CN116762293A

CN116762293A - Transmission Control Protocol (TCP) packet loss recovery technique

Info

Publication number: CN116762293A
Application number: CN202280009735.3A
Authority: CN
Inventors: S·卡纳马拉普蒂; H·班迪瓦德; U·S·卡达里
Original assignee: Qualcomm Inc
Current assignee: Qualcomm Inc
Priority date: 2021-01-19
Filing date: 2022-01-10
Publication date: 2023-09-15

Abstract

Aspects of the present disclosure generally relate to wireless communications. In some aspects, a User Equipment (UE) may detect Transmission Control Protocol (TCP) packet loss based at least in part on a Packet Data Convergence Protocol (PDCP) payload of a packet. The UE may send a plurality of retransmission requests for the packet based at least in part on the detection of TCP packet loss for the packet. Many other aspects are described.

Description

Transmission Control Protocol (TCP) packet loss recovery technique

Cross Reference to Related Applications

This patent application claims priority from U.S. provisional patent application No. 63/199,718, entitled "TECHNIQUES FOR TRANSMISSION CONTROL PROTOCOL (TCP) PACKET LOSS RECOVERY", filed on day 19 of 2021, and U.S. non-provisional patent application No. 17/647,421, entitled "TECHNIQUES FOR TRANSMISSION CONTROL PROTOCOL (TCP) PACKET LOSS RECOVERY", filed on day 7 of 2022, which provisional applications are expressly incorporated herein by reference.

Technical Field

Aspects of the present disclosure generally relate to techniques and apparatus for Transmission Control Protocol (TCP) packet loss recovery for wireless communications.

Background

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcast. A typical wireless communication system may employ multiple-access techniques that are capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple-access techniques include Code Division Multiple Access (CDMA) systems, time Division Multiple Access (TDMA) systems, frequency Division Multiple Access (FDMA) systems, orthogonal Frequency Division Multiple Access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, time division synchronous code division multiple access (TD-SCDMA) systems, and Long Term Evolution (LTE). LTE/LTE-advanced is an enhanced set of Universal Mobile Telecommunications System (UMTS) mobile standards promulgated by the third generation partnership project (3 GPP).

A wireless network may include one or more base stations that support communication for a User Equipment (UE) or multiple UEs. The UE may communicate with the base station via downlink and uplink communications. "downlink" (or "DL") refers to the communication link from a base station to a UE, and "uplink" (or "UL") refers to the communication link from a UE to a base station.

The above multiple access techniques have been employed in various telecommunications standards to provide a common protocol that enables different UEs to communicate at the city, country, region, and/or global level. The New Radio (NR), which may be referred to as 5G, is an enhanced set of LTE mobile standards promulgated by 3 GPP. NR aims to better support mobile broadband internet access by improving spectrum efficiency, reducing costs, improving services, utilizing new spectrum, and better fusing with other open standards, in particular ways including: orthogonal Frequency Division Multiplexing (OFDM) with Cyclic Prefix (CP) on the downlink (CP-OFDM), CP-OFDM and/or single carrier frequency division multiplexing (SC-FDM) on the uplink (also known as discrete fourier transform spread OFDM (DFT-s-OFDM)), and support beamforming, multiple Input Multiple Output (MIMO) antenna technology, and carrier aggregation. As the demand for mobile broadband access continues to increase, further improvements in LTE, NR and other radio access technologies remain useful.

Disclosure of Invention

In some aspects, a User Equipment (UE) for wireless communication includes: a memory; and one or more processors coupled to the memory, the one or more processors configured to: detecting Transmission Control Protocol (TCP) packet loss based at least in part on a Packet Data Convergence Protocol (PDCP) payload of the packet; and transmitting a plurality of retransmission requests for the packet based at least in part on the detection of TCP packet loss for the packet.

In some aspects, a method of wireless communication performed by a UE includes: detecting TCP packet loss based at least in part on a PDCP payload of the packet; and transmitting a plurality of retransmission requests for the packet based at least in part on the detection of TCP packet loss for the packet.

In some aspects, a non-transitory computer-readable medium storing a set of instructions for wireless communication includes one or more instructions that, when executed by one or more processors of a UE, cause the UE to: detecting TCP packet loss based at least in part on a PDCP payload of the packet; and transmitting a plurality of retransmission requests for the packet based at least in part on the detection of TCP packet loss for the packet.

In some aspects, an apparatus for wireless communication comprises: means for detecting TCP packet loss based at least in part on the PDCP payload of the packet; and means for sending a plurality of retransmission requests for the packet based at least in part on the detection of TCP packet loss for the packet.

In some aspects, a UE for wireless communication includes: a memory; and one or more processors coupled to the memory, the one or more processors configured to: detecting a TCP packet loss based at least in part on the TCP sequence and without a PDCP loss; and transmitting a plurality of retransmission requests for the packet based at least in part on the detection of TCP packet loss for the packet.

In some aspects, a method of wireless communication performed by a UE includes: detecting a TCP packet loss based at least in part on the TCP sequence and without a PDCP loss; and transmitting a plurality of retransmission requests for the packet based at least in part on the detection of TCP packet loss for the packet.

In some aspects, a non-transitory computer-readable medium storing a set of instructions for wireless communication includes one or more instructions that, when executed by one or more processors of a UE, cause the UE to: detecting a TCP packet loss based at least in part on the TCP sequence and without a PDCP loss; and transmitting a plurality of retransmission requests for the packet based at least in part on the detection of TCP packet loss for the packet.

In some aspects, an apparatus for wireless communication comprises: means for detecting a TCP packet loss based at least in part on the TCP sequence and without a PDCP loss; and means for sending a plurality of retransmission requests for the packet based at least in part on the detection of TCP packet loss for the packet.

Aspects generally include a method, apparatus, system, computer program product, non-transitory computer readable medium, user equipment, base station, wireless communication device, and/or processing system as substantially described herein with reference to and as illustrated by the accompanying drawings and description.

The foregoing has outlined rather broadly the features and technical advantages of examples in accordance with the present disclosure in order that the detailed description that follows may be better understood. Additional features and advantages will be described hereinafter. The disclosed concepts and specific examples may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. The nature of the concepts disclosed herein, both as to their organization and method of operation, together with related advantages will be better understood from the following description when considered in connection with the accompanying drawings. Each of the figures is provided for the purpose of illustration and description, and is not intended as a definition of the limits of the claims.

Drawings

So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to aspects, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only certain typical aspects of this disclosure and are therefore not to be considered limiting of its scope, for the description may admit to other equally effective aspects. The same reference numbers in different drawings may identify the same or similar elements.

Fig. 1 is a diagram illustrating an example of a wireless network according to the present disclosure.

Fig. 2 is a diagram illustrating an example of a base station communicating with a User Equipment (UE) in a wireless network according to the present disclosure.

Fig. 3 is a diagram illustrating an example of user plane protocol stacks and control plane protocol stacks of a BS and a core network for communication with a UE according to the present disclosure.

Fig. 4 is a diagram illustrating an example of a radio access network according to the present disclosure.

Fig. 5 is a diagram illustrating an example of an IAB network architecture according to the present disclosure.

Fig. 6 is a diagram illustrating an example of a Transmission Control Protocol (TCP) data flow resulting in packet loss according to the present disclosure.

Fig. 7 is a diagram illustrating an example associated with TCP packet loss recovery in accordance with the present disclosure.

Fig. 8-9 are diagrams illustrating exemplary processes associated with TCP packet loss recovery according to the present disclosure.

Fig. 10-11 are block diagrams of exemplary apparatuses for wireless communication according to the present disclosure.

Detailed Description

Aspects of the disclosure are described more fully hereinafter with reference to the accompanying drawings. This disclosure may, however, be embodied in many different forms and should not be construed as limited to any specific structure or function presented throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. It will be appreciated by those skilled in the art that the scope of the present disclosure is intended to cover any aspect of the disclosure disclosed herein, whether implemented independently of or in combination with any other aspect of the disclosure. For example, an apparatus may be implemented or a method practiced using any number of the aspects set forth herein. Furthermore, the scope of the present disclosure is intended to cover an apparatus or method that is practiced with other structure, functions, or structures and functions that are in addition to or different from the aspects of the present disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of the claims.

Several aspects of the telecommunications system will now be presented with reference to various apparatus and techniques. These devices and techniques will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as "elements"). These elements may be implemented using hardware, software, or a combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

Although aspects may be described herein using terms commonly associated with 5G or New Radio (NR) Radio Access Technologies (RATs), aspects of the disclosure may be applied to other RATs, such as 3G RATs, 4G RATs, and/or RATs after 5G (e.g., 6G).

Fig. 1 is a diagram illustrating an example of a wireless network 100 according to the present disclosure. The wireless network 100 may be or include elements of a 5G (e.g., NR) network and/or a 4G (e.g., long Term Evolution (LTE)) network, etc. Wireless network 100 may include one or more base stations 110 (shown as BS 110a, BS 110b, BS 110c, and BS 110 d), user Equipment (UE) 120 or multiple UEs 120 (shown as UE 120a, UE 120b, UE 120c, UE 120d, and UE 120 e), and/or other network entities. Base station 110 is the entity in communication with UE 120. Base stations 110 (sometimes referred to as BSs) may include, for example, NR base stations, LTE base stations, nodes B, eNB (e.g., in 4G), gnbs (e.g., in 5G), access points, and/or transmit-receive points (TRPs). Each base station 110 may provide communication coverage for a particular geographic area. In the third generation partnership project (3 GPP), the term "cell" can refer to a coverage area of a base station 110 and/or a base station subsystem serving the coverage area, depending on the context in which the term is used.

The base station 110 may provide communication coverage for a macrocell, a picocell, a femtocell, and/or another type of cell. A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs 120 through service subscriptions. The pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs 120 through service subscriptions. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow limited access by UEs 120 associated with the femto cell (e.g., UEs 120 in a Closed Subscriber Group (CSG)). The base station 110 for a macro cell may be referred to as a macro base station. The base station 110 for a pico cell may be referred to as a pico base station. The base station 110 for a femto cell may be referred to as a femto base station or an in-home base station. In the example shown in fig. 1, BS 110a may be a macro base station for macro cell 102a, BS 110b may be a pico base station for pico cell 102b, and BS 110c may be a femto base station for femto cell 102 c. A base station may support one or more (e.g., three) cells.

In some examples, the cells may not necessarily be fixed, and the geographic area of the cells may move according to the location of the moving base station 110 (e.g., a mobile base station). In some examples, base stations 110 may be interconnected with each other and/or to one or more other base stations 110 or network nodes (not shown) in wireless network 100 through various types of backhaul interfaces, such as direct physical connections or virtual networks, using any suitable transmission network.

The wireless network 100 may include one or more relay stations. A relay station is an entity that may receive data transmissions from an upstream station (e.g., base station 110 or UE 120) and send data transmissions to a downstream station (e.g., UE 120 or base station 110). The relay station may be a UE 120 that may relay transmissions for other UEs 120. In the example shown in fig. 1, BS 110d (e.g., a relay base station) may communicate with BS 110a (e.g., a macro base station) and UE 120d to facilitate communications between BS 110a and UE 120 d. The base station 110 for relaying communication may be referred to as a relay station, a relay base station, a relay, or the like.

The wireless network 100 may be a heterogeneous network including different types of base stations 110, such as macro base stations, pico base stations, femto base stations, relay base stations, and so on. These different types of base stations 110 may have different transmit power levels, different coverage areas, and/or different impact on interference in the wireless network 100. For example, macro base stations may have a high transmit power level (e.g., 5 to 40 watts), while pico base stations, femto base stations, and relay base stations may have a lower transmit power level (e.g., 0.1 to 2 watts).

The network controller 130 may be coupled to or in communication with a set of base stations 110 and may provide coordination and control for these base stations 110. The network controller 130 may communicate with the base stations 110 via backhaul communication links. Base stations 110 may communicate with each other directly or indirectly via wireless or wired backhaul communication links.

UEs 120 may be dispersed throughout wireless network 100, and each UE 120 may be fixed or mobile. UE 120 may include, for example, an access terminal, a mobile station, and/or a subscriber unit. UE 120 may be a cellular telephone (e.g., a smart phone), a Personal Digital Assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a Wireless Local Loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, a superbook, a medical device, a biometric device, a wearable device (e.g., a smartwatch, smart clothing, smart glasses, a smartwristband, smart jewelry (e.g., a smartring or smart bracelet)), an entertainment device (e.g., a music device, a video device, and/or a satellite radio), a vehicle component or sensor, a smart meter/sensor, an industrial manufacturing device, a global positioning system device, and/or any other suitable device configured to communicate via a wireless or wired medium.

Some UEs 120 may be considered Machine Type Communication (MTC) or evolved or enhanced machine type communication (eMTC) UEs. MTC UEs and/or eMTC UEs may include, for example, robots, drones, remote devices, sensors, meters, monitors, and/or location tags, which may communicate with a base station, another device (e.g., a remote device), or some other entity. Some UEs 120 may be considered internet of things (IoT) devices and/or may be implemented as NB-IoT (narrowband IoT) devices. Some UEs 120 may be considered customer premises equipment. UE 120 may be included within a housing that houses components of UE 120, such as processor components and/or memory components. In some examples, the processor component and the memory component may be coupled together. For example, a processor component (e.g., one or more processors) and a memory component (e.g., memory) may be operatively coupled, communicatively coupled, electronically coupled, and/or electrically coupled.

In general, any number of wireless networks 100 may be deployed in a given geographic area. Each wireless network 100 may support a particular RAT and may operate on one or more frequencies. The RAT may be referred to as a radio technology, an air interface, etc. The frequencies may be referred to as carriers, frequency channels, etc. Each frequency may support a single RAT in a given geographical area to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks may be deployed.

In some examples, two or more UEs 120 (e.g., shown as UE 120a and UE 120 e) may communicate directly using one or more sidelink channels (e.g., without using base station 110 as an intermediary for communicating with each other). For example, UE 120 may communicate using peer-to-peer (P2P) communication, device-to-device (D2D) communication, a vehicle-to-everything (V2X) protocol (e.g., which may include a vehicle-to-vehicle (V2V) protocol, a vehicle-to-infrastructure (V2I) protocol, or a vehicle-to-pedestrian (V2P) protocol), and/or a mesh network. In such examples, UE 120 may perform scheduling operations, resource selection operations, and/or other operations described elsewhere herein as being performed by base station 110.

Devices of wireless network 100 may communicate using electromagnetic spectrum, which may be subdivided by frequency or wavelength into various categories, bands, channels, etc. For example, devices of wireless network 100 may communicate using one or more operating frequency bands. In 5G NR, two initial operating bands have been identified as frequency range names FR1 (410 MHz-7.125 GHz) and FR2 (24.25 GHz-52.6 GHz). It should be appreciated that although a portion of FR1 is greater than 6GHz, in various documents and articles FR1 is commonly referred to as (interchangeably) "below 6GHz" frequency band. FR2 sometimes suffers from similar naming problems, although it differs from the very high frequency (EHF) band (30 GHz-300 GHz) identified by the International Telecommunications Union (ITU) as the "millimeter wave" band, it is often referred to in documents and articles as the (interchangeably) "millimeter wave" band.

The frequency between FR1 and FR2 is commonly referred to as the mid-band frequency. Recent 5G NR studies have identified the operating band of these mid-band frequencies as frequency range designation FR3 (7.125 GHz-24.25 GHz). The frequency band falling within FR3 may inherit FR1 characteristics and/or FR2 characteristics, and thus may effectively extend the characteristics of FR1 and/or FR2 to mid-band frequencies. In addition, higher frequency bands are currently being explored to extend 5G NR operation above 52.6 GHz. For example, three higher operating bands have been identified as frequency range names FR4a or FR4-1 (52.6 GHz-71 GHz), FR4 (52.6 GHz-114.25 GHz) and FR5 (114.25 GHz-300 GHz). Each of these higher frequency bands falls within an EHF (extremely high frequency) band.

In view of the above examples, unless specifically stated otherwise, it should be understood that if the term "below 6GHz" or the like is used herein, it may broadly represent frequencies that may be less than 6GHz, may be within FR1, or may include mid-band frequencies. Furthermore, unless specifically stated otherwise, it should be understood that if the term "millimeter wave" or the like is used herein, it may broadly represent frequencies that may include mid-band frequencies, may be within FR2, FR4-a or FR4-1 and/or FR5, or may be within the EHF (extremely high frequency) band. It is contemplated that frequencies included in these operating bands (e.g., FR1, FR2, FR3, FR4-a, FR4-1, and/or FR 5) may be modified and that the techniques described herein are applicable to those modified frequency ranges.

In some aspects, UE 120 may include a communication manager 140. As described in more detail elsewhere herein, the communication manager 140 can detect Transmission Control Protocol (TCP) packet loss based at least in part on a Packet Data Convergence Protocol (PDCP) payload of the packet; and transmitting a plurality of retransmission requests for the packet based at least in part on the detection of TCP packet loss for the packet. In some aspects, the communication manager 140 can detect TCP packet loss based at least in part on TCP sequence and without PDCP loss; and transmitting a plurality of retransmission requests for the packet based at least in part on the detection of TCP packet loss for the packet. Additionally or alternatively, communication manager 140 may perform one or more other operations described herein. In some aspects, the base station 110 may include a communication manager 150. As described in more detail elsewhere herein, communication manager 150 may receive a retransmission request from UE 120 and may retransmit one or more lost packets based at least in part on receiving the retransmission request. Additionally or alternatively, communication manager 150 may perform one or more other operations described herein.

As described above, fig. 1 is provided as an example. Other examples may differ from what is described with respect to fig. 1.

Fig. 2 is a diagram illustrating an example 200 of a base station 110 in communication with a UE 120 in a wireless network 100 according to the present disclosure. Base station 110 may be equipped with a set of antennas 234a through 234T, such as T antennas (T.gtoreq.1). UE 120 may be equipped with a set of antennas 252a through 252R, such as R antennas (r≡1).

At base station 110, transmit processor 220 may receive data intended for UE 120 (or a group of UEs 120) from data source 212. Transmit processor 220 may select one or more Modulation and Coding Schemes (MCSs) for UE 120 based at least in part on one or more Channel Quality Indicators (CQIs) received from UE 120. Base station 110 may process (e.g., encode and modulate) data for UE 120 based at least in part on the MCS selected for UE 120 and may provide data symbols for UE 120. Transmit processor 220 may process system information (e.g., for semi-Static Resource Partitioning Information (SRPI)) and control information (e.g., CQI requests, grants, and/or upper layer signaling) and provide overhead symbols and control symbols. The transmit processor 220 may generate reference symbols for reference signals (e.g., cell-specific reference signals (CRS) or demodulation reference signals (DMRS)) and synchronization signals (e.g., primary Synchronization Signals (PSS) or Secondary Synchronization Signals (SSS)). A Transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, the overhead symbols, and/or the reference symbols, if applicable, and may provide a set of output symbol streams (e.g., T output symbol streams) to a corresponding set of modems 232 (e.g., T modems) (shown as modems 232a through 232T). For example, each output symbol stream may be provided to a modulator component (shown as MOD) of modem 232. Each modem 232 may process a respective output symbol stream (e.g., for OFDM) using a respective modulator component to obtain an output sample stream. Each modem 232 may also process (e.g., convert to analog, amplify, filter, and/or upconvert) the output sample stream using a corresponding modulator component to obtain a downlink signal. Modems 232a through 232T may transmit a set of downlink signals (e.g., T downlink signals) via a corresponding set of antennas 234 (e.g., T antennas) (shown as antennas 234a through 234T).

At UE 120, a set of antennas 252 (shown as antennas 252a through 252R) may receive the downlink signals from base station 110 and/or other base stations 110 and a set of received signals (e.g., R received signals) may be provided to a set of modems 254 (e.g., R modems) (shown as modems 254a through 254R). For example, each received signal may be provided to a demodulator component (shown as DEMOD) of modem 254. Each modem 254 may condition (e.g., filter, amplify, downconvert, and/or digitize) a received signal using a corresponding demodulator component to obtain input samples. Each modem 254 may use a demodulator assembly to further process the input samples (e.g., for OFDM) to obtain received symbols. MIMO detector 256 may obtain the received symbols from modem 254, perform MIMO detection on the received symbols if applicable, and may provide detected symbols. Receive processor 258 may process (e.g., demodulate and decode) the detected symbols, may provide decoded data for UE 120 to a data sink 260, and may provide decoded control information and system information to controller/processor 280. The term "controller/processor" may refer to one or more controllers, one or more processors, or a combination thereof. The channel processor may determine a Reference Signal Received Power (RSRP) parameter, a Received Signal Strength Indicator (RSSI) parameter, a Reference Signal Received Quality (RSRQ) parameter, and/or a CQI parameter, etc. In some examples, one or more components of UE 120 may be included in housing 284.

The network controller 130 may include a communication unit 294, a controller/processor 290, and a memory 292. The network controller 130 may comprise, for example, one or more devices in a core network. The network controller 130 may communicate with the base station 110 via a communication unit 294.

The one or more antennas (e.g., antennas 234a through 234t and/or antennas 252a through 252 r) may include or be included in one or more antenna panels, one or more antenna groups, one or more groups of antenna elements and/or one or more antenna arrays, etc. The antenna panel, antenna group, group of antenna elements, and/or antenna array may include one or more antenna elements (within a single housing or multiple housings), a group of coplanar antenna elements, a group of non-coplanar antenna elements, and/or one or more antenna elements coupled to one or more transmit and/or receive components (such as one or more components of fig. 2).

On the uplink, at UE 120, transmit processor 264 may receive and process data from data source 262 and control information from controller/processor 280 (e.g., for reports including RSRP, RSSI, RSRQ and/or CQI). Transmit processor 264 may generate reference symbols for one or more reference signals. The symbols from transmit processor 264 may be precoded by a TX MIMO processor 266 if applicable, further processed by modem 254 (e.g., for DFT-s-OFDM or CP-OFDM), and transmitted to base station 110. In some examples, modem 254 of UE 120 may include a modulator and a demodulator. In some examples, UE 120 includes a transceiver. The transceiver may include any combination of antennas 252, modems 254, MIMO detector 256, receive processor 258, transmit processor 264, and/or TX MIMO processor 266. The transceiver may be used by a processor (e.g., controller/processor 280) and memory 282 to perform aspects of any of the methods described herein (e.g., with reference to fig. 7-11).

At base station 110, uplink signals from UE 120 and/or other UEs may be received by antennas 234, processed by a modem 232 (e.g., a demodulator component of modem 232, shown as DEMOD), detected by a MIMO detector 236 (if applicable), and further processed by a receive processor 238 to obtain decoded data and control information sent by UE 120. The receive processor 238 may provide the decoded data to a data sink 239 and the decoded control information to a controller/processor 240. The base station 110 may include a communication unit 244 and may communicate with the network controller 130 via the communication unit 244. Base station 110 may include a scheduler 246 to schedule one or more UEs 120 for downlink and/or uplink communications. In some examples, modem 232 of base station 110 may include a modulator and a demodulator. In some examples, base station 110 includes a transceiver. The transceiver may include any combination of antennas 234, modems 232, MIMO detector 236, receive processor 238, transmit processor 220, and/or TX MIMO processor 230. The transceiver may be used by a processor (e.g., controller/processor 240) and memory 242 to perform aspects of any of the methods described herein (e.g., with reference to fig. 7-11).

The controller/processor 240 of the base station 110, the controller/processor 280 of the UE 120, and/or any other components of fig. 2 may perform one or more techniques associated with Transmission Control Protocol (TCP) packet loss recovery, as described in more detail elsewhere herein. For example, controller/processor 240 of base station 110, controller/process 280 of UE 120, and/or any other component of fig. 2 may perform or direct operations such as process 800 of fig. 8, process 900 of fig. 9, and/or other processes described herein. Memory 242 and memory 282 may store data and program codes for base station 110 and UE 120, respectively. In some examples, memory 242 and/or memory 282 may include a non-transitory computer-readable medium storing one or more instructions (e.g., code and/or program code) for wireless communication. For example, the one or more instructions, when executed by one or more processors of base station 110 and/or UE 120 (e.g., directly, or after compilation, conversion, and/or interpretation), may cause the one or more processors, UE 120, and/or base station 110 to perform or direct operations such as process 800 of fig. 8, process 900 of fig. 9, and/or other processes described herein. In some examples, the execution instructions may include execution instructions, conversion instructions, compilation instructions, and/or interpretation instructions, among others.

In some aspects, UE 120 includes: means for detecting a Packet Data Convergence Protocol (PDCP) packet loss based at least in part on a PDCP payload of the packet; and/or means for sending a plurality of retransmission requests for the packet based at least in part on the detection of TCP packet loss for the packet. In some aspects, UE 120 includes: means for detecting a TCP packet loss based at least in part on the TCP sequence and without a PDCP loss; and means for sending a plurality of retransmission requests for the packet based at least in part on the detection of TCP packet loss for the packet. In some aspects, UE 120 includes means for transmitting a set of repetitions of a duplicate acknowledgement based at least in part on detection of TCP packet loss of the packet. In some aspects, UE 120 includes means for detecting TCP packet loss based at least in part on a size of the PDCP payload or a content of the PDCP payload. In some aspects, UE 120 includes means for detecting TCP packet loss based at least in part on the inspection of the header of the PDCP payload. In some aspects, UE 120 includes means for detecting TCP packet loss based at least in part on the packet being invalid. In some aspects, UE 120 includes means for detecting TCP packet loss based at least in part on the packet having a zero payload or a dummy payload. In some aspects, UE 120 includes means for detecting TCP packet loss based at least in part on expiration of a PDCP timer of UE 120. In some aspects, UE 120 includes means for detecting a Radio Link Control (RLC) packet loss. Means for causing UE 120 to perform the operations described herein may include, for example, one or more of antenna 252, demodulator 254, MIMO detector 256, receive processor 258, transmit processor 264, TX MIMO processor 266, modulator 254, controller/processor 280, or memory 282.

Although the blocks in fig. 2 are illustrated as distinct components, the functionality described above with respect to the blocks may be implemented in a single hardware, software, or combined component, or in various combinations of components. For example, the functions described with respect to transmit processor 264, receive processor 258, and/or TX MIMO processor 266 may be performed by or under the control of controller/processor 280.

As described above, fig. 2 is provided as an example. Other examples may differ from what is described with respect to fig. 2.

Fig. 3 is a diagram illustrating an example 300 of user plane protocol stacks and control plane protocol stacks of a base station 110 and a core network for communicating with a UE 120 according to the present disclosure.

In the user plane, the UE 120 and the base station 110 may include respective Physical (PHY) layers, medium Access Control (MAC) layers, radio Link Control (RLC) layers, packet Data Convergence Protocol (PDCP) layers, and Service Data Adaptation Protocol (SDAP) layers. The user plane functions may handle user data transmissions between UE 120 and base station 110. On the control plane, UE 120 and base station 110 may include respective Radio Resource Control (RRC) layers. Further, UE 120 may include a non-access stratum (NAS) layer in communication with a NAS layer that accesses and manages mobility functions (AMFs). The AMF may be associated with a core network associated with the base station 110, such as a 5G core network (5 GC) or a next generation radio access network (NG-RAN). The control plane function may handle control information transmission between the UE and the core network. In general, if the first layer is farther from the PHY layer than the second layer, the first layer is said to be higher than the second layer. For example, the PHY layer may be referred to as the lowest layer, and the SDAP/PDCP/RLC/MAC layer may be referred to as higher than the PHY layer and lower than the RRC layer. The Application (APP) layer, not shown in fig. 3, may be higher than the SDAP/PDCP/RLC/MAC layer. In some cases, an entity may handle services and functions of a given layer (e.g., a PDCP entity may handle services or functions of a PDCP layer), although the description herein refers to a layer itself handling services or functions.

The RRC layer may handle communications related to configuring and operating UE 120, such as: broadcasting of system information related to an Access Stratum (AS) and NAS; paging initiated by 5GC or NG-RAN; establishment, maintenance and release of RRC connection between UE and NG-RAN, including addition, modification and release of carrier aggregation, and addition, modification and release of dual connectivity; security functions including key management; establishment, configuration, maintenance and release of Signaling Radio Bearers (SRBs) and Data Radio Bearers (DRBs); mobility functions (e.g., handover and context transfer, UE cell selection and reselection, control of cell selection and reselection, inter-RAT mobility); quality of service (QoS) management functions; UE measurement reporting and control of reporting; detection and recovery of radio link failure; and NAS messaging between NAS layer and lower layers of UE 120. The RRC layer is commonly referred to as layer 3 (L3).

The SDAP layer, the PDCP layer, the RLC layer, and the MAC layer may be collectively referred to as layer 2 (L2). Thus, in some cases, SDAP, PDCP, RLC and MAC layers are referred to as sub-layers of layer 2. On the transmitting side (e.g., if UE 120 is transmitting uplink communications or base station 110 is transmitting downlink communications), the SDAP layer may receive the data stream in the form of a QoS stream. QoS flows are associated with QoS identifiers that identify QoS parameters associated with the QoS flows and QoS Flow Identifiers (QFI) that identify the QoS flows. Policy and charging parameters are enforced on QoS flow granularity. A QoS flow may include one or more Service Data Flows (SDFs) so long as each SDF of the QoS flow is associated with the same policy and charging parameters. In some aspects, the RRC/NAS layer may generate control information to be transmitted and may map the control information to one or more radio bearers to provide to the PDCP layer.

The SDAP layer or the RRC/NAS layer can map QoS flows or control information to radio bearers. Therefore, it can be said that the SDAP layer handles QoS flows on the transmitting side. The SDAP layer can provide QoS flows to the PDCP layer via corresponding radio bearers. The PDCP layer may map radio bearers to RLC channels. The PDCP layer may handle various services and functions on the user plane including sequence numbering, header compression and decompression (if robust header compression is enabled), user data transmission, reordering and repetition detection (if needed to be delivered sequentially to layers above the PDCP layer), PDCP Protocol Data Unit (PDU) routing (in case of separate bearers), retransmission, ciphering and deciphering of PDCP Service Data Units (SDUs), PDCP SDU discard (e.g., according to a timer, as described elsewhere herein), PDCP re-establishment and data recovery for RLC Acknowledged Mode (AM), and duplication of PDCP PDUs. The PDCP layer may handle similar services and functions on the control plane including sequence numbering, ciphering, deciphering, integrity protection, control plane data transmission, duplicate detection, and duplication of PDCP PDUs.

The PDCP layer may provide data to the RLC layer in the form of PDCP PDUs via an RLC channel. The RLC layer can handle transmission of upper layer PDUs to the MAC and/or PHY layer, sequence numbering independent of PDCP sequence numbering, error correction via automatic repeat request (ARQ), segmentation and re-segmentation, reassembly of SDUs, RLC SDU discard, and RLC re-establishment.

The RLC layer may provide data mapped to the logical channels to the MAC layer. The services and functions of the MAC layer include: mapping between logical channels and transport channels (used by PHY layers as described below), multiplexing MAC SDUs belonging to one or different logical channels into/from Transport Blocks (TBs) delivered to/from the physical layer on transport channels, scheduling information reporting, error correction by Hybrid ARQ (HARQ), prioritization between UEs by means of dynamic scheduling, prioritization between logical channels of one UE by means of logical channel prioritization, and padding.

The MAC layer may encapsulate data from the logical channels into TBs and may provide the TBs to the PHY layer over one or more transport channels. The PHY layer may handle various operations related to data signaling, as described in more detail in connection with fig. 2. The PHY layer is commonly referred to as layer 1 (L1).

On the receiving side (e.g., if UE 120 is receiving downlink communications or base station 110 is receiving uplink communications), the operations may be similar to those described for the transmitting side, but vice versa. For example, the PHY layer may receive TBs and may provide the TBs to the MAC layer on one or more transport channels. The MAC layer may map the transport channel to a logical channel and may provide data to the RLC layer via the logical channel. The RLC layer may map logical channels to RLC channels and may provide data to the PDCP layer via the RLC channels. The PDCP layer may map RLC channels to radio bearers and may provide data to the SDAP layer or RRC/NAS layer via the radio bearers.

Data may be transferred between layers in the form of PDUs and SDUs. SDUs are data units that are transferred from a layer or sub-layer to a lower layer. For example, the PDCP layer may receive PDCP SDUs. The given layer may then encapsulate the data units into PDUs and may pass the PDUs to lower layers. For example, the PDCP layer may encapsulate PDCP SDUs into PDCP PDUs and may deliver the PDCP PDUs to the RLC layer. The RLC layer may receive PDCP PDUs as RLC SDUs, may encapsulate RLC SDUs into RLC PDUs, and so on. In practice, the PDU carries the SDU as a payload.

As described above, fig. 3 is provided as an example. Other examples may differ from what is described with respect to fig. 3.

Fig. 4 is a diagram illustrating an example 400 of a radio access network according to the present disclosure.

As shown at reference numeral 405, a conventional (e.g., 3G, 4G, or LTE) radio access network may include a plurality of base stations 410 (e.g., access Nodes (ANs)), wherein each base station 410 communicates with a core network via a wired backhaul link 415, such as a fiber optic connection. Base station 410 may communicate with UE 420 via access link 425, which may be a wireless link. In some aspects, the base station 410 shown in fig. 4 may be the base station 110 shown in fig. 1. In some aspects, UE 420 shown in fig. 4 may be UE 120 shown in fig. 1.

As indicated by reference numeral 430, the radio access network may include a wireless backhaul network, sometimes referred to as an Integrated Access and Backhaul (IAB) network. In an IAB network, at least one base station is an anchor base station 435 that communicates with the core network via a wired backhaul link 440 (such as a fiber optic connection). Anchor base station 435 may also be referred to as an IAB donor (or IAB-donor). The IAB network may include one or more non-anchor base stations 445, sometimes referred to as relay base stations or IAB nodes (or IAB-nodes). The non-anchor base station 445 may communicate with the anchor base station 435 directly or indirectly via one or more backhaul links 450 (e.g., via one or more non-anchor base stations 445) to form a backhaul path to the core network for carrying backhaul traffic. Backhaul link 450 may be a wireless link. Anchor base station 435 and/or non-anchor base station 445 may communicate with one or more UEs 455 via an access link 460, which may be a wireless link for carrying access traffic. In some aspects, the anchor base station 435 and/or the non-anchor base station 445 shown in fig. 4 may be the base station 110 shown in fig. 1. In some aspects, UE 455 shown in fig. 4 may be UE 120 shown in fig. 1.

As indicated by reference numeral 465, in some aspects, a radio access network including an IAB network may utilize millimeter wave technology and/or directional communication (e.g., beamforming) to communicate between base stations and/or UEs (e.g., between two base stations, between two UEs, and/or between a base station and a UE). For example, wireless backhaul links 470 between base stations may use millimeter wave signals to carry information and/or may be directed to target base stations using beamforming. Similarly, wireless access link 475 between the UE and the base station may use millimeter wave signals and/or may be directed to a target wireless node (e.g., UE and/or base station). In this way, inter-link interference may be reduced.

The configuration of the base station and the UE in fig. 4 is shown as an example, and other examples are also contemplated. For example, one or more base stations shown in fig. 4 may be replaced with one or more UEs that communicate via a UE-to-UE access network (e.g., a peer-to-peer network or a device-to-device network). In this case, an "anchor node" may refer to a UE that communicates directly with a base station (e.g., an anchor base station or a non-anchor base station).

As described above, fig. 4 is provided as an example. Other examples may differ from what is described with respect to fig. 4.

Fig. 5 is a diagram illustrating an example 500 of an IAB network architecture according to the present disclosure.

As shown in fig. 5, the IAB network may include an IAB donor 505 (shown as an IAB-donor) connected to the core network via a wired connection (shown as a wired backhaul). For example, the Ng interface of the IAB donor 505 may terminate at the core network. Additionally or alternatively, the IAB donor 505 may be connected to one or more devices of the core network that provide core access and mobility management functions (e.g., AMF). In some aspects, the IAB donor 505 may include a base station 110, such as an anchor base station, as described above in connection with 4. As shown, the IAB donor 505 may include a Central Unit (CU) that may perform Access Node Controller (ANC) functions and/or AMF functions. A CU may configure a Distributed Unit (DU) of the IAB donor 505 and/or may configure one or more IAB nodes 510 (e.g., MT and/or DU of the IAB node 510) connected to the core network via the IAB donor 505. Thus, a CU of the IAB donor 505 may control and/or configure the entire IAB network connected to the core network via the IAB donor 505, such as by using control messages and/or configuration messages (e.g., radio Resource Control (RRC) configuration messages or F1 application protocol (F1 AP) messages).

As further shown in fig. 5, the IAB network may include an IAB node 510 (shown as IAB node 1, IAB node 2, and IAB node 3) connected to the core network via an IAB donor 505. As shown, the IAB node 510 may include Mobile Terminal (MT) functionality (sometimes also referred to as UE functionality (UEF)) and may include DU functionality (sometimes also referred to as Access Node Functionality (ANF)). The MT function of an IAB node 510 (e.g., a child node) may be controlled and/or scheduled by another IAB node 510 (e.g., the parent node of the child node) and/or by an IAB donor 505. The DU function of an IAB node 510 (e.g., a parent node) may control and/or schedule other IAB nodes 510 (e.g., child nodes of the parent node) and/or UEs 120. Thus, a DU may be referred to as a scheduling node or scheduling component, and an MT may be referred to as a scheduled node or scheduled component. In some aspects, the IAB donor 505 may include DU functionality rather than MT functionality. That is, the IAB donor 505 may configure, control, and/or schedule communications for the IAB node 510 and/or the UE 120. UE 120 may include only MT functions and not DU functions. That is, communication of UE 120 may be controlled and/or scheduled by IAB donor 505 and/or IAB node 510 (e.g., a parent node of UE 120).

When a first node controls and/or schedules communication of a second node (e.g., when the first node provides DU functionality for MT functionality of the second node), the first node may be referred to as a parent node of the second node, and the second node may be referred to as a child node of the first node. The child node of the second node may be referred to as a grandchild node of the first node. Thus, the DU function of a parent node may control and/or schedule communication of child nodes of the parent node. The parent node may be an IAB donor 505 or an IAB node 510 and the child node may be an IAB node 510 or a UE 120. Communication of MT functions of the child node may be controlled and/or scheduled by a parent node of the child node.

As further shown in fig. 5, the link between UE 120 (e.g., it has only MT functionality and not DU functionality) and IAB donor 505, or the link between UE 120 and IAB node 510, may be referred to as access link 515. The access link 515 may be a wireless access link that provides radio access to the core network to the UE 120 via the IAB donor 505 and optionally via one or more IAB nodes 510. Thus, the network shown in fig. 5 may be referred to as a multi-hop network or a wireless multi-hop network.

As further shown in fig. 5, the link between an IAB donor 505 and an IAB node 510 or between two IAB nodes 510 may be referred to as a backhaul link 520. The backhaul link 520 may be a wireless backhaul link that provides radio access to the core network to the IAB node 510 via the IAB donor 505 and optionally via one or more other IAB nodes 510. In an IAB network, network resources (e.g., time resources, frequency resources, and/or space resources) for wireless communications may be shared between the access link 515 and the backhaul link 520. In some aspects, the backhaul link 520 may be a primary backhaul link or a secondary backhaul link (e.g., a backup backhaul link). In some aspects, a secondary backhaul link may be used if the primary backhaul link fails, becomes congested and/or becomes overloaded, etc. For example, if the main backhaul link between the IAB node 2 and the IAB node 1 fails, the backup link between the IAB node 2 and the IAB node 3 may be used for backhaul communication. As used herein, a "node" or "wireless node" may refer to an IAB donor 505 or an IAB node 510.

As described above, fig. 5 is provided as an example. Other examples may differ from what is described with respect to fig. 5.

Fig. 6 is a diagram illustrating an example 600 of a TCP data stream that results in packet loss on the downlink due to a timer discard at a base station in accordance with the present disclosure. As shown in fig. 6, different protocol layers exist in the UE (left), the base station (middle) and one or more core network devices (right).

As further shown in fig. 6, the data server may provide a set of M packets to a Gateway (GW) via an S1U interface, which may direct the set of M packets to the base station and UE as a set of N packets via an NG-U interface. The base station may receive the packet at a Packet Data Convergence Protocol (PDCP) Downlink (DL) entity of the CU and direct the packet as a set of P packets to a DU (and associated Radio Link Control (RLC) and Medium Access Control (MAC)/layer 1 (L1) entity) of the base station via the NR-U interface. The base station may transmit data to the UE via an over-the-air (OTA) interface, and the UE may pass the transmitted packets up a protocol stack from the MAC/L1 entity, RLC entity, and PDCP entity of the UE to a TCP entity/Higher Layer Operating System (HLOS) of the UE. Each of the above data transmissions may be associated with a buffer. For example, there may be a first buffer for the S1-U interface, a second buffer for the NG-U interface, a third buffer for the NR-U interface, or a fourth buffer for the OTA interface, etc.

Some of the data available in the buffer of the base station is not sent within the configuration time (e.g., before the timer associated with the data expires) due to a change in the load condition on the OTA interface. This situation may be referred to as timer discard (t_discard) because it may occur when the timer expires and a packet of data to be transmitted is discarded due to failure to meet a delay requirement, e.g., a delay requirement of real-time transport protocol (RTP) or TCP. When a packet is lost at the base station and access layer (AS) level, the UE may not receive an explicit notification of the packet loss. For example, the base station may send a set of PDCP packets having a PDCP Sequence Number (SN) and an RLC SN in sequence to the UE. Because PDCP packets are ordered ("clean") with respect to PDCP SNs and RLC SNs, no reordering occurs at the UE and the PDCP entity of the UE detects that the packets have been received correctly. However, since the PDCP entity of the base station discards the packet in the buffer of the base station, the PDCP packet may have an empty payload. In other words, the UE receives a MAC Service Data Unit (SDU) having 10 bytes, and the 10 bytes include a PDCP header of 3 bytes, an RLC header of 3 bytes, a MAC header of 2 bytes (a MAC header of 3 bytes if the SDU is less than 255 octets otherwise), and a dummy payload (e.g., padding bits) or zero payload (e.g., zero bits) of 2 bytes.

At the TCP entity of the UE, the UE may detect that the packet has been lost, and the UE may send a TCP Duplicate (DUP) Acknowledgement (ACK) to the base station for each packet. After a threshold number of DUP ACKs, retransmission of the discarded packets is triggered. For example, depending on the configuration, retransmissions may occur after a number in the range of 3 to 17 DUP ACKs. The interval between transmissions of DUP ACKs may be greater than a threshold, which may result in poor network performance for the UE.

As described above, fig. 6 is provided as an example. Other examples may differ from what is described with respect to fig. 6.

Some aspects described herein enable TCP packet loss recovery. For example, the UE may detect that the PDCP payload is a zero payload, an invalid payload, or a dummy payload, etc., and may determine that TCP packet loss has occurred at the base station (e.g., the base station has discarded TCP packets at a buffer of the PDCP entity of the base station). In this case, the UE may repeat transmission of the DUP ACK to trigger a fast retransmission of the lost packet. For example, rather than waiting to generate a threshold amount of DUP ACKs based at least in part on a threshold amount of detected packet loss, the UE may artificially generate multiple DUP ACKs for a single detected packet loss, thereby immediately triggering retransmission. In this way, the UE improves detection of packet loss and reduces the amount of time to retransmit lost packets, thereby improving the network performance of the UE.

Fig. 7 is a diagram illustrating an example 700 associated with TCP packet loss recovery in accordance with the present disclosure. As shown in fig. 7, example 700 includes communication between base station 110, UE 120, and one or more core network devices 710. In some aspects, base station 110 and UE 120 may be included in a wireless network, such as wireless network 100. Base station 110 and UE 120 may communicate via a wireless access link, which may include an uplink and a downlink.

As shown in fig. 7 and by reference numeral 720, UE 120 may detect a TCP packet loss. For example, UE 120 may detect TCP packet loss based at least in part on the PDCP payload of the packet. In this case, UE 120 may detect a TCP packet loss based at least in part on detecting a PDCP loss, as described herein. Additionally or alternatively, UE 120 may detect TCP packet loss based at least in part on the TCP sequence. In this case, UE 120 may detect TCP packet loss without PDCP loss, as described herein.

In some aspects, UE 120 may detect TCP packet loss by analyzing the content of the payload header. For example, after PDCP decryption, the UE 120 may parse the payload of the packet to determine where to send the packet up the protocol stack. In this case, UE 120 may parse the payload using an IP packet processing entity (e.g., an IP accelerator (IPA) entity), which may be a hardware component (IPA HW) or a software component (IPA SW). Based at least in part on parsing the payload, UE 120 may determine that the packet includes a dummy payload or other invalid type of payload added at the PDCP entity of base station 110. Additionally or alternatively, the UE may detect another type of packet loss, such as RLC packet loss. Additionally or alternatively, the UE may detect packet loss based at least in part on expiration of a PDCP timer at the UE. In some aspects, the UE may detect packet loss without PDCP loss. For example, the UE may detect an unordered TCP sequence indicating packet loss.

As shown in fig. 7 and further illustrated by reference numeral 730, UE 120 may send a retransmission request. For example, based at least in part on detecting a TCP packet loss, UE 120 may send a retransmission request to trigger retransmission of the packet (e.g., at the modem level of UE 120). In this case, UE 120 may send a set of immediate TCP DUP ACKs to trigger retransmission of the packet faster than if UE 120 waited to trigger retransmission at the TCP entity of UE 120. In some aspects, UE 120 may generate and send a set of repetitions (e.g., a threshold number K of repetitions) of the DUP ACK packet at a modem located at a header of a PDCP entity in a protocol stack of UE 120. Additionally or alternatively, UE 120 may generate and send the set of repetitions of the DUP ACK packet at the IPA HW or IPA SW entity of UE 120. In some aspects, UE 120 may generate and send the set of repetitions at a Higher Level Operating System (HLOS) driver level of UE 120. Additionally or alternatively, UE 120 may generate and send the set of repetitions at the TCP entity of UE 120 (but before other TCP retransmission criteria are met, thereby reducing the amount of time to trigger retransmissions). In this way, the UE 120 reduces the amount of time for retransmitting data discarded at the PDCP entity of the base station 110, thereby improving network and device performance.

As described above, fig. 7 is provided as an example. Other examples may differ from what is described with respect to fig. 7.

Fig. 8 is a diagram illustrating an example process 800 performed, for example, by a UE, in accordance with the present disclosure. Exemplary process 800 is an example of a UE (e.g., UE 120) performing operations associated with techniques for TCP packet loss recovery.

As shown in fig. 8, in some aspects, process 800 may include detecting TCP packet loss based at least in part on a PDCP payload of the packet (block 810). For example, the UE (e.g., using detection component 1008 shown in fig. 10) may detect TCP packet loss based at least in part on the PDCP payload of the packet, as described above.

As further shown in fig. 8, in some aspects, process 800 may include transmitting a plurality of retransmission requests for a packet based at least in part on detection of TCP packet loss for the packet (block 820). For example, the UE (e.g., using the transmission component 1004 shown in fig. 10) may transmit multiple retransmission requests for a packet based at least in part on detection of TCP packet loss for the packet, as described above.

Process 800 may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein.

In a first aspect, transmitting the plurality of retransmission requests includes: a set of repetitions of the duplicate acknowledgement is sent based at least in part on detection of TCP packet loss of the packet.

In a second aspect, alone or in combination with the first aspect, the set of repetitions is transmitted by a modem associated with a PDCP entity of the UE.

In a third aspect, alone or in combination with one or more of the first and second aspects, the set of repetitions is transmitted by a hardware or software component of the IP packet processing entity.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the set of repetitions is transmitted by a high-level operating system entity.

In a fifth aspect, alone or in combination with one or more of the first to fourth aspects, the set of repetitions is sent by a TCP entity.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, detecting TCP packet loss comprises: TCP packet loss is detected based at least in part on the size of the PDCP payload or the content of the PDCP payload.

In an eighth aspect, alone or in combination with one or more of the first to seventh aspects, the checking of the header of the PDCP payload is performed using hardware or software components of an IP packet processing entity.

In a ninth aspect, alone or in combination with one or more of the first to eighth aspects, the detection of TCP packet loss comprises: TCP packet loss is detected based at least in part on the packet being invalid.

In a tenth aspect, alone or in combination with one or more of the first to ninth aspects, the detection of TCP packet loss comprises: TCP packet loss is detected based at least in part on the packet having a zero payload or a dummy payload.

In an eleventh aspect, alone or in combination with one or more of the first to tenth aspects, the detection of TCP packet loss comprises: TCP packet loss is detected based at least in part on expiration of a PDCP timer of the UE.

In a twelfth aspect, alone or in combination with one or more of the first to eleventh aspects, the detection of TCP packet loss comprises: RLC packet loss is detected.

While fig. 8 shows exemplary blocks of process 800, in some aspects process 800 may include additional blocks, fewer blocks, different blocks, or a different arrangement of blocks than depicted in fig. 8. Additionally or alternatively, two or more blocks of process 800 may be performed in parallel.

Fig. 9 is a diagram illustrating an example process 900 performed, for example, by a UE, in accordance with the present disclosure. The example process 900 is an example of a UE (e.g., the UE 120) performing operations associated with TCP packet loss recovery.

As shown in fig. 9, in some aspects, process 900 may include detecting TCP packet loss based at least in part on TCP sequence and without PDCP loss (block 910). For example, the UE (e.g., using the communication manager 140 and/or detection component 1008 shown in fig. 10) can detect TCP packet loss based at least in part on the TCP sequence and without PDCP loss, as described above.

As further shown in fig. 9, in some aspects, process 900 may include transmitting a plurality of retransmission requests for a packet based at least in part on detection of TCP packet loss for the packet (block 920). For example, the UE (e.g., using communication manager 140 and/or transmission component 1004 shown in fig. 10) may transmit multiple retransmission requests for a packet based at least in part on detection of TCP packet loss for the packet, as described above.

Process 900 may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein.

In a first aspect, process 900 includes transmitting a set of repetitions of a duplicate acknowledgement based at least in part on detection of a TCP packet loss of a packet.

In a third aspect, alone or in combination with one or more of the first and second aspects, the set of repetitions is transmitted by a hardware or software component of an Internet Protocol (IP) packet processing entity.

While fig. 9 shows exemplary blocks of process 900, in some aspects process 900 may include additional blocks, fewer blocks, different blocks, or different arrangements of blocks than depicted in fig. 9. Additionally or alternatively, two or more blocks of process 900 may be performed in parallel.

Fig. 10 is a block diagram of an exemplary apparatus 1000 for wireless communication. The apparatus 1000 may be a UE, or the UE may include the apparatus 1000. In some aspects, the apparatus 1000 includes a receiving component 1002 and a transmitting component 1004 that can communicate with each other (e.g., via one or more buses and/or one or more other components). As shown, apparatus 1000 may communicate with another apparatus 1006, such as a UE, a base station, or another wireless communication device, using a receiving component 1002 and a transmitting component 1004. As further illustrated, the apparatus 1000 can include a detection component 1008 and the like.

In some aspects, the apparatus 1000 may be configured to perform one or more operations described herein. Additionally or alternatively, the apparatus 1000 may be configured to perform one or more processes described herein, such as process 800 of fig. 8 or process 900 of fig. 9, and the like. In some aspects, the apparatus 1000 includes a receiving component 1002 and a transmitting component 1004 that can communicate with each other (e.g., via one or more buses and/or one or more other components). Additionally or alternatively, one or more of the components shown in fig. 10 may be implemented within one or more of the components described above in connection with fig. 2. Additionally or alternatively, one or more components of the set of components may be at least partially implemented as software stored in memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by a controller or processor to perform functions or operations of the component.

The receiving component 1002 can receive a communication, such as a reference signal, control information, data communication, or a combination thereof, from the apparatus 1006. The receiving component 1002 can provide received communications to one or more other components of the apparatus 1000. In some aspects, the receiving component 1002 can perform signal processing (such as filtering, amplifying, demodulating, analog-to-digital converting, demultiplexing, deinterleaving, demapping, equalizing, interference cancellation or decoding, etc.) on the received communication and can provide the processed signal to one or more other components of the apparatus 1006. In some aspects, the receiving component 1002 can include one or more antennas, demodulators, MIMO detectors, receive processors, controllers/processors, memories, or a combination thereof for a UE as described above in connection with fig. 2.

The transmitting component 1004 can transmit a communication, such as a reference signal, control information, data communication, or a combination thereof, to the device 1006. In some aspects, one or more other components of the apparatus 1006 may generate a communication, and the generated communication may be provided to the sending component 1004 for sending to the apparatus 1006. In some aspects, the transmitting component 1004 can perform signal processing (such as filtering, amplifying, modulating, digital-to-analog converting, multiplexing, interleaving, mapping, encoding, or the like) on the generated communication and can transmit the processed signal to the device 1006. In some aspects, the transmit component 1004 can include one or more antennas, modulators, transmit MIMO processors, transmit processors, controllers/processors, memories, or combinations thereof of the UE described above in connection with fig. 2. In some aspects, the sending component 1004 may be co-located with the receiving component 1002 in a transceiver.

The detection component 1008 can detect TCP packet loss based at least in part on a PDCP payload of the packet. The sending component 1004 can send a plurality of retransmission requests for a packet based at least in part on detection of TCP packet loss for the packet.

The number and arrangement of components shown in fig. 10 are provided as examples. In practice, there may be additional components, fewer components, different components, or components in a different arrangement than shown in fig. 10. Further, two or more components shown in fig. 10 may be implemented within a single component, or a single component shown in fig. 10 may be implemented as a plurality of distributed components. Additionally or alternatively, one set (one or more) of components shown in fig. 10 may perform one or more functions described as being performed by another set of components shown in fig. 10.

Fig. 11 is a block diagram of an exemplary apparatus 1100 for wireless communications. The apparatus 1100 may be a BS, or the BS may include the apparatus 1100. In some aspects, apparatus 1100 includes a receiving component 1102 and a transmitting component 1104 that can communicate with each other (e.g., via one or more buses and/or one or more other components). As shown, apparatus 1100 may communicate with another apparatus 1106, such as a UE, a base station, or another wireless communication device, using a receiving component 1102 and a transmitting component 1104. As further illustrated, apparatus 1100 can include a retransmission component 1108 and the like.

In some aspects, apparatus 1100 may be configured to perform one or more operations described herein. Additionally or alternatively, apparatus 1100 may be configured to perform one or more processes described herein. In some aspects, the apparatus 1100 and/or one or more components illustrated in fig. 11 may comprise one or more components of the BS described above in connection with fig. 2. Additionally or alternatively, one or more of the components shown in fig. 11 may be implemented within one or more of the components described above in connection with fig. 2. Additionally or alternatively, one or more components of the set of components may be at least partially implemented as software stored in memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by a controller or processor to perform functions or operations of the component.

The receiving component 1102 can receive a communication, such as a reference signal, control information, data communication, or a combination thereof, from the device 1106. The receiving component 1102 can provide the received communication to one or more other components of the apparatus 1100. In some aspects, the receiving component 1102 can perform signal processing (such as filtering, amplifying, demodulating, analog-to-digital converting, demultiplexing, deinterleaving, demapping, equalizing, interference cancellation or decoding, etc.) on the received communication and can provide the processed signal to one or more other components of the apparatus 1106. In some aspects, the receiving component 1102 may include one or more antennas, demodulators, MIMO detectors, receive processors, controllers/processors, memory, or a combination thereof of the BS described above in connection with fig. 2.

The transmission component 1104 can transmit a communication, such as a reference signal, control information, data communication, or a combination thereof, to the device 1106. In some aspects, one or more other components of the apparatus 1106 may generate a communication, and the generated communication may be provided to the sending component 1104 for sending to the apparatus 1106. In some aspects, the transmit component 1104 can perform signal processing (such as filtering, amplifying, modulating, digital-to-analog converting, multiplexing, interleaving, mapping, encoding, or the like) on the generated communication and can transmit the processed signal to the device 1106. In some aspects, the transmit component 1104 may include one or more antennas, modulators, transmit MIMO processors, transmit processors, controllers/processors, memories, or combinations thereof of the BS described above in connection with fig. 2. In some aspects, the sending component 1104 may be co-located with the receiving component 1102 in a transceiver.

Retransmission component 1108 can cause retransmission of discarded data based at least in part upon receipt of a set of retransmission requests.

The number and arrangement of components shown in fig. 11 are provided as examples. In practice, there may be additional components, fewer components, different components, or components in a different arrangement than shown in fig. 11. Further, two or more components shown in fig. 11 may be implemented within a single component, or a single component shown in fig. 11 may be implemented as a plurality of distributed components. Additionally or alternatively, one set (one or more) of components shown in fig. 11 may perform one or more functions described as being performed by another set of components shown in fig. 11.

The following provides an overview of some aspects of the disclosure:

aspect 1: a method of wireless communication performed by a User Equipment (UE), the method comprising: detecting Transmission Control Protocol (TCP) packet loss based at least in part on a Packet Data Convergence Protocol (PDCP) payload of the packet; and transmitting a plurality of retransmission requests for the packet based at least in part on the detection of the TCP packet loss for the packet.

Aspect 2: the method of aspect 1, wherein sending the plurality of retransmission requests comprises: a set of repetitions of a duplicate acknowledgement is sent based at least in part on detection of the TCP packet loss of the packet.

Aspect 3: the method of aspect 2, wherein the set of repetitions is sent by a modem associated with a PDCP entity of the UE.

Aspect 4: a method according to any of aspects 2 to 3, wherein the set of repetitions is transmitted by a hardware or software component of an Internet Protocol (IP) packet processing entity.

Aspect 5: the method of any of aspects 2-4, wherein the set of repetitions is sent by a high-level operating system entity.

Aspect 6: the method of any of aspects 2-5, wherein the set of repetitions is sent by a TCP entity.

Aspect 7: the method of any of aspects 1-6, wherein detecting the TCP packet loss comprises: the TCP packet loss is detected based at least in part on a size of the PDCP payload or a content of the PDCP payload.

Aspect 8: the method of any of aspects 1-7, wherein the detecting of the TCP packet loss comprises: the TCP packet loss is detected based at least in part on an inspection of a header of the PDCP payload.

Aspect 9: the method of aspect 8, wherein the checking of the header of the PDCP payload is performed using hardware or software components of an Internet Protocol (IP) packet processing entity.

Aspect 10: the method of any of aspects 1-9, wherein the detecting of the TCP packet loss comprises: the TCP packet loss is detected based at least in part on the packet being invalid.

Aspect 11: the method of any of aspects 1-10, wherein the detecting of the TCP packet loss comprises: the TCP packet loss is detected based at least in part on the packet having a zero payload or a dummy payload.

Aspect 12: the method of any of aspects 1-11, wherein the detecting of the TCP packet loss comprises: the TCP packet loss is detected based at least in part on expiration of a PDCP timer of the UE.

Aspect 13: the method of any of aspects 1-12, wherein the detecting of the TCP packet loss comprises: radio Link Control (RLC) packet loss is detected.

Aspect 14: a method of wireless communication performed by a User Equipment (UE), the method comprising: detecting a Transmission Control Protocol (TCP) packet loss based at least in part on a TCP sequence and without a Packet Data Convergence Protocol (PDCP) loss; and transmitting a plurality of retransmission requests for the packet based at least in part on the detection of the TCP packet loss for the packet.

Aspect 15: the method of aspect 14, wherein sending the plurality of retransmission requests comprises: a set of repetitions of a duplicate acknowledgement is sent based at least in part on detection of the TCP packet loss of the packet.

Aspect 16: the method of aspect 15, wherein the set of repetitions is sent by a modem associated with a PDCP entity of the UE.

Aspect 17: the method of any of aspects 15-16, wherein the set of repetitions is transmitted by a hardware or software component of an Internet Protocol (IP) packet processing entity.

Aspect 18: the method of any of aspects 15-17, wherein the set of repetitions is sent by a high-level operating system entity.

Aspect 19: the method according to any of aspects 15 to 18, wherein the set of repetitions is sent by a TCP entity.

Aspect 20: the method of any of aspects 14-19, wherein detecting the TCP packet loss comprises: the TCP packet loss is detected based at least in part on a size of the PDCP payload or a content of the PDCP payload.

Aspect 21: the method of any of aspects 14-20, wherein the detecting of the TCP packet loss comprises: the TCP packet loss is detected based at least in part on an inspection of a header of the PDCP payload.

Aspect 22: the method of aspect 21, wherein the checking of the header of the PDCP payload is performed using hardware or software components of an Internet Protocol (IP) packet processing entity.

Aspect 23: the method of any of aspects 14-22, wherein the detecting of the TCP packet loss comprises: the TCP packet loss is detected based at least in part on the packet being invalid.

Aspect 24: the method of any of aspects 14-23, wherein the detecting of the TCP packet loss comprises: the TCP packet loss is detected based at least in part on the packet having a zero payload or a dummy payload.

Aspect 25: the method of any of aspects 14-24, wherein the detecting of TCP packet loss comprises: the TCP packet loss is detected based at least in part on expiration of a PDCP timer of the UE.

Aspect 26: the method of any of aspects 14-25, wherein the detecting of the TCP packet loss comprises: radio Link Control (RLC) packet loss is detected.

Aspect 27: an apparatus for wireless communication at a device, the apparatus comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method according to one or more of aspects 1 to 13.

Aspect 28: an apparatus for wireless communication, the apparatus comprising a memory and one or more processors coupled to the memory, the one or more processors configured to perform the method of one or more of aspects 1-13.

Aspect 29: an apparatus for wireless communication, the apparatus comprising at least one means for performing the method of one or more of aspects 1-13.

Aspect 30: a non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method of one or more of aspects 1-13.

Aspect 31: a non-transitory computer-readable medium storing a set of instructions for wireless communication, the set of instructions comprising one or more instructions that, when executed by one or more processors of a device, cause the device to perform the method of one or more of aspects 1-13.

Aspect 32: an apparatus for wireless communication at a device, the apparatus comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method according to one or more of aspects 14 to 26.

Aspect 33: an apparatus for wireless communication, the apparatus comprising a memory and one or more processors coupled to the memory, the one or more processors configured to perform the method of one or more of aspects 14-26.

Aspect 34: an apparatus for wireless communication, the apparatus comprising at least one means for performing the method of one or more of aspects 14-26.

Aspect 35: a non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method of one or more of aspects 14-26.

Aspect 36: a non-transitory computer-readable medium storing a set of instructions for wireless communication, the set of instructions comprising one or more instructions that, when executed by one or more processors of a device, cause the device to perform a method according to one or more of aspects 14-26.

The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the aspects to the precise form disclosed. Modifications and variations are possible in light of the above disclosure or may be acquired from practice of the aspects.

As used herein, the term "component" is intended to be broadly interpreted as hardware and/or a combination of hardware and software. "software" shall be construed broadly to mean instructions, instruction sets, code segments, program code, programs, subroutines, software modules, applications, software packages, routines, subroutines, objects, executable files, threads of execution, programs, and/or functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. As used herein, a "processor" is implemented in hardware and/or a combination of hardware and software. It is apparent that the systems and/or methods described herein may be implemented in different forms of hardware and/or combinations of hardware and software. The actual specialized control hardware or software code used to implement the systems and/or methods is not limiting of these aspects. Thus, the operation and behavior of the systems and/or methods were described without reference to the specific software code because one of ordinary skill in the art would understand that software and hardware could be designed to implement the systems and/or methods based at least in part on the description herein.

As used herein, a "meeting a threshold" may refer to a value greater than a threshold, greater than or equal to a threshold, less than or equal to a threshold, not equal to a threshold, etc., depending on the context.

Although specific combinations of features are recited in the claims and/or disclosed in the specification, such combinations are not intended to limit the disclosure of the various aspects. Many of these features may be combined in ways not specifically recited in the claims and/or disclosed in the specification. The disclosure of the various aspects includes each dependent claim combined with each other claim in the claim set. As used herein, a phrase referring to "at least one" of a list of items refers to any combination of these items, including individual members. As an example, "at least one of a, b, or c" is intended to encompass a, b, c, a + b, a + c, b + c, and a + b + c, as well as any combinations with multiples of the same element (e.g., a+a, a+a+a, a+a+b, a+a+c a+b+b, a+c+c, b+b, b+b+b a+b+b, a+c+c b+b, b+b+b.

No element, act, or instruction used herein should be construed as critical or essential unless explicitly described as such. Furthermore, as used herein, the articles "a" and "an" are intended to include one or more items, and may be used interchangeably with "one or more". Furthermore, as used herein, the article "the" is intended to include one or more items referenced in relation to the article "the" and may be used interchangeably with one or more. Furthermore, as used herein, the terms "set" and "group" are intended to include one or more items, and may be used interchangeably with "one or more". If only one item is intended to be used, the phrase "only one" or similar language is used. Furthermore, as used herein, the term "having (has, have, having)" and the like are intended to be open terms that do not limit the element to which they modify (e.g., the element "having" a may also have B). Furthermore, the phrase "based on" is intended to mean "based, at least in part, on" unless explicitly stated otherwise. Furthermore, as used herein, the term "or" when used in a series is intended to be inclusive and interchangeable with "and/or" unless explicitly stated otherwise (e.g., if used in combination with "any" or "only one of).

Claims

1. A User Equipment (UE) for wireless communication, the UE comprising:

a memory; and

one or more processors coupled to the memory, the one or more processors configured to:

detecting Transmission Control Protocol (TCP) packet loss based at least in part on a Packet Data Convergence Protocol (PDCP) payload of the packet; and

a plurality of retransmission requests for the packet is sent based at least in part on the detection of the TCP packet loss for the packet.

2. The UE of claim 1, wherein the one or more processors for sending the plurality of retransmission requests are configured to:

a set of repetitions of a duplicate acknowledgement is sent based at least in part on detection of the TCP packet loss of the packet.

3. The UE of claim 2, wherein the set of repetitions is transmitted by a modem associated with a PDCP entity of the UE.

4. The UE of claim 2, wherein the set of repetitions is transmitted by a hardware or software component of an Internet Protocol (IP) packet processing entity.

5. The UE of claim 2, wherein the set of repetitions is transmitted by a high-level operating system entity.

6. The UE of claim 2, wherein the set of repetitions is transmitted by a TCP entity.

7. The UE of claim 1, wherein the one or more processors to detect the TCP packet loss are configured to:

the TCP packet loss is detected based at least in part on a size of the PDCP payload or a content of the PDCP payload.

8. The UE of claim 1, wherein the detection of TCP packet loss comprises:

the TCP packet loss is detected based at least in part on an inspection of a header of the PDCP payload.

9. The UE of claim 8, wherein the checking of the header of the PDCP payload is performed using hardware or software components of an Internet Protocol (IP) packet processing entity.

10. The UE of claim 1, wherein the detection of TCP packet loss comprises:

the TCP packet loss is detected based at least in part on the packet being invalid.

11. The UE of claim 1, wherein the detection of TCP packet loss comprises:

the TCP packet loss is detected based at least in part on the packet having a zero payload or a dummy payload.

12. The UE of claim 1, wherein the detection of TCP packet loss comprises:

the TCP packet loss is detected based at least in part on expiration of a PDCP timer of the UE.

13. The UE of claim 1, wherein the detection of TCP packet loss comprises:

radio Link Control (RLC) packet loss is detected.

14. A User Equipment (UE) for wireless communication, the UE comprising:

a memory; and

detecting a Transmission Control Protocol (TCP) packet loss based at least in part on a TCP sequence and without a Packet Data Convergence Protocol (PDCP) loss; and

15. The UE of claim 14, wherein the one or more processors for sending the plurality of retransmission requests are configured to:

16. The UE of claim 15, wherein the set of repetitions is transmitted by a modem associated with a PDCP entity of the UE.

17. The UE of claim 15, wherein the set of repetitions is transmitted by a hardware or software component of an Internet Protocol (IP) packet processing entity.

18. The UE of claim 15, wherein the set of repetitions is transmitted by a high-level operating system entity.

19. The UE of claim 15, wherein the set of repetitions is transmitted by a TCP entity.

20. A method of wireless communication performed by a User Equipment (UE), the method comprising:

21. The method of claim 20, wherein the transmission of the plurality of retransmission requests comprises:

22. The method of claim 21, wherein the set of repetitions is transmitted by a modem associated with a PDCP entity of the UE.

23. The method of claim 21, wherein the set of repetitions is transmitted by a hardware or software component of an Internet Protocol (IP) packet processing entity.

24. The method of claim 21, wherein the set of repetitions is transmitted by a high-level operating system entity.

25. The method of claim 21, wherein the set of repetitions is transmitted by a TCP entity.

26. The method of claim 20, wherein the detecting of the TCP packet loss comprises:

27. The method of claim 20, wherein the detecting of the TCP packet loss comprises:

28. The method of claim 27, wherein the checking of the header of the PDCP payload is performed using hardware or software components of an Internet Protocol (IP) packet processing entity.

29. A method of wireless communication performed by a User Equipment (UE), the method comprising:

30. The method of claim 29, wherein the transmission of the plurality of retransmission requests comprises: