CN117134865A

CN117134865A - Communication method and device

Info

Publication number: CN117134865A
Application number: CN202210827300.1A
Authority: CN
Inventors: 张彦清; 姚楚婷; 李雪茹
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2022-05-17
Filing date: 2022-07-13
Publication date: 2023-11-28

Abstract

The application relates to a communication method and a communication device. The sending equipment compresses the first original data by using the first cache to obtain first compressed data, wherein the first cache is a cache corresponding to the UDC. The transmitting device transmits the first compressed data to the receiving device at a first time. The sending device receives first feedback information from the receiving device at a second moment, and indicates that the first compressed data is successfully received, wherein the first feedback information is physical layer feedback information or MAC layer feedback information. And the sending equipment updates the first buffer memory at a third moment according to the first original data to obtain a second buffer memory. The feedback mechanism corresponding to the first feedback information is utilized to feed back the successful or failed data receiving corresponding to the uplink compression technology, and the feedback mechanism of other protocol layers (such as a PDCP layer and the like) is not needed to be introduced, so that the feedback resource expenditure is reduced on the basis of ensuring the transmission reliability.

Description

Communication method and device

Cross Reference to Related Applications

The present application claims priority from the chinese patent application filed at month 17 of 2022, the chinese national intellectual property agency, application No. 202210538050.X, application name "an upstream compression transmission method", the entire contents of which are incorporated herein by reference.

Technical Field

The present application relates to the field of communications technologies, and in particular, to a communications method and apparatus.

Background

In order to meet the increasing rate demands of networks, it is becoming particularly important to improve the spectrum usage of different services, especially uplink transmission services. In order to alleviate the problem of uplink capacity limitation, an enhancement scheme adopting an uplink compression (uplink data compression, UDC) technology is proposed, which aims to reduce the size of each uplink data packet by compressing the uplink data packet, thereby reducing the rate requirement of uplink transmission and improving the capacity of uplink transmission.

Existing UDC techniques are commonly used for the packet data convergence protocol (packet data convergence protocol, PDCP) layer. The application mechanism of the UDC technology is that a transmitting end transmits UDC data to a receiving end, wherein the UDC data is carried in a PDCP packet. The receiving end may determine which PDCP packets failed to receive according to a Sequence Number (SN) included in a header of the received PDCP packet, and then the receiving end may transmit a PDCP control (control) protocol data unit (protocol data unit, PDU) to the transmitting end to indicate the PDCP packets failed to receive. After receiving the PDCP control PDU, the transmitting end may retransmit the PDCP packet with failed reception.

Such a mechanism as above is equivalent to adding a retransmission mechanism at the PDCP layer. However, at present, there are retransmission mechanisms in other protocol layers, and after adding the PDCP retransmission mechanism, the retransmission mechanism is equivalent to two layers, which may cause multiple retransmissions of the same UDC data, and waste transmission resources.

Disclosure of Invention

The embodiment of the application provides a communication method and a communication device, which are used for saving transmission resources.

In a first aspect, a communication method is provided, which method may be performed by a transmitting device, or by another device comprising the functions of the transmitting device, or by a chip system or other functional module capable of implementing the functions of the transmitting device, which chip system or functional module is for example provided in the transmitting device. The transmitting device is, for example, a terminal device in air interface communication, a terminal device in sidestream communication, or an STA in WiFi communication. The method comprises the following steps: compressing first original data by using a first cache to obtain first compressed data, wherein the first cache is a cache corresponding to UDC; transmitting the first compressed data to a receiving device at a first time; receiving first feedback information from the receiving device at a second moment, wherein the first feedback information is used for indicating that the first compressed data is successfully received, and the first feedback information is physical layer feedback information or MAC layer feedback information; responding to the first feedback information, updating the first buffer memory at a third moment according to the first original data to obtain a second buffer memory, wherein the second buffer memory comprises the first original data; wherein the second time is later than the first time and the third time is later than the second time.

In the embodiment of the application, the data receiving success or failure corresponding to the uplink compression technology can be fed back by utilizing the feedback mechanism corresponding to the first feedback information, and the feedback mechanism of other protocol layers (such as a PDCP layer and the like) is not needed to be introduced, so that the cost of feedback resources is reduced on the basis of ensuring the transmission reliability.

In an alternative embodiment, the method further comprises: and sending first information at a fourth time, wherein the first information comprises first indication information, the first indication information is used for indicating the receiving equipment to update a third buffer memory to obtain a fourth buffer memory, data contained in the third buffer memory are identical to data contained in the first buffer memory, data contained in the fourth buffer memory are identical to data contained in the second buffer memory, and the fourth time is later than the second time. The receiving device also maintains a buffer corresponding to the UDC, for example, a third buffer, and then the sending device may instruct the receiving device to update the third buffer through the first indication information, so that the update time of the buffer by the receiving device is consistent with the update time of the buffer by the sending device, and the consistency of the buffers at both ends is maintained.

In an alternative embodiment, the method further comprises: and receiving second feedback information at a fifth moment, wherein the second feedback information is used for indicating whether the first information is successfully received or not, and the fifth moment is later than the fourth moment. The receiving device may transmit the second feedback information to the transmitting device so that the transmitting device can determine whether the first information reception succeeds or fails.

In an alternative embodiment, when the second feedback information is a first value, the second feedback information is used to indicate that the first information is received successfully; or when the second feedback information is a second value, the second feedback information is used for indicating that the first information fails to be received. For example, a first value is "1" and a second value is "0"; alternatively, the first value is "ACK" and the second value is "NACK"; alternatively, the first value is "true", the second value is "false", and so on.

In an alternative embodiment, updating the first buffer at a third time according to the first raw data to obtain a second buffer includes: and when the second feedback information is the first value, updating the first buffer memory at the third moment according to the first original data to obtain the second buffer memory, wherein the third moment is later than the fifth moment. If the second feedback information is the first value, the sending device may determine that the receiving device has successfully received the first information, and the sending device may infer that the receiving device has been able to determine that the third cache needs to be updated. In this case, the sending device updates the first buffer again, which is equivalent to the sending device downloading the first buffer when determining that the receiving device can update the third buffer, which is beneficial to maintaining the consistency of the buffers at both ends.

In an alternative embodiment, the first information further includes second indication information, where the second indication information is used to indicate second compressed data, and the second compressed data is generated according to the second cache. The first information may also indicate second compressed data, e.g. the first information comprises second compressed data, e.g. the next compressed data to the first compressed data. That is, the transmitting device may instruct the receiving device to update the third buffer using the information for transmitting the next compressed data, and it is not necessary to transmit additional information for instructing the receiving device to update the third buffer, which is advantageous in saving transmission overhead.

In an alternative embodiment, the first information further includes second indication information, where the second indication information is used to indicate second compressed data, and the second compressed data is generated according to the first buffer. The sending device can update the first buffer memory to obtain a second buffer memory, and then compress the second buffer memory to obtain second compressed data according to the second buffer memory, so that the buffer memory can be updated in time; or, the sending device may not update the first buffer temporarily, but continue to compress the first buffer to obtain the second compressed data, for example, the sending device may update the first buffer after receiving the second feedback information, so that the sending device may update the first buffer after determining that the receiving device can update the third buffer, which is beneficial to maintaining consistency of the buffers at both ends.

In an alternative embodiment, the method further comprises: and sending second information, wherein the second information is used for indicating the first time length, so that the third time is equal to or later than the time after the first time length is added to the fourth time, or the third time is equal to or later than the time after the first time length is added to the fifth time. Generally, the time when the receiving device sends the feedback information is usually later than the time when the receiving device receives the compressed data, if the sending device receives the second feedback information and then updates the first buffer, and the receiving device receives the first indication information and then can update the third buffer, the update timing of the receiving device for the third buffer may not be consistent with the update timing of the sending device for the first buffer. For this purpose, a first time period may be set, for example, after the receiving device receives information for indicating to update the cache (for example, first indication information), the receiving device may wait for the first time period to update the formal cache; accordingly, when the transmitting device receives information (e.g., the second feedback information) indicating that the new compressed data has been received successfully, the transmitting device may also wait for the first time period to update the formal cache. By setting the first duration, the update time of the sending device and the receiving device for the cache can be kept consistent.

In an alternative embodiment, the first indication information is used to indicate a sequence number of the first compressed data. The first indication information may indicate a sequence number of the first compressed data, which corresponds to indicating that the receiving apparatus updates the third buffer according to the first compressed data. It can be seen that this indication is simpler and more definite.

In an alternative embodiment, the first indication information is a sequence number of the first compressed data. The first indication information is to indicate a sequence number of the first compressed data, for example in such a way that the first indication information comprises the sequence number of the first compressed data. In addition, the first indication information may indicate the sequence number of the first compressed data in other manners, which is not limited in the embodiment of the present application.

In an optional implementation manner, the first compressed data includes M compressed data arranged according to a sequence number, the first indication information is a sequence number of a last compressed data in the M compressed data, and M is a positive integer. For example, the receiving device can make sure by including the sequence number of the last compressed data in the first indication information, where the compressed data corresponding to the sequence number included in the first indication information and the compressed data corresponding to the sequence number before the sequence number are used to update the third buffer. In the indication mode, the first indication information comprises a serial number, so that the cost of the first information is saved.

In an alternative embodiment, the first compressed data includes M compressed data arranged according to a sequence number, the first information includes at least one set of fields, one set of fields in the at least one set of fields includes a start field and an end field, the start field includes a sequence number of a first compressed data in the set of compressed data in the M compressed data, the end field includes a sequence number of a last compressed data in the set of compressed data, and the set of compressed data is compressed data with consecutive sequence numbers. For example, there may be a discontinuity in sequence numbers of adjacent compressed data among the M compressed data, and then this implementation may be employed. In this way, the multiple sets of fields respectively include serial numbers of different compressed data, wherein one set of fields includes a set of continuous serial numbers, and the serial numbers of the different sets of fields include discontinuous serial numbers, so that the first indication information can completely indicate the M compressed data. And the field set only comprises the sequence number of the first compressed data and the last compressed data in a set of continuous compressed data, and the sequence number of each compressed data is not needed to be included, so that the overhead of the first information is saved.

In an alternative embodiment, the first compressed data includes M compressed data arranged according to a sequence number, the first information includes at least one set of fields, one set of fields in the at least one set of fields includes a start field and an offset field, the start field includes a sequence number of a first compressed data in the set of compressed data in the M compressed data, and the offset field includes an offset between a sequence number of a last compressed data in the set of compressed data and a sequence number of the first compressed data, and the set of compressed data is compressed data with consecutive sequence numbers. Such an implementation may be employed, for example, where there may be a discontinuity in sequence numbers of adjacent compressed data in the M compressed data. In this way, the set of fields may include the sequence number of the first compressed data in the set of compressed data, and an offset between the last compressed data and the first compressed data, which may be smaller than the sequence number of the last compressed data, thus saving the overhead of the first information even further.

In an alternative embodiment, the first compressed data includes M compressed data arranged according to a sequence number, the first information includes a first set of fields including a start field and an end field, the start field includes a sequence number of a first compressed data in a set of compressed data in the M compressed data, the end field includes a sequence number of a last compressed data in the set of compressed data, the set of compressed data is compressed data having a continuous sequence number, the second set of fields includes a sequence number field including a sequence number of one compressed data in the M compressed data, and M is an integer greater than or equal to 2. Such an implementation may also be employed, for example, where there may be a discontinuity in sequence numbers of adjacent compressed data in the M compressed data. Wherein, for example, there are multiple sets of compressed data in the M compressed data, where at least one set of compressed data may include only one compressed data, and if the one compressed data is also indicated by two fields, the resource overhead is wasted. Thus, for one compressed data, this may be indicated by a sequence number field, whereas if a set of compressed data comprises a plurality of compressed data, this may be indicated by a format similar to the first set of fields. In this way, the first indication information can indicate not only the M compressed data but also the overhead is small.

In an alternative embodiment, the first compressed data includes M compressed data, the first information includes at least one set of fields, one set of fields in the at least one set of fields includes a sequence number of N compressed data, the N compressed data are compressed data with continuous sequence numbers, the remaining fields in the at least one set of fields include sequence numbers of N-M compressed data, the M compressed data are compressed data remaining after excluding the N-M compressed data from the N compressed data, and N is an integer greater than or equal to M. In this way, the sequence number of the N compressed data may be indicated by a set of fields, and then the sequence number of the N-M compressed data may be indicated by the remaining fields, which is equivalent to excluding the N-M compressed data from the N compressed data, thus indicating the M compressed data. For example, if the number of N-M is small, this way of indication is advantageous for saving the overhead of the first information.

In an alternative embodiment, the first information further includes second indication information, and the second indication information is used to indicate second compressed data. The first information may also indicate second compressed data, e.g. the first information comprises second compressed data, e.g. the next compressed data to the first compressed data. That is, the transmitting device may instruct the receiving device to update the third buffer using the information for transmitting the next compressed data, and it is not necessary to transmit additional information for instructing the receiving device to update the third buffer, which is advantageous in saving transmission overhead.

In an alternative embodiment, the first indication information is used to indicate an offset between a sequence number of the first compressed data and a sequence number of the second compressed data. In the case where the first information includes the second indication information, the first indication information may also indicate the first compressed data by indicating an offset between a sequence number of the first compressed data and a sequence number of the second compressed data. The amount of data of the offset may be smaller than the amount of data of the sequence number of the first compressed data, and the overhead of the first information can be reduced by indicating the offset.

In a second aspect, another communication method is provided, which may be performed by a receiving device, or by another device comprising the functionality of the receiving device, or by a chip system or other functional module capable of implementing the functionality of the receiving device, the chip system or functional module being for example provided in the receiving device. The receiving device is, for example, an access network device in air interface communication, or a terminal device in sidestream communication, or an AP in WiFi communication, etc. The method comprises the following steps: receiving first compressed data from a transmitting device at a first time; transmitting first feedback information to the transmitting device at a second moment, wherein the first feedback information is used for indicating that the first compressed data is successfully received, and the first feedback information is physical layer feedback information or MAC layer feedback information; updating a third buffer memory at a sixth moment according to the first compressed data to obtain a fourth buffer memory, wherein the fourth buffer memory comprises first original data obtained by decompressing the first compressed data, and the third buffer memory is a buffer memory corresponding to an uplink compression technology UDC; wherein the second time is later than the first time, and the sixth time is later than the second time.

In an alternative embodiment, the method further comprises: and receiving first information at a fourth time, wherein the first information comprises first indication information, the first indication information is used for indicating the receiving equipment to update the third buffer to obtain the fourth buffer, and the fourth time is later than the second time.

In an alternative embodiment, the method further comprises: and sending second feedback information at a fifth moment, wherein the second feedback information is used for indicating whether the first information is successfully received or not, and the fifth moment is later than the fourth moment.

In an alternative embodiment, when the second feedback information is a first value, the second feedback information is used to indicate that the first information is received successfully; or when the second feedback information is a second value, the second feedback information is used for indicating that the first information fails to be received.

In an alternative embodiment, updating the third buffer at the sixth time according to the first compressed data to obtain the fourth buffer includes: and when the first information is successfully received, updating the third buffer memory at the sixth moment according to the first compressed data to obtain the fourth buffer memory.

In an alternative embodiment, the first information further includes second indication information, where the second indication information is used to indicate second compressed data, and the second compressed data is generated according to the second cache.

In an alternative embodiment, the first information further includes second indication information, where the second indication information is used to indicate second compressed data, and the second compressed data is generated according to the first buffer.

In an alternative embodiment, the method further comprises: and receiving second information, wherein the second information is used for indicating a first duration, so that the sixth moment is equal to or later than the moment after the first duration is added to the fourth moment, or so that the sixth moment is equal to or later than the moment after the first duration is added to the fifth moment.

In an alternative embodiment, the first indication information is used to indicate a sequence number of the first compressed data.

In an alternative embodiment, the first indication information is a sequence number of the first compressed data.

In an optional implementation manner, the first compressed data includes M compressed data arranged according to a sequence number, the first indication information is a sequence number of a last compressed data in the M compressed data, and M is a positive integer.

In an alternative embodiment, the first compressed data includes M compressed data arranged according to a sequence number, the first information includes at least one set of fields, one set of fields in the at least one set of fields includes a start field and an end field, the start field includes a sequence number of a first compressed data in the set of compressed data in the M compressed data, the end field includes a sequence number of a last compressed data in the set of compressed data, and the set of compressed data is compressed data with consecutive sequence numbers.

In an alternative embodiment, the first compressed data includes M compressed data arranged according to a sequence number, the first information includes at least one set of fields, one set of fields in the at least one set of fields includes a start field and an offset field, the start field includes a sequence number of a first compressed data in the set of compressed data in the M compressed data, and the offset field includes an offset between a sequence number of a last compressed data in the set of compressed data and a sequence number of the first compressed data, and the set of compressed data is compressed data with consecutive sequence numbers.

In an alternative embodiment, the first compressed data includes M compressed data arranged according to a sequence number, the first information includes a first set of fields including a start field and an end field, the start field includes a sequence number of a first compressed data in a set of compressed data in the M compressed data, the end field includes a sequence number of a last compressed data in the set of compressed data, the set of compressed data is compressed data having a continuous sequence number, the second set of fields includes a sequence number field including a sequence number of one compressed data in the M compressed data, and M is an integer greater than or equal to 2.

In an alternative embodiment, the first compressed data includes M compressed data, the first information includes at least one set of fields, one set of fields in the at least one set of fields includes a sequence number of N compressed data, the N compressed data are compressed data with continuous sequence numbers, the remaining fields in the at least one set of fields include sequence numbers of N-M compressed data, the M compressed data are compressed data remaining after excluding the N-M compressed data from the N compressed data, and N is an integer greater than or equal to M.

In an alternative embodiment, the first information further includes second indication information, where the second indication information is used to indicate second compressed data, and the first indication information is used to indicate an offset between a sequence number of the first compressed data and a sequence number of the second compressed data.

Regarding the technical effects brought about by the second aspect or various alternative embodiments, reference may be made to the description of the technical effects of the first aspect or corresponding embodiments.

In a third aspect, a communication device is provided. The communication device may be the transmitting apparatus described in the first aspect, or a communication apparatus including the transmitting apparatus, or a functional module in the transmitting apparatus, such as a baseband device or a chip system, etc. In an alternative implementation, the communication device includes a baseband device and a radio frequency device. In another alternative implementation, the communication device includes a processing unit (sometimes also referred to as a processing module) and a transceiver unit (sometimes also referred to as a transceiver module). The transceiver unit can realize a transmission function and a reception function, and may be referred to as a transmission unit (sometimes referred to as a transmission module) when the transceiver unit realizes the transmission function, and may be referred to as a reception unit (sometimes referred to as a reception module) when the transceiver unit realizes the reception function. The transmitting unit and the receiving unit may be the same functional module, which is called a transceiver unit, and which can implement a transmitting function and a receiving function; alternatively, the transmitting unit and the receiving unit may be different functional modules, and the transmitting and receiving unit is a generic term for these functional modules.

The processing unit is used for compressing first original data by using a first cache to obtain first compressed data, wherein the first cache is a cache corresponding to the UDC; the transceiver unit (or the transmitting unit) is configured to transmit the first compressed data to a receiving device at a first time; the receiving and transmitting unit (or the receiving unit) is configured to receive first feedback information from the receiving device at a second moment, where the first feedback information is used to indicate that the first compressed data is received successfully, and the first feedback information is physical layer feedback information or MAC layer feedback information; the processing unit is further configured to update the first buffer at a third time according to the first original data in response to the first feedback information, and obtain a second buffer, where the second buffer includes the first original data. Wherein the second time is later than the first time and the third time is later than the second time.

In an alternative embodiment, the communication apparatus further comprises a storage unit (sometimes also referred to as a storage module), and the processing unit is configured to be coupled to the storage unit and execute a program or instructions in the storage unit, so that the communication apparatus performs the function of the transmitting device according to the first aspect.

In a fourth aspect, another communication device is provided. The communication device may be the receiving apparatus described in the second aspect, or a communication apparatus including the receiving apparatus, or a functional module in the receiving apparatus, such as a baseband device or a chip system, etc. The communication device comprises a processing unit (sometimes also referred to as processing module) and a transceiver unit (sometimes also referred to as transceiver module), the description of which may be referred to in relation to the third aspect.

Wherein the transceiver unit (or the receiving unit) is configured to receive first compressed data from a transmitting device at a first time; the receiving and transmitting unit (or the transmitting unit) is configured to send first feedback information to the transmitting device at a second moment, where the first feedback information is used to indicate that the first compressed data is successfully received, and the first feedback information is physical layer feedback information or MAC layer feedback information; the processing unit is configured to update a third buffer at a sixth time according to the first compressed data to obtain a fourth buffer, where the fourth buffer includes first raw data obtained by decompressing the first compressed data, and the third buffer is a buffer corresponding to the UDC. Wherein the second time is later than the first time, and the sixth time is later than the second time.

In an alternative embodiment, the communication apparatus further comprises a storage unit (sometimes also referred to as a storage module), and the processing unit is configured to be coupled to the storage unit and execute a program or instructions in the storage unit, so that the communication apparatus performs the function of the receiving device described in the second aspect.

In a fifth aspect, there is provided a further communication apparatus, which may be a transmitting device, or a chip or chip system for use in a transmitting device; alternatively, the communication means may be a receiving device or a chip or chip system for use in a receiving device. The communication device comprises a communication interface and a processor, and optionally a memory. Wherein the memory is configured to store a computer program, and the processor is coupled to the memory and the communication interface, and when the processor reads the computer program or instructions, the processor causes the communication apparatus to perform the method performed by the transmitting device or the receiving device in the above aspects.

A sixth aspect provides a communication system comprising a transmitting device for performing the communication method according to the first aspect and a receiving device for performing the communication method according to the second aspect.

In a seventh aspect, a computer readable storage medium is provided for storing a computer program or instructions that, when executed, cause a transmitting device or a receiving device of the above aspects to perform a method.

In an eighth aspect, there is provided a computer program product comprising instructions which, when run on a computer, cause the method of the above aspects to be carried out.

In a ninth aspect, a chip system is provided, including a processor and an interface, where the processor is configured to invoke and execute instructions from the interface, so that the chip system implements the methods of the above aspects.

Drawings

Fig. 1A is a schematic diagram of a PDCP header and a UDC header;

fig. 1B is a schematic diagram of a UDC header of a control PDU;

FIG. 1C is a schematic diagram of an application mechanism of the UDC technique;

fig. 2 is a schematic diagram of an application scenario according to an embodiment of the present application;

fig. 3, fig. 6, and fig. 7 are several flowcharts of a communication method according to an embodiment of the present application;

FIGS. 4A and 4B are two flowcharts of a data transceiving process according to an embodiment of the present application;

FIG. 5 is a schematic diagram illustrating the operation of the primary cache and the backup cache according to an embodiment of the present application;

FIG. 8 is a timing diagram of a data transmission process;

Fig. 9A to 9J are schematic diagrams of several implementations of the first indication information according to the embodiments of the present application;

FIG. 10 is a schematic diagram of an apparatus according to an embodiment of the present application;

fig. 11 is a schematic view of yet another apparatus according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application more apparent, the embodiments of the present application will be described in further detail with reference to the accompanying drawings.

In the embodiments of the present application, the number of nouns, unless otherwise indicated, means "a singular noun or a plural noun", i.e. "one or more". "at least one" means one or more, and "a plurality" means two or more. "and/or", describes an association relationship of an association object, and indicates that there may be three relationships, for example, a and/or B, and may indicate: a alone, a and B together, and B alone, wherein a, B may be singular or plural. The character "/" generally indicates that the context-dependent object is an "or" relationship. For example, A/B, means: a or B. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). For example, at least one (one) of a, b, or c, represents: a, b, c, a and b, a and c, b and c, or a and b and c, wherein a, b, c may be single or plural.

The ordinal terms such as "first," "second," and the like in the embodiments of the present application are used for distinguishing a plurality of objects, and are not used for limiting the size, content, sequence, timing, priority, importance, and the like of the plurality of objects. For example, the first radio resource control (radio resource control, RRC) request message and the second RRC request message may be the same message or different messages, and such names do not indicate the difference in content, size, application scenario, transmitting/receiving end, priority, importance, or the like of the two messages. In addition, the numbers of the steps in the embodiments described in the present application are only for distinguishing different steps, and are not used for limiting the sequence of the steps. For example, S301 may occur before S302, or may occur after S302, or may also occur concurrently with S302.

In the following, some terms or concepts in the embodiments of the present application are explained for easy understanding by those skilled in the art.

In the embodiment of the application, the terminal device is a device with a wireless transceiver function, and may be a fixed device, a mobile device, a handheld device (such as a mobile phone), a wearable device, a vehicle-mounted device, or a wireless apparatus (such as a communication module, a modem, or a chip system) built in the device. The terminal device is used for connecting people, objects, machines and the like, and can be widely used in various scenes, including but not limited to the following scenes: cellular communication, device-to-device communication (D2D), internet of vehicles (vehicle to everything, V2X), machine-to-machine/machine-type communications, M2M/MTC), internet of things (internet of things, ioT), virtual Reality (VR), augmented reality (augmented reality, AR), industrial control (industrial control), unmanned aerial vehicle (self driving), remote medical (remote media), smart grid (smart grid), smart furniture, smart office, smart wear, smart transportation, smart city (smart city), unmanned aerial vehicle, robotic, etc. in a scene. The terminal device may sometimes be referred to as a UE, a terminal, an access station, a UE station, a remote station, a wireless communication device, or a user equipment, among others. For convenience of description, in the embodiment of the present application, a UE is taken as an example for illustrating a terminal device.

The network device in the embodiment of the application comprises an access network device and/or a core network device. The access network equipment is equipment with a wireless receiving and transmitting function and is used for communicating with the terminal equipment. The access network devices include, but are not limited to, base stations (base transceiver stations (base transceiver station, BTS), node B, eNodeB/eNB, or gNodeB/gNB), transceiver points (transmission reception point, TRP), base stations for subsequent evolution of the third generation partnership project (3rd generation partnership project,3GPP), access nodes in wireless fidelity (wireless fidelity, wi-Fi) systems, wireless relay nodes, wireless backhaul nodes, and the like. The base station may be: macro base station, micro base station, pico base station, small station, relay station, etc. Multiple base stations may support networks of the same access technology or may support networks of different access technologies. A base station may comprise one or more co-sited or non-co-sited transmission reception points. The access network device may also be a radio controller, a Centralized Unit (CU), and/or a Distributed Unit (DU) in the context of a cloud radio access network (cloud radio access network, CRAN). The access network device may also be a server or the like. For example, the network device in the vehicle-to-everything (vehicle to everything, V2X) technology may be a Road Side Unit (RSU). The following describes an access network device using a base station as an example. The base station may communicate with the terminal device or may communicate with the terminal device through the relay station. A terminal device may communicate with multiple base stations in different access technologies. The core network device is used for realizing the functions of mobile management, data processing, session management, policy and charging, etc. The names of devices implementing the core network function in the systems of different access technologies may be different, and the embodiment of the present application is not limited to this. Taking a 5G system as an example, the core network device includes: access and mobility management functions (access and mobility management function, AMF), session management functions (session management function, SMF), policy control functions (policy control function, PCF) or user plane functions (user plane function, UPF), etc.

In the embodiment of the present application, the communication device for implementing the function of the network device may be a network device, or may be a device capable of supporting the network device to implement the function, for example, a chip system, and the device may be installed in the network device. In the technical solution provided in the embodiment of the present application, the device for implementing the function of the network device is exemplified by the network device, and the technical solution provided in the embodiment of the present application is described.

The UDC may enable new data to be compressed based on previously compressed data, thereby reducing data transmission rate requirements. For example, for a certain service, there is a strong similarity between the data, so new data can be compressed with reference to the compressed data to reduce the packet capacity. For example, when browsing web pages or watching video, uplink data mainly includes transmission control protocol (transmission control protocol, TCP) feedback data or text description data, and a large number of repetitive characters easily occur between the data, for example, among the data of the TCP feedback data, the actual content (acknowledgement (ACK) or Negative Acknowledgement (NACK)) is mostly internet protocol (internet protocol, IP) packet header content, such as IP address, and the like, which are basically unchanged for the same service. Therefore, UDC can be adopted, and transmission of repeated characters is reduced by the following manner based on the foregoing compression coding, thereby reducing the capacity of the data packet. Further, for the services such as browsing web pages, the text content carried by different data can be considered to have higher repetition rate, and the repeated transmission of text data can be reduced by UDC, so that the capacity of data packets is reduced.

For UDCs, new data is compressed based on the compressed data. For example, the sender maintains a compression buffer (buffer), which may also be referred to as dictionary (dictionary), or considers that the compression buffer contains a dictionary. When new data (for example, called original data) is to be transmitted, the transmitting end may search the compression buffer for the same character as the character included in the original data, and compress the original data according to the searched character in the compression buffer to obtain compressed data. After the compressed data is obtained, the original data corresponding to the compressed data is written into the compressed buffer. Wherein the size of the compression buffer is fixed, e.g. 8K bytes or 32K bytes, etc. Thus, if the compression buffer is full, the newly written data will overflow the old data in the compression buffer, e.g., the earliest stored data in the compression buffer will be purged to write the new data. The receiving end also maintains a compression buffer, and after receiving the compressed data, the receiving end decompresses the compressed data based on the compression buffer. Therefore, in order to enable reliable transmission of UDC data, the states of the compression buffer at the receiving end and the compression buffer at the transmitting end should be kept identical, or the contents of the two compression buffers should be kept identical.

Existing UDC techniques are commonly used for PDCP layers in cellular networks. Fig. 1A illustrates a PDCP header (header) and a UDC header, and fig. 1A exemplifies that the length of PDCP SN is 12 bits (bits). In fig. 1A, the first 2 bytes are PDCP headers, the third byte is a UDC header, and the fourth byte may include UDC data. The "FU" field is used to indicate whether the data corresponding to the UDC packet header is subjected to UDC compression, the "FR" field is used to indicate whether the UDC compression buffer is reset, and the "check sum" field is used for the receiving end to check whether the UDC compression buffer is synchronous. If the receiving end does not pass the check for "checksum", the UDC buffers at the receiving and transmitting ends are not synchronized, and the receiving end may send a control PDU to the transmitting end, where the UDC packet header of the control PDU may refer to fig. 1B, where the "FE" field is used to indicate whether "checksum" passes. Illustratively, when the value of the "FE" field is "1", which indicates that "checksum" fails the check, the transmitting end may reset the UDC compression buffer of the transmitting end, and after resetting, send a data packet (packet header is shown in fig. 1A) using the reset UDC compression buffer, and the "FR" field in the packet header of the data packet informs the receiving end to reset the UDC compression buffer. After receiving the data packet, the receiving end can reset the UDC compression buffer, and process the data packet according to the reset UDC compression buffer.

For example, an application mechanism of the UDC technology may refer to fig. 1C. The transmitting end transmits 5 PDCP packets, namely PDCP packets 1 to 5, to the receiving end, wherein one PDCP packet carries one UDC data, and the UDC data carried by the PDCP packet is compressed data. The receiving end receives the PDCP packets 1 and 2 successfully, and the receiving end can update the compression buffer of the receiving end according to the UDC data included in the PDCP packets 1 and 2. And after receiving the PDCP packet 4, the receiving end finds that the PDCP packet 3 has not been received, and at this time, the receiving end cannot decompress the PDCP packet 4. The receiving end may transmit a PDCP control PDU to the transmitting end to indicate failure of reception of the PDCP packet 3. After receiving the PDCP control PDU, the transmitting end retransmits the PDCP packet 3, and after receiving the PDCP packet 3, the receiving end may update a compression buffer of the receiving end according to the UDC data carried by the PDCP packet 3, so as to decompress the PDCP packet 4 and subsequent PDCP packets through the updated compression buffer.

Such a communication procedure as above corresponds to adding a retransmission mechanism to the PDCP layer. But currently there are also retransmission mechanisms at other protocol layers, such as physical layer in the communication between UEs or between UEs and access network devices; or there is a feedback mechanism of the medium access control (media access control, MAC) layer in the communication of Stations (STAs) of a wireless fidelity (wireless fidelity, wiFi) system with Access Points (APs). Then after adding the retransmission mechanism of the PDCP layer, which is equivalent to having two layers of retransmission mechanisms, multiple retransmissions of the same UDC data may result, which is more wasteful of transmission resources.

In view of this, a technical solution of the embodiment of the present application is provided. In the embodiment of the present application, the first feedback information is physical layer feedback information or MAC layer feedback information, for example, the sending device and the receiving device are both terminal devices, or the sending device is a terminal device and the receiving device is an access network device, and then the first feedback information may be physical layer feedback information; for another example, the transmitting device is a STA, the receiving device is an AP, and the first feedback information may be MAC layer feedback information. It can be understood that, in the embodiment of the present application, the success or failure of data reception corresponding to the uplink compression technology can be fed back by using the feedback mechanism corresponding to the first feedback information, and no feedback mechanism of other protocol layers (such as PDCP layers) is required to be introduced, so that the probability of repetition of the feedback mechanism is reduced, and the transmission overhead is saved.

The technical solution provided in the embodiment of the present application may be applied to a fourth generation mobile communication technology (the 4th generation,4G) system, for example, a long term evolution (long term evolution, LTE) system, or may be applied to a 5G system, for example, an NR system, or may also be applied to a next generation mobile communication system or other similar communication systems, or may also be applied to a short-range communication system, for example, a WiFi system or other short-range communication systems, which is not specifically limited. In addition, the technical scheme provided by the embodiment of the application can be applied to device-to-device (D2D) scenes, such as NR-D2D scenes and the like, or can be applied to V2X scenes, such as NR-V2X scenes and the like. For example, the method can be applied to the Internet of vehicles, such as V2X and the like, or can be applied to the fields of intelligent driving, auxiliary driving, intelligent network vehicle connection and the like. If applied to the D2D scene, both communication parties can be UE; if applied to a cellular scenario, the sender of the communication may be a UE, the receiver a network device (e.g., an access network device), or both parties may be network devices; if applied to a short-range communication scenario, taking a WiFi scenario as an example, the sender of the communication may be a STA and the receiver an AP.

Fig. 2 is a schematic diagram of an application scenario according to an embodiment of the present application. Fig. 2 includes a transmitting device and a receiving device, e.g., both the transmitting device and the receiving device are UEs; or the sending equipment is UE, and the receiving equipment is access network equipment; alternatively, the transmitting device is an STA, and the receiving device is an AP.

In order to better describe the embodiments of the present application, the method provided by the embodiments of the present application is described below with reference to the accompanying drawings. In the drawings corresponding to the embodiments of the present application, the steps indicated by the broken lines are optional steps unless specifically described below. The "data" in the embodiments of the present application is data corresponding to an uplink compression technology, where the data may include original data and compressed data. For example, "raw data" refers to data before compression by an upstream compression technique, or refers to data obtained by decompression by an upstream compression technique; the "compressed data" refers to data obtained by compressing "raw data" by an upstream compression technique. The upstream compression technique is, for example, UDC technique, or other techniques capable of compression encoding based on the preamble by the following. In the following description, the uplink compression technique is exemplified by the UDC technique.

In various embodiments of the present application, if the technical solution of the embodiments of the present application is applied to SL communication or Uu interface communication, the "SN" and the "PDCP SN" may be the same concept and may be replaced with each other.

An embodiment of the present application provides a communication method, please refer to fig. 3, which is a flowchart of the method. The method can be applied to the network architecture shown in fig. 2, for example, the transmitting device involved in the method is the transmitting device in fig. 2, and the receiving device involved in the method is the receiving device in fig. 2.

S301, the sending device compresses first original data by using the first cache to obtain first compressed data. The first cache is, for example, a cache corresponding to the UDC technology, and may also be referred to as a UDC cache.

Referring to fig. 4A, a transmission and reception flow of data may be referred to. Fig. 4A illustrates an example in which both the transmitting device and the receiving device are UEs, or side-line transmission. Alternatively, the transmitting device and the receiving device may communicate via a Sidelink (SL), e.g., the radio link control (radio link control, RLC) layer may be a non-acknowledged mode (unacknowledged mode, UM) or a (transmission mode, TM); or the sending device is the UE, and the receiving device is the access network device. The first raw data may include one or more data to be transmitted, for example, data to be transmitted. If the first raw data includes a plurality of data, the plurality of data can be processed separately, and fig. 4A shows a process of processing one of the data included in the first raw data.

In fig. 4A, a transmitting device adds a sequence number to first raw data (for example, a step shown by "sequence number" in fig. 4A), and compresses (compacts) the first raw data to which the sequence number is added according to the UDC technology in the PDCP layer, for example, the transmitting device may compress the first raw data to which the sequence number is added using a first buffer, to obtain compressed data, for example, the first compressed data in the embodiment of the present application is the compressed data. After obtaining the compressed data, the PDCP layer may add a UDC header to the compressed data. Wherein the UDC header may refer to fig. 1A. The first raw data is associated with PDCP service data units (service data unit, SDUs), so that the PDCP layer packs the data to which the UDC header is added, performs operations such as integrity protection (integrity protection), ciphering (ciphering), and the like, adds a PDCP header (add PDCP header) to the result obtained by the operation, obtains a PDCP protocol data unit (protocol data unit, PDU) according to the result to which the PDCP header is added, and finally sends the PDCP protocol data unit (protocol data unit, PDU) to the RLC layer corresponding to the route (routing) shown in fig. 4A. The PDCP header may refer to fig. 1A. The RLC layer regards the received information as RLC SDUs. The RLC layer performs operations such as segmentation for the RLC SDU, adds an RLC header to the RLC SDU to obtain an RLC PDU, and transmits the RLC PDU to a medium access control (media access control, MAC) layer of the transmitting apparatus. The MAC layer adds a MAC packet header to the received data, and multiplexes the data to which the MAC packet header is added into a MAC PDU (MPDU). For example, in one multiplexing manner, the MAC layer may add data to which the MAC packet header is added to the MPDU, and the MPDU may include the data to which the MAC packet header is added. Among other things, the main function of the MAC layer is to multiplex (e.g., add) a plurality of data from an upper layer (e.g., RLC layer) into one MPDU and pass the MPDU to a Physical (PHY) layer. The physical layer performs cyclic redundancy check (cyclic redundancy check, CRC), channel coding, interleaving, rate matching, mapping, etc. on the MPDU, and maps the obtained data to a Transport Block (TB) for transmission.

The physical layer of the receiving device performs channel decoding on the received TB, and performs CRC decoding on the result obtained after the channel decoding. If the CRC decoding is passed, the receiving device may feed back an Acknowledgement (ACK) to the transmitting device through the physical layer according to a hybrid automatic repeat request (hybrid automatic repeat request, HARQ) mechanism, to indicate that the TB is successfully received; if the CRC decoding fails, the receiving device may feed back a Negative Acknowledgement (NACK) to the transmitting device through the physical layer to indicate that the TB has failed to receive. During transmission between the transmitting device and the receiving device, each TB may correspond to one HARQ process number, and typically the HARQ feedback result is also for the HARQ process. In addition, if the CRC decoding is successful, the physical layer of the receiving device delivers the decoding result to the MAC layer, and the MAC layer delivers the decoding result to the RLC layer after performing corresponding processing (e.g., removing the MAC header), and the RLC layer delivers the decoding result to the PDCP layer after performing corresponding processing (e.g., removing the RLC header). The PDCP layer may remove the PDCP header of the received information, decrypt (determine) the information from which the header is removed, verify (integrity verification) the integrity, and if the verification is passed, the PDCP layer may reorder (reorder) the received information, associate the reordered information to PDCP PDUs, remove the UDC header of the PDCP PDUs, decompress (decompress) the information from which the UDC header is removed according to the UDC technique, sequentially deliver and repeatedly detect (in order delivery and duplication detection) the decompressed data.

Fig. 4A further includes a flow of transmission and reception of control information. Unlike the data processing flow, if the PDCP layer has no associated PDCP SDU, such as PDCP control information, for the information to be transmitted, the PDCP layer of the transmitting device does not need to perform integrity protection and ciphering steps after adding a UDC header to the compressed PDCP control information, but adds a PDCP header to the information, and transmits the information to which the PDCP header is added to the RLC layer. Illustratively, one type of PDCP control information is a robust header interspersed with compressed feedback (interspersed robust header compression feedback, interspersed ROHC feedback) packets. In addition, if the receiving device determines that the corresponding packet is PDCP control information according to the PDCP packet header, the PDCP layer of the receiving device does not need to perform decryption and other processing after removing the PDCP packet header of the received information, but can remove the UDC packet header of the received information, decompress the information from which the UDC packet header is removed according to the UDC technology, and sequentially deliver and repeatedly detect the decompressed data; alternatively, after removing the UDC header of the received information, the receiving device may not need to perform processing such as UDC decompression on the header removed information, but may directly deliver the header removed information in order, and repeatedly detect the header removed information.

Referring to fig. 4B, another transmission and reception procedure of data is shown. Fig. 4B illustrates a transmitting device as STA, a receiving device as AP, or a WiFi system as an example. Alternatively, the transmitting device and the receiving device may communicate via a WiFi link at this time. To implement UDC technology in WiFi systems, a UDC layer may be added in the communication protocol layer, i.e., both the protocol layers of the transmitting device and the receiving device may be added to implement the UDC function. Wherein the UDC layer may be located between a logical link control (logical link control, LLC) layer and a MAC layer. If the UDC layer is located between the LLC layer and the MAC layer, feedback can be performed by the MAC layer. Or if the LLC layer also has a guarantee mechanism, the UDC layer can be positioned above the LLC layer, at the moment, feedback can be carried out by the LLC layer, and the UDC layer can utilize feedback information of the LLC layer to execute operations such as data transceiving and the like. Therefore, in the WiFi system, the first feedback information in the embodiment of the present application may be MAC layer information or LLC layer information. In the embodiment of the present application, the UDC layer is exemplified between the LLC layer and the MAC layer, and thus the first feedback information is exemplified as the MAC layer information.

For example, in a WiFi system, when internet protocol (internet protocol, IP) data arrives at the LLC layer of a transmitting device, the LLC layer adds a MAC address, a subnet intervention protocol (subnetwork access protocol, SNAP) address, and a frame check sequence (frame check sequence, FCS) to the IP data, resulting in processed data. The UDC layer may perform UDC compression on data processed by the LLC layer according to a UDC cache (e.g., a first cache), to obtain compressed data, for example, the processed data is first original data, and the compressed data is first compressed data in the embodiment of the present application. The UDC layer may add a UDC header to the compressed data, and the compressed data added with the UDC header may be delivered to the MAC layer as a MAC SDU. The MAC layer adds a MAC header to the received data, wherein the MAC address in the MAC header is the same as the MAC address of the LLC layer. And the MAC layer may regenerate the FCS for the data to form MPDUs that may be delivered to the physical layer of the transmitting device for transmission. After receiving the MPDU, the receiving device checks whether the data is received correctly according to the FCS included in the MPDU. If the MPDU is correctly received, the MAC layer of the receiving device feeds back ACK to the sending device, delivers the MSDU corresponding to the MPDU to the UDC layer of the receiving device, and then decompresses the data carried by the MSDU.

S302, the sending device sends first compressed data to the receiving device at a first moment. Accordingly, the receiving device receives the first compressed data from the transmitting device at the first time. "time of day" in various embodiments of the present application may be understood as a point in time or as a period of time, for example, a subframe (subframe), a slot (slot), a mini-slot (mini-slot), an orthogonal frequency division multiplexing (orthogonal frequency division multiplexing, OFDM) symbol (symbol), or the like. For example, the first time instant may refer to a point in time, or to one or more time slots, etc.

As can be seen from the description of S301, after obtaining the first compressed data, the transmitting device may further process the first compressed data, and finally, the transmitting device may send a transmission packet carrying the first compressed data. In SL transmission or Uu interface transmission, the transmission packet is, for example, TB; in WiFi system transmission, the transmission packet is, for example, an MDU. Accordingly, the receiving device receives the first compressed data, which may also be understood as a transmission packet carrying the first compressed data. For example, the first raw data includes one or more data, and the first compressed data may include one or more compressed data, where one of the compressed data may be carried by one of the transmission packets, for example, the compressed data has a one-to-one correspondence with the transmission packet; alternatively, a plurality of compressed data may be carried by one transport packet; alternatively, one compressed data may be carried by a plurality of transport packets. Thus, the number of transport packets for carrying the first compressed data may be one or more.

S303, the receiving device sends the first feedback information to the sending device at the second moment. Correspondingly, the sending device receives the first feedback information from the receiving device at the second moment. The first feedback information may indicate success or failure of the first compressed data reception. In the embodiment of the present application, the first feedback information is, for example, physical layer feedback information, such as HARQ feedback information. For example, if the first feedback information is a first value, indicating that the first compressed data reception was successful; or if the first feedback information is the second value, indicating that the first compressed data fails to be received. The first value is, for example, "1", "true", or "ACK", etc., and the second value is, for example, "0", "false", or "NACK", etc. In the embodiment of the application, the first value is mainly taken as ACK, and the second value is taken as NACK as an example.

Taking the SL scenario where both the transmitting device and the receiving device are UEs as an example. It may be appreciated that if the first feedback information is an ACK, the transmitting device may consider that the TB corresponding to the HARQ process corresponding to the ACK has been successfully received by the receiving device. Further, if the TB corresponding to the HARQ process carries compressed data, the transmitting device may also consider that the compressed data has been successfully received by the receiving device, and the physical layer of the transmitting device may indicate to the PDCP layer of the transmitting device that the first original data (or the first compressed data) corresponding to the first compressed data has been successfully received. Or if the first feedback information is NACK, the transmitting device may consider that the receiving device fails to receive the TB corresponding to the HARQ process corresponding to the NACK. Further, if the TB corresponding to the HARQ process carries compressed data, the transmitting device may also consider that the compressed data fails to be received, and the physical layer of the transmitting device may indicate to the PDCP layer of the transmitting device that the first original data (or the first compressed data) corresponding to the first compressed data fails to be received. In the embodiment of the application, the feedback mechanism (such as the physical layer feedback mechanism) corresponding to the first feedback information is utilized to feed back the success or failure of the data receiving corresponding to the uplink compression technology, and the feedback mechanism of other protocol layers (such as the PDCP layer and the like) is not needed to be introduced, so that the probability of repetition of the feedback mechanism is reduced, and the transmission overhead is saved.

Wherein if the number of TBs for carrying the first compressed data is 1, the receiving apparatus transmits first feedback information to the transmitting apparatus for the TBs. If the transmitting device receives the first feedback information of the HARQ process corresponding to the TB, the transmitting device may consider that the first compressed data is received successfully or failed. For example, the first compressed data is transmitted by a TB with a HARQ process number of 3, if the receiving device successfully decodes the TB, the receiving device may send first feedback information corresponding to the TB to the transmitting device, where the first feedback information is ACK; the transmitting device may determine that the first compressed data is successfully received if it receives the ACK corresponding to HARQ process number 3. Or if the receiving device fails to decode the TB, the receiving device may send first feedback information corresponding to the TB to the sending device, where the first feedback information is NACK; the transmitting device may determine that the first compressed data reception fails if it receives a NACK corresponding to HARQ process number 3. The number of TBs used for carrying the first compressed data is 1 may be two cases, where one case is that the TB is only used for carrying the first compressed data, and is no longer used for carrying other compressed data, and the sending device may determine that the first compressed data is received successfully or fails according to the first feedback information of the HARQ process corresponding to the TB; in another case, the TB is used for carrying other compressed data in addition to the first compressed data, and the sending device may also determine that the first compressed data and the other compressed data are received successfully or fail according to the first feedback information of the HARQ process corresponding to the TB.

Alternatively, if the number of TBs for carrying the first compressed data is greater than 1, i.e., a plurality of TBs for carrying the first compressed data, the receiving apparatus may transmit first feedback information to the transmitting apparatus for each of the plurality of TBs, and the receiving apparatus may transmit a plurality of first feedback information for the plurality of TBs. If the transmitting device receives a plurality of first feedback information corresponding to the plurality of TBs, the transmitting device may consider that the first compressed data is received successfully or failed. For example, the first compressed data is transmitted by the TB1 with the HARQ process number 3 and the TB2 with the HARQ process number 4, if the receiving device successfully decodes the TB1, the receiving device may send first feedback information 1 corresponding to the TB1 to the transmitting device, where the first feedback information 1 is ACK, and if the receiving device successfully decodes the TB2, the receiving device may send first feedback information 2 corresponding to the TB2 to the transmitting device, where the first feedback information 2 is ACK; the transmitting device may determine that the first compressed data is successfully received if it receives the ACK corresponding to HARQ process number 3 and the ACK corresponding to HARQ process number 4. Or if the receiving device fails to decode any one or two of the TBs 1 and 2, the receiving device may send first feedback information corresponding to the TB whose decoding fails to the transmitting device, where the first feedback information is NACK; the transmitting device may determine that the first compressed data reception fails if receiving a NACK corresponding to HARQ process number 3 and/or HARQ process number 4.

Take a WiFi scenario where the transmitting device is a STA and the receiving device is an AP as an example. As will be appreciated, if the first feedback information is an ACK, the transmitting device may consider that the MPDU corresponding to the ACK has been successfully received by the receiving device. Further, if the TB carries compressed data, the transmitting device may also consider that the compressed data has been successfully received by the receiving device, and the MAC layer of the transmitting device may indicate to the UDC layer of the transmitting device that the first original data (or the first compressed data) corresponding to the first compressed data has been successfully received. Alternatively, if the first feedback information is NACK, the transmitting apparatus may consider that the receiving apparatus fails to receive the MPDU corresponding to the NACK. Further, if the MPDU carries compressed data, the transmitting device may also consider that the compressed data fails to be received, and the MAC layer of the transmitting device may indicate to the UDC layer of the transmitting device that the first original data (or the first compressed data) corresponding to the first compressed data fails to be received. In the embodiment of the application, the data receiving success or failure corresponding to the uplink compression technology can be fed back by utilizing the feedback mechanism (such as the MAC layer feedback mechanism) corresponding to the first feedback information, and the feedback mechanism of other protocol layers (such as the PDCP layer and the like) is not needed to be introduced, so that the probability of repetition of the feedback mechanism is reduced, and the transmission overhead is saved.

Wherein if the number of MPDUs for carrying the first compressed data is 1, the receiving apparatus transmits first feedback information to the transmitting apparatus for the MPDU. And if the sending device receives the first feedback information corresponding to the MPDU, the sending device can consider that the first compressed data is successfully or failed to be received. For example, the first compressed data is transmitted by an MPDU, if the receiving device successfully decodes the MPDU, the receiving device may send first feedback information corresponding to the MPDU to the transmitting device, where the first feedback information is ACK; the transmitting device may determine that the first compressed data is received successfully if an ACK corresponding to the MPDU is received. Or if the receiving device fails to decode the MPDU, the receiving device may send first feedback information corresponding to the MPDU to the transmitting device, where the first feedback information is NACK; the transmitting device may determine that the first compressed data fails to be received if a NACK corresponding to the MPDU is received. The number of MPDUs for carrying the first compressed data may be 1, where one case is that the MPDU is only used for carrying the first compressed data, and is no longer used for carrying other compressed data, and the transmitting device may determine that the first compressed data is received successfully or fails according to the first feedback information corresponding to the MPDU; in another case, the MPDU is configured to carry, in addition to the first compressed data, other compressed data, and the transmitting device may also determine, according to the first feedback information corresponding to the MPDU, that the first compressed data and the other compressed data are received successfully or fail.

Alternatively, if the number of MPDUs for carrying the first compressed data is greater than 1, that is, a plurality of MPDUs for carrying the first compressed data, the receiving apparatus may transmit first feedback information to the transmitting apparatus for the plurality of MPDUs, respectively. The transmitting device may consider that the first compressed data is received successfully or failed if the transmitting device receives the first feedback information (including the plurality of first feedback information) corresponding to the plurality of MPDUs. For example, the first compressed data is transmitted by MPDU1 and MPDU2, if the receiving apparatus successfully decodes MPDU1, the receiving apparatus may transmit first feedback information 1 corresponding to MPDU1 to the transmitting apparatus, and the first feedback information 1 is ACK, and if the receiving apparatus successfully decodes MPDU2, the receiving apparatus may transmit first feedback information 2 corresponding to MPDU2 to the transmitting apparatus, and the first feedback information 2 is ACK; the transmitting device may determine that the first compressed data is received successfully if it receives the ACK corresponding to MPDU1 and the ACK corresponding to MPDU 2. Or if the receiving device fails to decode any one or two of the MPDUs 1 and 2, the receiving device may send first feedback information corresponding to the MPDUs that fail to decode to the transmitting device, where the first feedback information is NACK; the transmitting device may determine that the first compressed data reception fails if receiving a NACK corresponding to MPDU1 and/or MPDU 2.

S304, the sending equipment responds to the first feedback information, updates the first buffer memory at a third moment according to the first original data, and obtains a second buffer memory. The second cache may include the first raw data.

Alternatively, the embodiment of the application can provide two types of caches, one of which can be called a standby cache and the other of which can be called a formal cache, and the two types of caches are caches corresponding to the UDC technology. It is understood that the buffer utilized to compress the original data is a formal buffer, and the buffer used to store the data to be added to the formal buffer is a backup buffer. Wherein both the sending device and the receiving device may maintain both caches. For example, the formal cache of the sending device may be referred to as a first cache before being updated, e.g., before performing S304; the formal cache may be referred to as a second cache after being updated, for example, after S304 is performed. That is, for convenience of description, in the embodiment of the present application, the non-updated formal cache maintained by the sending device is referred to as a first cache, and the updated formal cache is referred to as a second cache.

The transmitting device cannot determine whether the primary buffer can be updated with the first primary data (the primary buffer at this time is referred to as the first buffer) before receiving the first feedback information, and therefore, the PDCP layer of the transmitting device may temporarily add the first primary data to the backup buffer before receiving the first feedback information. If the sending device receives the first feedback information corresponding to the first compressed data and the first feedback information is ACK, the physical layer of the sending device may indicate the PDCP layer that the first compressed data is received successfully, and the PDCP layer may take the first original data in the backup buffer from the backup buffer and put the first original data in the primary buffer into the primary buffer, so as to obtain the second buffer. The second buffer may be used for compression if the sending device is to compress other raw data.

Take the process of fig. 4A as an example. If SN of the first compressed data is 0 (SN of the first original data is also 0), the first compressed data is transmitted through the TB corresponding to HARQ process number 2 after being subjected to operations such as encapsulation, encoding and the like of the RLC layer, MAC layer and PHY layer. If the receiving device successfully decodes the TB, an ACK is sent to the sending device for the TB; if the receiving device fails to decode the TB, NACK is fed back to the transmitting device for the TB. After receiving the HARQ feedback (e.g., the first feedback information) corresponding to the HARQ process number 2, if the HARQ feedback is ACK, the physical layer of the transmitting device may determine that the first compressed data with SN of 0 is successfully received, so that the physical layer may notify the layer (e.g., PDCP layer) where the UDC is located that the data with SN of 0 (or the compressed data with SN of 0; or the original data with SN of 0) may be used for compression of the subsequent data. The PDCP layer may extract primary data having an SN of 0 (e.g., first primary data) from the standby buffer of the transmitting device and add the primary data to the first buffer, thus obtaining a second buffer.

And S305, the receiving device updates the third buffer memory at the sixth moment according to the first compressed data to obtain a fourth buffer memory.

The receiving device may also maintain a reserve cache and a formal cache. For example, the formal cache of the receiving device may be referred to as a third cache before being updated, e.g., before performing S305; the formal cache may be referred to as a fourth cache after being updated, for example, after S305 is executed. That is, for convenience of description, the non-updated formal cache maintained by the receiving device is referred to as a third cache, and the updated formal cache is referred to as a fourth cache. The third buffer corresponds to the first buffer of the sending device, for example, the data included in the third buffer is the same as the data included in the first buffer; the fourth buffer corresponds to the second buffer of the transmitting device, for example, the fourth buffer includes the same data as the second buffer.

The transmitting device may perform S304 if the first compressed data reception is successful, and the receiving device may also perform S305. The sixth time may be later than the third time, earlier than the third time, or the same time as the third time. The receiving device obtains the fourth buffer according to the first compressed data and the third buffer, which can be understood that the receiving device obtains the fourth buffer according to the original data corresponding to the first compressed data and the third buffer. For example, the receiving device may add the first original data obtained by decompressing the first compressed data to the third buffer, where the obtained buffer is the fourth buffer.

Referring to fig. 5, a working schematic diagram of a primary buffer and a backup buffer in the primary data transmission process may correspond to the UDC compression step in the data transceiving flow shown in fig. 4A, or correspond to the UDC compression step in the data transceiving flow shown in fig. 4B in fig. 5. In fig. 5, the primary data of sn=0, 1 is stored in both the first buffer of the transmitting device and the third buffer of the receiving device, and the primary data of sn=2, 3 is stored in the backup buffer of the transmitting device. This situation of fig. 5 may occur when the transmitting device has transmitted primary data with sn=0, 1, 2, 3 to the receiving device, and the transmitting device has received physical layer feedback (corresponding to fig. 4A) or MAC layer feedback (corresponding to fig. 4B) corresponding to the primary data with sn=0, 1 from the receiving device, and the transmitting end has indicated the receiving device to update the formal cache through the UDC header. Since the transmitting device has not received physical layer feedback or MAC layer feedback of the raw data of sn=2, 3 from the receiving device, the raw data of sn=2, 3 is also placed in the backup buffer of the transmitting device and the backup buffer of the receiving device.

If fig. 5 is applied to the data transceiving process shown in fig. 4A, if the transmitting device receives an ACK of a physical layer from the receiving device and the TB corresponding to the HARQ process corresponding to the ACK carries primary data of sn=2, the physical layer of the transmitting device may notify the PDCP layer of the transmitting device that the primary data of sn=2 has been successfully received, at which time the PDCP layer may instruct the receiving device to update the formal cache by adding an update indication to the UDC header of the new primary data (e.g., primary data of sn=4) that is transmitted. If fig. 5 is applied to the data transceiving process shown in fig. 4B, if the transmitting device receives an ACK from the MAC layer of the receiving device and the MPDU corresponding to the ACK carries sn=2 original data, the physical layer of the transmitting device may notify the UDC layer of the transmitting device that sn=2 original data has been successfully received, where the UDC layer may instruct the receiving device to update the formal cache by adding an update indication to the UDC header of the transmitted new original data (such as sn=4 original data). Alternatively, the sending device and the receiving device update the formal cache, and may have different implementation mechanisms, which are described below by way of example.

1. The first implementation mechanism. Please refer to fig. 6, which is a flowchart of the implementation mechanism.

S601, the sending device sends first information to the receiving device at a fourth moment. Accordingly, the receiving device receives the first information from the transmitting device at the fourth time.

Under the first implementation mechanism, after the transmitting device performs S304, S601 may be performed. The first information may include first indication information, which may indicate that the receiving apparatus obtains the fourth buffer according to the third buffer, or the first indication information may indicate that the receiving apparatus updates the third buffer, or the first indication information may indicate that the receiving apparatus obtains the fourth buffer, or the first indication information may indicate that the receiving apparatus updates the formal buffer according to the first compressed data (or, the first raw data). Wherein the fourth time may be later than the second time.

Optionally, the first information may further include second indication information, the second indication information may indicate second compressed data, and the second compressed data may be generated according to the second cache. That is, after the transmitting device executes S304, the next raw data may be continuously compressed by using the second buffer, for example, the next raw data is the second raw data, the data obtained after the second raw data is compressed is called second compressed data, and the transmitting device may transmit the second compressed data to the receiving device. For example, the first information may be a data packet including the second compressed data. Optionally, the second indication information includes, for example, SN of the second compressed data. That is, the transmitting device may carry the first indication information in the data packet including the next compressed data to instruct the receiving device to update the formal cache, without separately transmitting the first indication information, so that the utilization rate of the first information may be effectively improved. How the first indication information instructs the receiving device to update the official cache will be described later.

After S601, the receiving device may perform S305. That is, after receiving the first information, the receiving device may update the third buffer according to the indication of the first indication information, to obtain the fourth buffer.

The example of fig. 5 continues. For example, if the first feedback information indicates that the primary data with sn=2 has been successfully received, the sending device may take the primary data with sn=2 out of the standby buffer in S304, and add the primary data to the first buffer to obtain a second buffer, where the second buffer includes primary data with sn=0, 1, and 2. The transmitting device compresses the primary data with sn=4 by using the second buffer memory to obtain compressed data with sn=4, and then transmits the compressed data with sn=4 to the receiving device through the first information. The first information may include second indication information, for example, SN of compressed data including sn=4, and first indication information, which may indicate the receiving apparatus to update the formal cache. After receiving the first information, the receiving device may take the sn=2 original data out of the standby buffer (i.e. the receiving device does not directly add the sn=2 original data to the main buffer but put the sn=2 original data into the standby buffer after decompressing the sn=2 compressed data), and adds the sn=2 original data to the third buffer to obtain a fourth buffer, where the fourth buffer may include sn=0, 1, and 2 original data. Next, the receiving apparatus decompresses the sn=4 compressed data using the fourth buffer, to obtain sn=4 original data.

2. The second implementation mechanism. Please refer to fig. 7, which is a flowchart of the implementation mechanism.

S701, the transmitting device transmits the first information to the receiving device at the fourth time. Accordingly, the receiving device receives the first information from the transmitting device at the fourth time.

Under the second implementation mechanism, the transmitting device, after executing S303, temporarily does not execute S304, but may execute S701. The first information may include first indication information, and the content indicated by the first indication information may refer to the preamble. Wherein the fourth time may be later than the second time.

Optionally, the first information may further include second indication information, where the second indication information may indicate second compressed data, and the second compressed data may be generated according to the first buffer under the second implementation mechanism. That is, after the transmitting device receives the first feedback information in S303, the transmitting device may continue to compress the next raw data using the first buffer, for example, the next raw data is second raw data, and the data obtained after compressing the second raw data is called second compressed data, and the transmitting device may transmit the second compressed data to the receiving device. For example, the first information may be a data packet including the second compressed data. Optionally, the second indication information includes, for example, SN of the second compressed data. That is, the transmitting device may carry the first indication information in the data packet including the next compressed data to instruct the receiving device to update the formal cache, without separately transmitting the first indication information, so that the utilization rate of the first information may be effectively improved. How the first indication information instructs the receiving device to update the official cache will be described later.

S702, the receiving device decompresses the second compressed data according to the third buffer memory.

If the receiving device receives the first information successfully, although the first information indicates the receiving device to update the formal cache, the receiving device decompresses the second compressed data carried by the first information by using the third cache before updating the third cache.

After S702, that is, after the receiving apparatus decompresses the second compressed data according to the third buffer, the receiving apparatus may execute S305.

S703, the receiving device sends the second feedback information to the sending device at the fifth time. Correspondingly, the sending device receives the second feedback information from the receiving device at the fifth moment. Wherein the fifth time may be later than the fourth time. The second feedback information may indicate the success or failure of the first information reception. For example, if the value of the second feedback information is the first value, indicating that the first information reception is successful; or if the value of the second feedback information is the second value, indicating that the first information reception fails. For further implementations of the second feedback information reference is made to the previous description of the first feedback information.

The transmitting device may perform S304 if the second feedback information indicates that the first information reception is successful.

The example of fig. 5 continues. For example, if the first feedback information indicates that the primary data with sn=2 has been successfully received, the transmitting device continues to compress the primary data with sn=4 by using the first buffer (the first buffer may include primary data with sn=0, 1), so as to obtain compressed data with sn=4, and then sends the compressed data with sn=4 to the receiving device through the first information. The first information may include second indication information, for example, SN of compressed data including sn=4, and first indication information, which may indicate the receiving apparatus to update the formal cache. After receiving the first information, the receiving device may decompress the sn=4 compressed data carried by the first information by using a third buffer (the third buffer may include sn=0, 1 raw data), to obtain sn=4 raw data. After decompression, the receiving device may update the third buffer with sn=2 original data, e.g. the receiving device may take sn=2 original data out of the standby buffer and put it into the third buffer, where the obtained buffer is the fourth buffer, and the fourth buffer may include sn=0, 1,2 original data. The receiving device transmits second feedback information to the transmitting device indicating that the compressed data of sn=4 is received successfully. After receiving the second feedback information, the sending device may update the first buffer with the sn=2 original data, for example, the sending device may take the sn=2 original data out of the standby buffer and put the sn=2 original data into the first buffer, where the obtained buffer is the second buffer, and the second buffer may include sn=0, 1, and 2 original data.

In an actual communication system, when the receiving device sends physical layer feedback (or MAC layer feedback) generally later than the time when compressed data is received, for the second implementation mechanism described above, the update timing of the receiving device and the sending device for the formal cache may not be consistent. Taking the SL scenario where the transmitting device and the receiving device are both UEs as an example, the transmitting device transmits sn=4 compressed data to the receiving device on the physical side link shared channel (physical sidelink shared channel, PSSCH) of the T0 slot in fig. 8, and the header of the packet carrying the compressed data indicates that the original data with sn=2 is updated into the formal buffer. The receiving device transmits HARQ feedback of compressed data with sn=4 to the transmitting device, but the transmission of the HARQ feedback is at least two time slots apart, e.g. the HARQ feedback is transmitted on at least the physical side link feedback channel (physical sidelink feedback channel, PSFCH) of the T3 time slot. Therefore, the transmitting device can update the formal cache only in the T3 time slot, but the receiving device may update the formal cache in the T1 time slot or the T2 time slot, which means that the timing of updating the formal cache by the transmitting device and the receiving device is inconsistent, so that the formal caches at both ends cannot be aligned, and decompression failure may be caused.

Thus, optionally, in the second implementation mechanism above, after the receiving device receives the information for indicating to update the cache, it may wait for the first time period to update the official cache; accordingly, when the transmitting device receives information (e.g., the second feedback information) indicating that the new compressed data has been received successfully, the transmitting device may also wait for the first time period to update the formal cache. Units of the first duration, such as subframes, slots, OFDM symbols, or milliseconds.

Alternatively, one timer may be configured for each of the transmitting apparatus and the receiving apparatus, for example, the timer of the transmitting apparatus is referred to as a first timer, and the timer of the receiving apparatus is referred to as a second timer. The timing duration of the first timer may be equal to the timing duration of the second timer, where the timing duration is, for example, a first duration, and the ending time of the first duration is, for example, a third time, and the starting time of the first duration is, for example, a fourth time or a fifth time. If the ending time of the first duration is the third time and the starting time of the first duration is the fourth time, for the receiving device, the first duration may indicate a time delay between the time when the receiving device receives the first indication information and the time when the first indication information is actually effective (i.e., the receiving device updates the third buffer); or if the ending time of the first duration is the third time and the starting time of the first duration is the fifth time, for the receiving device, the first duration may instruct the receiving device to send, to the sending device, a physical layer feedback or a time delay between times when the MAC layer feedback corresponding to a transmission packet (for example, a TB or an MPDU) for indicating that the first indication information is carried and the first indication information is actually valid.

The first time period may be configured by the transmitting device and notified to the receiving device, or configured by the receiving device and notified to the transmitting device, or predefined by the protocol, or may be preconfigured in both the transmitting device and the receiving device. Take the example of the first duration being configured by the sending device and informing the receiving device. For example, the transmitting device may transmit second information to the receiving device, the second information may indicate the first duration. The second information may be sent in a semi-static manner, e.g., the second information may be carried in a radio resource control (radio resource control, RRC) message, the second information may be valid for a second duration, e.g., greater than or equal to the first duration; or the second information may be valid in one or more time slots; or the second information may be valid within one or more OFDM symbols. Alternatively, the second information may be sent in other manners, for example, the second information may be sent by signaling such as a MAC Control Element (CE).

For example, the first time period may have a start time of the fourth time period and an end time of the third time period. Taking the first time period as an example of 5 time slots. With continued reference to fig. 8, the transmitting device instructs the receiving device to update the primary data with sn=2 to the primary buffer by the header of the packet carrying the compressed data with sn=4 in the T1 slot, and at this time, the starting time of the T1 slot is the fourth time, and the receiving device does not update the primary buffer immediately after receiving the instruction, but waits for 5 slots and then updates the primary buffer. Optionally, the receiving device may start counting from the T1 slot, and update the formal buffer when the 5 th slot arrives (T5 slot), for example, the receiving device may update the formal buffer when the last OFDM symbol of the T5 slot ends, or may update the formal buffer at the beginning time domain position of the first OFDM symbol of the T6 slot, where the ending time domain position of the last OFDM symbol of the T5 slot or the beginning time domain position of the first OFDM symbol of the T6 slot is the third time; alternatively, since the receiving device receives the last few OFDM symbols of the T1 slot, the receiving device may start counting from the next slot (i.e., the T2 slot) of the T1 slot, and may update the official buffer when the 5 th slot arrives (T6 slot), e.g., the receiving device may update the official buffer when the last OFDM symbol of the T6 slot ends, or may also update the official buffer at the beginning time domain position of the first OFDM symbol of the T7 slot. The mechanism for updating the official cache is similar to the receiving device for the sending device.

Or, for example, the starting time of the first duration is the fifth time, and the ending time is the third time. Taking the first time period as an example of 5 time slots. With continued reference to fig. 8, the transmitting device instructs the receiving device to update the original data with sn=2 into the formal buffer through the header of the data packet carrying the compressed data with sn=4 in the T1 slot, and after receiving the data packet, the receiving device may send physical layer feedback or MAC layer feedback to the transmitting device in the T4 slot to indicate that the data packet is received successfully. And the receiving device does not update the official cache immediately, but waits for 5 slots before updating the official cache. Alternatively, the receiving device may start counting from the T4 slot, and update the official buffer when the 5 th slot arrives (T8 slot), e.g. the receiving device may update the official buffer when the last OFDM symbol of the T8 slot ends, or may update the official buffer at the beginning time-domain position of the first OFDM symbol of the T9 slot. The mechanism for updating the official cache is similar to the receiving device for the sending device.

In either of the above two examples, for example, the transmitting device transmits a compressed data in the T3 slot, the compressed data should be compressed in the non-updated regular cache, and the receiving device should also be decompressed in the non-updated regular cache. Therefore, the regular caches at the receiving and transmitting ends can be kept consistent because the time for updating the regular caches at the receiving and transmitting ends is aligned, and the success rate of compression and decompression is improved.

In the foregoing, the first indication information may indicate the receiving device to update the formal cache, and optionally, one indication manner of the first indication information is that the first indication information may indicate the first compressed data, so as to indirectly indicate the receiving device to update the formal cache according to the first compressed data. The first indication information may be indicative of the first compressed data in a number of different ways, some of which are described by way of example below.

A. The first way of indication. The first indication information may indicate a sequence number of the first compressed data, for example, indicate SN of the first compressed data.

The first indication information indicates a sequence number of the first compressed data in an alternative manner, the first indication information includes the sequence number of the first compressed data. Wherein, if the first compressed data includes a plurality of compressed data, the first indication information includes a sequence number of the first compressed data, it may mean that the first indication information includes a sequence number of some or all of the plurality of compressed data.

There are various ways in which the first indication information includes the sequence number of the first compressed data, and the way in which the first indication information includes the sequence number of the first compressed data is described below by taking the example in which the first indication information is included in the UDC header of the first information.

A1, the first indication information comprises serial numbers of all compressed data in the first compressed data. The first compressed data may include one or more compressed data, and the first indication information may include sequence numbers of all the compressed data. The indication mode is clear, and the receiving device can directly obtain the serial numbers of all compressed data included in the first compressed data.

Referring to fig. 9A, a schematic diagram of a PDCP packet header and a UDC packet header, where the UDC packet header may be included in first information, and the UDC packet header may include first indication information. In comparison with the UDC header shown in fig. 1A, a new field is added to the UDC header in fig. 9A, for example, the added new field is collectively referred to as a first field, and the first field may include at least one field, and the first field may be used to carry the first indication information. In the embodiment of the present application, a field is used to carry a piece of information, which may also be described as the field includes the information. For example, the first field is used to carry a sequence number of the compressed data, which may also be described as the first field including the sequence number of the compressed data. Fig. 9A is an example of a SL scenario in which both the transmitting device and the receiving device are UEs.

For example, the first field includes a field shown as "PDCN SN update" in fig. 9A, and the PDCP SN update field can be used to carry sequence numbers of all compressed data included in the first compressed data. The length of the PDCP SN update field in fig. 9A is merely an example, and in practical applications, the length of the PDCP SN update field can be extended according to the length of sequence numbers of all compressed data included in the first compressed data.

Optionally, the first field may further include a first indication field, for example, a "U" field of the UDC packet header in fig. 9A, where the U field may indicate whether to update the official cache. That is, the first information may indicate whether to update the official cache through the U field, and if the U field indicates to update the official cache, then indicate which compressed data to update the official cache through the PDCP SN update field. For example, if the value of the U field is "1", it indicates to update the formal cache; if the value of the U field is "0," it indicates that the official cache is not updated. Wherein, if the U field indicates to update the formal cache, the PDCP SN update may carry a PDCP SN for updating the compressed data of the formal cache; if the U field indicates that the formal cache is not updated, the PDCP SN update may be null or the PDCP SN update field may not exist to reduce the overhead of the UDC header.

Or, the U field may be absent, and if the PDCP SN update field carries PDCP SNs, it indicates to update the formal cache according to the compressed data corresponding to the PDCP SNs; and if the PDCP SN update field does not carry a PDCP SN (e.g., the PDCP SN update field is null), or if the PDCP SN update field does not exist, indicating that the official cache is not updated.

In addition, the PDCP header in fig. 9A includes a PDCP SN field for carrying the PDCP SN of the compressed data newly transmitted this time. For an explanation of the other fields shown in fig. 9A, reference is made to the description of fig. 1A above.

For example, the transmitting device instructs the receiving device to update the formal buffer according to the compressed data with sn=2 through the UDC header of the data packet carrying the compressed data with sn=4, at this time, the PDCP SN field in fig. 9A may carry a value of sn= 4,U field of "1", and the PDCP SN update field may carry sn=2.

Referring back to fig. 9B, another schematic diagram of a UDC packet header may be included in the first information, where the UDC packet header may carry the first indication information. A new field is added to the UDC header in fig. 9B, for example, the added new field is collectively referred to as a first field, where the first field may include at least one field, and the first field may be used to carry the first indication information. Fig. 9B is an example of a WiFi scenario in which a transmitting device is a STA and a receiving device is an AP.

For example, the first field includes a field shown as "SN update" in fig. 9B, and the SN update field may be used to carry sequence numbers of all compressed data included in the first compressed data. The length of the SN update field in fig. 9B is merely an example, and in practical applications, the length of the SN update field may be extended according to the length of sequence numbers of all compressed data included in the first compressed data.

Optionally, the first field may further include a first indication field, for example, a "U" field of the UDC header in fig. 9B, and reference is made to the foregoing for description of the U field.

In addition, the PDCP header in fig. 9B includes an SN field for carrying SN of the compressed data newly transmitted this time. For an explanation of the other fields shown in fig. 9B, reference is made to the previous description of fig. 1A or fig. 9A.

For example, the transmitting device instructs the receiving device to update the formal cache according to the compressed data with sn=2 through the UDC header of the data packet carrying the compressed data with sn=4, at this time, the SN field in fig. 9B may carry the sn= 4,U field with a value of "1", and the SN update field may carry sn=2.

A2, the first indication information comprises a serial number of the last compressed data in the first compressed data. For example, the first compressed data includes M compressed data, and the first indication information may include a sequence number of the last compressed data of the M compressed data, where M is a positive integer. The last compressed data in the M compressed data refers to the last compressed data in the M compressed data, which is ordered according to the sequence number.

Taking the SL scenario where both the transmitting device and the receiving device are UEs as an example, reference may be continued to fig. 9A. Unlike the A1 mode, in the A2 mode, the PDCP SN update field in fig. 9A does not carry the sequence number of all compressed data included in the first compressed data, but carries the sequence number of the last compressed data in the M compressed data, that is, the PDCP SN update carries one PDCP SN, which can effectively reduce the overhead of the UDC header. For more description about the A2 mode (e.g., U field and PDCP packet header, etc.), reference can be made to the A1 mode.

For example, the transmitting device instructs the receiving device to update the formal buffer according to the compressed data with sn=2, 3 through the UDC header of the data packet carrying the compressed data with sn=4, at this time, the PDCP SN field in fig. 9A may carry sn= 4,U field with a value of "1", and the PDCP SN update field may carry sn=3. At this time, if the original data possibly included in the formal cache of the receiving device is sn=0, 1, the receiving device may update the original data with sn=2, 3 to the formal cache according to the indication of the UDC packet header.

Taking the example of a WiFi scenario in which the transmitting device is a STA and the receiving device is an AP, reference may be continued to fig. 9B. Unlike the A1 mode, in the A2 mode, the SN update field in fig. 9B does not carry the sequence number of all compressed data included in the first compressed data, but carries the sequence number of the last compressed data in the M compressed data, that is, the SN update carries one SN, which can effectively reduce the overhead of the UDC header. For more description about the A2 mode (e.g., U field and PDCP packet header, etc.), reference can be made to the A1 mode.

For example, the transmitting device instructs the receiving device to update the formal buffer according to the compressed data of sn=2, 3 by the UDC packet header of the packet carrying the compressed data of sn=4, at this time, the SN field in fig. 9B may carry the sn= 4,U field with a value of "1", and the SN update field may carry sn=3. At this time, if the original data possibly included in the formal cache of the receiving device is sn=0, 1, the receiving device may update the original data with sn=2, 3 to the formal cache according to the indication of the UDC packet header.

A3, the first compressed data comprises M compressed data, the M compressed data belong to K groups, the first indication information comprises a serial number of the first compressed data in each of the K groups, and the first indication information comprises a serial number of the last compressed data in each of the K groups. K is a positive integer. Wherein, the first compressed data in a group of compressed data refers to the first compressed data in the group of compressed data which is ordered according to the serial number; the last compressed data in a set of compressed data refers to the last compressed data in the set of compressed data ordered by sequence number.

For example, a first field is added to the UDC header, the first field including K sets of fields, the K sets of fields may carry first indication information, e.g., a set of fields may carry a sequence number of a set of compressed data. A set of K sets of fields may include a start field that may carry a sequence number of a first compressed data of the set of compressed data and an end field that may carry a sequence number of a last compressed data of the set of compressed data. If k=1, the first field may comprise a set of fields. For example, if the sequence numbers of at least two adjacent compressed fields in the M compressed fields are discontinuous, an A1 mode or an A3 mode may be adopted, and if the A3 mode is adopted, the overhead of the UDC packet header can be saved compared with the A1 mode.

Referring to fig. 9C, a schematic diagram of a PDCP packet header and a UDC packet header, where the UDC packet header may be included in the first information, and the UDC packet header may carry the first indication information. Fig. 9C is an example of a SL scenario in which both the transmitting device and the receiving device are UEs. In fig. 9C, the first compressed data is exemplified as including two sets of compressed data, and thus the first field is exemplified as including 2 sets of fields. For example, a first set of fields in the first field includes a first PDCP SN start (start) field from top to bottom and a first PDCP SN end (end) field from top to bottom. The second set of fields in the first field includes a second PDCP SN start field from top to bottom and a second PDCP SN end field from top to bottom. Taking the first set of fields as an example, optionally, the first set of fields may further include a second indicator field, for example, located between the PDCP SN start field and the PDCP SN end field, for example, including an "E" field in fig. 9C, etc. The second indication field may indicate whether the UDC header further includes a sequence number for updating the formally cached compressed data, or whether the UDC header further includes a next set of fields for updating the formally cached data. For example, if the value of the E field is "1", indicating that the UDC packet header also includes a sequence number for updating formally cached compressed data, the receiving device may continue decoding; if the value of the E field is "0", indicating that the UDC header no longer includes a sequence number for updating formally buffered compressed data, the receiving device does not have to continue decoding. For example, both sets of fields in fig. 9C carry PDCP SNs, where the E field in the first set of fields (i.e., the first E field from top to bottom) may have a value of "1" and the E field in the second set of fields (i.e., the first E field from top to bottom) may have a value of "0". The second set of fields includes similar content and is not repeated. Where if k=1, fig. 9C may not include the second set of fields.

For example, if the transmitting device instructs the receiving device to update to the formal cache according to the compressed data of sn= 4,5,6,7,10 through the UDC header of the first information, the first compressed data may include two sets of compressed data, wherein the first set of compressed data includes compressed data of sn=4, 5,6,7, and wherein the second set of compressed data includes compressed data of sn=10. Then in fig. 9C, the PDCP SN start field of the first set of fields may carry sn=4, the PDCP SN end field may carry sn=7, and the first E field has a value of "1", so the receiving device will continue to decode the UDC header. Both the PDCP SN start field and PDCP SN end field of the second set of fields in fig. 9C may carry sn=10, with the second E field having a value of "0".

Referring back to fig. 9D, another schematic diagram of a UDC packet header may be included in the first information, where the UDC packet header may carry the first indication information. Fig. 9D is an example of a WiFi scenario in which the transmitting device is a STA and the receiving device is an AP. In fig. 9D, the first compressed data is exemplified as including two sets of compressed data, and thus the first field is exemplified as including 2 sets of fields. For example, a first set of fields in the first field includes a first SN start field from top to bottom, and a first SN end field from top to bottom. The second set of fields in the first field includes a second SN start field from top to bottom and a second SN end field from top to bottom. Optionally, the first field may further include a second indicator field, for example, located between the first and second sets of fields, for example, including the "E" field in fig. 9D, etc. The second indication field may indicate whether the UDC header further includes a sequence number for updating the formally cached compressed data, or whether the UDC header further includes a next set of fields for updating the formally cached data. For example, if the value of the E field is "1", indicating that the UDC packet header also includes a sequence number for updating formally cached compressed data, the receiving device may continue decoding; if the value of the E field is "0", indicating that the UDC header no longer includes a sequence number for updating formally buffered compressed data, the receiving device does not have to continue decoding. For example, the second set of fields in fig. 9D also carries SN, where the value of the E field may be "1". Wherein, if k=1, fig. 9C may not include the second set of fields, and the value of the E field may be "0".

For example, if the transmitting device instructs the receiving device to update to the formal cache according to the compressed data of sn= 4,5,6,7,10 through the UDC header of the first information, the first compressed data may include two sets of compressed data, wherein the first set of compressed data includes compressed data of sn=4, 5,6,7, and wherein the second set of compressed data includes compressed data of sn=10. Then in fig. 9D, the SN start field of the first set of fields may carry sn=4, the SN end field may carry sn=7, and the first E field has a value of "1", so the receiving device will continue to decode the UDC header. Both the SN start field and the SN end field of the second set of fields in fig. 9D may carry sn=10, with the value of the second E field being "0".

As can be seen from fig. 9C or fig. 9D, it is possible that only one compressed data of the set of compressed data comprised by the first compressed data, for which case the first field may be modified to save the overhead of the UDC header. For example, the first field may also include K groups of fields, one of which may include a start field and an end field, to which reference is made to the foregoing description; and K is also included in the K group of fields ₁ Group field (K) ₁ Positive integer less than K), K ₁ A set of fields in the set of fields may include a sequence number field that may carry a sequence number of a set of compressed data that includes only one compressed data, i.e., the sequence number field need only carry a sequence number of one compressed data.

Referring to fig. 9E, a schematic diagram of a PDCP header and a UDC header, where the UDC header may be included in the first information, and the UDC header may carry the first indication information. Fig. 9E exemplifies a SL scenario in which both the transmitting device and the receiving device are UEs. In fig. 9E, the first compressed data is exemplified as including two sets of compressed data, and thus the first field is exemplified as including 2 sets of fields. For example, the first set of fields in the first field includes a first PDCP SN start field from top to bottom and a first PDCP SN end field from top to bottom. Optionally, the set of fields may further include a third indication field, for example, located between the PDCP SN start field and the PDCP SN end field. Optionally, the third indication field may include a first sub-indication field, for example, a first "E1" field from top to bottom in fig. 9E, and a second sub-indication field, for example, a first "E2" field from top to bottom in fig. 9E. The first sub-indication field may indicate whether the UDC header further includes a sequence number for updating a formally cached set of compressed data, or whether the UDC header further includes a set of start and end fields; the second sub-indication field may indicate whether the UDC header further includes a sequence number for updating a compressed data of the formal cache or whether the UDC header further includes a sequence number field. For example, if the value of the E1 field is "1", it indicates that the UDC packet header further includes a set of start field and end field; alternatively, the value of the E1 field is "0", indicating that the UDC header no longer includes a set of start and end fields. For example, if the value of the E2 field is "1", it indicates that the UDC packet header further includes a sequence number field; alternatively, the value of the E2 field is "0", indicating that the UDC header no longer includes a sequence number field. Equivalently, the fields of the different groups included in the first field in fig. 9E may be differently formatted, and thus may be indicated by different sub-indication fields, respectively. Optionally, the number of types of fields included in the first field and the number of sub-indication fields included in the third indication field may be equal. Alternatively, the E1 field and the E2 field may be replaced by the E field in fig. 9C, which indicates whether the UDC header further includes a set of fields, and the types of the set of fields are not distinguished.

In fig. 9E, a second set of fields in the first field includes a second PDCP SN field from top to bottom. Optionally, the second set of fields may further include a fourth indication field, e.g., located after the PDCP SN field. Optionally, the fourth indication field may include a third sub-indication field, for example, a second "E1" field from top to bottom in fig. 9E, and a fourth sub-indication field, for example, a second "E2" field from top to bottom in fig. 9E. The manner of indication of these fields etc. can be referred to in the previous paragraph.

For example, if the transmitting device instructs the receiving device to update to the formal cache according to the compressed data of sn= 4,5,6,7,10 through the UDC header of the first information, the first compressed data may include two sets of compressed data, wherein the first set of compressed data includes compressed data of sn=4, 5,6,7, and wherein the second set of compressed data includes compressed data of sn=10. Then in fig. 9C, the PDCP SN start field of the first set of fields may carry sn=4, the PDCP SN end field may carry sn=7, the first E1 field has a value of "0", and the first E2 field has a value of "1", so the receiving device may continue to decode the UDC header. The PDCP SN field of the second set of fields in fig. 9C may carry sn=10, with the value of the second E1 field and the value of the second E2 field both being "0".

Referring back to fig. 9F, another schematic diagram of a UDC packet header may be included in the first information, where the UDC packet header may carry the first indication information. Fig. 9F exemplifies a WiFi scenario in which the transmitting device is a STA and the receiving device is an AP. In fig. 9F, the first compressed data is exemplified by including three sets of compressed data, and thus the first field is exemplified by including 3 sets of fields. For example, a first set of fields in the first field includes a first SN start field from top to bottom, and a first SN end field from top to bottom. The second set of fields in the first field includes a second SN start field from top to bottom and a second SN end field from top to bottom. The third set of fields in the first field includes a second SN field from top to bottom. Optionally, the first field may further include a third indication field, including, for example, a field located between the first set of fields and the second set of fields, including, for example, a first "E1" field from top to bottom in fig. 9F, "E2" field, and so on. Optionally, the first field may further include a fourth indication field, for example, located between the second set of fields and the third set of fields, for example, including a second "E1" field, "E2" field, from top to bottom in fig. 9F, and so on. Wherein, the third indication field is used for indicating the second group of fields, the fourth indication field is used for indicating the third group of fields, and the description of fig. 9E can be referred to for indication modes and the like. It can be appreciated that if the first field further includes more groups of fields, further indication fields may also be included, which is not described in detail.

For example, if the transmitting device instructs the receiving device to update to the formal cache according to the compressed data of sn= 4,5,7,8,10 through the UDC header of the first information, the first compressed data may include three sets of compressed data, where the first set of compressed data includes compressed data of sn=4, 5, the second set of compressed data includes compressed data of sn=7, 8, and the third set of compressed data includes compressed data of sn=10. Then in fig. 9F, the SN start field of the first set of fields may carry sn=4, the SN end field may carry sn=5, the first E1 field has a value of "1", and the first E2 field has a value of "0", so the receiving device may continue to decode the UDC header. The SN start field of the second set of fields may carry sn=7, the SN end field may carry sn=8, the value of the second E1 field is "0", and the value of the second E2 field is "1", so the receiving device may continue to decode the UDC header. The SN field of the third set of fields may carry sn=10.

For the A3 mode, the types of fields included in the first field may be different (e.g., the first field may include a start field and an end field, and further include a sequence number field, etc.), so that, optionally, the first indication field may indicate the type of the first set of fields included in the first field. For example, the first indication field may include the U field and the R field in fig. 9E or 9F, which corresponds to the two fields combined as the first indication field. For example, the value of the first indication field is "00", indicating that there is no first set of fields, and the receiving device does not have to continue decoding; if the value of the first indication field is "01", the first group of fields is a start field and an end field; if the value of the first indication field is "10", it means that the type of the first set of fields is a sequence number field, and so on. Equivalently, whether the first group of fields exist or not can be indicated through the first indication field, or the type of the first group of fields can be indicated, so that the indication mode is more flexible. In other manners, if the first field also includes multiple types of fields, the first indication field may also be implemented in a similar manner, without limitation.

A4, the first compressed data comprises M compressed data, the M compressed data belong to K groups, the first indication information comprises the sequence number of the first compressed data in each group of the K groups, which is ordered according to the sequence number, and the first indication information comprises the offset of the last compressed data in each group of the K groups, which is ordered according to the sequence number, and the first compressed data. K is a positive integer. In the embodiment of the present application, the "offset" may also be referred to as "offset", and these two features may be replaced with each other, which will not be described in detail later.

For example, a first field is added in the UDC header, the first field including a K group of fields, the K group of fields being capable of carrying the first indication information. A set of K sets of fields may include a start field that may carry a sequence number of a first compressed data of the set of compressed data and an offset field that may carry an offset between a last compressed data of the set of compressed data and the first compressed data of the set of compressed data. For example, if the sequence numbers of at least two adjacent compressed fields in the M compressed fields are discontinuous, an A1 mode, an A3 mode or an A4 mode may be adopted, and if the A3 mode or the A4 mode is adopted, the overhead of the UDC packet header can be saved compared with the A1 mode. If the A4 mode is adopted, the cost of the UDC packet head can be further saved compared with the A3 mode.

Referring to fig. 9G, a schematic diagram of a PDCP packet header and a UDC packet header, where the UDC packet header may be included in the first information, and the UDC packet header may carry the first indication information. Fig. 9G exemplifies a SL scenario in which both the transmitting apparatus and the receiving apparatus are UEs. In fig. 9G, the first compressed data is exemplified by two sets of compressed data, and thus the first field is exemplified by 2 sets of fields. For example, a first set of fields in the first field includes a first PDCP SN start field from top to bottom and includes a first PDCP SN offset (offset) field from top to bottom. The second set of fields in the first field includes a second PDCP SN start field from top to bottom and a second PDCP SN offset field from top to bottom. Taking the first set of fields as an example, optionally, the set of fields may further include a fifth indicator field, for example, located between the PDCP SN start field and the PDCP SN offset field, for example, including an "E" field in fig. 9G, etc. Regarding the fifth indication field, reference may be made to the previous description of the first indication field. The second set of fields includes similar content and is not repeated. For example, both sets of fields in fig. 9G carry PDCP SNs, where the E field in the first set of fields (i.e., the first E field from top to bottom) may have a value of "1" and the E field in the second set of fields (i.e., the first E field from top to bottom) may have a value of "0".

For example, if the transmitting device instructs the receiving device to update to the formal cache according to the compressed data of sn= 4,5,6,7,10 through the UDC header of the first information, the first compressed data may include two sets of compressed data, wherein the first set of compressed data includes compressed data of sn=4, 5,6,7, and wherein the second set of compressed data includes compressed data of sn=10. Then in fig. 9G, the PDCP SN start field of the first set of fields may carry sn=4, the PDCP SN offset field may carry 3, and the first E field has a value of "1", so the receiving device will continue to decode the UDC header. The PDCP SN start field of the second set of fields may carry sn= 10,PDCP SN offset field may carry 0 and the second E field has a value of "0".

Referring back to fig. 9H, another schematic diagram of a UDC packet header may be included in the first information, where the UDC packet header may carry the first indication information. Fig. 9H exemplifies a WiFi scenario in which the transmitting device is a STA and the receiving device is an AP. In fig. 9H, the first compressed data is exemplified as including two sets of compressed data, and thus the first field is exemplified as including 2 sets of fields. For example, a first set of fields in the first field includes a first SN start field from top to bottom and a first SN offset field from top to bottom. The second set of fields in the first field includes a second SN start field from top to bottom and a second SN offset field from top to bottom. Optionally, the first field may further include a sixth indication field, e.g., located between the first set of fields and the second set of fields, e.g., including a first "E" field from top to bottom in fig. 9H, etc. In addition, the first field may also include a seventh indication field, e.g., located between the second set of fields and the third set of fields, e.g., the diagram includes a second "E" field from top to bottom in 9H, etc. Wherein, the fields between the sixth indication fields are used for indicating the second group of fields, the seventh indication fields are used for indicating the third group of fields, and the contents such as indication modes of the fields can refer to the previous.

For example, if the transmitting device instructs the receiving device to update to the formal cache according to the compressed data of sn= 4,5,6,7,10 through the UDC header of the first information, the first compressed data may include two sets of compressed data, where the first set of compressed data includes compressed data of sn=4, 5,6,7, and the second set of compressed data includes compressed data of sn=10. Then in fig. 9H, the SN start field of the first set of fields may carry sn=4, the SN offset field may carry 3, and the first E field has a value of "1", so the receiving device will continue to decode the UDC header. The SN start field of the second set of fields may carry sn=10 and the SN offset field may carry sn=0, and the second E field has a value of "0", so the receiving device stops decoding the UDC header.

Alternatively, in the A4 mode, the first field may further include a field for carrying a single SN. For example, fig. 9G may also be extended to further include a sequence number field for carrying a single SN, e.g., the PDCP SN end field in fig. 9E may be replaced with a PDCP SN offset field; similarly, fig. 9H may be extended to further include a sequence number field for carrying a single SN, for example, the SN end field in fig. 9F may be replaced with an SN offset field.

Or in the A4 manner, one of the K sets of fields may include an offset field that may carry an offset between a set of compressed data and a last compressed data of the set of compressed data, and an end field that may carry a sequence number of the last compressed data of the set of compressed data, which is not repeated.

A5, the first compressed data comprises M compressed data, the first indication information comprises the serial numbers of the first compressed data and the last compressed data which are ordered according to the serial numbers in the N compressed data, and the first indication information also comprises the serial numbers of part or all of the N-M compressed data. The serial numbers of the N compressed data are continuous, the N compressed data comprise M compressed data, M is a positive integer smaller than or equal to N, and N is a positive integer.

For example, a first field is added in the UDC header, the first field including a K group of fields, the K group of fields being capable of carrying the first indication information. The i-th field of the K-th field may include a start field, which may carry a sequence number of a first compressed data of the N compressed data, and an end field, which may carry a sequence number of a last compressed data of the N compressed data. Alternatively, the i-th field of the K-th field may include a start field that may carry a sequence number of a first compressed data of the N compressed data and an offset field that may carry an offset between a last compressed data of the N compressed data and the first compressed data. The i-th set of fields is, for example, the first set of fields in the K sets of fields, or may be any set of fields in the K sets of fields.

In addition, the K group field includes a K-1 group field in addition to the i group field. The K-1 set of fields may indicate N-M compressed data, e.g., the K-1 set of fields may carry a sequence number of some or all of the N-M compressed data. For example, the N-M compressed data are further divided into H groups of compressed data according to the continuity of the sequence numbers, and H is a positive integer. The K-1 group field carries the sequence number of some or all of the H group compressed data, and the carrying manner may refer to any one of the A1 manner to the A4 manner. Equivalently, N pieces of compressed data are indicated by the i-th group field, and compressed data that needs to be removed from the N pieces of compressed data (i.e., N-M pieces of compressed data) are indicated by the K-1 group field, then equivalently, N pieces of compressed data are indicated by the K group field.

B. The second way of indication. The first indication information may indicate an offset of the first compressed data.

Optionally, the first information may further include second indication information, where the second indication information may indicate second compressed data, and the second compressed data is, for example, compressed data that is newly sent to the receiving device. Then, the offset of the first compressed data indicated by the first indication information is, for example, an offset between the sequence number of the first compressed data and the sequence number of the second compressed data, or an offset between the sequence number of the first compressed data and the sequence number of the last compressed data already stored in the current UDC cache (e.g. the first cache or the third cache).

Referring to fig. 9I, a schematic diagram of a PDCP packet header and a UDC packet header, where the UDC packet header may be included in first information, and the UDC packet header may carry first indication information and second indication information. Fig. 9I exemplifies a SL scenario in which both the transmitting device and the receiving device are UEs. For example, the PDCP SN field in fig. 9I is used to carry second indication information, such as PDCP SN including second compressed data. The PDCP SN offset field in fig. 9I may be used to carry first indication information, e.g., including an offset between the PDCP SN of the first compressed data and the PDCP SN of the second compressed data.

For example, the transmitting device instructs the receiving device to update the formal buffer according to the compressed data with sn=1 through the UDC header of the data packet carrying the compressed data with sn=4, at this time, the PDCP SN field in fig. 9I may carry the sn= 4,U field with a value of "1", and the PDCP SN offset field may carry sn=3 or sn=2. Wherein, if PDCP SN offset carries sn=2, PDCP sn=2-1 of the second compressed data, indicating PDCP sn=sn of the first compressed data, i.e. the offset is 0 at this time, which is also regarded as "sn=1" to be subtracted. Other offsets in embodiments of the present application may be similarly processed. For further details regarding fig. 9I, reference may be made to the description of fig. 9A.

Referring back to fig. 9J, another schematic diagram of a UDC packet header may be included in the first information, where the UDC packet header may carry the first indication information and the second indication information. Fig. 9J exemplifies a WiFi scenario in which the transmitting device is a STA and the receiving device is an AP. For example, the SN field in fig. 9J is used to carry second indication information, such as SN including second compressed data. The SN offset field in fig. 9J may be used to carry first indication information, e.g., including an offset between the SN of the first compressed data and the SN of the second compressed data.

For example, the transmitting device instructs the receiving device to update the formal buffer according to the compressed data with sn=1 through the UDC header of the data packet carrying the compressed data with sn=4, at this time, the PDCP SN field in fig. 9J may carry a value of sn= 4,U field of "1", and the SN offset field may carry sn=3. For further details with respect to fig. 9J, reference is made to the description of fig. 9B.

In addition to the above various manners, the first indication information may indicate the first compressed data in other manners, which is not limited by the embodiment of the present application.

In the embodiment of the application, the feedback mechanism corresponding to the first feedback information is utilized to feed back the success or failure of the data receiving corresponding to the UDC technology, and the feedback mechanism of other protocol layers (such as a PDCP layer and the like) is not needed to be introduced, so that the cost of feedback resources is reduced on the basis of ensuring the transmission reliability. And the sending device can indicate the compressed data for updating the formal cache in various modes, so that the method is flexible.

Fig. 10 is a schematic structural diagram of a communication device according to an embodiment of the present application. The communication apparatus 1000 may be a transmitting device or circuitry of the transmitting device in the embodiments shown in any of the figures 3, 6 or 7 for implementing the method corresponding to the transmitting device in the above method embodiments. Alternatively, the communication apparatus 1000 may be a receiving device or a circuit system of the receiving device in the embodiment shown in any one of fig. 3, fig. 6 or fig. 7, for implementing the method corresponding to the receiving device in the above method embodiment. Specific functions can be seen from the description of the method embodiments described above. One type of circuitry is, for example, a chip system.

The communication device 1000 comprises at least one processor 1001. The processor 1001 may be used for internal processing of the device, implementing certain control processing functions. Optionally, the processor 1001 includes instructions. Alternatively, the processor 1001 may store data. Alternatively, the different processors may be separate devices, may be located in different physical locations, and may be located on different integrated circuits. Alternatively, the different processors may be integrated in one or more processors, e.g., integrated on one or more integrated circuits.

Optionally, the communications device 1000 includes one or more memories 1003 for storing instructions. Optionally, the memory 1003 may also store data therein. The processor and the memory may be provided separately or may be integrated.

Optionally, the communication device 1000 includes a communication line 1002, and at least one communication interface 1004. Among them, since the memory 1003, the communication line 1002, and the communication interface 1004 are optional, they are all indicated by broken lines in fig. 10.

Optionally, the communication device 1000 may also include a transceiver and/or an antenna. Wherein the transceiver may be used to transmit information to or receive information from other devices. The transceiver may be referred to as a transceiver, a transceiver circuit, an input-output interface, etc. for implementing the transceiver function of the communication device 1000 via an antenna. Optionally, the transceiver comprises a transmitter (transmitter) and a receiver (receiver). Illustratively, a transmitter may be used to generate a radio frequency (radio frequency) signal from the baseband signal, and a receiver may be used to convert the radio frequency signal to the baseband signal.

The processor 1001 may include a general purpose central processing unit (central processing unit, CPU), microprocessor, application specific integrated circuit (application specific integrated circuit, ASIC), or one or more integrated circuits for controlling the execution of programs in accordance with aspects of the present application.

Communication line 1002 may include a pathway to transfer information between the aforementioned components.

Communication interface 1004, using any transceiver-like means for communicating with other devices or communication networks, such as ethernet, radio access network (radio access network, RAN), wireless local area network (wireless local area networks, WLAN), wired access network, etc.

The memory 1003 may be, but is not limited to, a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (random access memory, RAM) or other type of dynamic storage device that can store information and instructions, or an electrically erasable programmable read-only memory (electrically erasable programmable read-only memory, EEPROM), a compact disc read-only memory (compact disc read-only memory) or other optical disk storage, optical disk storage (including compact disc, laser disc, optical disc, digital versatile disc, blu-ray disc, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. The memory 1003 may be separate and coupled to the processor 1001 by communication lines 1002. Alternatively, the memory 1003 may be integral to the processor 1001.

The memory 1003 is used for storing computer-executable instructions for executing the present application, and is controlled to be executed by the processor 1001. The processor 1001 is configured to execute computer-executable instructions stored in the memory 1003, thereby implementing steps performed by the transmitting apparatus according to the embodiment shown in any one of fig. 3, fig. 6, or fig. 7, or implementing steps performed by the receiving apparatus according to the embodiment shown in any one of fig. 3, fig. 6, or fig. 7.

Alternatively, the computer-executable instructions in the embodiments of the present application may be referred to as application program codes, which are not particularly limited in the embodiments of the present application.

In a particular implementation, the processor 1001 may include one or more CPUs, such as CPU0 and CPU1 in fig. 10, as one embodiment.

In a particular implementation, as one embodiment, the communications device 1000 may include multiple processors, such as processor 1001 and processor 1005 in FIG. 10. Each of these processors may be a single-core (single-CPU) processor or may be a multi-core (multi-CPU) processor. A processor herein may refer to one or more devices, circuits, and/or processing cores for processing data (e.g., computer program instructions).

When the apparatus shown in fig. 10 is a chip, for example, a chip of a transmitting device or a chip of a receiving device, the chip includes a processor 1001 (may further include a processor 1005), a communication line 1002, a memory 1003, and a communication interface 1004. In particular, the communication interface 1004 may be an input interface, a pin, or a circuit, etc. Memory 1003 may be a register, cache, or the like. Processor 1001 and processor 1005 may be a general purpose CPU, microprocessor, ASIC, or one or more integrated circuits configured to control the execution of the programs of the communication method of any of the embodiments described above.

The embodiment of the application can divide the functional modules of the device according to the method example, for example, each functional module can be divided corresponding to each function, and two or more functions can be integrated in one processing module. The integrated modules may be implemented in hardware or in software functional modules. It should be noted that, in the embodiment of the present application, the division of the modules is schematic, which is merely a logic function division, and other division manners may be implemented in actual implementation. For example, in the case of dividing each functional module into respective functional modules by corresponding respective functions, fig. 11 shows a schematic diagram of an apparatus, and the apparatus 1100 may be the transmitting device or the receiving device, or a chip in the transmitting device or a chip in the receiving device, which are involved in each of the above-described method embodiments. The apparatus 1100 comprises a transmitting unit 1101, a processing unit 1102 and a receiving unit 1103.

It should be understood that the apparatus 1100 may be used to implement the steps performed by a transmitting device or a receiving device in the communication method according to the embodiments of the present application, and the relevant features may refer to the embodiments shown in any one of the foregoing fig. 3, fig. 6, or fig. 7, which are not repeated herein.

Alternatively, the functions/implementation procedures of the transmitting unit 1101, the receiving unit 1103, and the processing unit 1102 in fig. 11 may be implemented by the processor 1001 in fig. 10 calling computer-executable instructions stored in the memory 1003. Alternatively, the functions/implementation procedures of the processing unit 1102 in fig. 11 may be implemented by the processor 1001 in fig. 10 calling computer-executable instructions stored in the memory 1003, and the functions/implementation procedures of the transmitting unit 1101 and the receiving unit 1103 in fig. 11 may be implemented by the communication interface 1004 in fig. 10.

Alternatively, when the apparatus 1100 is a chip or a circuit, the functions/implementation procedures of the transmitting unit 1101 and the receiving unit 1103 may also be implemented by pins or circuits, or the like.

The present application also provides a computer readable storage medium storing a computer program or instructions which, when executed, implement the method performed by a transmitting device or a receiving device in the foregoing method embodiments. Thus, the functions described in the above embodiments may be implemented in the form of software functional units and sold or used as independent products. Based on such understanding, the technical solution of the present application may be embodied in essence or contributing part or part of the technical solution in the form of a software product stored in a storage medium, comprising several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present application. The storage medium includes: a usb disk, a removable hard disk, a ROM, a RAM, a magnetic disk, or an optical disk, etc.

The present application also provides a computer program product comprising: computer program code which, when run on a computer, causes the computer to perform the method performed by the transmitting device or the receiving device in any of the method embodiments described above.

The embodiment of the application also provides a processing device, which comprises a processor and an interface; the processor is configured to perform a method performed by the transmitting device or the receiving device according to any of the method embodiments described above.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, produces a flow or function in accordance with embodiments of the present application, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. The computer instructions may be stored in or transmitted from one computer-readable storage medium to another, for example, by wired (e.g., coaxial cable, optical fiber, digital Subscriber Line (DSL)), or wireless (e.g., infrared, wireless, microwave, etc.). The computer readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that contains an integration of one or more available media. The usable medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a magnetic tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a Solid State Disk (SSD)), or the like.

The various illustrative logical blocks and circuits described in connection with the embodiments of the application may be implemented or performed with a general purpose processor, a digital signal processor (digital signal processor, DSP), an application specific integrated circuit (application specific integrated circuit, ASIC), a field-programmable gate array (field-programmable gate array, FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the general purpose processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a digital signal processor and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a digital signal processor core, or any other similar configuration.

The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software unit executed by a processor, or in a combination of the two. The software elements may be stored in RAM, flash memory, ROM, erasable programmable read-only memory (EPROM), EEPROM, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. In an example, a storage medium may be coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC, which may reside in a terminal device. In the alternative, the processor and the storage medium may reside in different components in a terminal device.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

The matters in the various embodiments of the present application may be referenced to each other and terms and/or descriptions in the various embodiments may be consistent and may refer to each other in the absence of specific illustrations and logic conflicts with each other, and the technical features of the various embodiments may be combined to form new embodiments in accordance with their inherent logic relationships.

It will be understood that, in the embodiments of the present application, the transmitting device and/or the receiving device may perform some or all of the steps in the embodiments of the present application, these steps or operations are merely examples, and other operations or variations of the various operations may also be performed in the embodiments of the present application. Furthermore, the various steps may be performed in a different order presented in accordance with embodiments of the application, and it is possible that not all of the operations in the embodiments of the application may be performed.

Claims

1. A communication method applied to a transmitting device, the method comprising:

compressing first original data by using a first cache to obtain first compressed data, wherein the first cache is a cache corresponding to an uplink compressed UDC technology;

transmitting the first compressed data to a receiving device at a first time;

receiving first feedback information from the receiving device at a second moment, wherein the first feedback information is used for indicating that the first compressed data is successfully received, and the first feedback information is physical layer feedback information or Media Access Control (MAC) layer feedback information;

responding to the first feedback information, updating the first buffer memory at a third moment according to the first original data to obtain a second buffer memory, wherein the second buffer memory comprises the first original data;

wherein the second time is later than the first time and the third time is later than the second time.

2. The method according to claim 1, wherein the method further comprises:

and sending first information at a fourth time, wherein the first information comprises first indication information, the first indication information is used for indicating the receiving equipment to update a third buffer memory to obtain a fourth buffer memory, data contained in the third buffer memory are identical to data contained in the first buffer memory, data contained in the fourth buffer memory are identical to data contained in the second buffer memory, and the fourth time is later than the second time.

3. The method according to claim 2, wherein the method further comprises:

and receiving second feedback information at a fifth moment, wherein the second feedback information is used for indicating whether the first information is successfully received or not, and the fifth moment is later than the fourth moment.

4. The method of claim 3, wherein the step of,

when the second feedback information is a first value, the second feedback information is used for indicating that the first information is successfully received; or alternatively, the first and second heat exchangers may be,

and when the second feedback information is a second value, the second feedback information is used for indicating the failure of receiving the first information.

5. The method of claim 4, wherein updating the first buffer at a third time based on the first raw data to obtain a second buffer comprises:

and when the second feedback information is the first value, updating the first buffer memory at the third moment according to the first original data to obtain the second buffer memory, wherein the third moment is later than the fifth moment.

6. The method of claim 2, wherein the first information further comprises second indication information indicating second compressed data, wherein the second compressed data is generated from the second cache.

7. The method of claim 2, wherein the first information further comprises second indication information indicating second compressed data, wherein the second compressed data is generated from the first cache.

8. The method of claim 7, wherein the method further comprises:

and sending second information, wherein the second information is used for indicating the first time length, so that the third time is equal to or later than the time after the first time length is added to the fourth time, or the third time is equal to or later than the time after the first time length is added to the fifth time.

9. The method according to any one of claims 2 to 8, wherein the first indication information is used to indicate a sequence number of the first compressed data.

10. The method of claim 9, wherein the first indication information is a sequence number of the first compressed data.

11. The method of claim 10, wherein the first compressed data comprises M compressed data arranged by sequence number, the first indication information is a sequence number of a last compressed data in the M compressed data, and M is a positive integer.

12. The method of claim 10, wherein the first compressed data comprises M compressed data arranged by sequence number, the first information comprises at least one set of fields, one set of the at least one set of fields comprises a start field and an end field, the start field comprises a sequence number of a first compressed data in the set of compressed data in the M compressed data, the end field comprises a sequence number of a last compressed data in the set of compressed data, and the set of compressed data is compressed data with consecutive sequence numbers.

13. The method of claim 10, wherein the first compressed data comprises M compressed data arranged by sequence number, the first information comprises at least one set of fields, one set of the at least one set of fields comprises a start field and an offset field, the start field comprises a sequence number of a first compressed data in the one set of compressed data, the offset field comprises an offset between a sequence number of a last compressed data in the one set of compressed data and a sequence number of the first compressed data, and the one set of compressed data is compressed data having a sequence number that is consecutive.

14. The method of claim 10, wherein the first compressed data comprises M compressed data arranged by sequence number, the first information comprises a first set of fields and a second set of fields, the first set of fields comprises a start field and an end field, the start field comprises a sequence number of a first compressed data of a set of compressed data of the M compressed data, the end field comprises a sequence number of a last compressed data of the set of compressed data, the set of compressed data is a compressed data with consecutive sequence numbers, the second set of fields comprises a sequence number field, the sequence number field comprises a sequence number of one compressed data of the M compressed data, and M is an integer greater than or equal to 2.

15. The method of claim 10, wherein the first compressed data comprises M compressed data, the first information comprises at least one set of fields, one set of fields in the at least one set of fields comprises a sequence number of N compressed data, the N compressed data is compressed data with consecutive sequence numbers, the remaining fields in the at least one set of fields comprise a sequence number of N-M compressed data, the M compressed data is compressed data remaining after excluding the N-M compressed data from the N compressed data, and N is an integer greater than or equal to M.

16. The method according to any one of claims 2 to 8, wherein the first information further includes second indication information for indicating second compressed data.

17. The method of claim 16, wherein the first indication information is used to indicate an offset between a sequence number of the first compressed data and a sequence number of the second compressed data.

18. A method of communication, for use with a receiving device, the method comprising:

receiving first compressed data from a transmitting device at a first time;

transmitting first feedback information to the transmitting device at a second moment, wherein the first feedback information is used for indicating that the first compressed data is successfully received, and the first feedback information is physical layer feedback information or MAC layer feedback information;

updating a third buffer memory at a sixth moment according to the first compressed data to obtain a fourth buffer memory, wherein the fourth buffer memory comprises first original data obtained by decompressing the first compressed data, and the third buffer memory is a buffer memory corresponding to UDC;

wherein the second time is later than the first time, and the sixth time is later than the second time.

19. The method of claim 18, wherein the method further comprises:

and receiving first information at a fourth time, wherein the first information comprises first indication information, the first indication information is used for indicating the receiving equipment to update the third buffer to obtain the fourth buffer, and the fourth time is later than the second time.

20. The method of claim 19, wherein the method further comprises:

and sending second feedback information at a fifth moment, wherein the second feedback information is used for indicating whether the first information is successfully received or not, and the fifth moment is later than the fourth moment.

21. The method of claim 20, wherein the step of determining the position of the probe is performed,

22. The method according to claim 20 or 21, wherein updating the third buffer at a sixth time based on the first compressed data to obtain a fourth buffer comprises:

and when the first information is successfully received, updating the third buffer memory at the sixth moment according to the first compressed data to obtain the fourth buffer memory.

23. The method of claim 19, wherein the first information further comprises second indication information indicating second compressed data, wherein the second compressed data is generated from the second cache.

24. The method of claim 19, wherein the first information further comprises second indication information indicating second compressed data, wherein the second compressed data is generated from the first cache.

25. The method of claim 24, wherein the method further comprises:

and receiving second information, wherein the second information is used for indicating a first duration, so that the sixth moment is equal to or later than the moment after the first duration is added to the fourth moment, or so that the sixth moment is equal to or later than the moment after the first duration is added to the fifth moment.

26. The method according to any one of claims 19 to 25, wherein the first indication information is used to indicate a sequence number of the first compressed data.

27. The method of claim 26, wherein the first indication information is a sequence number of the first compressed data.

28. The method of claim 27, wherein the first compressed data includes M compressed data arranged by sequence number, the first indication information is a sequence number of a last compressed data in the M compressed data, and M is a positive integer.

29. The method of claim 27, wherein the first compressed data comprises M compressed data arranged by sequence number, the first information comprises at least one set of fields, one set of the at least one set of fields comprises a start field and an end field, the start field comprises a sequence number of a first compressed data in the one set of compressed data, the end field comprises a sequence number of a last compressed data in the one set of compressed data, and the one set of compressed data is compressed data having a sequence number that is consecutive.

30. The method of claim 27, wherein the first compressed data comprises M compressed data arranged by sequence number, wherein the first information comprises at least one set of fields, wherein one set of fields in the at least one set of fields comprises a start field and an offset field, wherein the start field comprises a sequence number of a first compressed data in the one set of compressed data, wherein the offset field comprises an offset between a sequence number of a last compressed data in the one set of compressed data and a sequence number of the first compressed data, and wherein the one set of compressed data is compressed data having a sequence number that is consecutive.

31. The method of claim 27, wherein the first compressed data comprises M compressed data arranged by sequence number, wherein the first information comprises a first set of fields and a second set of fields, wherein the first set of fields comprises a start field and an end field, wherein the start field comprises a sequence number of a first compressed data of a set of compressed data of the M compressed data, wherein the end field comprises a sequence number of a last compressed data of the set of compressed data, wherein the set of compressed data is a compressed data having a consecutive sequence number, wherein the second set of fields comprises a sequence number field, wherein the sequence number field comprises a sequence number of one compressed data of the M compressed data, and wherein M is an integer greater than or equal to 2.

32. The method of claim 27, wherein the first compressed data comprises M compressed data, the first information comprises at least one set of fields, one set of fields in the at least one set of fields comprises a sequence number of N compressed data, the N compressed data is compressed data with consecutive sequence numbers, the remaining fields in the at least one set of fields comprise a sequence number of N-M compressed data, the M compressed data is compressed data remaining after excluding the N-M compressed data from the N compressed data, and N is an integer greater than or equal to M.

33. The method according to any one of claims 19 to 25, wherein the first information further includes second indication information for indicating second compressed data, and the first indication information is for indicating an offset between a sequence number of the first compressed data and a sequence number of the second compressed data.

34. A communication device comprising a processor and a memory, the memory and the processor being coupled, the processor being configured to perform the method of any one of claims 1-17 or to perform the method of any one of claims 18-33.

35. A computer readable storage medium for storing a computer program which, when run on a computer, causes the computer to perform the method of any one of claims 1 to 17 or causes the computer to perform the method of any one of claims 18 to 33.

36. A chip system, the chip system comprising:

a processor and an interface from which the processor invokes and executes instructions that when executed implement the method of any one of claims 1 to 17 or the method of any one of claims 18 to 33.

37. A computer program product, characterized in that the computer program product comprises a computer program which, when run on a computer, causes the computer to carry out the method according to any one of claims 1 to 17 or causes the computer to carry out the method according to any one of claims 18 to 33.