Techniques for radio link control acknowledgement mode in wireless networks

Abstract

The present application relates to devices and components including apparatuses, systems and methods for radio link control (RLC) acknowledgement mode (AM) in a wireless network.

Description

[0001] Cross Reference to Related Applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 698,437, filed September 24, 2024, entitled “TECHNOLOGIES FOR RADIO LINK CONTROL ACKNOWLEDGED MODE IN A WIRELESS NETWORK,” the contents of which are incorporated by reference herein in their entirety for all purposes. TECHNICAL FIELD

[0003] The present application relates generally to communication networks, and specifically to technologies for radio link control acknowledged mode in a wireless network. BACKGROUND

[0004] Third Generation Partnership Project (3GPP) Technical Specifications (TSs) define standards for wireless networks. These TSs describe aspects related to signaling traffic through systems that include wireless networks. BRIEF DESCRIPTION OF DRAWINGS

[0005] Figure 1 A network environment is illustrated in accordance with some embodiments.

[0006] Figure 2 An example transmitter-initiated procedure for reducing radio link control (RLC) service data unit (SDU) retransmissions is illustrated in accordance with some embodiments.

[0007] Figure 3 An example receiver-initiated procedure for reducing RLC SDU retransmissions is illustrated in accordance with some embodiments.

[0008] Figure 4 An example combined procedure for reducing RLC SDU retransmissions is illustrated in accordance with some embodiments.

[0009] Figure 5 An example procedure for data volume calculation is illustrated in accordance with some embodiments.

[0010] Figure 6 An example procedure is illustrated in accordance with some embodiments.

[0011] Figure 7 Another example procedure is illustrated in accordance with some embodiments.

[0012] Figure 8 Another example procedure is illustrated in accordance with some embodiments.

[0013] Figure 9 The operational flow / algorithm structure according to some implementation schemes is illustrated.

[0014] Figure 10 Another operational flow / algorithm structure based on some implementation schemes is illustrated.

[0015] Figure 11 Another operational flow / algorithm structure based on some implementation schemes is illustrated.

[0016] Figure 12 Examples of user equipment based on some implementation schemes are shown.

[0017] Figure 13 Examples of network devices based on some implementation schemes are shown. Detailed Implementation

[0018] The following detailed description refers to the accompanying drawings. The same reference numerals may be used to identify the same or similar elements in different drawings. In the following description, specific details, such as particular structures, architectures, interfaces, and techniques, are set forth for illustrative and non-limiting purposes to provide a thorough understanding of various aspects of the various embodiments. However, it will be apparent to those skilled in the art that various aspects of the various embodiments may be practiced in other examples departing from these specific details. In some instances, descriptions of well-known devices, circuits, and methods have been omitted so as not to obscure the description of the various embodiments with unnecessary detail. For the purposes of this document, the phrases “A / B” and “A or B” refer to (A), (B), or (A and B); and the phrase “based on A” means “at least partially based on A,” for example, it can be “based solely on A” or it can be “partially based on A.”

[0019] The following is a glossary of terms that may be used in this disclosure.

[0020] As used herein, the term "circuit" refers to a hardware component configured to provide the described functionality, is part of, or includes such hardware components. Hardware components may include electronic circuits, logic circuits, processors (shared, dedicated, or grouped) or memories (shared, dedicated, or grouped), application-specific integrated circuits (ASICs), field-programmable devices (FPDs) (e.g., field-programmable gate arrays (FPGAs), programmable logic devices (PLDs), complex PLDs (CPLDs), high-capacity PLDs (HCPLDs), structured ASICs, or programmable system-on-a-chip (SoCs)), or digital signal processors (DSPs). In some embodiments, the circuit may execute one or more software or firmware programs to provide at least some of the described functionality. The term "circuit" may also refer to a combination of one or more hardware elements (or combinations of circuits used in electrical or electronic systems) and program code for executing the functionality. In these embodiments, the combination of hardware elements and program code may be referred to as a particular type of circuit.

[0021] As used herein, the term "processor circuit" means, is part of, or includes a circuit capable of sequentially and automatically performing a series of arithmetic or logical operations or recording, storing, or transmitting digital data. The term "processor circuit" may also refer to an application processor, baseband processor, central processing unit (CPU), graphics processing unit, single-core processor, dual-core processor, triple-core processor, quad-core processor, or any other device capable of executing or otherwise operating computer-executable instructions (such as program code, software modules, and / or functional procedures).

[0022] As used herein, the term "interface circuit" refers to, is part of, or includes a circuit that enables the exchange of information between two or more components or devices. The term "interface circuit" can refer to one or more hardware interfaces, such as buses, I / O interfaces, peripheral component interfaces, and network interface cards.

[0023] As used herein, the term "user equipment" or "UE" refers to equipment having radio communication capabilities that allow a user to access network resources within a communication network. The term "user equipment" or "UE" may be considered synonymous with and may be referred to as a client, mobile phone, mobile device, mobile terminal, user terminal, mobile unit, mobile station, mobile user, subscriber, user, remote station, access agent, user agent, receiver, radio equipment, reconfigurable radio equipment, or reconfigurable mobile device. Furthermore, the term "user equipment" or "UE" can include any type of wireless / wired equipment or any computing device that includes a wireless communication interface.

[0024] As used herein, the term "computer system" means any type of interconnected electronic device, computer device, or component thereof. Additionally, the term "computer system" or "system" can refer to various components of a computer that are communicatively coupled to each other. Furthermore, the term "computer system" or "system" can refer to multiple computer devices or multiple computing systems that are communicatively coupled to each other and configured to share computing resources or network resources.

[0025] As used herein, the term "resource" refers to physical or virtual devices, physical or virtual components within a computing environment, or physical or virtual components within a particular device, such as computer equipment, mechanical equipment, memory space, processor / CPU time, processor / CPU utilization, processor and accelerator load, hardware time or utilization, power, input / output operations, port or network sockets, channel / link allocation, throughput, memory utilization, storage, network, database, and application or workload units. "Hardware resource" can refer to computing, storage, or network resources provided by physical hardware components. "Virtualized resource" can refer to computing, storage, or network resources provided by virtualization infrastructure to an application, device, or system. The terms "network resource" or "communication resource" can refer to resources accessible by a computer device / system via a communication network. The term "system resource" can refer to any kind of shared entity providing services and can include computing or network resources. System resources can be considered as a coherent set of functions, network data objects, or services accessible through a server, wherein such system resources reside on a single host or multiple hosts and can be clearly identified.

[0026] As used herein, the term "channel" refers to any tangible or intangible transmission medium used to transmit data or data streams. The term "channel" may be synonymous or equivalent with "communication channel," "data communication channel," "transmission channel," "data transmission channel," "access channel," "data access channel," "link," "data link," "carrier," "radio frequency carrier," or any other similar term indicating a means or medium through which data is transmitted. Additionally, as used herein, the term "link" refers to a connection between two devices used for transmitting and receiving information.

[0027] As used in this article, the terms "instantiate" and "instantiate" refer to the creation of an instance. "Instance" also refers to the concrete occurrence of an object, which may occur, for example, during the execution of program code.

[0028] The term "connection" can refer to an established signaling relationship between two or more elements at a common communication protocol layer through a communication channel, link, interface, or reference point.

[0029] As used herein, the term "network element" refers to physical or virtualized equipment or infrastructure used to provide wired or wireless communication network services. The term "network element" may be considered synonymous with or referred to as a networked computer, network hardware, network equipment, network node, or virtualized network function.

[0030] The term "information element" refers to a structural element that contains one or more fields. The term "field" refers to the individual content of an information element, or the data element that contains that content. An information element may include one or more additional information elements.

[0031] Figure 1 A network environment 100 according to some implementation schemes is illustrated. Network environment 100 may include a user equipment (UE) 104 communicatively coupled to a base station 108 of a radio access network (RAN) 110. UE 104 and base station 108 may communicate via a 3GPPTS-compatible air interface, such as an interface defining a fifth-generation (5G) new radio (NR) system or higher. Base station 108 may provide user plane and control plane protocol termination to UE 104.

[0032] In some implementations, UE 104 and base station 108 may establish a data radio bearer (DRB) to support data transmission over a wireless link between the two nodes. In one example, these DRBs may be used for services from extended reality (XR) applications that contain large amounts of data conveying real and virtual images and audio for presentation to a user.

[0033] Network environment 100 may also include core network 112. For example, core network 112 may include a 5th generation core network (5GC) or a newer generation core network. Core network 112 may be coupled to base station 108 via fiber optic or wireless backhaul. Core network 112 may provide functions to UE 104 via base station 108. These functions may include managing subscriber profile information, subscriber location, service authentication, or handover of voice and data sessions.

[0034] Network environment 100 may also include external data network 120. External data network 120 may include a system of interconnecting nodes that facilitate data transmission between UE 104 and various application servers and other service providers. Base station 108 and core network 112 may route application data between UE 104 and external data network 120 or application servers. These application servers host web applications, cloud storage, and multimedia streaming services that communicate with UE 104 via standardized protocols and interfaces defined by 3GPP, thereby ensuring secure and efficient data exchange.

[0035] This document describes operations performed by devices (e.g., UE 104, base station 108, and / or devices of core network 112) that can be performed wholly, substantially, or partially by processing circuitry implemented on the devices. Additionally, this document describes operations performed by the “network” that can be performed by devices of RAN 110 (e.g., base station 108), devices of core network 112, and / or components thereof.

[0036] Core network 112 may include a User Plane Function (UPF) 122, which provides routing and forwarding of user plane packets between base station 108 and external data network 120. BS 108 can receive uplink packets from UE 104 via DRB and can send uplink packets to UPF 122 via General Packet Radio Service (GPRS) Tunneling Protocol-User Plane (GTP-U) tunneling. UPF 122 can remove packet headers and forward these packets to external data network 120. UPF 122 can map downlink packets from external data network to a specific Quality of Service (QoS) flow belonging to a specific PDU session before forwarding them to BS 108. BS 108 can map this traffic to the appropriate DRB for delivery to UE 104.

[0037] UE 104 may include application layer 114, which generates application services to be transmitted to another device via network environment 100. In some implementations, the application layer may have XR applications that generate XR services. However, the implementation is not limited to XR use cases.

[0038] 3GPP TS can define protocol stacks, such as network protocol stack 130 or UE protocol stack 135. A protocol stack can be a set of communication protocols. In some examples, the protocol stack can be designed in a layered architecture for modularity, where each layer provides specific functionality. This design allows changes in one layer without affecting other layers, thus facilitating upgrades and improvements. These layers may include a physical layer (Layer 1, L1, or PHY) responsible for establishing and maintaining physical links 120. Control and data bits can be transmitted via the air interface and physical link 120. The protocol stack (e.g., network protocol stack 130 or UE protocol stack 135) may include a data link layer (Layer 2, L2), which can be divided into Media Access Control (MAC), Radio Link Control (RLC) 118a-b, and Packet Data Convergence Protocol (PDCP) 116a-b sublayers. Layer 2 can be responsible for managing the connectivity and mobility of UE 104 between the cell and the network. In some instances, application layers 114a-b are not included in the protocol stack.

[0039] The RLC 118a-b sublayer is responsible for reliable data transmission. RLC 118a-b may include a transmitting entity 150a-b and a receiving entity 160a-b. At the transmitting end, the transmitting entity 150a-b can segment data from higher layers (e.g., PDCP layer 116a-b or application layer 114a-b) and add sequence numbers and headers. These packets can then be transmitted via the air interface (e.g., via physical link 120). At the receiving end, the receiving entity 160a-b of the RLC layer 118a-b can, for example, use sequence number and header information to reassemble the packets back into the original data, ensuring correct order and detecting any lost packets. If a packet is detected as lost or corrupted, the RLC layer 118a-b at the receiver can request a retransmission from the transmitter.

[0040] In downlink transmission, base station 108 is the transmitter, and UE 104 is the receiver. The transmitting entity 150a of RLC layer 118a of base station 108 transmits packets to UE 104 via physical link 120. The receiving entity 160b of RLC layer 118b of UE 104 receives and reassembles the packets. In some implementations, packets transmitted by RLC layers 118a-b may be referred to as RLC Protocol Data Units (PDUs).

[0041] The receiving entity 160a of the RLC layer 118a of base station 108 can be referred to as a peer entity of the transmitting entity 150b of the RLC layer 118b of UE 104. Similarly, the receiving entity 160b of the RLC layer 118b of UE 104 can be referred to as a peer entity of the transmitting entity 150a of the RLC layer 118a of base station 108.

[0042] In some instances, packets received by a layer from a higher layer are called Service Data Units (SDUs) of that layer. Packets sent from that layer to lower layers are called PDUs of that layer. For example, packets received from PDCP layers 116a-b are called PDCPSDUs, and packets transmitted from PDCP layers 116a-b to RLC layers 118a-b are called PDCP PDUs.

[0043] RLC layers 118a-b can be configured as Acknowledgment Mode (AM) RLC. In AM RLC, each transmitted PDU is assigned a sequence number. The receiver can transmit acknowledgments (ACKs) for correctly received PDUs and negative acknowledgments (NACKs) for lost or erroneous PDUs. Upon receiving a NACK or in the absence of an ACK associated with the PDU, the transmitter can retransmit the corresponding PDU.

[0044] In some implementations, application layers 114a-b can generate packets and group these packets into a PDU set. PDCP layers 116a-b can receive packets and generate PDCP PDUs. Each PDCP PDU can be associated with one or more application layer packets or PDU sets. RLC layers 118a-b can receive PDCP PDUs and generate RLC PDUs. Each RLC PDU can be associated with one or more PDCP PDUs, and similarly, can be associated with one or more application layer packets or PDU sets.

[0045] In some implementations, the sending PDCP entity may start a drop timer when a PDCP SDU is received from the upper layer. The drop timer may track the buffering time of each SDU at PDCP layers 116a-b. In some instances, the sending PDCP entity may drop the PDCP SDU and its corresponding PDCP PDU when the drop timer expires for the PDCP SDU or when the successful delivery of the PDCP SDU is acknowledged (e.g., via ACK).

[0046] Each PDCP SDU maintains its own drop timer. This is true even for PDCPSDUs belonging to the same PDU set. A PDU set can include one or more PDUs carrying a payload (e.g., a frame or video slice for XR services) of a single information element generated at the application level. PDCPSDUs belonging to the same PDU set do not necessarily arrive simultaneously. This can be due to, for example, uplink (UL) jitter in tethered use cases, where packets experience different jitter before reaching the UE. Therefore, each PDCP SDU can have different remaining time, even if they belong to the same PDU set. PDU set drop can be configured when the application layer can only utilize the PDU set if all packets of the PDU set are received. When PDU set drop is configured, the drop of one PDCP SDU can trigger the drop of other PDCP SDUs in the same PDU set. To ensure data is useful to the application layer, it is beneficial to send all packets of the PDU set immediately, regardless of the remaining time of each individual PDCP SDU.

[0047] In some implementations, RLC PDUs can be identified as delay-critical based on the discard timer of their corresponding PDCP PDU. RLC layers 118a-b can prioritize the transmission or retransmission of delay-critical RLC PDUs. For example, transmission entities 150a-b can prioritize delay-critical AM data (AMD) RLC PDUs regardless of whether they are for initial transmission or retransmission.

[0048] The transmitting device can perform a Buffer Status Report (BSR) to report the amount of data waiting to be transmitted (including buffered RLCSDUs) and / or perform a Delay Status Report (DSR) to report the amount of delay-critical data (including buffered delay-critical RLC SDUs). BSR / DSR can be reported in the uplink MAC control element (CE). The data volume calculations for BSR and DSR are defined in 3GPP TS 38.322, Section 5.5, V18.1.0 (July 12, 2024).

[0049] Under existing 3GPP specifications, RLC layer 118a-b can continue to retransmit RLC SDUs even after the corresponding packet has been dropped. This may cause delays in the forward shift of the transmission window at the transmitting side and / or the receive window at the receiving side, thus delaying the transmission of newly arriving packets. Additionally, retransmission unnecessarily consumes radio resources.

[0050] Several methods have been developed to address the unnecessary retransmission of outdated RLCSDUs (e.g., due to the expiration of the discard timer for the corresponding PDCP SDU). Figure 2 A transmitter-initiated process 200 according to some implementation schemes is illustrated. At 204 of process 200, the transmitting-side RLC (Tx RLC) determines (e.g., based on the expiration of an associated discard timer) that one or more packets have been discarded. Based on this determination, the Tx RLC stops the retransmission of one or more packets. Additionally, the Tx RLC triggers an RLC control PDU (or another form of signaling) to notify the receiving-side RLC (Rx RLC) that one or more packets will no longer be retransmitted because they have been discarded by the transmitter. For example, the RLC control PDU may include a bitmap where each bit represents an RLC SDU, and the values ​​(0 or 1) of these bits indicate whether the corresponding RLC SDU has been discarded. At 208 of process 200, the Tx RLC sends the RLC control PDU to the Rx RLC. At 212 of process 200, the Rx RLC advances the receive window based on the RLC control PDU.

[0051] Figure 3 A receiver-initiated process 300 according to some implementation schemes is illustrated. At 304 of process 300, the RxRLC determines that one or more packets are considered to be dropped by the TxRLC. For example, this determination can be based on a timer or a counter for transmission failures. At 308 of process 300, the RxRLC can transmit a status report to the transmitter to identify the one or more packets determined to be dropped. At 312 of process 300, the TxRLC can stop the retransmission of one or more packets based on the status report (if it has not yet stopped), and can accordingly advance the transmission window.

[0052] Figure 4 A combined process 400 according to some implementation schemes is illustrated. Process 400 may combine aspects of processes 200 and 300. For example, at 404 of process 400, the Tx RLC determines that one or more packets have been dropped and stops the retransmission of one or more packets. At 408 of process 400, the Rx RLC determines that one or more packets are considered dropped and triggers a status report to notify the Tx RLC. At 412, the Rx RLC sends the status report to the Tx RLC. At 416 of process 400, the Tx RLC advances the transmission window based on the status report.

[0053] Therefore, for (for example, such as) Figure 2 The transmitter-initiated method shown can send a new RLC control PDU from the transmitter to the receiver to notify the receiver of one or more RLCSDUs that will no longer be retransmitted (e.g., have been discarded). However, RLC control PDUs are not considered in the current definition of data volume calculations used for BSR and DSR.

[0054] Additionally, for example, such as Figure 3 The receiver-initiated method and (e.g., as shown) Figure 4 In the combined method shown, the receiver sends a status report to the transmitter to advance the transmission window. The status report should be sent as soon as possible to synchronize the transmission and reception windows. However, if a disable timer is running (e.g., based on the previous transmission of the status report), the receiver may need to wait for the disable timer to expire before transmitting the status report, causing a delay.

[0055] On the other hand, triggering autonomous retransmission of RLC SDUs without feedback has been envisioned as a method to reduce latency caused by RLC-AM operations. For example, once a Tx-RLC becomes latency critical, it can autonomously trigger a retransmission of the RLC SDU even if it has not yet received status feedback for the corresponding RLC SDU. Considering PDU set discarding, when autonomous retransmission for a packet is triggered, this can also trigger autonomous retransmission for one or more other packets (e.g., all other packets) belonging to the same PDU set. This can allow all packets in the PDU set to be delivered faster, which may be particularly important when PDU set discarding is configured. For example, when autonomous retransmission for a first RLC SDU is triggered, if both the first and second RLC SDUs belong to the same PDU set, the Tx-RLC can also trigger autonomous retransmission for the second RLC SDU, regardless of the remaining time before the second RLC SDU is discarded. Therefore, when retransmission for all PDUs in the PDU set is triggered, the amount of data for RLC PDUs awaiting retransmission can surge. The UE may not have sufficient UL resources to retransmit the corresponding RLC SDU, especially since the network may not know whether a discretionary retransmission has been triggered (and how many discretionary retransmissions have been triggered). In addition, discretionary retransmissions used for a large number of packets can have a significant impact on network capacity.

[0056] The various implementation schemes described in this paper address these issues and other features.

[0057] Data volume calculation

[0058] In some implementations, the data volume calculations used for BSR and / or DSR can be modified based on one or more discarded RLC SDUs (or fragments thereof) and / or whether an RLC PDU has been triggered (and not yet transmitted) to notify the receiving entity of one or more discarded RLC SDUs. For example, when BSR and / or DSR are triggered, the UE, as the transmitting entity, can calculate the associated buffer data volume and / or delay critical data volume, respectively.

[0059] In implementations, the UE can identify one or more RLC SDUs (or fragments thereof) pending initial transmission or retransmission (e.g., stored in the transmission buffer) but discarded by the PDCP layer. The UE can avoid including the identified one or more RLC SDUs (or fragments thereof) in the data volume calculation. The RLC layer can receive an indication from the associated PDCP layer indicating the one or more discarded RLC SDUs. As discussed above, in some implementations, the RLC layer can stop the retransmission of one or more RLC SDUs based on an indication from the PDCP layer. The RLC layer can then remove one or more RLC SDUs from the transmission buffer based on this indication. Therefore, the RLC layer can manage RLC SDUs considered to be awaiting transmission or retransmission without waiting for the data volume calculation to be triggered.

[0060] Alternatively, the UE may determine whether an RLC control PDU for drop notification (e.g., to notify the receiving entity that one or more RLC SDUs have been dropped) has been triggered but not yet transmitted. This may be related to transmitter-initiated procedure 200 to avoid unnecessary retransmissions. If an RLC control PDU has been triggered but not yet transmitted, the UE may include the size of the RLC control PDU in the data volume calculation. Note that the RLC control PDU used to notify the receiving entity that one or more RLC SDUs will no longer be retransmitted can be referred to by any suitable name, such as "drop notification" and / or "RLC sequence number (SN) gap notification".

[0061] Figure 5 An example process 500 for data volume calculation is illustrated according to some implementation schemes. Process 500 can be performed by a UE (e.g., UE 104) or its components.

[0062] At 504, process 500 may include initiating the calculation of RLC data volume for BSR and / or DSR.

[0063] At 508, process 500 may include identifying whether any RLCSDU (or fragment thereof) pending initial transmission or retransmission has been discarded, and avoiding including the identified RLC SDU (or fragment thereof) in the data volume calculation.

[0064] At 512, process 500 may include determining whether a control PDU for discarding a notification has been triggered but not yet sent, and if so, including the control PDU in the data volume calculation. It should be noted that in some embodiments, the operations at 508 and 512 can be performed independently of each other. That is, in some embodiments, the UE can perform operation 512 without simultaneously performing operation 508.

[0065] In one example, Section 5.5 of 3GPP TS 38.322 can be updated as follows to take into account the transmission of RLC control PDUs (the underlined content is added):

[0066] For the purpose of MAC buffer status reporting, the UE should consider the following as RLC data volume:

[0067] - RLC SDUs and RLC SDU fragments that have not yet been included in the RLC data PDU;

[0068] - RLC data PDUs pending initial transmission;

[0069] - RLC data PDUs (RLC AM) pending retransmission;

[0070] - RLC control PDU for discard notification not yet sent .

[0071] For the purpose of MAC delay status reporting, the UE should consider the following as delay-critical RLC data volume:

[0072] - Delay-critical RLC SDU segments and delay-critical RLC SDU segments that have not yet been included in the RLC data PDU;

[0073] - Pending initial transmission of RLC data PDUs containing delay-critical RLC SDU or delay-critical RLCSDU segments;

[0074] - RLC data PDUs (RLC AM) pending retransmission;

[0075] - RLC control PDU for discard notification not yet sent .

[0076] Status report from receiver

[0077] As discussed above, in (for example, such as) Figure 3 The receiver-initiated method and (e.g., as shown) Figure 4 In the combined method shown, the receiving entity can transmit a status report to the sending entity to indicate that one or more RLCSDUs are considered to have been discarded by the sending entity. The receiving entity can determine that an RLC SDU has been discarded based on, for example, a timer. However, the sending entity may currently have a running disable timer associated with the transmission of the status report. For example, a disable timer can be started based on the transmission of a previous status report, and the sending entity should not transmit another status report until the disable timer expires.

[0078] In various embodiments described herein, if a status report for a discard notification is triggered by a receiving entity while the disable timer is running, the receiving entity can still transmit the status report for the discard notification (e.g., before the disable timer expires). In some embodiments, the receiving entity may stop running the disable timer, send a status report when the disable timer is stopped, and then restart the disable timer after sending the status report. In other embodiments, the sending entity may treat the disable timer as unsuitable for status reports for discard notifications. The disable timer may still be suitable for other types of status reports, such as status reports for ACK / NACK feedback.

[0079] The receiving and sending entities can move their respective receiving and sending windows forward based on the status report.

[0080] In some implementations, the status report used for the drop notification may include an ACK for one or more RLC SDUs that are considered to have been dropped. In other implementations, the status report may include a unique indicator (separate from the ACK) to indicate that the RLC SDU is considered to have been dropped. The sending entity may stop retransmitting one or more RLC SDUs based on the status report.

[0081] Figure 6 Example process 600 according to some implementation schemes is illustrated. Process 600 can be performed by a receiving entity (such as UE 104, base station 108, or components thereof).

[0082] At 604, process 600 may include determining that one or more RLC SDUs have been discarded. This determination may be based on a timer, for example.

[0083] At 608, process 600 may include generating a status report based on the determination. In some embodiments, the status report may include an ACK for one or more RLC SDUs that have been determined to have been discarded.

[0084] At 612, process 600 may include determining whether a disable timer for status reporting is running. If the disable timer is not running, then at 616, process 600 may include transmitting the status report to the transmitter. The receiving entity may further start the disable timer based on the transmission of the status report.

[0085] If it is determined at 612 that the timer is running, then at 620, process 600 may include stopping the timer. Process 600 may then proceed to box 616, where a status report is transmitted to the transmitter. The receiving entity may further restart the timer (e.g., restart or re-enable it from the time the timer stopped at 620).

[0086] Therefore, process 600 enables the faster sending of status reports for discard notifications without waiting for the disable timer to expire.

[0087] BSR / DSR triggering based on autonomous RLC retransmission

[0088] Implementation schemes may include techniques for triggering BSR and / or DSR based on autonomous RLC retransmission. For example, the transmitting entity (e.g., UE and / or base station) may determine the number and / or data volume of RLC SDUs (or fragments thereof) based on autonomous retransmission of one or more RLC SDUs (or fragments thereof) that have been triggered, and may trigger BSR and / or DSR based on that number and / or data volume (e.g., based on determining that the number and / or data volume exceeds a corresponding threshold). The threshold may be zero or a positive non-zero value.

[0089] Figure 7 Example procedure 700 for triggering BSR and / or DSR according to some implementation schemes is illustrated. Procedure 700 may be performed by a sending entity (e.g., a UE such as UE 104 and / or a base station such as base station 108 or components thereof).

[0090] At 704, process 700 may include triggering a discretionary retransmission of at least one RLC SDU. In some embodiments, discretionary retransmission of the first RLC SDU may be triggered if the first RLC SDU has been submitted to the lower layer for transmission, has not yet received a positive acknowledgment (ACK), and the associated remaining discard time has decreased below a threshold. In some embodiments, discretionary retransmission of the second RLC SDU may also be triggered if the second RLC SDU belongs to the same PDU set as the first RLC SDU, and the second RLC SDU has been submitted to the lower layer for transmission and has not yet been positively acknowledged (e.g., has not yet received an ACK).

[0091] At 708, process 700 may include determining whether conditions related to one or more RLC SDUs that have been triggered for autonomous retransmission and are still pending are met. If the conditions are met, process 700 may include triggering a BSR and / or DSR report at 712. The BSR and / or DSR report may be triggered for the corresponding LCH and / or LCG.

[0092] In one example, the sending entity can determine the number of RLC SDUs (or fragments thereof) that have been autonomously retransmitted and are still pending (not yet sent) since the last BSR / DSR report for the corresponding LCH and / or LCG. The sending entity can trigger BSR and / or DSR reports based on the determined number exceeding a threshold (which can be zero or a positive non-zero value).

[0093] In another example, the sending entity can determine the total amount of RLC SDU (or fragments thereof) that have been autonomously retransmitted and are still pending (not yet sent) since the last BSR / DSR report for the corresponding LCH and / or LCG. The sending entity can trigger BSR and / or DSR reports based on the determined amount of data exceeding a threshold (which can be zero or a positive non-zero value).

[0094] In another example, the sending entity may determine the number of one or more delay-critical RLC SDUs (or fragments thereof) that have been autonomously retransmitted and remain pending (not yet sent) since the last BSR / DSR report for the corresponding LCH and / or LCG. The sending entity may trigger BSR and / or DSR reports based on the determined number exceeding a threshold (which may be zero or a positive non-zero value). In some implementations, the sending entity may additionally or alternatively determine the number of important RLC SDUs (e.g., those with at least a threshold importance level) that have been autonomously retransmitted and remain pending. For example, the sending entity may determine the total number of delay-critical RLC SDUs and important RLC SDUs and trigger BSR and / or DSR reports based on this total number being greater than a corresponding threshold.

[0095] In another example, the sending entity may determine the total amount of data for delayed critical RLC SDUs (or fragments thereof) that have been autonomously retransmitted and are still pending (not yet sent) since the last BSR / DSR report for the corresponding LCH and / or LCG. The sending entity may trigger BSR and / or DSR reports based on the determined amount exceeding a threshold (which may be zero or a positive non-zero value). In some implementations, the sending entity may additionally or alternatively determine the amount of data for important RLC SDUs (e.g., those with at least a threshold importance level) that have been autonomously retransmitted and are still pending. For example, the sending entity may determine the total amount of data for delayed critical RLC SDUs and important RLC SDUs, and trigger BSR and / or DSR reports based on this total amount being greater than a corresponding threshold.

[0096] Constraints on autonomous RLC retransmission

[0097] In some implementations, the transmitting entity can trigger an autonomous RLC retransmission subject to one or more constraints (e.g., restrictions). In some implementations, the network can configure one or more constraints for the UE.

[0098] Figure 8Example process 800 according to various implementation schemes is illustrated. Process 800 can be performed by a transmitting entity (e.g., a UE such as UE 104 or a component thereof). Although process 800 is described with respect to a transmitting entity as a UE, aspects of process 800 can also be performed when the transmitting entity is a base station (e.g., base station 108 or a component thereof).

[0099] At 804, process 800 may include receiving configuration information for one or more restrictions associated with autonomous RLC retransmission. In some embodiments, the configuration information may indicate the maximum number of times an RLC SDU can be autonomously considered for retransmission. For example, an RLC SDU may be autonomously retransmitted up to N times. After N retransmissions, even if the conditions for autonomous retransmission are met, RLC SDUs may no longer be considered for autonomous retransmission. In some embodiments, the configuration information may indicate the maximum number of RLC SDUs from a given PDU set that can be considered for autonomous retransmission. For example, if multiple RLCSDUs from the PDU set simultaneously meet the conditions for autonomous retransmission, the sending entity may trigger autonomous retransmission for a subset of RLC SDUs (e.g., N RLCSDUs, where N is indicated by the configuration information). In some embodiments, the configuration information may indicate the maximum number of RLC SDUs that may be pending retransmission simultaneously. For example, if the maximum number of RLCSDUs pending retransmission already exists, the sending entity may not trigger autonomous retransmission for additional RLC SDUs even if the conditions are met.

[0100] In some implementations, configuration information can configure a disallow timer for autonomous retransmission. For example, a transmitting entity can start a disallow timer based on triggering or performing an autonomous retransmission for one or more RLC SDUs. The transmitting entity can delay triggering or performing an autonomous retransmission for the same RLC SDU or another RLC SDU until the disallow timer expires. The length of the disallow timer and / or the conditions for starting the disallow timer (e.g., the number of autonomous retransmissions used to trigger the disallow timer) can be configured for the UE via configuration information. The disallow timer can operate per RLCSDU (e.g., one disallow timer is running for each RLC SDU) or per RLC entity (e.g., one disallow timer is running for all RLC SDUs).

[0101] At 808, process 800 may include determining that conditions for triggering autonomous retransmission of one or more RLC SDUs are met. In some embodiments, autonomous retransmission of the first RLC SDU may be triggered if the first RLC SDU has been submitted to the lower layer for transmission, has not yet received a positive acknowledgment (ACK), and the associated remaining discard time has decreased below a threshold. In some embodiments, autonomous retransmission of the second RLC SDU may also be triggered if the second RLC SDU belongs to the same PDU set as the first RLC SDU, and the second RLC SDU has been submitted to the lower layer for transmission and has not yet been positively acknowledged (e.g., has not yet received an ACK).

[0102] At 812, process 800 may include determining whether one or more configured limits have been reached. If the limit has not been reached, process 800 may include triggering a discretionary retransmission of one or more RLC SDUs at 816. If the limit has been reached, process 800 may include preventing the triggering of a discretionary retransmission of one or more RLC SDUs at 820.

[0103] In some implementations, the sending entity can recheck at a later time whether one or more limits have been met, and if one or more limits are no longer met, it can trigger a retransmission of one or more RLC SDUs at that time. In other implementations, (e.g., if a discard timer expires before a limit is no longer met) one or more RLC SDUs may not be retransmitted further.

[0104] Cancellation of autonomous retransmission

[0105] In some implementations, the sending entity can trigger a discretionary retransmission for the RLC SDU, but can receive a positive acknowledgment (ACK) before performing the retransmission. In these cases, the sending entity can cancel the discretionary retransmission. For example, the sending entity can remove the RLC SDU from the send (or retransmit) buffer.

[0106] The following is a sample update to section 5.2.3.1.1 of 3GPP TS 38.322 (the added content in underlined text):

[0107] Upon receiving a positive acknowledgment for an RLC SDU with SN=x, the sending side of the AM RLC entity should:

[0108] - Send an indication of successful delivery of the RLC SDU to the upper layer;

[0109] - Set TX_Next_Ack to be equal to the SN of the RLC SDU with the smallest SN, whose SN falls within the range TX_Next_Ack <= SN <= TX_Next, and for which no positive acknowledgment has been received;

[0110] - Stop considering RLC SDU as pending (e.g. in case of a previous triggering of autonomous retransmission of this RLC SDU) Retransmission

[0111] Example operation flow / algorithm structure

[0112] Figure 9 An operational flow / algorithm structure 900 according to some implementation schemes is illustrated. The operational flow / algorithm structure 900 can be executed by a UE (such as UE 104, UE 1200 or components therein, such as baseband processor 1204A)).

[0113] The operation flow / algorithm structure 900 may include triggering the autonomous retransmission of one or more RLC SDUs at 904. In some implementations, the autonomous retransmission of the first RLC SDU may be triggered if the first RLC SDU has been submitted to the lower layer for transmission, has not yet received a positive acknowledgment (ACK), and the associated remaining discard time has decreased below a threshold. In some implementations, the second RLC SDU may also be triggered for autonomous retransmission if the second RLC SDU belongs to the same PDU set as the first RLC SDU, and the second RLC SDU has been submitted to the lower layer for transmission and has not yet been positively acknowledged (e.g., has not yet received an ACK).

[0114] The operation procedure / algorithm structure 900 may also include determining at 908 that the conditions related to autonomous retransmission have been met. Conditions may include, for example: the number or amount of data for RLC SDUs (or fragments thereof) that have been triggered and are still pending autonomous retransmission since the last BSR / DSR report for the corresponding LCH or LCG exceeds a threshold; the number or amount of data for latency-critical RLC SDUs (or fragments thereof) that have been triggered and are still pending autonomous retransmission since the last BSR / DSR report for the corresponding LCH or LCG exceeds a threshold; and / or the number or amount of data for latency-critical and important RLC SDUs (or fragments thereof) that have been triggered and are still pending autonomous retransmission since the last BSR / DSR report for the corresponding LCH or LCG exceeds a threshold.

[0115] The operation flow / algorithm structure 900 may also include, at 912, instructing the lower layer to trigger a buffer status report or a delayed status report based on this determination.

[0116] Figure 10Another operational flow / algorithm structure 1000 is illustrated according to some implementation schemes. The operational flow / algorithm structure 1000 can be executed by a UE (such as UE 104, UE 1200, or components therein, such as baseband processor 1204A)).

[0117] The operation flow / algorithm structure 1000 may include receiving configuration information at 1004 to indicate restrictions on autonomous retransmission of RLC SDUs. The operation flow / algorithm structure 1000 may also include triggering autonomous retransmission of one or more RLC SDUs based on the restrictions at 1008.

[0118] In some implementations, the configuration information may indicate the maximum number of times an RLC SDU can be autonomously considered for retransmission. For example, an RLC SDU may be autonomously retransmitted up to N times. After N retransmissions, even if the conditions for autonomous retransmission are met, RLC SDUs may no longer be considered for autonomous retransmission. In some implementations, the configuration information may indicate the maximum number of RLC SDUs from a given PDU set that can be considered for autonomous retransmission. For example, if multiple RLCSDUs from the PDU set simultaneously meet the conditions for autonomous retransmission, the sending entity may trigger autonomous retransmission for a subset of RLC SDUs (e.g., N RLCSDUs, where N is indicated by the configuration information). In some implementations, the configuration information may indicate the maximum number of RLC SDUs that may be pending retransmission simultaneously. For example, if the maximum number of RLCSDUs pending retransmission already exists, the sending entity may not trigger autonomous retransmission for additional RLC SDUs even if the conditions are met.

[0119] In some implementations, configuration information can configure a disallow timer for autonomous retransmission. For example, a transmitting entity can start a disallow timer based on triggering or performing an autonomous retransmission for one or more RLC SDUs. The transmitting entity can delay triggering or performing an autonomous retransmission for another RLC SDU until the disallow timer expires. The length of the disallow timer and / or the conditions for starting the disallow timer (e.g., the number of autonomous retransmissions used to trigger the disallow timer) can be configured for the UE via configuration information.

[0120] Figure 11 Another operational flow / algorithm structure 1100 according to some implementation schemes is illustrated. The operational flow / algorithm structure 1100 can be performed by a receiving entity, such as a UE, such as UE 104, UE 1200 or components therein (e.g., baseband processor 1204A); and / or a base station, such as base station 108, network device 1300 or components therein (e.g., baseband processor 1304A).

[0121] The operation flow / algorithm structure 1100 may include determining at 1104 that the RLC SDU has been discarded by the transmitter device. In one example, this determination may be based on one or more timers.

[0122] The operation flow / algorithm structure 1100 may also include, at 1108, identifying that a timer is inactive associated with sending a status report. For example, the timer may be started based on the sending of a previous status report (e.g., with ACK / NACK information including other RLC SDUs).

[0123] The operation flow / algorithm structure 1100 may also include, at 1112, triggering a first status report for the RLC SDU for transmission before the disable timer expires, based on this determination. In some implementations, the disable timer may be stopped to enable the transmission of the first status report. The disable timer may be started / restarted based on the transmission of the first status report.

[0124] Example device

[0125] Figure 12 UE 1200 is illustrated according to some implementation schemes. UE 1200 may be similar to UE 104 and is substantially interchangeable with it.

[0126] The UE 1200 can be any mobile or non-mobile computing device, such as, for example, a mobile phone, computer, tablet, industrial wireless sensor (e.g., microphone, carbon dioxide sensor, pressure sensor, humidity sensor, thermometer, motion sensor, accelerometer, laser scanner, fluid level sensor, stock sensor, voltmeter / ammeter, or actuator), video surveillance / monitoring device (e.g., camera or camcorder), wearable device (e.g., smartwatch), or Internet of Things device.

[0127] UE 1200 may include a processor 1204, RF interface circuitry 1208, memory / storage device 1212, user interface 1216, sensor 1220, drive circuitry 1222, power management integrated circuit (PMIC) 1224, antenna 1226, and battery 1228. The components of UE 1200 may be implemented as integrated circuits (ICs), portions of such integrated circuits (ICs), discrete electronic devices or other modules, logic components, hardware, software, firmware, or combinations thereof. In some embodiments, RF interface circuitry 1208 may be included within processor 1204. Figure 12 The block diagram is intended to show a high-level view of some of the components of the UE 1200. However, some of the components shown may be omitted, additional components may be present, and different arrangements of the components shown may occur in other specific implementations.

[0128] The components of UE 1200 can be coupled to various other components via one or more interconnects 1232, which can represent any type of interface, input / output, bus (local, system, or extended), transmit line, trace, or optical connector that allows various circuit components (on common or different chips or chipsets) to interact with each other.

[0129] Processor 1204 may include processor circuitry, such as, for example, baseband processor circuitry (BB) 1204A, central processing unit circuitry (CPU) 1204B, and graphics processing unit circuitry (GPU) 1204C. Processor 1204 may include any type of circuitry or processor circuitry that executes or otherwise operates computer-executable instructions (such as program code, software modules, or functional procedures from memory / storage device 1212) to cause UE 1200 to perform operations associated with RLC AM as described herein. Processor 1204 may also include interface circuitry 1204D to enable communication, such as communicatively coupling the processor circuitry to one or more other components of UE 1200.

[0130] In some implementations, the baseband processor 1204A can access the communication protocol stack 1236 in the memory / storage device 1212 to communicate over a 3GPP-compliant network. Generally, the baseband processor 1204A can access the communication protocol stack 1236 to: perform user plane functions at the PHY, MAC, RLC, PDCP, SDAP, and PDU layers; and perform control plane functions at the PHY, MAC, RLC, PDCP, RRC, and NAS layers. In some implementations, PHY layer operations may be additionally / optionally performed by components of the RF interface circuitry 1208.

[0131] The baseband processor 1204A can generate or process baseband signals or waveforms carrying information in 3GPP-compliant networks. In some implementations, the waveforms used for NR can be based on cyclic prefix OFDM (CP-OFDM) in the uplink or downlink, and Discrete Fourier Transform Extended OFDM (DFT-S-OFDM) in the uplink.

[0132] The memory / storage device 1212 may include one or more non-transitory computer-readable media, which include instructions (e.g., communication protocol stack 1236) that can be executed by one or more processors in processor 1204 to cause UE 1200 to perform operations associated with RLC AM as described herein.

[0133] The memory / storage device 1212 includes any type of volatile or non-volatile memory that can be distributed throughout the UE 1200. In some embodiments, some of the memory / storage devices 1212 may be located on the processor 1204 itself (e.g., the memory / storage device 1212 may be part of a chipset corresponding to the baseband processor 1204A), while other memory / storage devices 1212 are located external to the processor 1204 but are accessible via a memory interface. The memory / storage device 1212 may include any suitable volatile or non-volatile memory, such as, but not limited to, dynamic random access memory (DRAM), static random access memory (SRAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, solid-state memory, or any other type of memory device technology.

[0134] RF interface circuitry 1208 may include transceiver circuitry and a radio frequency front-end module (RFEM) that allows UE 1200 to communicate with other devices via a radio access network. RF interface circuitry 1208 may include various components arranged in the transmit or receive path. These components may include, for example, switches, mixers, amplifiers, filters, synthesizer circuitry, and control circuitry.

[0135] In the receiving path, the RFEM can receive the radiated signal from the air interface via antenna 1226 and continue to filter and amplify the signal (using a low-noise amplifier). This signal can be provided to the receiver of the transceiver, which downconverts the RF signal into a baseband signal that is provided to the baseband processor of processor 1204.

[0136] In the transmission path, the transceiver's transmitter up-converts the baseband signal received from the baseband processor and provides the RF signal to the RFEM. The RFEM can then amplify the RF signal using a power amplifier before it is radiated across the air interface via antenna 1226.

[0137] In various implementations, the RF interface circuit 1208 can be configured to transmit / receive signals in a manner compatible with NR access technologies.

[0138] Antenna 1226 may include antenna elements to convert electrical signals into radio waves for propagation through the air and to convert received radio waves back into electrical signals. These antenna elements may be arranged in one or more antenna panels. Antenna 1226 may have omnidirectional, directional, or combinations thereof antenna panels to enable beamforming and multiple-input multiple-output communication. Antenna 1226 may include a microstrip antenna, patch antenna, phased array antenna, or a printed antenna fabricated on the surface of one or more printed circuit boards. Antenna 1226 may have one or more panels designed for a specific frequency band (including bands in FR1 or FR2).

[0139] User interface 1216 includes various input / output (I / O) devices designed by the UE to enable a user to interact with 1200. User interface 1216 includes input device circuitry and output device circuitry. Input device circuitry includes any physical or virtual components for accepting input, particularly including one or more physical or virtual buttons (e.g., a reset button), a physical keyboard, a keypad, a mouse, a touchpad, a touchscreen, a microphone, a scanner, or a headset. Output device circuitry includes any physical or virtual components for displaying information or otherwise conveying information (such as sensor readings, actuator positions, or other similar information). Output device circuitry may include any number or combination of audio or visual displays, particularly including one or more simple visual outputs / indicators (e.g., binary status indicators such as light-emitting diodes (LEDs) and multi-character visual outputs), or more complex outputs (e.g., display devices or touchscreens such as liquid crystal displays (LCDs), LED displays, quantum dot displays, and projectors)), wherein the output of characters, graphics, and multimedia objects is generated or produced by the operation of the UE 1200.

[0140] Sensor 1220 may include devices, modules, or subsystems designed to detect events or changes in its environment and transmit information about the detected events (sensor data) to other devices, modules, or subsystems. Examples of such sensors include: inertial measurement units including accelerometers, gyroscopes, or magnetometers; microelectromechanical systems (MEMS) or nanoelectromechanical systems (NEMS) including 3-axis accelerometers, 3-axis gyroscopes, or magnetometers; level sensors; flow sensors; temperature sensors (e.g., thermistors); pressure sensors; barometric pressure sensors; gravimeters; altimeters; image capture devices (e.g., cameras or lensless aperture sensors); light detection and ranging sensors; proximity sensors (e.g., infrared radiation detectors); depth sensors; ambient light sensors; ultrasonic transceivers; and microphones or other similar audio capture devices.

[0141] The driving circuitry 1222 may include software and hardware elements that operate to control specific devices embedded in, attached to, or otherwise communicatively coupled to the UE 1200. The driving circuitry 1222 may include various drivers that allow other components to interact with or control various input / output (I / O) devices that may exist within or be connected to the UE 1200. For example, the driving circuitry 1222 may include a display driver for controlling and allowing access to a display device, a touchscreen driver for controlling and allowing access to a touchscreen interface, a sensor driver for acquiring sensor readings of sensor 1220 and controlling and allowing access to sensor 1220, an actuator positioning for acquiring electromechanical components or a driver for controlling and allowing access to electromechanical components, a camera driver for controlling and allowing access to an embedded image capture device, and an audio driver for controlling and allowing access to one or more audio devices.

[0142] The PMIC 1224 manages the power supplied to various components of the UE 1200. Specifically, relative to the processor 1204, the PMIC 1224 can control power source selection, voltage scaling, battery charging, or DC-DC conversion.

[0143] Battery 1228 can power UE 1200, but in some examples, UE 1200 may be installed and deployed in a fixed location and may have a power source coupled to the grid. Battery 1228 may be a lithium-ion battery, a metal-air battery such as a zinc-air battery, an aluminum-air battery, a lithium-air battery, etc. In some specific implementations, such as in vehicle-based applications, battery 1228 may be a typical lead-acid automotive battery.

[0144] Figure 13 Network device 1300 is illustrated according to some implementation schemes. Network device 1300 may be similar to base station 108 and is substantially interchangeable with it.

[0145] Network device 1300 may include processor 1304, RF interface circuitry 1308 (if implemented as a base station), core network (CN) interface circuitry 1314, memory / storage device circuitry 1312, and antenna structure 1326.

[0146] The components of network device 1300 can be coupled to various other components via one or more interconnects 1328.

[0147] The processor 1304, RF interface circuit 1308, memory / storage device circuit 1312 (including communication protocol stack 1310), antenna structure 1326, and interconnect 1328 can be similar to those relative to... Figure 12 Similar named elements are shown and described.

[0148] Processor 1304 may include processor circuitry, such as, for example, baseband processor circuitry (BB) 1304A, central processing unit circuitry (CPU) 1304B, and graphics processing unit circuitry (GPU) 1304C. Processor 1304 may include any type of circuitry or processor circuitry that executes or otherwise operates computer-executable instructions (such as program code, software modules, or functional processes from memory / storage device circuitry 1312) to cause network device 1300 to perform the operations associated with RLC AM as described herein. Processor 1304 may also include interface circuitry 1304D to communicatively couple processor circuitry to one or more other components of network device 1300.

[0149] The CN interface circuit 1314 can provide connectivity to a core network (e.g., a 5GC using a 5G core network (5GC) compatible network interface protocol (such as Carrier Ethernet) or some other suitable protocol). Network connectivity can be provided to / from network device 1300 via fiber optic or wireless backhaul. The CN interface circuit 1314 may include one or more dedicated processors or FPGAs to communicate using one or more of the aforementioned protocols. In some implementations, the CN interface circuit 1314 may include multiple controllers for providing connectivity to other networks using the same or different protocols.

[0150] As is widely recognized, the use of personally identifiable information should comply with privacy policies and practices that are generally accepted to meet or exceed industry or governmental requirements for protecting user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and users should be clearly informed of the nature of authorized use.

[0151] For one or more embodiments, at least one of the components shown in one or more of the foregoing figures may be configured to perform one or more operations, techniques, processes, or methods described in the Embodiments section below. For example, the baseband circuitry described above in conjunction with one or more of the foregoing figures may be configured to operate according to one or more examples below. As another example, circuitry associated with the UE, base station, or network element described above in conjunction with one or more of the foregoing figures may be configured to operate according to one or more embodiments described in the Embodiments section below.

[0152] Embodiments

[0153] Further exemplary implementations are provided in the following sections.

[0154] Example 1 includes a method comprising: triggering a self-retransmission of one or more Radio Link Control (RLC) Service Data Units (SDUs); determining that a condition associated with the self-retransmission has been met; and instructing a lower layer to trigger a buffer status report or a delay status report based on the determination.

[0155] Example 2 includes the method according to Example 1 or some other example herein, wherein the condition includes the number or amount of data of the one or more RLC SDUs exceeding a threshold.

[0156] Example 3 includes the method according to Example 1 or some other embodiment herein, wherein the condition includes the number or amount of data of the delay-critical SDUs in the one or more RLC SDUs exceeding a threshold, wherein the delay-critical SDUs have a discard remaining time less than a remaining time threshold.

[0157] Example 4 includes the method according to Example 1 or some other embodiment of this document, wherein the condition includes the total number or total data volume of the delay-critical SDUs and important SDUs in the one or more RLC SDUs exceeding a threshold, wherein the delay-critical SDUs have a discard remaining time less than a remaining time threshold, and the important SDUs have at least a threshold importance level.

[0158] Example 5 includes the method according to Example 1 or some other embodiment of this document, further comprising determining the amount of data for the buffer status report or the delay status report, the amount of data being used to include RLC control protocol data units (PDUs) indicating that one or more RLC SDUs will no longer be retransmitted.

[0159] Example 6 includes the method according to Example 1 or some other embodiment of this document, and further includes determining the amount of data for the buffer status report or the delay status report, the amount of data being used to exclude one or more RLC SDUs that will no longer be retransmitted.

[0160] Example 7 includes the method according to Example 1 or some other embodiment herein, further comprising: receiving configuration information for indicating restrictions on autonomous retransmission of RLC Service Data Units (SDUs), wherein autonomous retransmission of one or more RLC SDUs is triggered based on the restrictions.

[0161] Example 8 includes the method according to Example 7 or some other embodiment herein, wherein the limitations include: the maximum number of times an RLC SDU can be autonomously retransmitted; the maximum number of RLC SDUs in the Protocol Data Unit (PDU) set that can be simultaneously triggered for autonomous retransmission; the maximum number of RLC SDUs that can be pending autonomous retransmission at the same time; or a disable timer for controlling the frequency of autonomous retransmission of the one or more RLC SDUs.

[0162] Example 9 includes a method comprising: receiving configuration information indicating restrictions on autonomous retransmission of Radio Link Control (RLC) Service Data Units (SDUs); and triggering autonomous retransmission of one or more RLC SDUs based on the restrictions.

[0163] Example 10 includes the method according to Example 9 or some other embodiment herein, wherein the limitation includes the maximum number of times the RLC SDU can be autonomously retransmitted.

[0164] Example 11 includes the method according to Example 9 or some other embodiment herein, wherein the limitation includes the maximum number of RLC SDUs of the set of Protocol Data Units (PDUs) that can be triggered simultaneously for autonomous retransmission.

[0165] Example 12 includes the method according to Example 9 or some other embodiment herein, wherein the limitation includes the maximum number of RLC SDUs that can be pending autonomous retransmission simultaneously.

[0166] Example 13 includes the method according to Example 9 or some other embodiment herein, wherein the limitation includes configuration information for a disable timer used to control the frequency of autonomous retransmission of the one or more RLC SDUs.

[0167] Example 14 includes the method according to Example 9 or some other embodiment herein, wherein triggering the autonomous retransmission of the one or more RLC SDUs includes triggering the autonomous retransmission of a first RLC SDU, and wherein the method further includes: receiving an acknowledgment for the first RLC SDU after triggering the autonomous retransmission of the first RLC SDU; and canceling the autonomous retransmission of the first RLC SDU based on the acknowledgment.

[0168] Example 15 includes the method according to Example 9 or some other embodiment herein, further comprising: determining that a condition related to the autonomous retransmission has been met; and generating a buffer status report or delay status report for transmission based on the determination, wherein the condition includes: the number or amount of data of the one or more RLC SDUs exceeds a first threshold; the number or amount of data of delay-critical SDUs in the one or more RLC SDUs exceeds a second threshold, wherein the delay-critical SDUs have a discard remaining time less than a remaining time threshold; or the total number or total amount of data of delay-critical SDUs and important SDUs in the one or more RLC SDUs exceeds a third threshold, wherein the important SDUs have at least a threshold importance level.

[0169] Example 16 includes a method comprising: determining that a Radio Link Control (RLC) Service Data Unit (SDU) has been discarded by a transmitter device; identifying that a prohibition timer associated with a transmission status report is running; and, based on the determination, triggering a first status report for the RLC SDU for transmission before the prohibition timer expires.

[0170] Example 17 includes the method according to Example 16 or some other embodiment herein, wherein the first status report includes confirmation of the RLC SDU.

[0171] Example 18 includes the method according to Example 16 or some other embodiment herein, and further includes stopping the disable timer based on the determination.

[0172] Example 19 includes the method according to Example 16 or some other embodiment herein, further comprising restarting the disable timer based on sending the first status report.

[0173] Example 20 includes the method according to Example 16 or some other embodiment herein, further comprising starting the disable timer based on sending a second status report prior to the first status report.

[0174] Example 21 includes a method comprising: triggering a Radio Link Control (RLC) Protocol Data Unit (PDU) to indicate one or more RLC Service Data Units (SDUs) that will not be retransmitted; determining a data amount for a buffer status report or a delay status report, wherein the data amount includes the RLC PDUs that have been triggered but not yet transmitted; and triggering the transmission of the buffer status report or the delay status report.

[0175] Example 22 includes the method according to Example 21 or some other embodiment herein, wherein the data volume excludes the one or more RLC SDUs that will not be retransmitted.

[0176] Example 23 includes a method comprising: triggering a self-retransmission of a Radio Link Control (RLC) Service Data Unit (SDU); receiving an acknowledgment for the RLC SDU after triggering the self-retransmission; and canceling the self-retransmission of the RLC SDU based on the acknowledgment.

[0177] Example 24 includes the method according to Example 23 or some other embodiment herein, wherein the autonomous retransmission of the RLC SDU is triggered based on determining that the RLC SDU has a discard time remaining below a threshold.

[0178] Another embodiment may include an apparatus comprising one or more elements for performing the method described or associated with any of Embodiments 1 to 24 or any other method or process described herein.

[0179] Another embodiment may include one or more non-transitory computer-readable media, the one or more non-transitory computer-readable media including instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform one or more elements of the method or any other method or process described herein according to any one of embodiments 1 to 24.

[0180] Another embodiment may include an apparatus comprising one or more elements for performing the methods described or associated with any one of Embodiments 1 to 24 or any other methods or processes described herein.

[0181] Another embodiment may include the methods, techniques or processes described or associated with any one of embodiments 1 to 24 or any part or component thereof.

[0182] Another embodiment may include an apparatus comprising: one or more processors; and one or more computer-readable media including instructions that, when executed by the one or more processors, cause the one or more processors to perform a method, technique, or process described or associated with any one or more of embodiments 1 to 24.

[0183] Another embodiment may include signals described or associated with any one of embodiments 1 to 24 or any part or component thereof.

[0184] Another embodiment may include datagrams, information elements, packets, frames, segments, PDUs, or messages as described or associated with any one of embodiments 1 to 24 or any part or component thereof, or otherwise described in this disclosure.

[0185] Another embodiment may include a signal encoded with data as described or associated with any one of embodiments 1 to 24 or a part or component thereof, or otherwise described in this disclosure.

[0186] Another embodiment may include signals encoded as datagrams, IEs, packets, frames, segments, PDUs, or messages as described or associated with any one of embodiments 1 to 24 or any part or component thereof, or otherwise described in this disclosure.

[0187] Another embodiment may include an electromagnetic signal carrying computer-readable instructions, wherein execution of the computer-readable instructions by one or more processors will cause the one or more processors to perform the methods, techniques or processes described or associated with any one or more of embodiments 1 to 24.

[0188] Another embodiment may include a computer program comprising instructions, wherein execution of the program by a processing element will cause the processing element to perform a method, technique, or process described or associated with any one or a portion thereof according to Embodiments 1 to 24.

[0189] Another embodiment may include signals in a wireless network as shown and described herein.

[0190] Another embodiment may include a method for communicating in a wireless network as shown and described herein.

[0191] Another embodiment may include a system for providing wireless communication as shown and described herein.

[0192] Another embodiment may include a device for providing wireless communication as shown and described herein.

[0193] Unless otherwise expressly stated, any of the embodiments described above may be combined with any other embodiment (or combination of embodiments). The foregoing description of one or more specific embodiments provides illustration and description, but is not intended to be exhaustive or to limit the scope of the embodiments to the precise forms disclosed. In view of the teachings above, modifications and variations are possible, or modifications and variations may be obtained from the practice of various embodiments.

[0194] Although the above embodiments have been described in considerable detail, many variations and modifications will become apparent to those skilled in the art once the above disclosure is fully understood. It is intended that the following claims be construed as encompassing all such variations and modifications.

Claims

1. A method comprising: Identify at least one restriction on autonomous retransmission of a service data unit (SDU) for radio link control (RLC), wherein the at least one restriction includes the maximum number of times the same RLC SDU can be autonomously retransmitted; as well as The first RLC SDU is autonomously retransmitted based on the aforementioned restrictions.

2. The method of claim 1, wherein the at least one limitation further includes the maximum number of RLC SDUs of a set of Protocol Data Units (PDUs) capable of being triggered simultaneously for autonomous retransmission.

3. The method of claim 1, wherein the at least one limitation includes the maximum number of RLC SDUs that can be pending autonomous retransmission simultaneously.

4. The method of claim 1, wherein the at least one limitation further includes configuration information for a timer that disables the autonomous retransmission frequency of the RLC SDU.

5. The method according to claim 1, further comprising: After triggering the autonomous retransmission of the first RLC SDU, an acknowledgment is received for the first RLC SDU; as well as The autonomous retransmission of the first RLC SDU is cancelled based on the confirmation.

6. The method according to claim 1, further comprising: It has been determined that the conditions related to the autonomous retransmission have been met; as well as Based on the determination, a buffer status report or delay status report for transmission is generated.

7. The method of claim 6, wherein the conditions include: The number or data volume of at least one RLC SDU exceeds the first threshold; The number or amount of data of at least one delayed critical SDU exceeds a second threshold, wherein the at least one delayed critical SDU has a remaining discard time less than a remaining time threshold; or The total number or total data volume of delayed critical SDUs and important SDUs exceeds a third threshold, wherein the important SDUs have at least a threshold importance level.

8. One or more non-transitory computer-readable media having instructions that, when executed, cause processor circuitry to: Triggering autonomous retransmission of at least one Radio Link Control (RLC) Service Data Unit (SDU); It has been determined that the conditions related to the autonomous retransmission have been met; and Based on the determination, the lower layer is instructed to trigger a buffer status report or a delayed status report.

9. One or more non-transitory computer-readable media according to claim 8, wherein the condition includes the number or amount of data of the at least one RLC SDU exceeding a threshold.

10. One or more non-transitory computer-readable media according to claim 8, wherein the condition includes the number or amount of data of at least one delay-critical SDU in the at least one RLC SDU exceeding a threshold, wherein the at least one delay-critical SDU has a discard remaining time less than a remaining time threshold.

11. One or more non-transitory computer-readable media according to claim 8, wherein the condition includes the total number or total data volume of the delay-critical SDUs and important SDUs of the at least one RLC SDU exceeding a threshold, wherein the delay-critical SDUs have a discard remaining time less than a remaining time threshold, and the important SDUs have at least a threshold importance level.

12. The one or more non-transitory computer-readable media of claim 8, wherein the instructions, when executed, further cause the processor circuitry to determine the amount of data for the buffer status report or the delay status report, the amount of data being used to include an RLC control protocol data unit (PDU) indicating that at least one RLC SDU will no longer be retransmitted.

13. One or more non-transitory computer-readable media according to claim 8, wherein the instructions, when executed, further cause the processor circuitry to determine the amount of data for the buffer status report or the delay status report, the amount of data being used to exclude at least one RLC SDU that will no longer be retransmitted.

14. One or more non-transitory computer-readable media according to claim 8, wherein the instructions, when executed, further cause the processor circuitry to identify a restriction on autonomous retransmission of an RLC SDU, wherein the autonomous retransmission of at least one RLC SDU is triggered according to the restriction.

15. One or more non-transitory computer-readable media according to claim 14, wherein the limitation includes: The maximum number of times an RLC SDU can be autonomously retransmitted; The maximum number of RLC SDUs in the Protocol Data Unit (PDU) set that can be triggered simultaneously for autonomous retransmission; The maximum number of RLC SDUs that can be pending autonomous retransmission at the same time; or A timer that disables the autonomous retransmission frequency of the RLC SDU.

16. One or more non-transitory computer-readable media according to claim 8, wherein the instructions, when executed, further cause the processor circuitry to: Start a timer that disables the transmission of status reports; It has been determined that the first RLC SDU has been discarded by the transmitter device; and Based on the determination, a first status report for the first RLC SDU is triggered for transmission before the prohibition timer expires.

17. One or more non-transitory computer-readable media according to claim 16, wherein the first status report includes an acknowledgment of the RLC SDU.

18. An apparatus comprising Processor circuitry used to perform the following operations: Trigger autonomous retransmission of Radio Link Control (RLC) Service Data Unit (SDU); After the autonomous retransmission of the RLC SDU is triggered, an acknowledgment is received for the RLC SDU; and Based on the confirmation, cancel the autonomous retransmission of the RLC SDU; and An interface circuit is coupled to the processor circuit to enable communication.

19. The apparatus of claim 18, wherein the autonomous retransmission of the RLC SDU is triggered based on determining that the RLC SDU has a discard time remaining below a threshold.

20. The apparatus of claim 18, wherein the autonomous retransmission of the RLC SDU is based on the fact that the number of times the RLC SDU has been autonomously retransmitted is less than the maximum number of times the same RLC SDU can be autonomously retransmitted.

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