notification according to at least one example embodiment; and

[0067] Figure 6 is a flow diagram illustrating activities associated with sending a drop notification according to at least one example embodiment. DETAILED DESCRIPTION

[0068] Embodiments of the present invention and their potential advantages are described with reference to the accompanying drawings. Figures 1 to 6 To understand.

[0069] Some embodiments will now be described more fully below with reference to the accompanying drawings, in which some but not all embodiments are shown. Various embodiments of the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these examples are provided so that the present disclosure will satisfy applicable legal requirements. Similar reference numerals refer to similar elements throughout. As used herein, the terms "data," "content," "information," and similar terms may be used interchangeably to refer to data that can be sent, received, and / or stored in accordance with embodiments of the present invention. Therefore, the use of any such terms should not be construed as limiting the spirit and scope of embodiments of the present invention.

[0070] Additionally, as used herein, the term 'circuit' refers to (a) a pure hardware circuit implementation (e.g., an implementation in analog circuits and / or digital circuits); (b) a combination of a circuit and (one or more) computer program products including software and / or firmware instructions stored on one or more computer-readable memories, which work together to cause the device to perform one or more functions described herein; and (c) circuits, such as, for example, (one or more) microprocessors or portions of (one or more) microprocessors, which require software or hardware to operate even if the software or firmware is not physically present. This definition of "circuit" applies to all uses of the term herein, including use in any claims. As a further example, as used herein, the term 'circuit' also includes an implementation including one or more processors and / or (one or more) portions thereof and accompanying software and / or firmware. As another example, as used herein, the term 'circuit' also includes, for example, a baseband integrated circuit or application processor integrated circuit for a mobile phone or a similar integrated circuit in a server, cellular network device, other network device, and / or other computing device.

[0071] As defined herein, "non-transitory computer-readable media" referring to physical media (eg, volatile or non-volatile memory devices) may be distinguished from "transitory computer-readable media" referring to electromagnetic signals.

[0072] Figure 11 is a block diagram showing an apparatus (such as an electronic apparatus 100) according to at least one example embodiment. However, it should be understood that the electronic apparatus shown and described below is merely an illustration of an electronic apparatus that can benefit from embodiments of the present invention, and therefore should not be considered to limit the scope of the present invention. Although the electronic apparatus 100 is illustrated and will be described below for the purpose of example, other types of electronic apparatuses can easily adopt embodiments of the present invention. The electronic apparatus 100 can be a network node, such as a user equipment (UE) or a base station, or can be a personal digital assistant (PDA), a pager, a mobile computer, a desktop computer, a television, a gaming device, a laptop computer, a tablet computer, a media player, a camera, a video recorder, a mobile phone, a global positioning system (GPS) device, a car, a self-service machine, an electronic table and / or any other type of electronic system. In addition, the apparatus of at least one example embodiment need not be the entire electronic apparatus, but can be a component or a group of components of the electronic apparatus in other example embodiments. For example, the apparatus can be an integrated circuit, a group of integrated circuits, etc.

[0073] Further, devices can readily employ embodiments of the present invention regardless of their intent to provide mobility. In this regard, although embodiments of the present invention may be described in conjunction with mobile applications, it should be understood that embodiments of the present invention may be used in conjunction with a variety of other applications both within and outside the mobile communications industry. For example, a device may be at least a portion of a non-portable device, such as a large screen television, an electronic table, a self-service machine, a car, etc.

[0074] In at least one example embodiment, the electronic device 100 includes a processor 110 and a memory 140. The processor 110 may be any type of processor, controller, embedded controller, processor core, etc. In at least one example embodiment, the processor 110 uses computer program code to cause the device to perform one or more actions. The memory 140 may include volatile memory (such as volatile random access memory (RAM) including a cache area for temporary storage of data) and / or other memory, for example, non-volatile memory that may be embedded and / or may be removable. The non-volatile memory may include EEPROM, flash memory, etc. The memory 140 may store any of several pieces of information and data. The information and data may be used by the electronic device 100 to implement one or more functions of the electronic device 100, such as the functions described herein. In at least one example embodiment, the memory 140 includes a computer program code, so that the memory and the computer program code are configured to work with the processor to cause the device to perform one or more actions described herein.

[0075] The electronic device 100 may further include a transceiver 120. In at least one example embodiment, the transceiver 120 is coupled to one or more antennas 130. In at least one example embodiment, the processor 110 provides signals to the transceiver 120 and / or receives signals from the transceiver 120. The signals may include signaling information according to a communication interface standard, user voice, received data, user generated data, etc. The transceiver 120 may operate using one or more air interface standards, communication protocols, modulation types, and access types. By way of illustration, the electronic transceiver 120 can operate according to second generation (2G) wireless communication protocols IS-136 (time division multiple access (TDMA)), Global System for Mobile Communications (GSM) and IS-95 (code division multiple access (CDMA)), according to third generation (3G) wireless communication protocols such as Universal Mobile Telecommunications System (UMTS), CDMA2000, Wideband CDMA (WCDMA) and Time Division Synchronous CDMA (TD-SCDMA), and / or according to fourth generation (4G) wireless communication protocols (such as LTE), fifth generation (5G) protocols (such as new radio (NR) wireless network protocols such as 802.11), short range wireless protocols (such as Bluetooth), etc.

[0076] The processor 110 may include components such as circuits for implementing audio, video, communication, navigation, logic functions, etc. and for implementing embodiments of the present invention, including, for example, one or more functions described herein. For example, the processor 110 may include components such as digital signal processor devices, microprocessor devices, various analog-to-digital converters, digital-to-analog converters, processing circuits, and other support circuits for performing various functions, including, for example, one or more functions described herein. The device may perform control and signal processing functions of the electronic device 100 among these devices according to their respective capabilities. Therefore, the processor 110 may include the function of encoding and interleaving messages and data before modulation and transmission. The processor 110 may additionally include an internal voice encoder and may include an internal data modem. Further, the processor 110 may include the function of operating one or more software programs, which may be stored in a memory and, among other things, may enable the processor 110 to implement at least a portion of an embodiment, including, for example, one or more functions described herein. For example, the processor 110 may operate a connection program, such as a conventional Internet browser. For example, the connection program can allow the electronic device 100 to send and receive Internet content, such as location-based content and / or other web page content, according to the Transmission Control Protocol (TCP), Internet Protocol (IP), User Datagram Protocol (UDP), Internet Message Access Protocol (IMAP), Post Office Protocol (POP), Simple Mail Transfer Protocol (SMTP), Wireless Application Protocol (WAP), Hypertext Transfer Protocol (HTTP), etc.

[0077] The electronic device 100 may include a user interface for providing output and / or receiving input. The electronic device 100 may include an output device, which may include an audio output device (such as a ringer, headphones, speakers), a tactile output device (such as a vibration transducer, an electronic deformable surface, an electronic deformable structure), a visual output device (such as a display and / or a light). The electronic device 100 may include an input device, such as a light sensor, a proximity sensor, a microphone, a touch sensor, a force sensor, a button, a keyboard, a motion sensor, a magnetic field sensor, a camera, etc. In at least one example embodiment, the device receives an indication of an input. The device may receive an indication from a sensor, a driver, a separate device, etc. The information indicating the input may include information that conveys information indicating the input, indicating aspects of the input, indicating the occurrence of the input, etc.

[0078] Figure 2An example of a wireless communication system 200 according to at least one example embodiment is illustrated. The wireless communication system 200 includes one or more base stations 202, a user equipment (UE) 201, and a core network 203. The term network node refers to a base station or a UE. In some examples, the wireless communication system 200 may be a long term evolution (LTE), an advanced LTE (LTE-A) network, or a new radio (NR) network. In some cases, the wireless communication system 200 may support enhanced broadband communications, ultra-reliable (i.e., mission-critical) communications, low-latency communications, and communications with low-cost and low-complexity devices. In order to improve the reliability of some communications (e.g., ultra-reliable low-latency communications (URLLC) packets), the wireless communication system 200 may be configured to generate and send duplicate packets. In such a duplication system, a sending device (e.g., a base station 202 or a UE 201) may duplicate packets. The original packet and the duplicated packet may be sent to a receiving device (e.g., a base station 202 or a UE 201). Sending multiple packets including the same information may improve the likelihood that the receiving device receives the information included in the multiple packets.

[0079] One or more base stations 202 can communicate wirelessly with one or more UEs 201 via one or more base station antennas. Each base station 202 can provide communication coverage for its respective geographic coverage area. The communication link in the wireless communication system 200 may include an uplink transmission from the UE 201 to the base station 202 or a downlink transmission from the base station 202 to the UE 201. According to various techniques, control information and data can be multiplexed on an uplink channel or a downlink channel. Control information and data can be multiplexed on a downlink channel, for example, using time division multiplexing (TDM) technology, frequency division multiplexing (FDM) technology, or a hybrid TDM-FDM technology. In some examples, the control information sent during a transmission time interval (TTI) of a downlink channel can be distributed in a cascaded manner between different control areas (e.g., between a common control area and one or more UE-specific control areas).

[0080] Multiple UEs may be dispersed throughout the wireless communication system 200, and each UE 201 may be fixed or mobile. UE 201 may also be referred to as a mobile station, a user station, a mobile unit, a user unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile user station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a mobile phone, a user agent, a mobile client, a client, or some other suitable term. UE 201 may also be a cellular phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless phone, a personal electronic device, a handheld device, a personal computer, a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, a machine type communication (MTC) device, a household appliance, a car, etc.

[0081] In some cases, UE 201 may also be able to communicate directly with other UEs (e.g., using point-to-point (P2P) or device-to-device (D2D) protocols). One or more of a group of UEs utilizing D2D communication may be within the coverage area of ​​a cell. Other UEs in such a group may be outside the coverage area of ​​the cell or otherwise unable to receive transmissions from base station 202. In some cases, a group of UEs communicating via D2D communication may utilize a one-to-many (1:M) system, in which each UE transmits to each other UE in the group. In some cases, base station 202 facilitates the scheduling of resources for D2D communication. In other cases, D2D communication is implemented independently of base station 202.

[0082] Some UEs, such as MTC or IoT devices, may be low-cost or low-complexity devices and may provide automated communication between machines, i.e., machine-to-machine (M2M) communication. M2M or MTC may refer to data communication technologies that allow devices to communicate with each other or with a base station without human intervention. For example, M2M or MTC may refer to communications from devices that integrate sensors or meters to measure or capture information and relay that information to a central server or application that can utilize the information or present it to a person interacting with the program or application. Some UEs may be designed to collect information or enable automated behavior of machines. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based business charging.

[0083] In some cases, MTC devices may operate using half-duplex (one-way) communications at a reduced peak rate. MTC devices may also be configured to enter a power-saving "deep sleep" mode when not engaged in active communications. In some cases, MTC or IoT devices may be designed to support mission-critical functions, and the wireless communication system may be configured to provide ultra-reliable communications to these functions.

[0084] Base station 202 can communicate with core network 203 and with one or more other base stations. For example, the base station can interface with core network 203 via a backhaul link (e.g., S1, etc.). Base stations can communicate with each other directly or indirectly (e.g., via core network 203) via other backhaul links (e.g., X2, etc.). The base station can perform radio configuration and scheduling for communicating with the UE, or can operate under the control of a base station controller (not shown). In some examples, base station 202 can be a macro cell, a small cell, a hotspot, etc. The base station may also be referred to as an evolved NodeB (NB), such as an eNB, a gNB, etc.

[0085] The base station 202 can be connected to the core network 203 via an S1 interface. The core network can be an evolved packet core network (EPC), which can include at least one mobility management entity (MME), at least one serving gateway (S-GW) and at least one packet data network (PDN) gateway (P-GW). The MME can be a control node that handles signaling between the UE 201 and the EPC. All user Internet Protocol (IP) packets can be transmitted through the S-GW, which itself can be connected to the P-GW. The P-GW can provide IP address allocation and other functions. The P-GW can be connected to the network operator IP service. The operator's IP services can include the Internet, intranet, IP multimedia subsystem (IMS) and packet switching (PS) streaming media services.

[0086] The core network 203 may provide user authentication, access authorization, tracking, IP connectivity, and other access, routing, or mobility functions. At least some of the network devices, such as the base station 202, may include subcomponents, such as an access network entity, which may be an example of an access node controller (ANC). Each access network entity may communicate with a number of UEs through a number of other access network transport entities, each of which may be an example of a smart radio head or a transmit / receive point (TRP). In some configurations, the various functions of each access network entity or base station may be distributed across various network devices (e.g., radio heads and access network controllers) or merged into a single network device (e.g., base station 202).

[0087] The wireless communication system 200 can operate in the ultra-high frequency (UHF) frequency region using a frequency band of 700 MHz to 2600 MHz (2.6 GHz), although some networks (e.g., wireless local area networks (WLANs)) can use frequencies up to 4 GHz. This region may also be referred to as a decimeter band because the length of the wavelength ranges from about 1 decimeter to 1 meter. UHF waves can be propagated primarily by sight and may be blocked by buildings and environmental features. However, the waves can penetrate walls sufficiently to provide services to UEs located indoors. Compared to transmissions using smaller frequencies (and longer waves) of the high frequency (HF) or very high frequency (VHF) portion of the spectrum, the transmission of UHF waves is characterized by smaller antennas and shorter ranges (e.g., less than 100 km). In some cases, the wireless communication system 200 may also utilize an extremely high frequency (EHF) portion of the spectrum (e.g., from 30 GHz to 300 GHz). This region may also be referred to as a millimeter band because the length of the wavelength ranges from about 1 millimeter to 1 centimeter. Therefore, EHF antennas can be even smaller and closer than UHF antennas. In some cases, this may facilitate the use of antenna arrays (eg, for directional beamforming) within UE 201. However, EHF transmissions may be subject to even greater atmospheric attenuation and shorter range than UHF transmissions.

[0088] Thus, the wireless communication system 200 can support millimeter wave (mmW) communications between UEs and base stations. Devices operating in mmW or EHF bands can have multiple antennas to allow beamforming. That is, the base station 202 can use multiple antennas or antenna arrays to perform beamforming operations for directional communication with the UE 201. Beamforming (also referred to as spatial filtering or directional transmission) is a signal processing technique that can be used at a transmitter (e.g., a base station) to shape and / or direct the entire antenna beam in the direction of a target receiver (e.g., a UE). This can be achieved by combining the elements in the antenna array in such a way that transmitted signals at specific angles experience constructive interference, while other signals experience destructive interference.

[0089] A multiple-input multiple-output (MIMO) wireless system uses a transmission scheme between a transmitter (e.g., a base station) and a receiver (e.g., a UE) where both the transmitter and the receiver are equipped with multiple antennas. Some portions of the wireless communication system 200 may use beamforming. For example, the base station 202 may have an antenna array having rows and columns of antenna ports that the base station may use for beamforming when communicating with the UE 201. Signals may be sent multiple times in different directions (e.g., the beamforming may be different for each transmission). A mmW receiver (e.g., a UE) may try multiple beams (e.g., antenna subarrays) when receiving synchronization signals.

[0090] In some cases, the antennas of base station 202 or UE 201 may be located within one or more antenna arrays that may support beamforming or MIMO operations. One or more base station antennas or antenna arrays may be placed side by side on an antenna assembly, such as an antenna tower. In some cases, the antennas or antenna arrays associated with base station 202 may be located at different geographic locations. Base station 202 may use multiple antennas or antenna arrays to perform beamforming operations for directional communication with UE 201.

[0091] In some cases, the wireless communication system 200 can be a packet-based network that operates according to a layered protocol stack. In the user plane, the communication at the bearer layer or PDCP layer can be based on IP. In some cases, the RLC layer can perform packet segmentation and reorganization to communicate through logical channels. The medium access control (MAC) layer can perform priority processing and multiplex logical channels into transport channels. The MAC layer can also use hybrid automatic repeat request (HARQ) to provide retransmission at the MAC layer to improve link efficiency. In the control plane, the radio resource control (RRC) protocol layer can provide the establishment, configuration and maintenance of the RRC connection between the network equipment or core network 203 that supports the radio bearer of user plane data for UE 201. At the physical (PHY) layer, the transport channel can be mapped to the physical channel.

[0092] The time interval in LTE or NR can be expressed in terms of a basic time unit (which can be T s =1 / 30,720,000 seconds sampling period). Time resources can be expressed in multiples of 10ms (T f =307200T s ) radio frames, which can be identified by a system frame number (SFN) ranging from 0 to 1023. Each frame can include 10 1 ms subframes numbered from 0 to 9. The subframe can be further divided into two 0.5 ms time slots, each of which contains 6 or 7 modulation symbol periods (depending on the length of the cyclic prefix added in front of each symbol). In addition to the cyclic prefix, each symbol contains 2048 sample periods. In some cases, the subframe can be the minimum scheduling unit, also known as TTI. In other cases, the TTI can be shorter than the subframe, or can be dynamically selected (for example, in short TTI bursts or in selected component carriers using short TTIs).

[0093] A resource element may consist of one symbol period and one subcarrier (e.g., 15KHz frequency range). A resource block may contain 12 consecutive subcarriers in the frequency domain, and for a normal cyclic prefix in each orthogonal frequency division multiplexing (OFDM) symbol, may contain 7 consecutive OFDM symbols in the time domain (one time slot), or may contain 84 resource elements. The number of bits carried by each resource element may depend on the modulation scheme (the configuration of symbols that can be selected within each symbol period). Therefore, the more resource blocks a UE receives and the higher the modulation scheme, the higher the data rate may be.

[0094] The wireless communication system 200 may support operation on multiple cells or carriers, a feature that may be referred to as carrier aggregation (CA) or multi-carrier operation. A carrier may also be referred to as a component carrier (CC), layer, channel, etc. The terms "carrier", "component carrier", "cell" and "channel" may be used interchangeably herein. UE 201 may be configured with multiple downlink CCs and one or more uplink CCs for carrier aggregation. Carrier aggregation may be used with both frequency division duplex (FDD) component carriers and time division duplex (TDD) component carriers.

[0095] In some cases, the wireless communication system 200 can utilize both licensed and unlicensed radio frequency spectrum bands. For example, the wireless communication system 200 can adopt LTE license assisted access (LTE-LAA) or LTE unlicensed (LTE U) radio access technology or NR technology in an unlicensed band (such as the 5GHz Industrial, Scientific and Medical (ISM) band). When operating in an unlicensed radio frequency spectrum band, wireless devices (such as base stations 202 and UE 201) can adopt a listen-before-talk (LBT) procedure to ensure that the channel is clear before sending data. In some cases, operations in unlicensed bands can be based on a CA configuration combined with a CC operating in a licensed band. Operations in an unlicensed spectrum can include downlink transmissions, uplink transmissions, or both. Duplexing in an unlicensed spectrum can be based on FDD, TDD, or a combination of the two.

[0096] Figure 3 is a diagram illustrating a protocol stack 300 according to at least one example embodiment. Figure 3 The examples are merely examples and do not necessarily limit the scope of the claims.

[0097] In at least one example embodiment, the physical (PHY) layer 304 provides information transmission services to higher layers using physical channels. The PHY layer 304 can be connected to the medium access control (MAC) layer 303 located on the higher layer via the transport channel. Data can be transmitted between the MAC layer 303 and the PHY layer 304 via the transport channel. Data can be transmitted between the physical layer of the transmitting side and the physical layer of the receiving side via the physical channel. The physical channel uses time and frequency as radio resources. In some cases, the physical channel is modulated using an orthogonal frequency division multiple access (OFDMA) scheme in the downlink and modulated using a single carrier frequency division multiple access (SC-FDMA) scheme in the uplink.

[0098] In at least one example embodiment, the MAC layer 303 provides services to a higher layer radio link control (RLC) layer 302 via a logical channel. The RLC layer 302 of the second layer supports reliable data transmission. The functions of the RLC layer 302 can be implemented by the functional blocks of the MAC layer 303. The packet data convergence protocol (PDCP) layer 301 performs a header compression function to reduce unnecessary control information for enabling efficient transmission of an Internet Protocol (IP) packet (such as an IP version 4 (IPv4) packet or an IP version 6 (IPv6) packet) in a radio interface having a relatively small bandwidth.

[0099] In at least one example embodiment, the PDCP layer is implemented by way of a PDCP entity that performs various actions of the PDCP layer. In this manner, an operating network node includes one or more PDCP entities for performing PDCP layer activities. In operation, the PDCP entity receives data for transmission from a higher layer in a PDCP service data unit (SDU). The PDCP entity performs various operations, such as header compression, uplink data compression, integrity protection, ciphering, etc., on the PDCP SDUs for transmission that it receives from a higher layer. The PDCP performs these operations on the received PDCP SDUs to generate a PDCP packet data unit (PDU), which is sent to a lower layer for transmission by way of the PDCP entity sending the PDCP SDUs.

[0100] The transmitting PDCP entity may track the successful delivery of the PDCP SDUs to the receiving PDCP entity. For example, the transmitting PDCP entity may receive a PDCP status report from the receiving PDCP entity indicating which PDCP SDUs have been received and which PDCP SDUs have not been received, which allows the transmitting PDCP entity to take action on received and unreceived PDCP SDUs.

[0101] In at least one example embodiment, the PDCP entity has a plurality of SDUs for transmission that it has received from higher layers.For example, the PDCP entity may use a buffer to store the plurality of PDCP SDUs for transmission.

[0102] In some cases, it may be desirable to discard one or more PDCP SDUs so that a network node (such as a UE or a base station) does not send the SDUs. For example, there may be a timer that tracks the amount of time after a PDCP SDU is received from an upper layer to determine whether to discard the PDCP SDU, which timer may be referred to as a discard timer. In such an example, the discard timer may be started or restarted when the PDCP entity receives a PDCP SDU for transmission from a higher layer. In such an example, it may be desirable to discard the PDCP SDU when the discard timer expires. In this way, when circumstances prevent the transmission of a PDCP SDU from a plurality of PDCP SDUs for transmission before the discard timer expires, the PDCP entity may discard one or more PDCP SDUs from the plurality of PDCP SDUs for transmission so as to reduce the number of buffered PDCP SDUs for transmission.

[0103] In some cases, it may be desirable to limit the discarding of PDCP SDUs to low importance SDUs. For example, there may be a timer that tracks the amount of time after a low importance PDCP SDU is received from an upper layer to determine whether to discard the low importance PDCP SDU, which timer may be referred to as a low importance discard timer. In such an example, when the PDCP entity receives a low importance PDCP SDU for transmission from a higher layer, the low importance discard timer may be started or restarted. In such an example, it may be desirable to discard the low importance PDCP SDU when the discard timer expires. In this way, when circumstances prevent the transmission of low importance PDCP SDUs from multiple PDCP SDUs for transmission before the low importance discard timer expires, the PDCP entity may discard one or more low importance PDCP SDUs from the multiple PDCP SDUs for transmission so as to reduce the number of buffered low importance PDCP SDUs for transmission, which may have the effect of providing an improved opportunity to transmit PDCP SDUs of higher importance rather than low importance PDCP SDUs.

[0104] Figure 4 is a diagram illustrating a set of PDCP PDUs 400 according to at least one example embodiment. Figure 4 The examples are merely examples and do not necessarily limit the scope of the claims. In at least one example embodiment, a PDCP entity receives PDCP SDUs 401 to 410 for transmission.

[0105] In some cases, there may be multiple PDCP PDUs that are closely related to each other. In such a case, these PDCP PDUs may belong to a PDCP PDU set. In such a case, the PDCP SDUs corresponding to the PDCP PDUs in the PDCP PDU set also belong to the PDCP PDU set. For example, PDCP SDUs 401 to 410 and corresponding PDCP PDUs may belong to a single PDCP PDU set. In another example, PDCP SDUs 401 to 403, 406, 408 and 410 and corresponding PDCP PDUs belong to a first PDCP SDU set, while PDCP SDUs 404, 405, 407 and 409 and corresponding PDCP PDUs belong to a second PDCP SDU set.

[0106] In some cases, when any PDCP SDU from a PDCP SDU set is discarded, it may be desirable to discard all PDCP SDUs in the PDCP SDU set. For example, in some cases, a receiving PDCP entity may not benefit from receiving only a subset of PDCP SDUs in a PDCP SDU set. In such an example, in the event that one or more PDCP SDUs are discarded from a PDCP SDU set, the remaining PDCP SDUs in the PDCP SDU set are discarded, thereby improving efficiency by avoiding sending PDCP SDUs that are not needed by the receiving PDCP entity. In at least one example embodiment, in the event that the PDCP entity discards PDCP SDUs in a PDCP SDU set, the PDCP entity discards the remaining PDCP SDUs in the PDCP SDU set from the PDCP SDUs for transmission. In some cases, it may be desirable to discard only unsent PDCP SDUs from a plurality of PDCP SDUs for transmission, and retain the sent PDCP SDUs in a plurality of PDCP SDUs for transmission. For example, in the case where a first group of PDCP SDUs from a PDCP SDU set has been transmitted before the PDCP SDUs are discarded, it may be desirable to discard the remaining untransmitted PDCP SDUs in the PDCP SDU set from the plurality of PDCP SDUs for transmission and retain the first group of PDCP SDUs in the PDCP SDUs for transmission. In this way, by retaining the first group of PDCP SDUs that have been transmitted, the PDCP entity can still process a PDCP status report that includes PDCP status information related to the PDCP SDUs in the first group of PDCP SDUs.

[0107] In some cases, discarding one or more PDCP SDUs may cause inefficiency in the receiving PDCP entity. For example, the receiving PDCP entity may continue to wait to receive the discarded PDCP SDU. It may be desirable to improve the efficiency of the receiving PDCP entity by notifying the receiving PDCP entity of the discarded PDCP SDU by the sending PDCP entity so that the receiving PDCP entity knows the discarded PDCP SDU. In at least one example embodiment, the PDCP entity sends a discard notification. In at least one example embodiment, the discard notification is a notification indicating that the PDCP entity has discarded one or more PDCP SDUs. In at least one example embodiment, the discard notification includes information indicating one or more discarded SDUs. In at least one example embodiment, the discard notification is a PDCP control PDU. For example, the discard notification can be a PDCP SDU discard report control PDU, a PDCP SN gap report control PDU, etc.

[0108] In at least one example embodiment, the PDCP entity generates a discard notification based on the discarding of at least one PDCP SDU. For example, the discard notification may be generated based on a SN associated with the discarded PDCP SDU. In such an example, the discard notification may be generated based on the SN of the discarded PDCP SDU, such that the SN is indicated by the discard notification.

[0109] There are various ways in which a discard notification may provide information indicating a discarded PDCP SDU. For example, a discard notification may indicate a discarded PDCP SDU by way of a count or SDN associated with the PDCP SDU. As previously described, in some cases, there may be multiple discarded PDCP SDUs. In some cases, the multiple discarded PDCP SDUs may be consecutive. For example, there may be a situation where PDCP SDUs 402 to 407 are discarded from multiple PDCP SDUs 400. In such a case, the multiple discarded PDCP SDUs are consecutive. In other cases, the multiple discarded PDCP SDUs may be non-consecutive. For example, there may be a situation where PDCP SDUs 401, 404, and 408 are discarded from multiple PDCP SDUs 400. In such a case, the multiple discarded PDCP SDUs are non-consecutive.

[0110] In the case where there are multiple discarded PDCP SDUs, the discard notification may include a bitmap indication and / or a range indication indicating multiple discarded PDCP SDUs. In at least one example embodiment, the UE receives configuration information indicating that the discard notification, bitmap indication and / or range indication are enabled. The configuration information may be received by way of one or more RRC messages (such as an RRC reconfiguration message). For example, the configuration may be included in an information element included in the RRC message. In some cases, when the corresponding discard notification, bitmap indication and / or range indication are enabled, the configuration information may be included in the information element. For example, the configuration information may indicate that the corresponding discard notification, bitmap indication and / or range indication is disabled by the way that it is not present in the information element. In at least one example embodiment, the configuration information indicates that the discard notification has been enabled. In at least one example embodiment, the configuration information indicates that the discard notification including the bitmap indication has been enabled. In at least one example embodiment, the configuration information indicates that the discard notification including the range indication has been enabled.

[0111] In at least one example embodiment, the PDCP entity determines whether to generate a discard notification based on the configuration information. In at least one example embodiment, the PDCP entity determines whether to include a bitmap indication in the discard notification based on the configuration information. In at least one example embodiment, the PDCP entity determines whether to include a range indication in the discard notification based on the configuration information.

[0112] In at least one example embodiment, the discard notification indicates the discard of the PDCP SDU by way of a bitmap indication and a first discarded PDCP SDU indication. In at least one example embodiment, the first discarded PDCP SDU indication identifies a PDCP SDU that starts a plurality of discarded PDCP SDUs. In at least one example embodiment, the first discarded PDCP SDU indication is a count. In at least one example embodiment, the first discarded PDCP SDU indication is a sequence number (SN).

[0113] In at least one example embodiment, the bitmap indication is a set of bits, wherein each bit position of the bitmap indication corresponds to a PDCP SDU following a first discarded PDCP SDU. In at least one example embodiment, each bit position of the bitmap indication corresponds to a PDCP SDU following a first discarded PDCP SDU. In at least one example embodiment, the first bit in the bitmap corresponds to a PDCP SDU that immediately follows a PDCP SDU corresponding to the first discarded PDCP SDU indication. In at least one example embodiment, the nth bit in the bitmap corresponds to a PDCP SDU that is n PDCP SDUs following the PDCP SDU corresponding to the first discarded PDCP SDU indication. For example, the nth bit in the bitmap may correspond to a PDCP SDU having a count or a count or SN of the first discarded PDCP SDU or SN+n. In at least one example embodiment, each bit value in the bitmap indication indicates whether the corresponding PDCP SDU is discarded. For example, a bit value of 1 may indicate that the corresponding PDCP SDU is discarded, such that a bit value of 0 indicates that the corresponding PDCP SDU is not discarded. In another example, a bit value of 0 may indicate that the corresponding PDCP SDU is discarded, such that a bit value of 1 indicates that the corresponding PDCP SDU is not discarded. In at least one example embodiment, each bit value in the bitmap indicates whether the corresponding PDCP SDU is discarded or sent (e.g., sent by the PDCP entity to a lower layer for transmission). For example, a bit value of 1 may indicate that the corresponding PDCP SDU is discarded, such that a bit value of 0 indicates that the corresponding PDCP SDU is sent. In another example, a bit value of 0 may indicate that the corresponding PDCP SDU is discarded, such that a bit value of 1 indicates that the corresponding PDCP SDU is sent.

[0114] In at least one example embodiment, the PDPC entity generates a bitmap indication. In at least one example embodiment, generating the bitmap indication includes determining a size of the bitmap indication. In some cases, it may be desirable that the bitmap indication is an integer number of bytes. In at least one example embodiment, the size of the bitmap indication is an integer multiple of 8. In at least one example embodiment, the size of the bitmap indication is determined such that the bitmap includes a bit corresponding to the last discarded PDCP SDU and less than 8 subsequent additional bits that make the size of the bitmap indication an integer multiple of 8.

[0115] In at least one example embodiment, a discard notification indicates the discard of a PDCP SDU by way of one or more bitmap indications and multiple discarded PDCP SDU indications. For example, the discard notification may include multiple bitmap indications and first discarded PDCP SDU indication pairs. However, in some cases, in order to ensure the overhead associated with the bitmap, there may be a discarded PDCP SDU that is not sufficiently close to another discarded PDCP SDU. In such a case, it may be desirable to indicate the discarded PDCP SDU by way of a first discarded PDCP SDU indicator without any corresponding bitmap indicator.

[0116] In at least one example embodiment, the discard notification indicates the discard of the PDCP SDU by way of a range indication. In at least one example embodiment, the range indication indicates a group of consecutive discarded PDCP SDUs. In at least one example embodiment, the range indication includes a first discarded PDCP SDU indication. The first discarded PDCP SDU indication may be a count, an SN, etc. In at least one example embodiment, the range indication includes a first discarded PDCP SDU indication and a last discarded PDCP SDU indication. In at least one example embodiment, the last discarded PDCP SDU indication indicates the last PDCP SDU included in the range indication. It should be noted that the term "last PDCP SDU" does not necessarily refer to the absolutely final discarded PDCP SDU, but refers to the last PDCP SDU included in the range indication. Specifically, there may be another discarded PDCP SDU in a later count or SN, which count or SN is not included in the range of the range indication. For example, other discarded SDUs may be included in different range indications, bitmap indications, etc. In at least one example embodiment, the last discarded PDCP SDU indication directly indicates the last PDCP SDU of the range indication. For example, the last discarded PDCP SDU indication may be a count, SN, etc. identifying the last discarded PDCP SDU. In at least one example embodiment, the last discarded PDCP SDU indication indirectly indicates the PDCP SDU. For example, the last discarded PDCP SDU indication may indicate the PDCP SDU by an offset from the first discarded PDCP SDU. In at least one example embodiment, the PDCP entity generates a range notification.

[0117] In at least one example embodiment, a discard notification indicates the discarding of a plurality of PDCP SDUs by way of a combination of one or more range indications with one or more bitmap indications and one or more corresponding first discarded PDCP SDU indications. For example, the discard notification may indicate the discarding of a first plurality of PDCP SDUs by way of one or more range indications, and may indicate the discarding of a second plurality of PDCP SDUs by way of one or more bitmap indications and one or more corresponding first discarded PDCP SDU indications. In some cases, there may be some non-consecutive discarded PDCP SDUs followed by consecutive discarded PDCP SDUs. In such a case, the discard notification may include first discarded PDCP SDU indications and corresponding bitmap indications for the non-consecutive discarded PDCP SDUs, and include a range indication for the consecutive discarded PDCP SDUs. In at least one example embodiment, the size of the bitmap indication is determined such that the last bit of the bitmap corresponds to a discarded PDCP SDU immediately preceding the PDCP SDU included in the range indication.

[0118] Figure 5 is a flow chart illustrating activities 500 associated with sending a discard notification according to at least one example embodiment. In at least one example embodiment, there is a set of operations associated with Figure 5 The device (e.g. Figure 1 The electronic device 100 or a portion thereof may utilize the set of operations. The device may include components for performing such operations, including, for example Figure 1 In an example embodiment, the device (e.g. Figure 1 The electronic device 100) has a memory (eg, Figure 1 The computer code is configured to communicate with the processor (e.g. Figure 1 The processor 110) works together to enable the device to execute Figure 5 A set of operations.

[0119] At block 501, an apparatus receives a plurality of PDCP SDUs for transmission. For example, the plurality of PDCP SDUs may be received by a PDCP entity of the apparatus and may be received from a higher layer, such as a layer above the PDCP layer.

[0120] At block 502, the apparatus discards at least one PDCP SDU from a plurality of PDCP SDUs for transmission. The discarding may be similar to the Figure 3 and Figure 4 Discard as described.

[0121] At block 503, the device sends a discard notification. As previously described, the discard notification may indicate the discard of a PDCP SDU, similar to the Figure 4 For example, the content of the discard notification may be based on the discard of at least one PDCP SDU.

[0122] Figure 6 is a flow diagram illustrating activities 600 associated with sending a discard notification according to at least one example embodiment. In at least one example embodiment, there is a set of operations associated with Figure 6 The device (e.g. Figure 1 The electronic device 100 or a portion thereof may utilize the set of operations. The device may include components for performing such operations, including, for example Figure 1 In an example embodiment, the device (e.g. Figure 1 The electronic device 100) has a memory (eg, Figure 1 The computer code is configured to communicate with the processor (e.g. Figure 1 The processor 110) works together to enable the device to execute Figure 6 A set of operations.

[0123] As previously described, the discard notification may include a bitmap indication or a range indication. However, there are situations in which the bitmap indication is more effective than the range indication, and there are other situations in which the range indication is more effective than the bitmap indication. For example, if there is a large number of consecutive discarded PDCP SDUs, the range indication may be more effective than the bitmap indication. However, if the number of consecutive discarded PDCP SDUs is low, the bitmap indication may be more effective than the range indication. In at least one example embodiment, when the combination of the bitmap indication and the first discarded PDCP SDU is larger than the corresponding range indication, the device determines to use the range notification to indicate a group of consecutive discarded PDCP SDUs instead of the combination of the bitmap indication and the first discarded PDCP SDU. In at least one example embodiment, when the combination of the bitmap indication and the first discarded PDCP SDU is larger than the corresponding range indication, a group of consecutive discarded PDCP SDUs is considered to be sufficiently consecutive. In at least one example embodiment, when the combination of the range indication is larger than the corresponding bitmap indication and the first discarded PDCP SDU, the device determines to use the combination of the bitmap indication and the first discarded PDCP SDU to indicate a group of consecutive discarded PDCP SDUs instead of the range notification. In at least one example embodiment, a group of consecutive discarded PDCP SDUs are considered to be sufficiently non-consecutive when a combination of the range indications is greater than the corresponding bitmap indication and the first discarded PDCP SDU.

[0124] In at least one example embodiment, the apparatus determines whether to include a bitmap indication or a range indication based on determining whether the discarded PDCP SDUs are sufficiently consecutive. In at least one example embodiment, determining whether the discarded PDCP SDUs are sufficiently consecutive includes determining whether the number of consecutive PDCP SDUs exceeds a range threshold. For example, when the number of consecutive PDCP SDUs is less than the range threshold (and in some embodiments, also includes the case where the number of consecutive PDCP SDUs is equal to the range threshold), the apparatus may determine that the discarded PDCP SDUs are sufficiently non-consecutive for the purpose of discard notification, and when the number of consecutive PDCP SDUs is greater than the range threshold (and in some embodiments, also includes the case where the number of consecutive PDCP SDUs is equal to the range threshold), the apparatus may determine that the discarded PDCP SDUs are sufficiently consecutive for the purpose of discard notification. The range threshold may be a number corresponding to the number of consecutive discarded SDUs, which must be fewer bits (or fewer octets) for the range indication than the combination of the bitmap indication and the corresponding first discarded PDCP SDU indication.

[0125] At block 601, an apparatus receives a plurality of PDCP SDUs for transmission, similar to Figure 5 As described in block 501 of FIG.

[0126] At block 602, the apparatus discards at least one PDCP SDU from a plurality of PDCP SDUs for transmission, similar to the Figure 5 As described in block 502 of FIG.

[0127] At block 603, the apparatus determines whether the discarded plurality of PDCP SDUs are sufficiently contiguous. If the discarded plurality of PDCP SDUs are sufficiently contiguous, the process proceeds to block 604. If the discarded plurality of PDCP SDUs are sufficiently non-contiguous, the process proceeds to block 605. As previously described, determining whether the discarded plurality of PDCP SDUs are sufficiently contiguous includes determining whether the number of contiguous PDCP SDUs in the discarded plurality of PDCP SDUs exceeds a range threshold. Thus, in at least one example embodiment, at block 603, the apparatus determines whether the number of contiguous PDCP SDUs in the discarded plurality of PDCP SDUs exceeds a range threshold. In such an embodiment, if the number of contiguous PDCP SDUs in the discarded plurality of PDCP SDUs exceeds the range threshold, the process proceeds to block 604, and if the number of contiguous PDCP SDUs in the discarded plurality of PDCP SDUs does not exceed the range threshold, the process proceeds to block 605.

[0128] At block 604, the apparatus includes a range indication in the discard notification to indicate discarding of the plurality of PDCP SDUs.

[0129] At block 605, the apparatus includes a bitmap indication and a corresponding first discarded PDCP SDU indication in a discard notification to indicate discarding of the plurality of PDCP SDUs.

[0130] Embodiments of the present invention may be implemented in software, hardware, application logic, or a combination of software, hardware, and application logic. The software, application logic, and / or hardware may reside on an apparatus, a separate device, or multiple separate devices. If desired, portions of the software, application logic, and / or hardware may reside on an apparatus, portions of the software, application logic, and / or hardware may reside on a separate device, and portions of the software, application logic, and / or hardware may reside on multiple separate devices. In an example embodiment, the application logic, software, or instruction set is maintained on any of a variety of conventional computer-readable media.

[0131] If desired, the different functions discussed herein may be performed in a different order and / or in parallel with each other. Furthermore, if desired, one or more of the above functions may be optional or may be combined.

[0132] Although individual aspects of the invention are set out in the independent claims, further aspects of the invention include other combinations of features from the described embodiments and / or dependent claims having features of the independent claims and not just the combinations explicitly set out in the claims.

[0133] It is also noted herein that while the above describes example embodiments of the invention, these descriptions should not be viewed in a limiting sense. Rather, changes and modifications may be made without departing from the scope of the invention as defined in the appended claims.

Claims

1. A device comprising: at least one processor; as well as at least one memory including computer program code, the memory and the computer program code being configured to work with the processor to cause the apparatus to perform at least the following operations: receiving, by a Packet Data Convergence Protocol (PDCP) entity of the apparatus, a plurality of PDCP service data units (SDUs) for transmission; discarding at least one PDCP SDU from a plurality of PDCP SDUs for transmission; as well as A discard notification is sent, where the discard notification indicates the discard of the at least one PDCP SDU by way of a bitmap indication and a first discarded PDCP SDU indication.

2. The apparatus of claim 1, wherein the memory comprises computer program code configured to, working with the processor, cause the apparatus to receive configuration information indicating that discard notification is enabled.

3. The apparatus of claim 1 , wherein the memory comprises computer program code configured to, working with the processor, cause the apparatus to generate the discard notification based on the discard of the at least one PDCP SDU.

4. The apparatus of claim 1 , wherein a first bit in the bitmap indication corresponds to a PDCP SDU that immediately follows the PDCP SDU indicated by the first discarded PDCP SDU indication.

5. The apparatus of claim 1 , wherein each bit position of the bitmap indication corresponds to a PDCP SDU that follows the PDCP SDU indicated by the first discarded PDCP SDU indication, and each bit value in the bitmap indication indicates whether the corresponding PDCP SDU is discarded.

6. The apparatus according to claim 1, wherein the discard notification further indicates the discard of the at least one PDCP SDU by way of a range indication, wherein the range indication includes a first discarded PDCP SDU indication and a last discarded PDCP SDU indication.

7. The apparatus of claim 1 , wherein discarding at least one PDCP SDU comprises discarding a plurality of PDCP SDUs, and the memory comprises computer program code configured to, working with the processor, cause the apparatus to include a range indication in the discard notification based on a determination that a number of consecutive discarded PDCP SDUs exceeds a range threshold.

8. The apparatus of claim 1 , wherein discarding at least one PDCP SDU comprises discarding a plurality of PDCP SDUs, and the memory comprises computer program code configured to, working with the processor, cause the apparatus to include the bitmap indication in the discard notification based on a determination that a number of consecutive discarded PDCP SDUs does not exceed a range threshold.

9. The apparatus of claim 1, wherein discarding at least one PDCP SDU comprises discarding a plurality of PDCP SDUs, the plurality of PDCP SDUs belonging to the same PDCP PDU set.

10. A method comprising: receiving, by a packet data convergence protocol (PDCP) entity, a plurality of PDCP service data units (SDUs) for transmission; discarding at least one PDCP SDU from a plurality of PDCP SDUs for transmission; as well as A discard notification is sent, where the discard notification indicates the discard of the at least one PDCP SDU by way of a bitmap indication and a first discarded PDCP SDU indication. The method of claim 10 , further comprising receiving configuration information indicating that discard notification is enabled.

12. The method of claim 10, further comprising generating the discard notification based on the discarding of the at least one PDCP SDU.

13. The method of claim 10, wherein a first bit in the bitmap indication corresponds to a PDCP SDU that immediately follows the PDCP SDU indicated by the first discarded PDCP SDU indication.

14. The method of claim 10, wherein each bit position of the bitmap indication corresponds to a PDCP SDU that follows the PDCP SDU indicated by the first discarded PDCP SDU indication, and each bit value in the bitmap indication indicates whether the corresponding PDCP SDU is discarded.

15. The method according to claim 10, wherein the discard notification further indicates the discarding of the at least one PDCP SDU by way of a range indication, wherein the range indication includes a first discarded PDCP SDU indication and a last discarded PDCP SDU indication.

16. The method of claim 10, wherein discarding at least one PDCP SDU comprises discarding a plurality of PDCP SDUs, and further comprising including a range indication in the discard notification based on a determination that a number of consecutive discarded PDCP SDUs exceeds a range threshold.

17. The method of claim 10, wherein discarding at least one PDCP SDU comprises discarding a plurality of PDCP SDUs, and further comprising including the bitmap indication in the discard notification based on a determination that a number of consecutive discarded PDCP SDUs does not exceed a range threshold.

18. The method of claim 10, wherein discarding at least one PDCP SDU comprises discarding a plurality of PDCP SDUs, the plurality of PDCP SDUs belonging to the same PDCP PDU set.

19. At least one non-transitory computer-readable medium encoded with instructions that, when executed by a processor, perform the following: receiving, by a packet data convergence protocol (PDCP) entity, a plurality of PDCP service data units (SDUs) for transmission; discarding at least one PDCP SDU from a plurality of PDCP SDUs for transmission; and A discard notification is sent, where the discard notification indicates the discard of the at least one PDCP SDU by way of a bitmap indication and a first discarded PDCP SDU indication.

Images