A communication method and a communication device

Abstract

The application relates to a communication method and a communication device. The communication device transmits a MAC PDU, which includes a first MAC SDU and a first MAC subheader. The first MAC subheader is the MAC subheader of the first MAC SDU. The first MAC SDU is carried on a first resource, and the first resource corresponds to a logical channel ID (LCID) or a data radio bearer (DRB). The first MAC subheader does not include the identification of the LCID or the DRB. Since the first MAC subheader can not include the identification of the LCID or the DRB, the receiving end can determine the LCID or the DRB corresponding to the first MAC SDU according to the resource carrying the first MAC SDU, thereby reducing the packet header of the MAC PDU.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a communication method and communication device. Background Technology

[0002] For Internet Protocol (IP) Multimedia Subsystem (IMS) voice packets, after the voice data is encoded at the sending end, each protocol layer that the voice data passes through adds a corresponding header, resulting in a large header for the final voice packet. If the amount of voice data is small, the header will occupy a larger proportion of the entire voice packet. Consequently, during the transmission of the voice packet, the proportion of effective data is smaller, and more resources are used to transmit the header, resulting in a waste of transmission resources. Summary of the Invention

[0003] This application provides a communication method and communication device for reducing the size of the packet header.

[0004] Firstly, a first communication method is provided. This method can be applied to a data transmitting end. Optionally, the data transmitting end is, for example, a terminal-side device, also referred to as a terminal device or a terminal. The terminal device is, for example, a terminal equipment, or other equipment including terminal equipment functions, or a circuit, or a system-on-a-chip (or, a chip, such as a modem chip, also known as a baseband chip, or a system-on-a-chip (SoC) chip containing a modem core, or a system-in-package (SIP) chip) or other functional module, which can implement the functions of the terminal equipment, and which is, for example, disposed in the terminal equipment. The method includes: transmitting a fourth MAC PDU, the fourth MAC PDU including a first MAC SDU and a first MAC subheader, the first MAC subheader being the MAC subheader of the first MAC SDU, wherein the first MAC SDU is carried on a first resource, the first resource corresponding to an LCID or a data radio bearer, and the first MAC subheader does not include the identifier of the LCID or the data radio bearer.

[0005] In this embodiment, the MAC sub-header (first MAC sub-header) of the first MAC SDU may not include the LCID or data radio bearer identifier. For example, the receiving end can determine the LCID or data radio bearer corresponding to the first MAC SDU based on the resources carrying the first MAC SDU. This reduces the amount of information in the MAC sub-header, thereby reducing the packet header of the first MAC PDU, lowering the proportion of the packet header in the first MAC PDU, and saving transmission resources.

[0006] In one alternative implementation, the first MAC sub-header includes the length information of the first MAC SDU. The first MAC sub-header may also indicate the length of the first MAC SDU, enabling the receiving end to determine the length of the first MAC SDU.

[0007] In an optional implementation, the fourth MAC PDU further includes a MAC CE and a second MAC subheader, wherein the second MAC subheader is the MAC subheader of the MAC CE. Both the first and second MAC subheaders include second indication information. The second indication information included in the first MAC subheader is a first value, which indicates that the first MAC subheader is the MAC subheader of a MAC SDU. The second indication information included in the second MAC subheader is a second value, which indicates that the second MAC subheader is the MAC subheader of a MAC CE. The fourth MAC PDU may include only a MAC SDU and not a MAC CE, or the fourth MAC PDU may include both a MAC SDU and a MAC CE. When the fourth MAC PDU includes a MAC CE, the first and second MAC subheaders may include the second indication information, allowing the receiving end to determine whether the current MAC subheader corresponds to a MAC SDU or a MAC CE based on the value of the second indication information.

[0008] Secondly, a second communication method is provided. This method can be applied to a data receiving end. Optionally, the data receiving end is, for example, a network-side device, also referred to as a network device. The network device is, for example, a network equipment, or other equipment including network equipment functions, or a circuit, or a chip system (or chip) or other functional module, which can implement the functions of the network equipment, and is, for example, disposed in the network equipment. The network equipment includes, for example, access network equipment and / or core network equipment. The access network equipment is, for example, a base station. The method includes: receiving a fourth MAC PDU, the fourth MAC PDU including a first MAC SDU and a first MAC subheader, the first MAC subheader being the MAC subheader of the first MAC SDU, wherein the first MAC SDU is carried on a first resource, the first resource corresponding to an LCID or a data radio bearer, and the first MAC subheader does not include the identifier of the LCID or the data radio bearer.

[0009] In one alternative implementation, the first MAC subheader includes the length information of the first MAC SDU.

[0010] In one optional implementation, the fourth MAC PDU further includes a MAC CE and a second MAC subheader, the second MAC subheader being the MAC subheader of the MAC CE. Both the first MAC subheader and the second MAC subheader include second indication information, wherein the second indication information included in the first MAC subheader is a first value, the first value being used to indicate that the first MAC subheader is the MAC subheader of the MAC SDU; and the second indication information included in the second MAC subheader is a second value, the second value being used to indicate that the second MAC subheader is the MAC subheader of the MAC CE.

[0011] For the technical effects of the second aspect or various alternative implementation methods, please refer to the introduction of the technical effects of the first aspect or corresponding implementation methods.

[0012] Thirdly, a third communication method is provided. This method can be applied to the data sending end; for an introduction to the data sending end, please refer to the first aspect. The method includes: sending a first MAC PDU, which comprises M MACSDUs, wherein the first MAC PDU includes a first PDCP header. The first PDCP header is the PDCP header of the first MAC SDU among the M MAC SDUs, and the first MAC PDU does not include the PDCP headers of the remaining M-1 MAC SDUs (excluding the first MACSDU), where M is an integer greater than or equal to 2.

[0013] In this embodiment of the application, the first MAC PDU includes the PDCP header of the first MAC SDU among M MAC SDUs, but does not include the PDCP headers of the other MAC SDUs among the M MAC SDUs. This reduces the number of PDCP headers included in the first MAC PDU, thereby effectively reducing the packet header of the first MAC PDU, reducing the proportion of the packet header in the first MAC PDU, and saving transmission resources.

[0014] In one optional implementation, the M MAC SDUs are determined according to a first rule, which includes: a MAC PDU comprising MAC SDUs carried within the same transport block, wherein the M MAC SDUs are carried within the same transport block; or, a MAC PDU comprising M consecutive MAC SDUs, wherein the M MAC SDUs are carried within the same transport block, or the M MAC SDUs are carried within multiple transport blocks. For example, specifying that a MAC SDU carried within one transport block can reduce the PDCP header according to the method of the embodiments of this application, or specifying that M consecutive MAC SDUs can reduce the PDCP header according to the method of the embodiments of this application, is more flexible.

[0015] In an optional implementation, the first rule includes a MAC PDU comprising MAC SDUs carried within the same transport block. The first MAC PDU further includes a PDCP control PDU, which is located before the M MAC SDUs. Optionally, the M MAC SDUs may include M PDCP PDUs; for example, the M MAC SDUs and the M PDCP PDUs may correspond one-to-one. If the PDCP control PDU is located between the M PDCP PDUs, the receiver may be unable to identify the M PDCP PDUs due to the missing PDCP headers of M-1 of them. Therefore, embodiments of this application can position the PDCP control PDU before the M PDCP PDUs (or the M MAC SDUs), thereby reducing the probability of incorrect identification by the receiver.

[0016] In one alternative implementation, the first rule includes a MAC PDU comprising M consecutive MAC SDUs, wherein the first MAC PDU does not include a PDCP control PDU. Alternatively, the first MAC PDU may not include a PDCP control PDU, thereby reducing the probability of receiver identification errors in a simpler manner.

[0017] In one alternative implementation, the PDCP sequence numbers of the M MAC SDUs satisfy the second rule.

[0018] In one optional implementation, the first rule includes that the MAC SDUs included in a MAC PDU are MAC SDUs carried within the same transport block, and the second rule includes that the PDCP sequence numbers of the M MAC SDUs are consecutive. For example, the PDCP sequence numbers of the M MAC SDUs can be consecutive, so that the receiving end can deduce the PDCP sequence numbers of the remaining MAC PDUs among the M MAC SDUs based on the PDCP sequence numbers included in the first PDCP header.

[0019] In one optional implementation, the first rule includes a MAC PDU comprising M consecutive MAC SDUs, and the second rule includes: the remainder when the PDCP sequence number of any of the M MAC SDUs is divided by M is 0. The receiving end can also determine the PDCP sequence number of the M MAC SDUs according to a corresponding calculation formula.

[0020] In one alternative implementation, the first MAC PDU is used to transmit voice data. Alternatively, the first MAC PDU may also transmit other types of data; the embodiments of this application do not limit the data types transmitted by the first MAC PDU.

[0021] Fourthly, a fourth communication method is provided. This method can be applied to a data receiving end; for an introduction to the data receiving end, please refer to the second aspect. The method includes: receiving a first MAC PDU, which comprises M MACSDUs, wherein the first MAC PDU includes a first PDCP header, which is the PDCP header of the first MAC SDU among the M MAC SDUs, and the first MAC PDU does not include the PDCP headers of the remaining M-1 MAC SDUs (excluding the first MACSDU), where M is an integer greater than or equal to 2.

[0022] In one optional implementation, the M MAC SDUs are determined according to a first rule, which includes: a MAC PDU comprising MAC SDUs carried within the same transport block, wherein the M MAC SDUs are carried within the same transport block; or, a MAC PDU comprising M consecutive MAC SDUs, wherein the M MAC SDUs are carried within the same transport block, or the M MAC SDUs are carried within multiple transport blocks.

[0023] In one optional implementation, the first rule includes a MAC PDU comprising MAC SDUs carried within the same transport block, wherein the first MAC PDU further includes a PDCP control PDU, the PDCP control PDU being located before the M MAC SDUs.

[0024] In one alternative implementation, the first rule includes a MAC PDU comprising M consecutive MAC SDUs, wherein the first MAC PDU does not include a PDCP control PDU.

[0025] In one alternative implementation, the PDCP sequence numbers of the M MAC SDUs satisfy the second rule.

[0026] In one optional implementation, the first rule includes that a MAC PDU includes MAC SDUs carried within the same transport block, and the second rule includes that the PDCP sequence numbers of the M MAC SDUs are consecutive.

[0027] In one optional implementation, the first rule includes a MAC PDU comprising M consecutive MAC SDUs, and the second rule includes: the remainder when the PDCP sequence number of any of the M MAC SDUs is divided by M is 0.

[0028] In one alternative implementation, the first MAC PDU is used to transmit voice data.

[0029] For the technical effects of the fourth aspect or various alternative implementation methods, please refer to the introduction of the technical effects of the third aspect or corresponding implementation methods.

[0030] Fifthly, a fifth communication method is provided. This method can be applied to the data sending end; for an introduction to the data sending end, please refer to the first aspect. The method includes: the first PDCP entity of the terminal generating M PDCP PDUs, where each of the M PDCP PDUs is a PDCP data PDU, and M is a positive integer; wherein, according to the fourth rule, the first PDCP entity ensures that M-1 of the M PDCP PDUs do not include a PDCP header; the first PDCP entity then delivers the processed M PDCP PDUs to the RLC layer of the terminal.

[0031] In one alternative implementation, the fourth rule includes one or more of the following: the M PDCP PDUs are transmitted via the first MAC PDU; or, M is pre-configured or pre-defined.

[0032] In one alternative implementation, each of the M PDCP PDUs includes voice data.

[0033] In one alternative implementation, the M PDCP PDUs are adjacent.

[0034] In an optional implementation, the method further includes: the first PDCP entity generating P PDCP control PDUs, where P is a positive integer; the MAC layer of the terminal adding the P PDCP control PDUs and the M PDCP PDUs to a first MAC PDU, wherein in the first MAC PDU, the P PDCP control PDUs are located before the M PDCP PDUs.

[0035] In one optional implementation, the M PDCP PDUs correspond to a first PDCP header, the first PDCP header including a PDCP SN, the length of the PDCP SN being 7 bits.

[0036] For information on the technical effects of the fifth aspect or various alternative implementation methods, please refer to the description of the technical effects of the third aspect or corresponding implementation methods.

[0037] Sixthly, a sixth communication method is provided. This method can be applied to a data sending end; for an introduction to the data sending end, please refer to the first aspect. The method includes: sending a second MAC PDU, the second MAC PDU including a first MAC SDU, wherein the first MAC SDU includes the payload of at least two PDCP PDUs, the first MAC SDU including a PDCP header, the PDCP header including first information, the first information being used to indicate the payload length of the at least two PDCP PDUs.

[0038] This application embodiment can aggregate (or cascade; or set together) multiple PDCP SDUs into a single PDCP PDU. This PDCP PDU only needs to include one PDCP header, eliminating the need for multiple PDCP headers and effectively reducing PDCP header overhead. Furthermore, for other protocol layers (such as the RLC layer or MAC layer), which receive a single data packet from an upper layer, these other protocol layers only need to add one header (e.g., an RLC header or a MAC header) to that single data packet, instead of adding multiple headers, thus also reducing header overhead for other protocol layers.

[0039] In one alternative implementation, the first information includes at least two length fields indicating the payload lengths of the at least two PDCP PDUs. Since at least two PDCP SDUs are aggregated within a single PDCP PDU, the payload lengths of the at least two PDCP SDUs can be indicated within the retained PDCP header, enabling the receiver to determine the at least two PDCP SDUs.

[0040] In one optional implementation, the first information further includes a first field, which indicates whether there is a next cascaded PDCP PDU. The first field allows the receiver to determine whether there are any more cascaded (or aggregated) PDCP PDUs, thereby increasing the probability of successful decoding. Alternatively, the number of specific cascaded PDCP PDUs can be predefined or preconfigured, in which case the first information may not include the first field.

[0041] In one optional implementation, the at least two MAC SDUs correspond to the same PDCP serial number; or, different MAC SDUs among the at least two MAC SDUs correspond to different PDCP serial numbers.

[0042] In one optional implementation, the first MAC SDU is encrypted using the PDCP sequence number of the at least two MAC SDUs; or, the first MAC SDU is encrypted using the PDCP sequence number of one of the at least two MAC SDUs. For example, if the at least two MAC SDUs correspond to the same PDCP sequence number, the data sender can use that PDCP sequence number to encrypt the PDCP SDUs included in the at least two MAC SDUs. As another example, if different MAC SDUs among the at least two MAC SDUs correspond to different PDCP sequence numbers, the data sender can use the PDCP sequence number of the at least two MAC SDUs to encrypt the PDCP SDUs included in the at least two MAC SDUs. For example, for a PDCP SDU included in a MAC SDU, the PDCP sequence number of that MAC SDU can be used to encrypt that PDCP SDU. As yet another example, if different MAC SDUs among the at least two MAC SDUs correspond to different PDCP sequence numbers, the data sender can use the PDCP sequence number of one of the at least two MAC SDUs to encrypt the PDCP SDUs included in the at least two MAC SDUs. This one MAC SDU can be, for example, any one of the at least two MAC SDUs.

[0043] In one alternative implementation, the second MAC PDU is used to transmit voice data.

[0044] The seventh aspect provides a seventh communication method. This method can be applied to a data receiving end; for an introduction to the data receiving end, please refer to the second aspect. The method includes: receiving a second MAC PDU, the second MAC PDU including a first MAC SDU, wherein the first MAC SDU includes the payload of at least two PDCP PDUs, the first MAC SDU including a PDCP header, the PDCP header including first information, the first information being used to indicate the payload length of the at least two PDCP PDUs.

[0045] In one alternative implementation, the first information includes at least two length fields, which are used to indicate the load length of the at least two PDCP PDUs.

[0046] In an alternative implementation, the first information further includes a first field, which indicates whether there is a next cascaded PDCP PDU.

[0047] In one optional implementation, the at least two MAC SDUs correspond to the same PDCP serial number; or, different MAC SDUs among the at least two MAC SDUs correspond to different PDCP serial numbers.

[0048] In one alternative implementation, the first MAC SDU is encrypted using the PDCP serial number of the at least two MAC SDUs; or, the first MAC SDU is encrypted using the PDCP serial number of one of the at least two MAC SDUs.

[0049] In one alternative implementation, the second MAC PDU is used to transmit voice data.

[0050] For the technical effects of the seventh aspect or various alternative implementations, please refer to the description of the technical effects of the sixth aspect or corresponding implementations.

[0051] Eighthly, an eighth communication method is provided. This method can be applied to a data sending end; for an introduction to the data sending end, please refer to the first aspect. The method includes: sending a third MAC PDU, the third MAC PDU including a first RLCPDU, the first RLC PDU being determined according to a third rule, the third rule indicating that the first RLC PDU does not include segmented RLC SDUs.

[0052] In this embodiment, the RLC layer of the data sending end may not segment the RLC SDU, so the information used to indicate segmentation may not be included in the RLC header, thus saving the overhead of the RLC header.

[0053] In an alternative implementation, the third MAC PDU does not include the RLC header of the first RLC PDU. In this implementation, since the first RLC PDU does not have an RLC header, header overhead is further saved.

[0054] In one alternative implementation, the transmission mode of the RLC entity corresponding to the third MAC PDU is TM. For example, when the transmission mode of the RLC entity is TM, the first RLC PDU does not have an RLC header.

[0055] In one optional implementation, the number of HARQ processes corresponding to the RLC entity is 1. The RLC sequence number included in the RLC header can be used for RLC layer sorting at the receiver. If the number of HARQ processes is 1, the receiver does not need to sort according to the RLC sequence number. Therefore, when the number of HARQ processes is 1, the first RLC PDU may not have an RLC header to reduce header overhead.

[0056] In one alternative implementation, the third MAC PDU is used to transmit voice data.

[0057] A ninth aspect provides a ninth communication method. This method can be applied to a data receiving end; for an introduction to the data receiving end, please refer to the second aspect. The method includes: receiving a third MAC PDU, the third MAC PDU including a first RLCPDU, the first RLC PDU being determined according to a third rule, the third rule indicating that the first RLC PDU does not include segmented RLC SDUs.

[0058] In an alternative implementation, the third MAC PDU does not include the RLC header of the first RLC PDU.

[0059] In one optional implementation, the transmission mode of the RLC entity corresponding to the third MAC PDU is TM.

[0060] In one optional implementation, the number of HARQ processes corresponding to the RLC entity is 1.

[0061] In one alternative implementation, the third MAC PDU is used to transmit voice data.

[0062] For the technical effects of the ninth aspect or various alternative embodiments, please refer to the description of the technical effects of the eighth aspect or corresponding embodiments.

[0063] A tenth aspect provides a tenth communication method. This method can be applied to a data transmitter; for an introduction to the data transmitter, please refer to the first aspect. The method includes: transmitting a first RLC PDU, the first RLC PDU comprising at least two RLC SDUs, the RLC header of the first RLC PDU comprising at least one length field, the at least one length field being used to indicate the length of the at least two RLC SDUs, or to indicate the length of the RoHC header included in the at least two RLC SDUs, wherein the number of bits occupied by each length field in some or all of the at least one length field is less than a first threshold.

[0064] In this embodiment of the application, for an RLC PDU that includes cascaded (or aggregated; or set) RLC SDUs, the number of bits occupied by the length field in the RLC header of the RLC PDU can be reduced to save the overhead of the RLC header.

[0065] In one alternative implementation, the first threshold is 11. Alternatively, the first threshold can be any other value, without limitation.

[0066] In an optional implementation, the RLC header further includes first indication information, which indicates the number of bits occupied by each length field. In this implementation, the number of bits occupied by the length field can be variable; for example, in cases of good RoHC compression performance, the length field can be shorter, thereby further reducing header overhead. Since the number of bits occupied by the length field is variable, the RLC header can indicate the number of bits occupied by the length field through the first indication information, allowing the receiving end to determine the number of bits occupied by the length field based on the first indication information.

[0067] In one optional implementation, the number of bits occupied by each length field is less than a second threshold, and the at least one length field is used to indicate the length of the RoHC header included in the at least two RLC SDUs; or, the number of bits occupied by each length field is greater than or equal to the second threshold, and the at least one length field is used to indicate the length of the at least two RLC SDUs. The length field can indicate the length of either the RoHC header or the RLC SDU, offering flexibility. The specific content indicated by the length field can be determined based on the number of bits occupied by the length field, thus avoiding the need for additional information and saving signaling overhead.

[0068] In an optional implementation, the RLC header further includes the RLC sequence number of the first RLC PDU, wherein the number of bits occupied by the RLC sequence number is less than a second threshold. In addition to reducing the number of bits occupied by the length field, this embodiment of the application can also reduce the number of bits occupied by the RLC sequence number, thereby further reducing header overhead.

[0069] In one alternative implementation, the second threshold is 5. Alternatively, it can be any other value, without limitation.

[0070] In one alternative implementation, the RLC header does not include the RLC sequence number of the first RLC PDU. The RLC header may also exclude the RLC sequence number, thereby further reducing header overhead.

[0071] Eleventh aspect, an eleventh communication method is provided. This method can be applied to a data receiving end; for an introduction to the data receiving end, please refer to the second aspect. The method includes: receiving a first RLC PDU, the first RLC PDU including at least two RLC SDUs, the RLC header of the first RLC PDU including at least one length field, the at least one length field being used to indicate the length of the at least two RLC SDUs, or to indicate the length of the RoHC header included in the at least two RLC SDUs, wherein the number of bits occupied by each length field in some or all of the at least one length field is less than a first threshold.

[0072] In one alternative implementation, the first threshold is 11.

[0073] In one alternative implementation, the RLC header further includes first indication information, which indicates the number of bits occupied by each length field.

[0074] In one alternative implementation, the number of bits occupied by each length field is less than a second threshold, and the at least one length field is used to indicate the length of the RoHC header included in the at least two RLC SDUs; or, the number of bits occupied by each length field is greater than or equal to the second threshold, and the at least one length field is used to indicate the length of the at least two RLC SDUs.

[0075] In one optional implementation, the RLC header further includes the RLC sequence number of the first RLC PDU, wherein the number of bits occupied by the RLC sequence number is less than a second threshold.

[0076] In one alternative implementation, the second threshold is 5.

[0077] In one alternative implementation, the RLC header does not include the RLC serial number of the first RLC PDU.

[0078] For information on the technical effects of the eleventh aspect or various alternative implementations, please refer to the description of the technical effects of the tenth aspect or corresponding implementations.

[0079] In a twelfth aspect, a twelfth communication method is provided. This method can be applied to a data sending end; for an introduction to the data sending end, please refer to the first aspect. The method includes: sending a fifth MAC PDU, wherein the fifth MAC PDU includes a first MAC SDU, and the fifth MAC PDU does not include the MAC subheader of the first MAC SDU.

[0080] The embodiments of this application do not require adding a MAC subheader to the MAC SDU, thereby significantly reducing the packet header overhead of the MACPDU.

[0081] In one optional implementation, the first MAC SDU is carried on a second resource, which corresponds to an LCID or a data radio bearer. The second resource, for example, corresponds to an LCID or a data radio bearer. The LCID can be the LCID corresponding to the RLC PDU included in the first MAC SDU, and the data radio bearer can be the data radio bearer corresponding to a first logical channel. The first logical channel can be the logical channel corresponding to the RLC PDU included in the first MAC SDU. For the receiving end, as long as the first MAC SDU is received through the second resource, it can be determined that the first MAC SDU corresponds to the LCID or the data radio bearer. Therefore, the MAC subheader of the first MAC SDU may not include the identifier of the LCID or the data radio bearer, or the MAC subheader of the first MAC SDU may not include any LCID or any data radio bearer identifier. This provides a premise that allows the first MAC SDU to not include a MAC subheader.

[0082] In one alternative implementation, the length of the first MAC SDU is equal to the time-domain length of the second resource. In this implementation, the length of the first MAC SDU can be determined by the receiver based on the time-domain length of the second resource. Therefore, the MAC subheader of the first MAC SDU does not necessarily need to indicate the length of the first MAC SDU, which provides another premise for allowing the first MAC SDU to not include a MAC subheader.

[0083] In one alternative implementation, the transmission mode of the first MAC SDU is TM. For example, when the transmission mode of the first MAC SDU is TM, the first MAC SDU does not include an RLC header.

[0084] In one optional implementation, the first MAC SDU is carried on a second resource, the second resource having an encoding rate less than or equal to 800 bps. Because the encoding rate of the second resource is less than or equal to 800 bps, the data transmitter does not need to pad bits on the resource when transmitting the first MAC SDU, allowing the length of the first MAC SDU to be equal to the time-domain length used for the second resource.

[0085] In one alternative implementation, the first MAC SDU or the fifth MAC PDU includes voice data.

[0086] The thirteenth aspect provides a thirteenth communication method. This method can be applied to a data receiving end; for an introduction to the data receiving end, please refer to the second aspect. The method includes: receiving a fifth MAC PDU, wherein the fifth MAC PDU includes a first MAC SDU, and the fifth MAC PDU does not include the MAC subheader of the first MAC SDU.

[0087] In one alternative implementation, the first MAC SDU is carried on a second resource, which corresponds to an LCID or a data radio bearer.

[0088] In one alternative implementation, the length of the first MAC SDU is equal to the time-domain length of the second resource.

[0089] In one alternative implementation, the transmission mode of the first MAC SDU is TM.

[0090] In one alternative implementation, the first MAC SDU is carried on a second resource, the second resource having an encoding rate of less than or equal to 800 bps.

[0091] In one alternative implementation, the first MAC SDU or the fifth MAC PDU includes voice data.

[0092] For details regarding the technical effects of the thirteenth aspect or various alternative embodiments, please refer to the description of the technical effects of the twelfth aspect or corresponding embodiments.

[0093] The fourteenth aspect provides a fourteenth communication method. This method can be applied to a data transmitter; for an introduction to the data transmitter, please refer to the first aspect. The method includes: transmitting a sixth MAC PDU, which includes K MAC SDUs and K MAC subheaders. Each of the K MAC subheaders corresponds one-to-one with one of the K MAC SDUs. The remaining MAC subheaders, excluding the third MAC subheader, do not include an LCID or a data radio bearer identifier. The third MAC subheader is the MAC subheader of the first MAC SDU among the K MAC SDUs. All K MAC SDUs correspond to the same LCID or the same data radio bearer, where K is a positive integer.

[0094] In this embodiment of the application, since the transmission resources and the identifiers of LCID or data radio bearers can have a corresponding relationship, the identifiers of LCID or data radio bearers may not be included in the MAC subheader, so as to reduce the overhead of the MAC subheader.

[0095] In one optional implementation, each of the K MAC sub-headers further includes a length field, which indicates the length of the corresponding MAC SDU or the length of the RoHC header included in the corresponding MAC SDU. The length field in the MAC sub-header can indicate either the length of the MAC SDU or the length of the RoHC header, providing flexibility in indicating the target.

[0096] In an optional implementation, each MAC sub-header further includes first indication information, which indicates the number of bits occupied by the length field. In this implementation, the number of bits occupied by the length field can be variable; for example, in cases of good RoHC compression performance, the length field can be shorter, thereby further reducing header overhead. Since the number of bits occupied by the length field is variable, the MAC sub-header can indicate the number of bits occupied by the length field through the first indication information, allowing the receiving end to determine the number of bits occupied by the length field based on the first indication information.

[0097] In one optional implementation, the number of bits occupied by the length field is less than the fourth threshold, and the length field is used to indicate the length of the RoHC header included in the corresponding MAC SDU; or, the number of bits occupied by the length field is greater than or equal to the fourth threshold, and the length field is used to indicate the length of the corresponding MAC SDU. The length field can indicate either the length of the RoHC header or the length of the MAC SDU, offering flexibility. The specific content indicated by the length field can be determined based on the number of bits occupied by the length field, thus eliminating the need for additional information and saving signaling overhead.

[0098] In one optional implementation, the third MAC subheader includes the LCID or the identifier of the data radio bearer; or, the K MAC SDUs are carried on a third resource, the third resource corresponding to the LCID, and the third MAC subheader does not include the LCID or the identifier of the data radio bearer. The third MAC subheader may include the LCID or the identifier of the data radio bearer, enabling the receiving end to determine the LCID or data radio bearer corresponding to the respective MAC SDU. Alternatively, the third resource may correspond to, for example, the LCID or the data radio bearer, and the receiving end can determine the LCID or the data radio bearer based on the third resource; in this case, the third MAC subheader may not include the LCID or the identifier of the data radio bearer to reduce the overhead of the MAC subheader.

[0099] In one optional implementation, in the sixth MAC PDU, the K MAC sub-headers and the K MACSDUs form K MAC sub-PDUs, and the K MAC sub-PDUs are adjacent to each other.

[0100] In one optional implementation, any one of the K MAC sub-headers further includes a second field, which indicates whether there is a next concatenated MAC SDU with the same LCID or data radio bearer. The receiver can determine the existence of a next concatenated MAC SDU based on the second field, thereby improving the decoding accuracy of the receiver.

[0101] In one optional implementation, the bits occupied by the second field belong to the length field in any of the MAC sub-headers. The length field is used to indicate the length of the corresponding MAC SDU, or to indicate the length of the RoHC header included in the corresponding MAC SDU. In this implementation, existing bits in the MAC sub-header can be reused as the second field, thus avoiding the need to add new bits to the MAC sub-header, which is beneficial for compatibility with existing MAC sub-header structures.

[0102] In an optional implementation, the sixth MAC PDU further includes a MAC CE and a fourth MAC subheader, wherein the fourth MAC subheader is the MAC subheader of the MAC CE. Both the third and fourth MAC subheaders include second indication information. The second indication information included in the third MAC subheader is a first value, which indicates that the first MAC subheader is the MAC subheader of a MAC SDU. The second indication information included in the fourth MAC subheader is a second value, which indicates that the second MAC subheader is the MAC subheader of a MAC CE. The sixth MAC PDU may include only a MAC SDU and not a MAC CE, or the sixth MAC PDU may include both a MAC SDU and a MAC CE. When the sixth MAC PDU includes a MAC CE, the third and fourth MAC subheaders may include the second indication information, allowing the receiving end to determine whether the current MAC subheader corresponds to a MAC SDU or a MAC CE based on the value of the second indication information.

[0103] In an optional implementation, the method further includes receiving second information, the second information being used to indicate K. K may be configured by a network device, or predefined by a protocol, etc.

[0104] In one alternative implementation, the sixth MAC PDU includes voice data.

[0105] The fifteenth aspect provides a fifteenth communication method. This method can be applied to a data receiving end; for an introduction to the data receiving end, please refer to the second aspect. The method includes: receiving a sixth MAC PDU, the sixth MAC PDU comprising K MAC SDUs, the sixth MAC PDU further comprising K MAC subheaders, the K MAC subheaders corresponding one-to-one with the K MAC SDUs, wherein the remaining MAC subheaders among the K MAC subheaders, except for the third MAC subheader, do not include an LCID or a data radio bearer identifier, the third MAC subheader being the MAC subheader of the first MAC SDU among the K MAC SDUs, and the K MAC SDUs all corresponding to the same LCID or the same data radio bearer, where K is a positive integer.

[0106] In one optional implementation, each of the K MAC sub-headers further includes a length field, which is used to indicate the length of the corresponding MAC SDU, or to indicate the length of the RoHC header included in the corresponding MAC SDU.

[0107] In one alternative implementation, each MAC subheader further includes first indication information, which indicates the number of bits occupied by the length field.

[0108] In one optional implementation, the number of bits occupied by the length field is less than the fourth threshold, and the length field is used to indicate the length of the RoHC header included in the corresponding MAC SDU; or, the number of bits occupied by the length field is greater than or equal to the fourth threshold, and the length field is used to indicate the length of the corresponding MAC SDU.

[0109] In one optional implementation, the third MAC subheader includes the LCID or the identifier of the data radio bearer; or, the K MAC SDUs are carried on a third resource, the third resource corresponding to the LCID, and the third MAC subheader does not include the LCID or the identifier of the data radio bearer.

[0110] In one optional implementation, in the sixth MAC PDU, the K MAC sub-headers and the K MACSDUs form K MAC sub-PDUs, and the K MAC sub-PDUs are adjacent to each other.

[0111] In an optional implementation, any one of the K MAC subheaders further includes a second field, the second field being used to indicate whether there is a next cascaded MAC SDU with the same LCID or data radio bearer.

[0112] In one optional implementation, the bits occupied by the second field belong to the length field in any of the MAC subheaders, the length field being used to indicate the length of the corresponding MAC SDU, or to indicate the length of the RoHC header included in the corresponding MAC SDU.

[0113] In one optional implementation, the sixth MAC PDU further includes a MAC CE and a fourth MAC subheader, the fourth MAC subheader being the MAC subheader of the MAC CE. Both the third MAC subheader and the fourth MAC subheader include second indication information, wherein the second indication information included in the third MAC subheader is a first value, the first value being used to indicate that the first MAC subheader is the MAC subheader of the MAC SDU; and the second indication information included in the fourth MAC subheader is a second value, the second value being used to indicate that the second MAC subheader is the MAC subheader of the MAC CE.

[0114] In an alternative implementation, the method further includes sending a second message, the second message being used to indicate K.

[0115] For information on the technical effects of the fifteenth aspect or various alternative embodiments, please refer to the description of the technical effects of the fourteenth aspect or corresponding embodiments.

[0116] In a sixteenth aspect, a communication device is provided. The communication device can be a data transmitting end as described in any one of the first, third, fifth, sixth, eighth, tenth, twelfth, or fourteenth aspects. The communication device possesses the functions of the aforementioned data transmitting end. For example, the communication device includes modules, units, or means corresponding to the operations involved in any one of the first, third, fifth, sixth, eighth, tenth, twelfth, or fourteenth aspects. These modules, units, or means can be implemented in software, hardware, or a combination of software and hardware. The communication device is, for example, a terminal device, or other device including terminal device functions, or a chip system (or chip or circuit) or other functional module capable of implementing the functions of a terminal device, and is, for example, disposed in a terminal device. In an optional implementation, the communication device includes a baseband device and a radio frequency device. In another optional implementation, the communication device includes a processing unit (sometimes also called a processing module) and a transceiver unit (sometimes also called a transceiver module). The transceiver unit is capable of both sending and receiving functions. When the transceiver unit performs the sending function, it can be called a sending unit (sometimes also called a sending module); when the transceiver unit performs the receiving function, it can be called a receiving unit (sometimes also called a receiving module). The sending unit and the receiving unit can be the same functional module, which is called the transceiver unit and can perform both sending and receiving functions; alternatively, the sending unit and the receiving unit can be different functional modules, and the transceiver unit is a collective term for these functional modules.

[0117] In one optional implementation, the transceiver unit (or the transmitting unit) is configured to transmit a fourth MAC PDU, the fourth MAC PDU including a first MAC SDU and a first MAC subheader, the first MAC subheader being the MAC subheader of the first MAC SDU, wherein the first MAC SDU is carried on a first resource, the first resource corresponding to an LCID or a data radio bearer, and the first MAC subheader does not include the identifier of the LCID or the data radio bearer.

[0118] In one optional implementation, the transceiver unit (or the transmitting unit) is configured to transmit a first MAC PDU, the first MAC PDU comprising M MAC SDUs, wherein the first MAC PDU comprises a first PDCP header, the first PDCP header being the PDCP header of the first MAC SDU among the M MAC SDUs, and the first MAC PDU not including the PDCP headers of the remaining M-1 MAC SDUs besides the first MAC SDU among the M MAC SDUs, where M is an integer greater than or equal to 2.

[0119] In one optional implementation, the processing unit is configured to generate M PDCPPDUs through a first PDCP entity, wherein the M PDCP PDUs are all PDCP data PDUs, M is a positive integer, and M-1 of the M PDCP PDUs do not include PDCP headers (e.g., implemented by the first PDCP entity according to a fourth rule); the processing unit is further configured to deliver the processed M PDCP PDUs to the RLC layer of the terminal through the first PDCP entity.

[0120] In one optional implementation, the transceiver unit (or the transmitting unit) is configured to transmit a second MAC PDU, the second MAC PDU including a first MAC SDU, wherein the first MAC SDU includes the payload of at least two PDCP PDUs, the first MAC SDU including a PDCP header, the PDCP header including first information, the first information being used to indicate the payload length of the at least two PDCP PDUs.

[0121] In one alternative implementation, the transceiver unit (or the transmitting unit) is configured to transmit a third MAC PDU, the third MAC PDU including a first RLC PDU, the first RLC PDU being determined according to a third rule indicating that the first RLC PDU does not include segmented RLC SDUs.

[0122] In one optional implementation, the transceiver unit (or the transmitting unit) is configured to transmit a first RLCPDU, the first RLC PDU comprising at least two RLC SDUs, the RLC header of the first RLC PDU comprising at least one length field, the at least one length field being used to indicate the length of the at least two RLC SDUs, or to indicate the length of the RoHC header included in the at least two RLC SDUs, wherein the number of bits occupied by each length field in some or all of the at least one length field is less than a first threshold.

[0123] In one optional implementation, the transceiver unit (or the transmitting unit) is configured to transmit a fifth MAC PDU, the fifth MAC PDU including a first MAC SDU, and the fifth MAC PDU not including the MAC subheader of the first MAC SDU.

[0124] In one optional implementation, the transceiver unit (or the transmitting unit) is used to transmit a sixth MAC PDU, which includes K MAC SDUs and K MAC subheaders. The K MAC subheaders correspond one-to-one with the K MAC SDUs. The remaining MAC subheaders among the K MAC subheaders, except for the third MAC subheader, do not include the LCID or the identifier of the data radio bearer. The third MAC subheader is the MAC subheader of the first MAC SDU among the K MAC SDUs. All K MAC SDUs correspond to the same LCID or the same data radio bearer, and K is a positive integer.

[0125] In an alternative embodiment, the communication device further includes a storage unit (sometimes also called a storage module), and a processing unit is configured to couple with the storage unit and execute programs or instructions in the storage unit to enable the communication device to perform the functions of a data transmitting end as described in any one of the first, third, fifth, sixth, eighth, tenth, twelfth, or fourteenth aspects.

[0126] In a seventeenth aspect, a communication device is provided. The communication device may be a data receiving end as described in any one of the second, fourth, seventh, ninth, eleventh, thirteenth, or fifteenth aspects. The communication device possesses the functions of the aforementioned data receiving end. For example, the communication device may include modules, units, or means corresponding to the operations involved in any one of the second, fourth, seventh, ninth, eleventh, thirteenth, or fifteenth aspects. These modules, units, or means may be implemented in software, hardware, or a combination of software and hardware. The communication device may be, for example, a network device, or other device including network device functions, or a chip system (or chip or circuit) or other functional module capable of implementing the functions of a network device, and may be, for example, disposed within a network device. In an optional 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 called a processing module) and a transceiver unit (sometimes also called a transceiver module). For details on the implementation of the transceiver unit, please refer to the description in aspect sixteen.

[0127] In one optional implementation, the transceiver unit (or the receiving unit) is configured to receive a fourth MAC PDU, the fourth MAC PDU including a first MAC SDU and a first MAC subheader, the first MAC subheader being the MAC subheader of the first MAC SDU, wherein the first MAC SDU is carried on a first resource, the first resource corresponding to an LCID or a data radio bearer, and the first MAC subheader does not include the identifier of the LCID or the data radio bearer.

[0128] In one optional implementation, the transceiver unit (or the receiving unit) is configured to receive a first MAC PDU, the first MAC PDU comprising M MAC SDUs, wherein the first MAC PDU includes a first PDCP header, the first PDCP header being the PDCP header of the first MAC SDU among the M MAC SDUs, and the first MAC PDU does not include the PDCP headers of the remaining M-1 MAC SDUs besides the first MAC SDU among the M MAC SDUs, where M is an integer greater than or equal to 2.

[0129] In one optional implementation, the transceiver unit (or the receiving unit) is configured to receive a second MAC PDU, the second MAC PDU including a first MAC SDU, wherein the first MAC SDU includes the payload of at least two PDCP PDUs, the first MAC SDU including a PDCP header, the PDCP header including first information, the first information being used to indicate the payload length of the at least two PDCP PDUs.

[0130] In one alternative implementation, the transceiver unit (or the receiving unit) is configured to receive a third MAC PDU, the third MAC PDU including a first RLC PDU, the first RLC PDU being determined according to a third rule indicating that the first RLC PDU does not include segmented RLC SDUs.

[0131] In one optional implementation, the transceiver unit (or the receiving unit) is configured to receive a first RLCPDU, the first RLC PDU comprising at least two RLC SDUs, the RLC header of the first RLC PDU comprising at least one length field, the at least one length field being used to indicate the length of the at least two RLC SDUs, or to indicate the length of the RoHC header included in the at least two RLC SDUs, wherein the number of bits occupied by each length field in some or all of the at least one length field is less than a first threshold.

[0132] In one optional implementation, the transceiver unit (or the receiving unit) is configured to receive a fifth MAC PDU, the fifth MAC PDU including a first MAC SDU, and the fifth MAC PDU not including the MAC subheader of the first MAC SDU.

[0133] In one optional implementation, the transceiver unit (or the receiving unit) is configured to receive a sixth MAC PDU, the sixth MAC PDU comprising K MAC SDUs, the sixth MAC PDU further comprising K MAC subheaders, the K MAC subheaders corresponding one-to-one with the K MAC SDUs, wherein the remaining MAC subheaders among the K MAC subheaders, except for the third MAC subheader, do not include the LCID or the identifier of the data radio bearer, the third MAC subheader being the MAC subheader of the first MAC SDU among the K MAC SDUs, and the K MAC SDUs all corresponding to the same LCID or the same data radio bearer, where K is a positive integer.

[0134] In an alternative embodiment, the communication device further includes a storage unit (sometimes also called a storage module), and the processing unit is configured to couple with the storage unit and execute programs or instructions in the storage unit to enable the communication device to perform the functions of a data receiving end as described in any one of the second, fourth, seventh, ninth, eleventh, thirteenth, or fifteenth aspects.

[0135] Eighteenthly, an apparatus is provided, the apparatus comprising a memory and one or more processors. The memory is used to store part or all of a computer program or instructions necessary for implementing the functions involved in any of the first, third, fifth, sixth, eighth, tenth, twelfth, or fourteenth aspects described above. The one or more processors are executable to carry out the computer program or instructions, which, when executed, cause the apparatus to implement the methods in any possible design or implementation of any of the first, third, fifth, sixth, eighth, tenth, twelfth, or fourteenth aspects described above.

[0136] In one possible design, the device may further include interface circuitry, wherein the processor is configured to communicate with other devices or components via the interface circuitry.

[0137] In one possible design, the device may also include the memory.

[0138] The aforementioned device may be a terminal, or a communication module in the terminal, or a chip in the terminal responsible for communication functions such as a modem chip (also known as a baseband chip) or a SoC or SIP chip containing a modem module.

[0139] Nineteenthly, an apparatus is provided, the apparatus comprising a memory and one or more processors. The memory is used to store part or all of a computer program or instructions necessary for implementing the functions described in the second, fourth, seventh, ninth, eleventh, thirteenth, or fifteenth aspects above. The one or more processors are executable to carry out the computer program or instructions, which, when executed, cause the apparatus to implement the methods in any possible design or implementation of the second, fourth, seventh, ninth, eleventh, thirteenth, or fifteenth aspects above.

[0140] In one possible design, the device may further include interface circuitry, wherein the processor is configured to communicate with other devices or components via the interface circuitry.

[0141] In one possible design, the device may also include the memory.

[0142] The aforementioned device may be a network device, a communication module in a network device, or a chip in a network device that is responsible for communication functions, such as a modem chip (also known as a baseband chip) or a SoC or SIP chip that contains a modem module.

[0143] A twentieth aspect provides a communication system comprising a data transmitter and / or a data receiver. The data transmitter is configured to perform the methods described in any one of the first, third, fifth, sixth, eighth, tenth, twelfth, or fourteenth aspects; the data receiver is configured to perform the methods described in any one of the second, fourth, seventh, ninth, eleventh, thirteenth, or fifteenth aspects. For example, the data transmitter may be implemented using the apparatus described in the sixteenth or eighteenth aspect; the data receiver may be implemented using the apparatus described in the seventeenth or nineteenth aspect.

[0144] In a twenty-first aspect, a computer-readable storage medium is provided for storing a computer program or instructions that, when executed, cause the methods performed by the data sending end or data receiving end in the above aspects to be implemented.

[0145] In a twenty-second aspect, a computer program product containing instructions is provided, which, when the computer program or instructions are run on a computer, causes the methods described in the above aspects to be implemented.

[0146] In a twentieth aspect, a chip system is provided, including a processor and an interface, the processor being configured to call and execute instructions from the interface to enable the chip system to implement the methods described above. Attached Figure Description

[0147] Figure 1 Here is an example of a structure for a voice data packet;

[0148] Figure 2 , Figures 3A to 3C These are schematic diagrams illustrating several application scenarios of embodiments of this application;

[0149] Figure 4 , Figure 7 , Figure 10 , Figure 11 , Figure 14 , Figure 17 , Figure 18 Flowcharts of several communication methods provided in the embodiments of this application;

[0150] Figure 5This is an example of one arrangement of the PDCP control PDU and PDCP PDU in the embodiments of this application;

[0151] Figure 6 This is an example of a PDCP header in an embodiment of this application;

[0152] Figure 8 This is an example of the PDCP header of the aggregated PDCP PDU in the embodiments of this application;

[0153] Figure 9 This is another example of the PDCP header of the aggregated PDCP PDU in the embodiments of this application;

[0154] Figure 12 This is an example of an RLC header in the embodiments of this application;

[0155] Figure 13 This is another example of an RLC header in the embodiments of this application;

[0156] Figure 15 This is an example of a MAC subheader in an embodiment of this application;

[0157] Figure 16 This is an example of the MAC subheader of MAC CE and the MAC subheader of MAC SDU in the embodiments of this application;

[0158] Figure 19 This is an example of K MAC sub-PDUs in an embodiment of this application;

[0159] Figure 20 This is an example of a MAC subheader in an embodiment of this application;

[0160] Figure 21 This is another example of a MAC subheader in the embodiments of this application;

[0161] Figure 22 A schematic diagram of an apparatus provided in an embodiment of this application;

[0162] Figure 23 This is a schematic diagram of another device provided in an embodiment of this application. Detailed Implementation

[0163] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the embodiments of this application will be further described in detail below with reference to the accompanying drawings.

[0164] In this application embodiment, the number of nouns, unless otherwise specified, refers to "singular nouns or plural nouns," that is, "one or more." "At least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the related objects before and after are in an "or" relationship. For example, A / B means: A or B. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c means: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, and c can be single or multiple.

[0165] The ordinal numbers such as "first" and "second" mentioned in the embodiments of this application are used to distinguish multiple objects, and are not used to limit the size, content, order, timing, priority, or importance of the multiple objects. Furthermore, the numbering of steps in the various embodiments described in this application is only to distinguish different steps and is not used to limit the order in which the steps are performed.

[0166] The following explanations of some terms or concepts used in the embodiments of this application are provided to facilitate understanding by those skilled in the art.

[0167] In this embodiment of the application, the terminal device is a device with wireless transceiver function, which may be a fixed device, a mobile device, a handheld device (e.g., a mobile phone), a wearable device, an in-vehicle device, or a wireless device (e.g., a communication module, a modem, or a chip system, etc.) built into the above devices. The terminal devices are used to connect people, things, and machines, and can be widely used in various scenarios, including but not limited to the following: satellite communication scenarios, sensing scenarios, cellular communication, non-terrestrial networks (NTN), device-to-device (D2D) communication, vehicle-to-everything (V2X) communication, machine-to-machine / machine-type communications (M2M / MTC), Internet of Things (IoT), virtual reality (VR), augmented reality (AR), industrial control, self-driving, remote medical, smart grid, smart furniture, smart office, smart wearables, smart transportation, smart city, drones, robots, and terminal devices in indoor commercial scenarios (such as mobile phone screen mirroring, file sharing, and mobile phone to VR glasses). When the terminal equipment is applied to V2X, it can also be called a V2X device, such as a smart car, digital car, unmanned car, driverless car, pilotless car, or automobile, self-driving car, or autonomous car, pure electric vehicle (EV), hybrid electric vehicle (HEV), range-extended electric vehicle (REEV), plug-in hybrid electric vehicle (PHEV), new energy vehicle, or roadside unit (RSU). The terminal equipment can also be a device used in D2D communication, such as an electricity meter or water meter.

[0168] Furthermore, in this embodiment, the terminal device can also be a terminal device in an IoT system. IoT is an important component of the future development of information technology. Its main technical feature is to connect objects to the network through communication technology, thereby realizing an intelligent network of human-machine interconnection and object-to-object interconnection.

[0169] The various terminal devices described above, if located in a vehicle (e.g., placed inside or installed inside a vehicle), can all be considered in-vehicle terminal devices, also known as on-board units (OBUs). The terminal device of this application can also be an in-vehicle module, in-vehicle component, in-vehicle chip, or in-vehicle unit built into a vehicle as one or more components or units. The vehicle can implement the methods of this application through the built-in in-vehicle module, in-vehicle component, in-vehicle chip, or in-vehicle unit.

[0170] The terminal equipment may sometimes be referred to as user equipment (UE), terminal, access station, UE station, remote station, wireless communication equipment, or user device, etc.

[0171] In this application embodiment, the communication device used to implement the terminal device function can be a terminal device, which can be a terminal device or a device capable of supporting the terminal device to implement the function, such as a communication module or chip system. This device can be installed in the terminal device. In the technical solutions provided in this application embodiment, the UE is used as an example to describe the technical solutions provided in this application embodiment.

[0172] The network devices in this application embodiment include, for example, access network devices (or access network elements) and / or core network devices (or core network elements). The access network devices are devices with wireless transceiver capabilities, used to communicate with the terminal devices. The access network devices include, but are not limited to, base stations (base transceiver stations (BTS), Node B, evolved Node B (eNodeB) / eNB, or the next generation Node B (gNodeB) / gNB), transmission reception points (TRPs), base stations evolved from the 3rd generation partnership project (3GPP), access nodes in wireless fidelity (Wi-Fi) systems, wireless relay nodes, wireless backhaul nodes, etc. The base stations can be: macro base stations, micro base stations, pico base stations, small cells, relay stations, etc. Multiple base stations can support networks using the same access technology or networks using different access technologies. A base station can contain one or more co-located or non-co-located transmission and reception points. The access network equipment can also be a radio controller, centralized unit (CU), and / or distributed unit (DU) in a cloud radioaccess network (CRAN) scenario. The access network equipment can also be a server, etc. In satellite communication systems, the access network equipment can be a satellite, a base station mounted on a satellite, or a gateway station (also called a ground station, earth station, signaling station, gateway, or gateway station). In some scenarios, the network equipment can also be a satellite communication terminal, such as a portable station, a fixed station, a vehicle-mounted or airborne satellite communication terminal. It should be understood that in these scenarios, the satellite communication terminal communicates with the satellite and can act as a micro base station or satellite data station to further provide data interfaces to user equipment accessing the satellite communication terminal. For example, the network equipment in V2X technology can be a roadside unit (RSU). The following explanation of the access network equipment uses a base station as an example. A base station can communicate with a terminal device, or it can communicate with a terminal device through a relay station. A terminal device can communicate with multiple base stations in different access technologies. The core network equipment is used to implement functions such as mobility management, data processing, session management, policy and accounting. The names of the equipment implementing core network functions may differ in systems using different access technologies; this application does not limit this.Taking the 5th generation (5G) mobile communication technology system as an example, the core network equipment includes, for example, access and mobility management function (AMF), session management function (SMF), policy control function (PCF), or user plane function (UPF), etc.

[0173] In a CU-DU architecture, or in an open RAN (ORAN) system, access network equipment may include one or more logical network elements such as CU, DU, CU-control plane (CP), CU-user plane (UP), or radio unit (RU). CU and DU can be separate entities or included in the same network element, such as a baseband unit (BBU). RU may be included in radio equipment or radio units, such as remote radio units (RRU), active antenna units (AAU), or remote radio heads (RRH).

[0174] In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, in an ORAN system, CU can also be called an open CU (O-CU), DU can also be called an open DU (O-DU), CU-CP can also be called an open CU-CP (O-CU-CP), CU-UP can also be called an open CU-UP (O-CU-CP), and RU can also be called an open RU (O-RU). For ease of description, this application uses CU, CU-CP, CU-UP, DU, and RU as examples in its embodiments. Any of the units among CU (or CU-CP, CU-UP), DU, and RU in the embodiments of this application can be implemented through software modules, hardware modules, or a combination of software modules and hardware modules.

[0175] The CU and DU can be configured according to the protocol layer functions of the wireless network they implement. For example, the CU can be configured to implement the functions of the Packet Data Convergence Protocol (PDCP) layer and above (such as the Radio Resource Control (RRC) layer and / or the Service Data Adaptation Protocol (SDAP) layer); the DU can be configured to implement the functions of protocol layers below the PDCP layer (such as one or more of the Radio Link Control (RLC) layer, Media Access Control (MAC) layer, or Physical (PHY) layer). As another example, the CU can be configured to implement the functions of protocol layers above the PDCP layer (such as the RRC and / or SDAP layers), and the DU can be configured to implement the functions of protocol layers below the PDCP layer (such as one or more of the RLC, MAC, or PHY layers).

[0176] The above CU and DU configurations are merely examples; the functions of the CU and DU can be configured as needed. For instance, the CU or DU can be configured to have more protocol layer functions, or only some protocol layer processing functions. For example, some RLC layer functions and protocol layer functions above the RLC layer can be placed in the CU, while the remaining RLC layer functions and protocol layer functions below the RLC layer can be placed in the DU. Furthermore, the functions of the CU or DU can be divided according to service type or other system requirements, such as by latency. Functions that require low latency can be placed in the DU, while functions that do not require low latency can be placed in the CU.

[0177] DU and RU can cooperate to implement the functions of the PHY layer. A DU can be connected to one or more RUs. The functions of DU and RU can be configured in various ways depending on the design. For example, a DU can be configured to implement baseband functions, and an RU can be configured to implement mid-RF functions. Another example is that a DU can be configured to implement higher-level functions in the PHY layer, and an RU can be configured to implement lower-level functions in the PHY layer, or to implement both lower-level and RF functions. Higher-level functions in the physical layer can include a portion of the physical layer's functions that are closer to the MAC layer, while lower-level functions in the physical layer can include another portion of the physical layer's functions that are closer to the mid-RF side.

[0178] In this application embodiment, the communication device used to implement the functions of a network device can be called a network device. This network device can be a network element, a network device, or a device capable of supporting the network device or network element to implement the function, such as a chip system. This device can be installed in the network device. In the technical solutions provided in this application embodiment, the device used to implement the functions of a network device is described as a network device (for example, the device used to implement the functions of an access network device is an access network device, and the device used to implement the functions of a core network device is a core network device).

[0179] The technical features involved in the embodiments of this application are described below.

[0180] For IMS voice data packets, after the voice data packet is encoded at the sending end, each protocol layer that the voice data packet passes through adds a corresponding header to the voice data packet. For example, see reference... Figure 1 This is an example of a voice data packet. For instance, after voice data is encoded, it reaches the IP / UDP / RTP layer. The IP / UDP / RTP layer can then add an IP / UDP / RTP header to the voice data, resulting in voice data packet A. This voice data is included as the payload in voice data packet A. Voice data packet A can be referred to as a PDCP service data unit (SDU).

[0181] When voice data packet A reaches the PDCP layer, the PDCP layer can perform robust header compression (RoHC) on the IP / UDP / RTP header within voice data packet A to obtain the RoHC header. Additionally, the PDCP layer can add a PDCP header to voice data packet A to obtain voice data packet B. Voice data packet B can be called a PDCP protocol data unit (PDU) or an RLC SDU.

[0182] When voice data packet B arrives at the RLC layer, the RLC layer performs the appropriate processing (e.g., segmentation and concatenation of Long Term Evolution (LTE) RLC entities, or segmentation of New Radio (NR) RLC entities). The RLC layer then adds an RLC header to the data packet containing voice data packet B, resulting in a data packet called voice data packet C. Voice data packet C can be called an RLC PDU or a MAC SDU.

[0183] When voice data packet C arrives at the MAC layer, the MAC layer performs appropriate processing (e.g., multiplexing resources for data packets from different logical channels, assembling MAC PDUs). Then, the MAC layer adds a MAC header to the data packet including voice data packet C, resulting in voice data packet D. Voice data packet D can be called a MAC PDU. This voice data packet D is then transmitted to the physical layer and sent by the physical layer.

[0184] As can be seen, each protocol layer adds a header before transmission. Since the payload of voice data packets is relatively small, the header occupies a larger proportion of the voice data packet D. For example, if we want to provide voice services via high-orbit satellites, the transmission rate is relatively low due to the long communication distance and significant path loss, such as 1–3 kilobits per second (kbps). To accommodate this transmission rate, the voice coding rate can be reduced, i.e., the coding rate of the original voice data packet payload can be reduced, for example, to 800 bits per second (bps). Refer to Table 1 for the possible transmission overhead of each layer's header in a voice data packet at a coding rate of 800 bps.

[0185] Table 1

[0186]

[0187]

[0188] As shown in Table 1, when the encoding rate is 800bps, the headers occupy a total of 44 bytes, while the payload is only 16 bits. This indicates that when transmitting voice data packets, the proportion of effective data (i.e., the payload) is relatively small, with more resources used for transmitting headers, resulting in a waste of transmission resources.

[0189] Therefore, in this embodiment of the application, the first MAC PDU only includes the PDCP header corresponding to the data packet in the first MACSDU among the M MAC SDUs, and does not include the PDCP headers corresponding to the data packets in the other MAC SDUs among the M MAC SDUs. This reduces the number of PDCP headers included in the first MAC PDU, thereby effectively reducing the number of PDCP headers included in the first MAC PDU, lowering the proportion of headers in the first MAC PDU, and saving transmission resources. The data packets in the MAC SDU are, for example, payloads.

[0190] The communication method provided in this application can be applied to fourth-generation (4G) communication systems, such as LTE communication systems, as well as 5G communication systems, such as 5G NR communication systems, or various communication systems evolved after 5G, such as future communication systems. The method provided in this application can also be applied to Bluetooth systems, wireless fidelity (Wi-Fi) systems, long-range radio (LoRa) systems, or vehicle-to-everything (V2X) systems. The method provided in this application can also be applied to sidelink (SL) communication. The method provided in this application can be applied to terrestrial networks (TN); or, the method provided in this application can also be applied to NTN, such as satellite communication systems, for example, transparent satellite architecture, backhaul satellite architecture, or regenerative satellite architecture, etc., without limitation. NTN can be a communication system integrated with other communication systems such as 4G, 5G mobile communication systems, or future communication systems, such as NR NTN, IoT NTN, etc.

[0191] Please refer to Figure 2 This is a schematic diagram of an application scenario according to an embodiment of this application. Figure 2 This includes a UE and network equipment, which may include access network equipment and / or core network equipment. For example, the UE camps on a cell provided by the network equipment. The UE may be located on the ground; the network equipment may be located on the ground or in the air, such as on a satellite, a drone, or an aircraft, or the network equipment may be a satellite, a drone, or an aircraft.

[0192] Please refer to this again. Figures 3A to 3C This diagram illustrates several network architectures of NTN, and also represents several application scenarios in embodiments of this application. Among them, the architecture where the UE connects to the terrestrial access network via satellite can be called a transparent satellite architecture (e.g., Figure 3A The architecture that places access network equipment on a satellite (or the satellite has the function of access network equipment) is called a regenerative satellite architecture or regenerative star architecture (e.g. Figure 3B The architecture where the UE connects to the terrestrial access network and then connects to the terrestrial network via satellite can be called a satellite backhaul architecture (e.g., UE connects to the terrestrial access network and then connects to the terrestrial network via satellite). Figure 3C ).

[0193] exist Figure 3A In this system, the network elements used for transmitting services (such as access network equipment and / or core network equipment) are all located on the ground. The UE accesses the network through the access network equipment located on the ground via satellite, and the satellite has a pass-through function.

[0194] exist Figure 3B In this configuration, access network equipment is mounted on a satellite, or the underlying processing modules of access network elements are mounted on a satellite, or the satellite possesses some or all of the functions of the access network equipment. Besides the access network equipment, other network elements used for service transmission (such as core network equipment) are located on the ground. Alternatively, some or all of the network elements in the core network can also be mounted on a satellite, or the satellite can possess some or all of the functions of the network elements in the core network.

[0195] exist Figure 3C In this system, the access network equipment is located on the ground. The UE communicates with the satellite through the ground access network and then connects to the ground network through the satellite.

[0196] Optional, Figure 3A , Figure 3B or Figure 3C The satellites in the system can also be replaced by aerial equipment such as drones or high-altitude aircraft.

[0197] The method provided in the embodiments of this application is described below with reference to the accompanying drawings. In the flowcharts corresponding to the various embodiments of this application, unless otherwise specified, all steps indicated by dashed lines are optional steps.

[0198] The various embodiments described herein can be implemented by a UE and a network device. The various embodiments described herein can be applied to... Figure 2 , Figures 3A to 3C The network architecture shown in any of the accompanying figures. For example, the UE described in the various embodiments of this document can be... Figure 2 , Figures 3A to 3C The UE in any of the accompanying drawings, and the network device described in the various embodiments of this document, can be... Figure 2 Network devices in, or could be Figures 3A to 3C The access network device in any of the accompanying figures. Alternatively, the various embodiments herein may also be performed between UEs, in which case “UE” hereafter can be replaced with “UE1” and “network device” hereafter can be replaced with “UE2”.

[0199] This application provides a first communication method, please refer to... Figure 4 Here is a flowchart of the method. Optional, Figure 4 The embodiments shown can be used in LTE systems, or in other communication systems.

[0200] S401, the UE sends a fourth MAC PDU. Correspondingly, the network device receives the fourth MAC PDU. The UE can send the fourth MAC PDU on the first resource, and the network device can receive the fourth MAC PDU on the first resource.

[0201] Optionally, the fourth MAC PDU can carry voice data, or it can carry other types of data. The encoding rate of the data (e.g., voice data) carried by the fourth MAC PDU can be 800bps, or it can be greater or less than 800bps, and this application embodiment does not impose any limitations.

[0202] Optionally, the network device can send an RRC message to the UE, which can be used to configure the first resource and logical channel, or to configure the association between the first resource and the data radio bearer (DRB). When the UE receives information for scheduling the first resource, it can send a fourth MAC PDU on the first resource, where the fourth MAC PDU is data on the logical channel associated with the first resource, or data on the DRB associated with the first resource.

[0203] Optionally, the UE can send the fourth MAC PDU on the TN or on the NTN. If the UE sends the fourth MAC PDU on the NTN, the network device can be in the air, for example... Figure 3B The network device can be a satellite, or a functional module located on a satellite; alternatively, the network device can also be located on the ground, for example... Figure 3C Alternatively, the network device may include air-based functional modules and ground-based functional modules, for example... Figure 3A The network equipment may include satellites (or functional modules on satellites) and ground gateway stations.

[0204] The fourth MAC PDU may include the first MAC SDU, and may also include the MAC subheader of the first MAC SDU, which may be referred to as the first MAC subheader. The fourth MAC PDU is carried on a first resource, which, for example, corresponds to a logical channel ID (LCID). This LCID may be the LCID corresponding to the RLC PDU included in the first MAC SDU. For the receiving end, as long as the first MAC SDU is received through the first resource, it can determine that the first MAC SDU corresponds to the LCID. Therefore, the first MAC subheader may not include the LCID, or the first MAC subheader may not include any LCID.

[0205] Alternatively, the first resource may correspond to a DRB, which could be the DRB corresponding to a first logical channel, and the first logical channel could be the logical channel corresponding to the RLC PDU included in the first MAC SDU. For the receiving end, as long as the first MAC SDU is received through the first resource, it can be determined that the first MAC SDU corresponds to the DRB. Therefore, the first MAC sub-header may not include the identifier of the DRB, or the first MAC sub-header may not include any identifier corresponding to the DRB (e.g., the corresponding LCID). It is evident that, since this embodiment of the application associates the transmission resource with an LCID or DRB, the first MAC sub-header may not include the identifier of the LCID or DRB, thereby reducing the overhead of the first MAC sub-header.

[0206] Optionally, the first MAC subheader may include length information for the first MAC SDU. For example, this length information may be a length field included in the first MAC subheader, which indicates the length of the first MAC SDU. This length field may be represented as "length" for example, or it may have other representations.

[0207] For reference Figure 5 This is an example of a MAC subheader. Figure 5 The left side shows a traditional MAC header, and the right side shows a MAC header provided in this application embodiment, for example, the right side shows a first MAC header. Figure 5 In the right-hand diagram, the first MAC subheader may include a length field, but not the LCID or the DRB identifier.

[0208] Optionally, in addition to transmitting the MAC SDU, the first resource may also transmit a MAC control element (CE), which, along with the first MAC SDU, is included in, for example, a fourth MAC PDU. The MAC CE also has a MAC subheader, for example called a second MAC subheader, and this second MAC subheader is not shortened; for example, it may include MAC CE LCID, etc. Optionally, on the first resource, the MAC subheader of the MAC CE may precede the MAC subheader of the MAC SDU.

[0209] Optionally, the second MAC subheader may include information indicating that the second MAC subheader is a MAC CE; the first MAC subheader may include information indicating that the second MAC subheader is a MAC SDU. For example, both the information included in the second MAC subheader and the information included in the first MAC subheader are referred to as second indication information, which may indicate that the MAC subheader containing the second indication information corresponds to a MAC CE or a MAC SDU. The second indication information may occupy one or more bits. Optionally, the second indication information may occupy one or more bits at the beginning of the MAC subheader, such as the first bit of the MAC subheader.

[0210] Optionally, the second indication information included in the first MAC subheader can be a first value, and the value of the second indication information included in the second MAC subheader can be a second value. The first value can indicate that the first MAC subheader is the MAC subheader of a MAC SDU; the second value can indicate that the second MAC subheader is the MAC subheader of a MAC CE.

[0211] Taking the second indication information occupying one bit as an example, for instance, the first value is "1" and the second value is "0". Then, if the bit is "1", it indicates that the MAC subheader where the second indication information is currently located corresponds to the MAC SDU, or indicates that the MAC subheader where the second indication information is currently located is the MAC subheader of the MAC SDU; or, if the bit is "0", it indicates that the MAC subheader where the second indication information is currently located corresponds to the MAC CE, or indicates that the MAC subheader where the second indication information is currently located is the MAC subheader of the MAC CE.

[0212] For reference Figure 6 This is an example of the MAC subheader for MAC CE and MAC subheader for MAC SDU. Figure 6 The left side shows the traditional MAC header, and the right side shows the MAC header provided in this application embodiment. For example, the first row on the right is the second MAC header, and the second row on the right is the first MAC header. Figure 6 In the right-hand diagram, the first MAC header may include a length field, but not the LCID or the DRB identifier. Figure 6 In the right image, the second MAC subheader is located before the first MAC subheader.

[0213] In this embodiment, since the transmission resource can correspond to the identifier of LCID or DRB, the MAC subheader may not include the identifier of LCID or DRB to reduce the overhead of the MAC subheader. Furthermore, if MAC CE and MAC SDU are transmitted on the same resource, the second indication information can be used to distinguish their MAC subheaders, thereby reducing the probability of incorrect identification by the receiver.

[0214] This application provides a second communication method, please refer to the embodiments therein. Figure 7 Here is a flowchart of the method.

[0215] S701, the UE sends the first MAC PDU. Correspondingly, the network device receives the first MAC PDU.

[0216] Optionally, the first MAC PDU is used to carry voice data, or it may carry other types of data. The encoding rate of the data (e.g., voice data) carried by the first MAC PDU may be 800 bps, or it may be greater than or less than 800 bps, and this application embodiment does not impose any limitations.

[0217] Optionally, the UE can send the first MAC PDU on the terrestrial network or on the NTN. If the UE sends the first MAC PDU on the NTN, the network device can be located in the air, for example... Figure 3B The network device can be a satellite, or a functional module located on a satellite; alternatively, the network device can also be located on the ground, for example... Figure 3C Alternatively, the network device may include air-based functional modules and ground-based functional modules, for example... Figure 3A The network equipment may include satellites (or functional modules on satellites) and ground gateway stations.

[0218] The first MAC PDU can include M MAC SDUs. M is a positive integer, for example, M is 1, or M can be greater than 1.

[0219] Optionally, the M MAC SDUs may come from the same DRB.

[0220] Optionally, the first MAC PDU may also include a first PDCP header, which may be, for example, the PDCP header corresponding to the data packets in a portion of the M MAC SDUs. For the remaining MAC SDUs other than the portion of MAC SDUs, the first MAC PDU may not include the PDCP header corresponding to the data packets in the remaining MAC SDUs.

[0221] For example, for the M MAC SDUs, the first MAC PDU may only include the PDCP header corresponding to the data packet in the first MAC SDU, excluding the PDCP headers corresponding to the data packets in the remaining MAC SDUs. That is, the first PDCP header is the PDCP header of the data packet in the first MAC SDU among the M MAC SDUs. Alternatively, the first MAC PDU may only include the PDCP header corresponding to the data packet in one of the M MAC SDUs, and the PDCP header corresponding to the MAC SDU including the PDCP control PDU, excluding the PDCP headers corresponding to the data packets in the remaining MAC SDUs. That is, the first PDCP header is the PDCP header of the data packet in one of the M MAC SDUs. Since the M MAC SDUs come from the same DRB, for example, from the same data packet transport bearer, the PDCP headers corresponding to the data packets in the M MAC PDUs are adjacent. Therefore, the PDCP SN corresponding to the other data packets that do not include PDCP headers can be derived from the PDCP SN included in the PDCP header of one data packet. In this way, it is equivalent to removing M-1 PDCP headers, thereby reducing the transmission overhead of the first MAC PDU. In this implementation, for example, M can be an integer greater than or equal to 2.

[0222] Alternatively, for example, the first MAC PDU may include the PDCP headers corresponding to data packets in a portion of the M MAC SDUs, but not the PDCP headers corresponding to data packets in the remaining M MAC SDUs. That is, the first PDCP header includes the PDCP headers of the data packets in that portion of the M MAC SDUs. The number of these data packets can be greater than or equal to 1 and less than M, and there is no restriction on which specific portion of the M MAC SDUs this portion belongs to. In this implementation, for example, M can be a positive integer.

[0223] Alternatively, the first MAC PDU may not include the PDCP headers corresponding to the M MAC SDUs, for example, it may not include the PDCP header of any one of the M MAC SDUs. In this implementation, M may be 1, for example.

[0224] Optionally, the data packets in the M MAC SDUs satisfy the first rule. The first rule may include, for example, that the data packets included in a MAC PDU are data packets carried within the same transport block (TB); or, the first rule may include, for example, that a MAC PDU includes M consecutive data packets with corresponding PDCP SNs. The data packets included in a MAC PDU may be data packets included in a MAC SDU within that MAC PDU.

[0225] Alternatively, it can be understood that the M MAC SDUs can satisfy the first rule, or that the M MAC SDUs can be determined according to the first rule. The first rule may include, for example, that a MAC PDU includes MAC SDUs carried within the same TB; or, for example, that a MAC PDU includes M MAC SDUs with consecutive PDCP SNs. This application embodiment uses the example of the M MAC SDUs satisfying the first rule.

[0226] The first rule can be, for example, a rule configured by the network device, a rule predefined by the protocol, or a rule negotiated between the UE and the network device.

[0227] If the first rule includes a MAC PDU containing MAC SDUs carried within the same TB, then for all MAC SDUs carried by the same TB, only the PDCP header corresponding to the data packet in the first MAC SDU needs to be retained, while the PDCP headers corresponding to the data packets in the remaining MAC SDUs need not be retained. The number of MAC SDUs carried by a TB can be fixed or variable; that is, the value of M can be the same or different for different TBs. For example, TB1 carries 3 MAC SDUs, while TB2 carries 2 MAC SDUs. Only one PDCP header needs to be retained for the MAC SDUs carried by the same TB; there is no limit to the number of MAC SDUs, making the approach quite flexible.

[0228] Specifically, PDCP can know in advance which MAC SDUs are carried within a TB. For example, the PDCP layer can determine which MAC SDUs are carried within a TB based on the uplink scheduling resource size indicated by the MAC layer. For instance, when the MAC layer needs to perform a transmission, it can request data from the RLC layer, such as requesting data that can be carried within a TB. The RLC layer can then forward or transparently transmit the MAC layer's request to the PDCP layer, thereby allowing the PDCP layer to know which MAC SDUs are carried within a TB.

[0229] If the first rule includes a MAC SDU comprising M consecutive MAC SDUs, it's equivalent to fixing that for each PDCP SN, only the PDCP header corresponding to the data packet in the first MAC SDU needs to be retained. These M MAC SDUs can be carried within the same TB, or they can be carried within multiple TBs. This approach fixes the value of M, simplifying the UE's processing. Furthermore, in this approach, the PDCP layer doesn't need to know which MAC SDUs are carried within a TB, reducing inter-layer interactions.

[0230] During transmission, the UE can transmit PDCP control PDUs in addition to PDCP PDUs. If the PDCP control PDU is located among M PDCP PDUs, the receiver may be unable to identify these M PDCP PDUs due to the missing PDCP headers of M-1 of them. These M PDCP PDUs correspond to the M MAC SDUs, or can be understood as each of the M MAC SDUs including one PDCP PDU, thus the M MAC SDUs collectively include the M PDCP PDUs. Therefore, optionally, if the first rule includes a MAC PDU whose MAC SDUs are carried within the same TB, the PDCP control PDU can be placed before the M PDCP PDUs, ensuring that the receiver can identify both the PDCP control PDU and the PDCP PDU through the PDCP header. Optionally, the PDCP control PDU and the M PDCP PDUs are located within the same TB. The PDCP PDUs described in this embodiment can be understood as PDCP data PDUs. For example, refer to Figure 8 This is an example of one arrangement of PDCP control PDU and PDCP PDU. Figure 8 Taking M=3 as an example, it can be seen that the PDCP control PDU is located before the three PDCP PDUs. Among these three PDCP PDUs, only the PDCP header of the first PDCP PDU is retained. The latter two PDCP PDUs do not include the PDCP header, but only the RoHC header and the load.

[0231] Alternatively, the first rule may include a MAC PDU containing MAC SDUs carried within the same TB, and the first MAC PDU may not include the PDCP control PDU. This reduces the probability of the receiver misidentifying or failing to identify the PDCP PDU, and further saves on the transmission overhead of the MAC PDU.

[0232] Alternatively, if the first rule includes a MAC SDU comprising M consecutive MAC SDUs with PDCP SNs, then the first MAC PDU may not include the PDCP control PDU. Under this first rule, the M MAC SDUs can be carried within one TB or multiple TBs. If the PDCP control PDU is located among the M PDCP PDUs included in the M MAC SDUs, the receiver may be unable to identify the M PDCP PDUs. Therefore, the first MAC PDU may not include the PDCP control PDU, thereby reducing the probability of the receiver misidentifying or failing to identify the PDCP PDU, and further saving MAC PDU transmission overhead.

[0233] Alternatively, the first rule may include a MAC SDU comprising M consecutive MAC SDUs, and the first MAC PDU may also include a PDCP control PDU. In this case, the receiving end of the first MAC PDU (e.g., a network device) can determine, through blind detection, whether a PDCP control PDU header exists within the first MAC PDU, thus distinguishing between PDCP control PDUs and PDCP PDUs. Alternatively, since PDCP control PDUs are primarily used for RoHC feedback, if the first MAC PDU may include a PDCP control PDU, the network device can determine, through blind detection, whether a RoHC feedback header exists within the first MAC PDU, thus distinguishing between PDCP control PDUs and PDCP PDUs.

[0234] As an optional implementation, the PDCP serial numbers of the M MAC SDUs can satisfy the second rule. The second rule is, for example, a continuity rule, meaning that the PDCP serial numbers of the M MAC SDUs can be consecutive. (See reference...) Figure 9This is an example of a PDCP header. As you can see, the PDCP header may include a D / C field and a PDCP SN. The D / C field is used by the receiver to distinguish whether the current data packet is a PDCP data PDU or a PDCP control PDU. For the receiver, based on the PDCP SN included in the PDCP header of the first MAC SDU out of the M MAC SDUs, the PDCP SNs of the remaining M-1 MAC SDUs can be calculated. For example, if the PDCP SN of the first MAC SDU is 'a', then the PDCP SN of the second MAC SDU out of the M MAC SDUs is 'a+1', the PDCP SN of the third MAC SDU out of the M MAC SDUs is 'a+2', and so on.

[0235] For example, the second rule includes: the remainder when the PDCP SN of any MAC SDU in the MAC SDU is divided by M is 0. Alternatively, this second rule can be expressed as:

[0236] SN i mod M = 0 (Formula 1)

[0237] In formula 1, SN i This represents the PDCP SN of any MAC SDU among the M MAC SDUs. i can be an integer from 0 to M-1, or an integer from 1 to M. mod represents the remainder operation.

[0238] For example, in an LTE system, the RLC layer can have reordering capabilities, or it can be assumed that the data packets submitted by the RLC layer to the upper layers are not out of order for the receiver. Therefore, the receiver of the first MAC PDU (e.g., a network device) can recover the PDCP SNs corresponding to the data packets of the remaining M-1 MAC SDUs based on the PDCP SN corresponding to the detected data packet of the first MAC SDU, or it can estimate the range of the PDCP SNs of the remaining M-1 MAC SDUs based on the detected PDCP SN of the first MAC SDU, and perform blind detection within that range.

[0239] Optionally, the first MAC PDU may include only the M MAC SDUs and exclude other MAC SDUs, or the first MAC PDU may include other MAC SDUs in addition to the M MAC SDUs. For example, the first MAC PDU may also include N MAC SDUs, which may satisfy one or more of the rules satisfied by the M MAC SDUs (e.g., the first rule, and / or whether the first MAC SDU includes the PDCP header corresponding to the data packets in the M MAC SDUs, etc.), or the N MAC SDUs may not satisfy all the rules satisfied by the M MAC SDUs, without restriction. N is a positive integer.

[0240] Optionally, the PDCP header (e.g., the PDCP header corresponding to the M MAC SDUs included in the first MAC PDU, such as the first PDCP header) may include a PDCP SN. Optionally, the PDCP SN may occupy 7 bits. For example, for voice data, the information content of voice data packets is relatively small, and the required air interface rate is low. Therefore, a 7-bit PDCP SN can meet the transmission rate requirements and can be used as the configuration of the PDCP entity corresponding to the voice data bearer.

[0241] The method provided in the embodiments of this application can also be understood as follows.

[0242] For example, the UE's PDCP layer (or a PDCP entity of the UE, such as the first PDCP entity) can generate M PDCPPDUs, all of which are PDCP data PDUs. M can be configured by the network device or predefined by the standard. Optionally, all M PDCP PDUs can be voice PDUs, for example, the payloads included in all M PDCP PDUs can be voice data. The first PDCP entity can, according to a corresponding rule (such as the fourth rule), ensure that M-1 of the M PDCP PDUs do not contain a PDCP header. Alternatively, the first PDCP entity can, according to the fourth rule, ensure that the M-1 PDCP PDUs do not contain a PDCP header when generating the M PDCP PDUs; for example, the first PDCP entity may not generate a PDCP header for the M-1 PDCP PDUs.

[0243] Optionally, the M PDCP PDUs can be adjacent to each other.

[0244] Optionally, the M PDCP PDUs can correspond to the aforementioned M MAC SDUs. For example, one of the MAC SDUs may include one of the M PDCP PDUs, and the M MAC SDUs and the M PDCP PDUs can correspond one-to-one.

[0245] The first PDCP entity can deliver the processed M PDCP PDUs to the lower layer, such as the UE's RLC layer.

[0246] Optionally, the fourth rule may include one or more of the following: the M PDCP PDUs are M PDCP PDUs with consecutive PDCP SNs, the M PDCP PDUs are transmitted through the same MAC PDU, or M is pre-configured (e.g., network device pre-configuration) or pre-defined (e.g., protocol pre-defined).

[0247] Optionally, the fourth rule can correspond to the first rule. For example, if the fourth rule includes that the M PDCP PDUs are M PDCP PDUs with consecutive PDCP SNs, then the first rule may include a MAC PDU including MAC SDUs carried within the same TB; and / or, if the fourth rule includes that the M PDCP PDUs are transmitted through the same MAC PDU, then the first rule may include a MAC PDU including M MAC SDUs with consecutive PDCP SNs.

[0248] The M PDCP PDUs refer to M consecutive PDCP PDUs in the PDCP SN. This can also be understood as the first PDCP entity being able to, based on network device configuration or standard predefined information, ensure that at least a portion of the M PDCP PDUs do not contain a PDCP header (e.g., through periodic processing), thereby reducing PDCP header overhead. Optionally, the M PDCP PDUs being M consecutive PDCP SNs, where M is preconfigured or predefined, can have the same meaning. For example, if M is preconfigured or predefined, it indicates that M consecutive PDCP PDUs in the PDCP SN can be determined.

[0249] The M PDCP PDUs are transmitted through the same MAC PDU, for example, the first MAC PDU. This can also be understood as the first PDCP entity determining, based on feedback from the UE's MAC layer (or MAC entity), that the M PDCP PDUs are transmitted through the same MAC TB. Since the PDCP SNs of adjacent PDCP SDUs are adjacent or consecutive, the receiver can deduce the PDCP SNs of other PDCP SDUs from the PDCP SN of one PDCP SDU, thereby reducing PDCP header overhead.

[0250] Optionally, the first PDCP entity can also generate P PDCP control PDUs, where P is a positive integer. When the P PDCP control PDUs and the M PDCP data PDUs are all transmitted through the first MAC PDU, the MAC layer (or MAC entity) can first place or arrange the P PDCP control PDUs in the first MAC PDU, and then place or arrange the M PDCP data PDUs. Optionally, the PDCP header of the P PDCP control PDUs can also include indication information, such as third indication information, to indicate whether the current PDCP header corresponds to a PDCP data PDU or a PDCP control PDU. Thus, when the receiving end receives the first MAC PDU, it can distinguish which or which of the PDCP PDUs corresponding to the first PDCP entity in the first MAC PDU are PDCP control PDUs and which or which are PDCP data PDUs according to the third indication information, and further determine the deletion of the PDCP header of the PDCP PDU according to the corresponding rules.

[0251] In this embodiment of the application, the first PDCP entity can ensure that M-1 of the M PDCP data PDUs do not include the PDCP header, thereby reducing the number of PDCP headers in the underlying transmission process and saving transmission resources.

[0252] In this embodiment, since the current voice data packets are relatively small and the required air interface rate is low, a 7-bit PDCP SN can meet the transmission rate requirements and can be used as the configuration for the PDCP entity corresponding to the voice data bearer. The first MAC PDU may only include the PDCP headers corresponding to the data packets of some of the M MAC SDUs, without including the PDCP headers corresponding to the data packets of the other M MAC SDUs. This reduces the number of PDCP headers included in the first MAC PDU, thereby effectively reducing the packet header of the first MAC PDU, lowering the proportion of the packet header in the first MAC PDU, and saving transmission resources.

[0253] This application provides a third communication method; please refer to [reference needed]. Figure 10 Here is a flowchart of the method.

[0254] S1001, the UE sends a second MAC PDU. Correspondingly, the network device receives the second MAC PDU.

[0255] Optionally, the second MAC PDU can carry voice data, or it can carry other types of data. The encoding rate of the data (e.g., voice data) carried by the second MAC PDU can be 800bps, or it can be greater or less than 800bps, and this application embodiment does not impose any limitations.

[0256] Optionally, the UE can send the second MAC PDU on the TN or on the NTN. If the UE sends the second MAC PDU on the NTN, the network device can be in the air, for example... Figure 3B The network device can be a satellite, or a functional module located on a satellite; alternatively, the network device can also be located on the ground, for example... Figure 3C Alternatively, the network device may include air-based functional modules and ground-based functional modules, for example... Figure 3A The network equipment may include satellites (or functional modules on satellites) and ground gateway stations.

[0257] The second MAC PDU may include one or more MAC SDUs, such as one of the MAC SDUs being the first MACSDU. The structures of the different MAC SDUs within these one or more MAC SDUs may be the same or different; this application mainly describes the first MAC SDU.

[0258] The first MAC SDU may include the payloads of at least two PDCP PDUs, or may include at least two PDCP SDUs. For example, the PDCP layer of a UE may obtain multiple PDCP SDUs. Traditionally, the PDCP layer combines each PDCP SDU into a single PDCP PDU and submits it to the RLC layer. The RLC layer adds an RLC header to each PDCP PDU before submitting it to the MAC layer, which then adds a MAC header to each PDCP PDU, resulting in multiple MAC PDUs. However, in this embodiment, the PDCP layer can aggregate at least two PDCP SDUs, for example, by placing the payloads of at least two PDCP SDUs (e.g., the payload in a PDCPSDU excluding the RoHC header) into the same PDCP PDU, thus obtaining only one PDCP PDU. Normally, for these at least two PDCP SDUs, the PDCP layer would add at least two PDCP headers. However, since this embodiment actually aggregates the at least two PDCP SDUs into one PDCP PDU, the PDCP layer only needs to add one PDCP header. For example, under the NR transport protocol, the RLC layer only needs to add an RLC header to this PDCP PDU, and the MAC layer only needs to add a MAC header to this PDCP PDU, thereby reducing the overall header overhead.

[0259] The first MAC SDU actually includes the payloads of at least two PDCP SDUs or PDCP PDUs. Therefore, the PDCP header of the first MAC SDU may include first information, which may indicate the payload length of the at least two PDCP SDUs or PDCP PDUs. When the receiving end of the first MAC PDU (e.g., a network device) receives the first MAC PDU, it can determine the payload length of the at least two PDCP SDUs or PDCP PDUs based on the first information, thereby recovering the at least two PDCP PDUs or PDCP PDUs.

[0260] For example, the first information may include at least two length fields, each corresponding one-to-one with one of the at least two PDCP SDUs or PDCP PDUs, where each length field can indicate the load length of the corresponding PDCP SDU or PDCP PDU. (See reference...) Figure 11 This is an example of a PDCP header for an aggregated (or cascaded) PDCP PDU. Figure 11 For example, there are at least two PDCP SDUs or the number of PDCP PDUs is 3. Figure 11The PDCP header may include a length field 1 corresponding to the first PDCP SDU or PDCP PDU, a length field 2 corresponding to the second PDCP SDU or PDCP PDU, and a length field 3 corresponding to the third PDCP SDU or PDCP PDU. Length field 1 indicates the load length of the first PDCP SDU or PDCP PDU, length field 2 indicates the load length of the second PDCP SDU or PDCP PDU, and length field 3 indicates the load length of the third PDCP SDU or PDCP PDU. Following length field 3 is, for example, data. Additionally, the PDCP header may include a D / C field, a PDCP SN, an F field, etc. The F field can indicate a length range.

[0261] Optionally, if the length range is configured to be fixed, then Figure 11 The F field can also be the E field. The E field indicates whether the next byte is a PDCP data SDU or a PDCP PDU. Alternatively, the E field can indicate whether the next byte still contains length range information. For more information on the E field, please refer to the description of the first field below.

[0262] For example, the first information may include at least one length field, which indicates the length of the at least two PDCP SDUs or PDCP PDUs. Each of the at least one length field may indicate the load length of the corresponding PDCP SDU or PDCP PDU. The number of the at least one length field may be less than the number of the at least two PDCP SDUs or PDCP PDUs; for example, the number of the at least one length field may be the number of the at least two PDCP SDUs or PDCP PDUs minus one. For example, the length of the last PDCP SDU or PDCP PDU may not be indicated by the at least one length field, but rather determined by subtracting the length indicated by the at least one length field from the total length of the at least two PDCP SDUs or PDCP PDUs.

[0263] You can continue to refer to this. Figure 11 For example, the number of at least two PDCP SDUs or PDCP PDUs is 4. Figure 11In this PDCP header, the F field can also be the E field. The PDCP header can include a length field 1 corresponding to the first PDCP PDU, a length field 2 corresponding to the second PDCP PDU, and a length field 3 corresponding to the third PDCP PDU. Length field 1 indicates the payload length of the first PDCP PDU, length field 2 indicates the payload length of the second PDCP PDU, and length field 3 indicates the payload length of the third PDCP PDU. The E field can be used to determine whether the next byte after length field 3 is a PDCP data PDU. If there is a fourth PDCP PDU, the length of the fourth PDCP PDU can be determined by the receiver subtracting the lengths of the first three PDCP PDUs from the total length.

[0264] Optionally, the at least two length fields can be arranged adjacent to each other.

[0265] Alternatively, any one of the at least two length fields can be arranged adjacent to the PDCPSDU or PDCP PDU corresponding to that length field, so as to Figure 11 For example, the arrangement could be: Length field 1 - First PDCP PDU - Length field 2 - Second PDCP PDU - Length field 3 - Third PDCP PDU. In this implementation, the E field can indicate whether there is a length field after the current PDCP SDU or PDCP PDU ends; or it can indicate whether the next byte after the current PDCP SDU or PDCP PDU ends is a length field or the last concatenated PDCP SDU. For more details on the E field, please refer to the description of the first field below.

[0266] Optionally, the first information may also include a first field, which may indicate whether a next cascaded PDCP SDU or PDCP PDU exists. The first field may occupy one or more bits. For example, the first field may be as follows: Figure 11 As shown by "E", the first MAC PDU can include at least one first field. Taking the first field occupying one bit as an example, if the value of the first field is "1", or if the first field exists, it indicates that there is another cascaded PDCP SDU or PDCPPDU. In this case, the receiving end (e.g., network device) of the first MAC PDU can continue to parse the length field after the first field. However, if the value of the first field is "0", or if the first field does not exist, it indicates that there is no next cascaded PDCP SDU or PDCP PDU. In this case, the receiving end (e.g., network device) of the first MAC PDU can stop parsing the length field and instead parse the data.

[0267] Alternatively, the first information may not include the first field. For example, the number of PDCPSDUs that can be cascaded within a PDCP PDU, or the number of PDCP SDUs or PDCP PDUs that can be cascaded within a MAC SDU, can be known in advance by the UE and the network device. For example, this number can be predefined by the protocol, configured by the network device, or negotiated by the UE and the network device. In this case, the PDCP header corresponding to the data packet in the first MAC SDU does not necessarily need to indicate whether there is a next cascaded PDCP SDU or PDCP PDU, but can instead indicate the payload length of each PDCP SDU or PDCP PDU, thereby further saving the overhead of the PDCP header. For example, refer to... Figure 12 This is another example of the PDCP header of an aggregated PDCP SDU or PDCP PDU. Figure 12 Taking the example where the number of at least two PDCP PDUs is fixed at 2. Figure 12 The PDCP header may include a length field 1 corresponding to the first PDCP PDU and a length field 2 corresponding to the second PDCP PDU. Length field 1 indicates the payload length of the first PDCP PDU, and length field 2 indicates the payload length of the second PDCP PDU. Following length field 2 is, for example, data. The PDCP header may also include a D / C field, PDCP SN, etc. It is evident that the PDCP header may not include the first field indicated by "E". Figure 12 For example, the PDCP header may not include field F, or the PDCP header may include field F; there is no restriction on this.

[0268] As an optional implementation, the at least two PDCP SDUs or PDCP PDUs may correspond to the same PDCP SN, that is, the PDCP SNs of the at least two PDCP SDUs or PDCP PDUs are the same. Then, the PDCP SN included in the PDCP header of the aggregated PDCP SDU or PDCP PDU can be this PDCP SN. In this case, even if a PDCP PDU includes multiple aggregated PDCP SDUs, since the PDCP SNs of these multiple PDCP SDUs are the same, the PDCP SNs of different PDCP PDUs can be consecutive.

[0269] Alternatively, the different PDCP SDUs or PDCP PDUs among the at least two PDCP SDUs or PDCP PDUs can correspond to different PDCP SNs; that is, the PDCP SNs of the different PDCP SDUs or PDCP PDUs can be different. Optionally, the PDCP SN included in the PDCP header of the aggregated PDCP SDU or PDCP PDU can be one of the at least two PDCP SNs, for example, the PDCP SN of the first PDCP PDU or PDCP SDU among the at least two PDCP PDUs or PDCP SDUs. In this case, if a PDCP PDU includes multiple aggregated PDCP SDUs, since the PDCP header of the multiple PDCP SDUs only includes one of the PDCP SNs, the PDCP SNs of the different PDCP PDUs can be discontinuous. If the PDCP SNs of the different PDCP PDUs or PDCP SDUs are different, optionally, the PDCP SNs of the at least two PDCP SDUs or PDCP PDUs can be continuous to facilitate the receiver in recovering the PDCP SNs of the at least two PDCP SDUs or PDCP PDUs.

[0270] After receiving the at least two PDCP SDUs, the UE's PDCP layer can encrypt them before submitting them to the RLC layer to improve transmission security. Optionally, the UE can use the PDCP SN of the at least two PDCP SDUs to encrypt them. For example, if the at least two PDCP SDUs correspond to one PDCP SN, the PDCP layer can use that PDCP SN to encrypt the at least two PDCP SDUs. Alternatively, if different PDCP SDUs correspond to different PDCP SNs, the PDCP layer can use all the PDCP SNs corresponding to the at least two PDCP SDUs to encrypt them. For example, for any one of the PDCP SDUs, the PDCP SN corresponding to that PDCP SDU can be used to encrypt it; or, the PDCP layer can also use one of the PDCP SNs corresponding to the at least two PDCP SDUs to encrypt them, providing greater flexibility in encryption methods. Wherein, if the PDCP layer uses one of the PDCP SNs corresponding to the at least two PDCP SDUs to encrypt the at least two PDCP SDUs, then the PDCP SN can be the PDCP SN of any one of the at least two PDCP SDUs.

[0271] This application embodiment aggregates (or cascades; or sets) multiple PDCP SDUs into a single PDCP PDU. This PDCP PDU only needs to include one PDCP header, eliminating the need for multiple PDCP headers and effectively reducing PDCP header overhead. Furthermore, for other protocol layers (such as the RLC layer or MAC layer), which receive a single data packet from an upper layer, these other protocol layers only need to add one header (e.g., an RLC header or a MAC header) to that single data packet, instead of adding multiple headers, thus also reducing header overhead for other protocol layers.

[0272] This application provides a fourth communication method, please refer to the embodiments. Figure 13 Here is a flowchart of the method. Optional, Figure 13 The embodiments shown can be used in NR systems, or in other communication systems, such as future communication systems.

[0273] S1301, the UE sends a third MAC PDU. Correspondingly, the network device receives the third MAC PDU.

[0274] Optionally, the third MAC PDU can carry voice data, or it can carry other types of data. The encoding rate of the data (e.g., voice data) carried by the third MAC PDU can be 800bps, or it can be greater or less than 800bps, and this application embodiment does not impose any limitations.

[0275] Optionally, the UE can send the third MAC PDU on the TN or on the NTN. If the UE sends the third MAC PDU on the NTN, the network device can be in the air, for example... Figure 3B The network device can be a satellite, or a functional module located on a satellite; alternatively, the network device can also be located on the ground, for example... Figure 3C Alternatively, the network device may include air-based functional modules and ground-based functional modules, for example... Figure 3A The network equipment may include satellites (or functional modules on satellites) and ground gateway stations.

[0276] The third MAC PDU may include the first RLC PDU. The first RLC PDU may not include segmented RLC SDUs. For example, the RLC SDUs included in the first RLC PDU may be determined according to a third rule, which may indicate that the RLC PDU does not include segmented RLC SDUs. The third rule may be predefined by the protocol, configured by the network device, or determined through negotiation between the UE and the network device.

[0277] The RLC layer has a segmentation function. For example, if the data volume of an RLC SDU is large, it can be divided into multiple RLC SDUs for transmission. If an RLC PDU includes segmented RLC SDUs, the RLC header of that RLC PDU needs to include information indicating the segmentation, resulting in a longer RLC header. Therefore, this application proposes not to perform segmentation at the RLC layer, for example, not to divide an RLC SDU into multiple RLC SDUs, so that the RLC header does not need to carry information indicating segmentation. For example, if the first RLC PDU is not segmented at the RLC layer, that is, the first RLC PDU does not include segmented RLC SDUs, then the RLC header of the first RLC PDU does not need to include information indicating segmentation, thereby reducing the length of the RLC header.

[0278] For example, when the MAC layer performs logical channel priority (LCP) packetization on data on the logical channel (LCH), the corresponding RLC layer does not segment the RLC SDU. This eliminates the need to include information indicating segmented RLC SDUs in the RLC header, thus reducing its length. Optionally, the RLC layer can match the data size provided by the MAC layer. For example, if the RLC needs to store 50 bits of data for the current TB, and an RLC SDU is 35 bits in size, then the RLC will only store one RLC SDU in that TB, without splitting the second RLC SDU to provide 50 bits of data.

[0279] Optionally, the first RLC PDU may not include an RLC header. For example, the first RLC SDU may not include a segmented RLC SDU, and the third MAC PDU may not include the RLC header of the first RLC PDU, thereby further reducing header overhead. For example, the RLC entity (or RLC layer) corresponding to the third MAC PDU may adopt transparent mode (TM). In TM, the RLC PDU included in the third MAC PDU may not include an RLC header. The transmission mode of the RLC entity can be configured by the network device. For example, if the network device configures the transmission mode of the RLC entity of the DRB used for transmitting voice data to TM, the RLC header of the RLC PDU processed by the RLC entity can be removed. Optionally, the LCP packet assembly scheme described above can also be used for the RLC entity, that is, the RLC entity does not perform segmentation.

[0280] As an optional implementation, the number of hybrid automatic repeat request (HARQ) processes corresponding to the RLC entity can be 1. Alternatively, if the number of HARQ processes corresponding to the RLC entity is 1, then the RLC entity can use a TM (Transfer Module), in which case the RLC PDU may not include an RLC header.

[0281] The RLC layer in this embodiment may not segment the RLC SDU, thus omitting information indicating segmentation from the RLC header and saving RLC header overhead. Optionally, the RLC PDU may also omit the RLC header, further saving header overhead.

[0282] This application provides a fifth communication method; please refer to [link / reference]. Figure 14 Here is a flowchart of the method. Optional, Figure 14 The embodiments shown can be used in LTE systems, or in other communication systems.

[0283] S1401, the UE sends the first RLC PDU. Correspondingly, the network device receives the first RLC PDU.

[0284] The UE can further process the first RLC PDU before sending it. For example, the first RLC PDU can also be processed by protocol layers such as the MAC layer before being sent, and there is no limitation on this. Optionally, the first RLC PDU can carry voice data, or it can carry other types of data. The encoding rate of the data (e.g., voice data) carried by the first RLC PDU can be 800bps, or it can be greater than or less than 800bps, and this application embodiment does not impose any limitations.

[0285] Optionally, the UE can send the first RLC PDU on the TN or on the NTN. If the UE sends the first RLC PDU on the NTN, the network device can be over the air, for example... Figure 3B The network device can be a satellite, or a functional module located on a satellite; alternatively, the network device can also be located on the ground, for example... Figure 3C Alternatively, the network device may include air-based functional modules and ground-based functional modules, for example... Figure 3A The network equipment may include satellites (or functional modules on satellites) and ground gateway stations.

[0286] The first RLC PDU may include at least two RLC SDUs, which can also be understood as the first RLC PDU being a cascaded RLC PDU. The first RLC PDU may also include an RLC header. This RLC header may include at least one length field, which may indicate the length of the at least two RLC SDUs, or indicate the length of the RoHC header included in the at least two RLC SDUs. For any one of the at least two RLC SDUs, it may include a PDCP header, a RoHC header, and a payload; the lengths of the RoHC headers included in different RLC SDUs may be the same or different.

[0287] When an RLC PDU includes multiple cascaded RLC SDUs, the RLC PDU may include a field indicating the length of the cascaded RLC SDUs, such as a length field, which can be represented as an LI field. In conventional schemes, the LI field occupies 11 bits, and the maximum length it can indicate is 2048 bytes. However, for voice data, the length of the RLC SDU carrying the voice data is shorter. For example, with an encoding rate of 800bps, the payload length can be 8 bytes, the IP / UDP / RTP header length is 40 bytes, and the PDCP header length is 1 byte, then the total length of the RLC SDU is 49 bytes, and 11 bits are not needed for indication. Based on the actual size of the voice data packet under low bitrate encoding, embodiments of this application propose that the number of bits occupied by each length field in at least one of the length fields included in the first RLC PDU can be less than a first threshold to reduce the overhead of the RLC header. Optionally, the first threshold is 11, or it can be other values. Optionally, the number of bits occupied by different length fields in the at least one length field can be the same. For example, different length fields in the at least one length field occupy the same number of bits, and this number of bits can be less than a first threshold. For instance, this number of bits could be 7 bits, which can indicate a maximum RLC SDU length of 128 bytes. Since the RLC header can be byte-aligned, using 7 bits for the RLC SDU length indication, combined with the extended indication field E, allows the length of the RLC SDU to be indicated using only one byte, making implementation easier. Alternatively, when the length of the RLC SDU can be further shortened, this number of bits can also be other values, such as 3 or 4, without restriction.

[0288] The number of at least one length field can be less than or equal to the number of at least two RLC SDUs. The value of the at least one length field can indicate the length of the corresponding RLC SDU, or the value of the at least one length field can be used by the receiver to determine the length of the RLC SDU. Optionally, the receiver can transmit only variable quantities based on information known to both the receiver and the transmitter, such as transmitting RoHC header length information or RoHC header length information superimposed with PDCP header length information. For example, the number of the at least one length field is equal to the number of the at least two RLC SDUs. The value of the first length field in the at least one length field can directly indicate the length of the first RLC SDU among the at least two RLC SDUs, or the value of the first length field can indicate the length of the RoHC header included in the first RLC SDU. The receiving end can determine the length of the RLC SDU based on information such as the coding rate and / or the PDCP header length. The value of the second length field in the at least one length field can directly indicate the length of the second RLC SDU among the at least two RLC SDUs, or the value of the second length field can indicate the length of the RoHC header included in the second RLC SDU. The receiving end can determine the length of the RLC SDU based on information such as the coding rate and / or the PDCP header length, and so on.

[0289] For example, the number of the at least one length field is less than the number of the at least two RLC SDUs. The value of the at least one length field can indicate the length of the corresponding RLC SDU, or the value of the at least one length field can be used by the receiver to determine the length of the corresponding RLC SDU. Optionally, the receiver can transmit only variable quantities based on information known to both the receiver and the transmitter, such as transmitting RoHC header length information or RoHC header length information superimposed with PDCP header length information. The value of the first length field in the at least one length field can indicate the length of the first RLC SDU among the at least two RLC SDUs, or the value of the first length field can indicate the length of the RoHC header included in the first RLC SDU. The receiver can determine the length of the RLC SDU based on information such as the coding rate and / or PDCP header length. The value of the second length field in the at least one length field can indicate the length of the second RLC SDU among the at least two RLC SDUs, or the value of the second length field can indicate the length of the RoHC header included in the second RLC SDU. The receiver can determine the length of the RLC SDU based on information such as the coding rate and / or PDCP header length, and so on. However, for the last RLCSDU among the at least two RLC SDUs, the length of the RLC SDU may not be indicated by the length field, nor may the length of the RoHC header included in the RLC SDU be indicated by the length field. For example, the receiver can estimate the length of the last RLC SDU based on the length of the RLC PDU and the lengths of the other RLC SDUs.

[0290] For reference Figure 15 This is an example of an RLC header. Figure 15 The left side shows a traditional RLC header, and the right side shows the RLC header provided in this embodiment. Taking a first RLC PDU comprising three cascaded RLC SDUs as an example, namely RLC SDU1 to RLC SDU3. The RLC header of the first RLC PDU includes two length fields (which can also be represented by "length"), namely length field 1 and length field 2. Figure 15 In the left figure, length field 1 indicates the length of RLC SDU1, and length field 2 indicates the length of RLC SDU2. Figure 15In the right figure, length field 1 can indicate the length of RLC SDU1, or the length of the RoHC header included in RLC SDU1; length field 2 can indicate the length of RLC SDU2, or the length of the RoHC header included in RLC SDU2. As shown in the right figure, this embodiment of the application adaptively reduces the length fields based on the low voice coding rate characteristics of voice data packets transmitted over non-terrestrial networks. For example, each length field occupies 7 bits, so the length field and field E occupy exactly one byte. Furthermore, by reducing the length fields, the length of the RLC header is reduced from 4 bytes to 3 bytes.

[0291] Optionally, the number of bits occupied by the length field in the RLC header can be variable. The length field in the RLC header can indicate the length of the RLC SDU or the length of the RoHC header included in the RLC SDU. Regardless of which indication, it includes the length of the RoHC header. The length of the RoHC header is related to RoHC compression. If the compression performance is good, the RoHC header length can be shorter, such as 1 byte or 3 bytes; if the compression performance is poor, the RoHC header length will be longer. That is, the length of the RoHC header is variable. It is evident that the length difference of multiple RLC SDUs transmitted by an RLC entity corresponding to one RB is mainly due to RoHC header compression. Therefore, this application proposes that the number of bits occupied by the length field can also be variable. For example, if the RoHC header is short or the compression performance is good, the number of bits occupied by each length field in some or all of the length fields included in the first RLC PDU can be less, for example, less than the second threshold, thereby further reducing the header overhead; or, if the RoHC header is long or the compression performance is poor, the number of bits occupied by each length field in some or all of the length fields included in the first RLC PDU can be more, for example, greater than or equal to the second threshold, so that the length field can indicate the length of the RLC SDU or the length of the RoHC header.

[0292] For the length fields included in the RLC header of the RLC PDU generated by the UE, the number of bits occupied by different length fields can be the same or different. As a possible implementation, using several possible header lengths after RoHC header compression, for example, the number of bits occupied by each length field in a partial length field can be less, while the number of bits occupied by each length field in the remaining length fields can be more. For example, the RoHC header corresponding to the partial length field has better compression performance, while the RoHC header corresponding to the remaining length fields has poorer compression performance. Optionally, the number of bits occupied by each length field can be less than 11 bits. Optionally, RLC SDUs corresponding to length fields with different bit counts can not be included in the same RLC PDU; for example, the length fields in the same RLC PDU may occupy the same number of bits, while the length fields in different RLC PDUs may occupy the same or different numbers of bits. Alternatively, RLC SDUs corresponding to length fields with different bit counts can also be included in the same RLC PDU; for example, the length fields in the same RLC PDU may occupy the same or different numbers of bits.

[0293] For example, with an encoding rate of 800 bps, a payload length of 8 bytes, a RoHC header length of 3 bytes, and a PDCP header length of 1 byte, the total length of the RLC SDU does not exceed 12 bytes. In this case, if the at least one length field indicates the length of at least two RLC SDUs, then each length field in the at least one length field can occupy 4 bits; or, since the payload is fixed, the length of the RLC SDU varies from 10 bytes to 12 bytes. If the at least one length field indicates the length range of at least two RLC SDUs, such as indicating the length of the RoHC header included in the RLC SDU, then each length field in the at least one length field can occupy 2 bits. The length of the RLC SDU can be determined based on the value indicated by these 2 bits. For example, a length field of "00" indicates that the RoHC header length is 1 byte, and the corresponding RLC SDU length is 10 bytes.

[0294] Optionally, the RLC header may include first indication information, which may indicate the number of bits occupied by each length field in some or all of the at least one length field. This first indication information may be represented as a length scale (LS), or other forms. Since the number of bits occupied by each length field is variable, it can be indicated by the first indication information, allowing the receiving end to clearly specify the number of bits occupied by each length field. The first indication information may occupy one or more bits, which may be newly added bits in the RLC header or existing bits in the RLC header. For example, if the first indication information occupies one bit, a "1" indicates that the number of bits occupied by each length field is less than a second threshold or that each length field is short, for example, occupying 3 bits; a "0" indicates that the number of bits occupied by each length field is greater than or equal to the second threshold or that the length field is long, for example, occupying 7 bits.

[0295] As mentioned earlier, the at least one length field can indicate the length of the RLC SDU or the length of the RoHC header included in the RLCSDU. The content indicated by the length field can be predefined by the protocol, pre-configured by the network device, determined through negotiation between the UE and the network device, or determined based on the first indication information. Taking the determination of the length field content based on the first indication information as an example: For instance, if the first indication information indicates that the number of bits occupied by each length field is less than a second threshold or indicates that each length field is short, then each length field can indicate the length of the RoHC header; or, if the first indication information indicates that the number of bits occupied by each length field is greater than or equal to the second threshold or indicates that the length field is long, then each length field can indicate the length of the RLC SDU. It is evident that there are multiple and flexible methods for determining the content indicated by the length field.

[0296] If the at least one length field indicates the length of at least two RLC SDUs, the receiving end of the first RLC PDU (e.g., a network device) can determine the length of the at least two RLC SDUs based on the value of the at least one length field. Alternatively, if the at least one length field indicates the length of the RoHC header included in the at least two RLC SDUs, the network device can determine the length of the at least two RLC SDUs based on the at least one length field and an offset. For example, for any one of the at least two RLC SDUs, the network device can determine the length of the RLC SDU based on the value of the length field indicating the RLC SDU and the offset corresponding to the RLC SDU, such as including the length of the PDCP header and the length of the RoHC header included in the RLC SDU.

[0297] For reference Figure 16 This is another example of an RLC header. Figure 16 The left side shows a traditional RLC header, and the right side shows the RLC header provided in this embodiment. Taking a first RLC PDU comprising three cascaded RLC SDUs as an example, namely RLC SDU1 to RLC SDU3. The RLC header of the first RLC SDU includes two length fields (which can also be represented by "length"), namely length field 1 and length field 2. Figure 16 In the left figure, length field 1 indicates the length of RLC SDU1, and length field 2 indicates the length of RLC SDU2. Figure 16 In the right-hand diagram, length field 1 indicates the length of the RoHC header included in RLC SDU1; length field 2 indicates the length of the RoHC header included in RLC SDU2. For example, if these three RLC SDUs are carried through the same TB, and all three RLC SDUs have good compression performance, then each of the two length fields in the first RLC PDU can be shorter, for example, occupying 3 bits. Figure 16As shown in the right figure, the two length fields and the two E2 fields occupy exactly one byte. For example, the payload length of the first RLC PDU is 8 bytes, the PDCP header length of these three RLC SDUs is one byte each, and the RoHC header lengths of these three RLC SDUs are 1 byte, 3 bytes, and 3 bytes respectively. Therefore, length field 1, for example, "001", indicates 1 byte; length field 2, for example, "010", indicates 3 bytes. For the network device, the length of RLC SDU1 can be determined to be 1+8+1=10 bytes, the length of RLC SDU2 to be 3+8+1=12 bytes, and the remainder to be the length of RLCSDU3. It can be seen that when three RLC SDUs are cascaded, by reducing the length fields, the length of the RLC header of the first RLCSDU can be reduced from 4 bytes to 2 bytes.

[0298] Optionally, the RLC header of the first RLC PDU may include the RLC SN of the first RLC PDU. The number of bits occupied by this RLC SN may be less than, for example, a second threshold. Alternatively, the number of bits occupied by the RLC SN can be reduced. For example, when the number of HARQ processes is limited, the maximum value of the RLC SN can be smaller, or the number of RLC SNs is limited, so fewer bits are needed to indicate the RLC SN, and the number of bits occupied by the RLC SN can be reduced. The second threshold may be, for example, 5, or it may be another value.

[0299] For example, in the case of only one HARQ process, the RLC layer of the receiving end (e.g., network device) does not need to perform sorting based on the RLC SN, so the RLC header of the first RLC PDU may not include the RLC SN.

[0300] If the number of bits occupied by the RLC SN is reduced, or if the RLC header excludes the RLC SN, then the reduced bit can be omitted from the RLC header. For example, if the RLC SN originally occupies 5 bits, and it is reduced to 4 bits, resulting in 1 bit, the RLC header can exclude this 1 bit. Or, if the RLC SN originally occupies 5 bits, and it is removed from the RLC header, resulting in 5 bits, the RLC header can exclude these 5 bits. This effectively reduces the size of the RLC header, thereby decreasing its overhead.

[0301] Alternatively, even if the number of bits occupied by the RLC SN is reduced or the RLC header does not include the RLC SN, the RLC header can still include the reduced bits, which can be used as reserved bits or for other purposes.

[0302] For example, Figure 16The right image shows an example using the RLC header excluding the RLC SN. Figure 16 In the right figure, some bits originally occupied by the RLC SN are used to carry the first indication information. Figure 16 The right figure is represented by LS), and the remaining bits are reserved bits ( Figure 16 The right figure is represented by R).

[0303] Optionally, the RLC header may also include a third field, which may indicate whether a next length field exists. For example... Figure 16 In the right-hand diagram, the third field is represented by E2. Alternatively, the third field can also use an existing field from the RLC header, such as field E (i.e., Figure 16 In the right-hand diagram, E2 can also be replaced with E), and there are no restrictions on this. For example, Figure 16 In the right figure, the first E2 indicates whether there is a length field 2, and the second E2 indicates whether there is a next length field after length field 2.

[0304] In this embodiment of the application, for an RLC PDU that includes a cascaded RLC SDU, the number of bits occupied by the length field in the RLC header of the RLC PDU can be reduced to save RLC header overhead. Optionally, the number of bits occupied by the length field can be variable; if the number of bits occupied by the length field is small, the RLC header overhead can be further reduced.

[0305] This application provides a sixth communication method; please refer to [link / reference]. Figure 17 Here is a flowchart of the method. Optional, Figure 17 The embodiments shown can be used in LTE systems, or in other communication systems.

[0306] S1701, the UE sends the fifth MAC PDU. Correspondingly, the network device receives the fifth MAC PDU.

[0307] Optionally, the fifth MAC PDU can carry voice data, or it can carry other types of data. The encoding rate of the data (e.g., voice data) carried by the fifth MAC PDU can be 800bps, or it can be greater than or less than 800bps, and this application embodiment does not impose any limitations.

[0308] Optionally, the UE can send the fifth MAC PDU on the TN or on the NTN. If the UE sends the fifth MAC PDU on the NTN, the network device can be in the air, for example... Figure 3B The network device can be a satellite, or a functional module located on a satellite; alternatively, the network device can also be located on the ground, for example... Figure 3CAlternatively, the network device may include air-based functional modules and ground-based functional modules, for example... Figure 3A The network equipment may include satellites (or functional modules on satellites) and ground gateway stations.

[0309] The fifth MAC PDU may include the first MAC SDU, and the fifth MAC PDU may not include the MAC subheader of the first MAC SDU. In other words, the first MAC SDU may not have a MAC subheader, or may not need to add a MAC subheader to the first MAC SDU, thereby reducing the packet header overhead of the first MAC PDU.

[0310] Optionally, the UE can transmit the first MAC SDU on the second resource, and the network device can receive the first MAC SDU on the second resource; that is, the first MAC SDU can be carried on the second resource. The second resource, for example, corresponds to an LCID, which can be the LCID corresponding to the RLC PDU included in the first MAC SDU. For the receiving end, as long as the first MAC SDU is received through the second resource, it can be determined that the first MAC SDU corresponds to the LCID. Therefore, the MAC subheader of the first MAC SDU may not include the LCID, or the MAC subheader of the first MAC SDU may not include any LCID.

[0311] Alternatively, the second resource may correspond to a DRB, which could be the DRB corresponding to a first logical channel, and the first logical channel could be the logical channel corresponding to the RLC PDU included in the first MAC SDU. For the receiving end, as long as the first MAC SDU is received through the second resource, it can be determined that the first MAC SDU corresponds to the DRB. Therefore, the MAC subheader of the first MAC SDU may not include the DRB identifier, or the MAC subheader of the first MAC SDU may not include any DRB identifier. It is evident that, since the embodiments of this application correspond transmission resources to LCIDs or DRBs, the MAC subheader of the first MAC SDU may not include the LCID or DRB identifier, thereby reducing the overhead of the MAC subheader of the first MAC SDU.

[0312] Optionally, the length of the first MAC SDU can be equal to the time-domain length of the second resource, or it can be understood that the first MAC SDU exactly occupies the time-domain space of the second resource without any padding bits. Therefore, for the receiving end, the length of the first MAC SDU can be determined based on the time-domain length of the second resource. Thus, the MAC sub-header of the first MAC SDU does not necessarily need to indicate its length. Optionally, the coding rate of the second resource can be less than or equal to 800 bps. For example, when scheduling resources for the UE, the network device can schedule resources with a coding rate less than or equal to 800 bps, so that the UE does not need to pad bits on the resource when sending the first MAC SDU, making the length of the first MAC SDU equal to the time-domain length of the resource.

[0313] In summary, since the MAC subheader of the first MAC SDU may not include the LCID (or DRB identifier) ​​or the length information of the first MAC SDU, a MAC subheader may not be added to the first MAC SDU, thereby reducing the packet header overhead of the first MAC PDU.

[0314] Optionally, the transmission mode of the first MAC SDU can be a transparent transmission mode, such as TM. In transparent transmission mode, the first MAC SDU can be made to not have a corresponding MAC sub-header.

[0315] The first MAC SDU can carry voice data, or it can carry other types of data. Taking the first MAC SDU carrying voice data as an example, in this embodiment of the application, a dedicated transmission resource (e.g., a second resource) can be configured for the voice data. This transmission resource can correspond to the LCID used for voice data transmission, thereby reducing the MAC subheader; and / or, in this embodiment of the application, a dedicated logical channel can be configured for the voice data. This logical channel can correspond to the DRB used for voice data transmission, thereby reducing the MAC subheader.

[0316] The embodiments of this application do not require adding a MAC subheader to the MAC SDU, thereby significantly reducing the packet header overhead of the MACPDU.

[0317] This application provides a seventh communication method, please refer to the embodiments. Figure 18 Here is a flowchart of the method. Optional, Figure 18 The embodiments shown can be used in LTE systems, or in other communication systems.

[0318] S1801, the UE sends the sixth MAC PDU. Correspondingly, the network device receives the sixth MAC PDU.

[0319] Optionally, the sixth MAC PDU can carry voice data, or it can carry other types of data. The encoding rate of the data (e.g., voice data) carried by the sixth MAC PDU can be 800bps, or it can be greater or less than 800bps, and this application embodiment does not impose any limitations.

[0320] Optionally, the UE can send the sixth MAC PDU on the TN or on the NTN. If the UE sends the sixth MAC PDU on the NTN, the network device can be in the air, for example... Figure 3B The network device can be a satellite, or a functional module located on a satellite; alternatively, the network device can also be located on the ground, for example... Figure 3C Alternatively, the network device may include air-based functional modules and ground-based functional modules, for example... Figure 3A The network equipment may include satellites (or functional modules on satellites) and ground gateway stations.

[0321] The sixth MAC PDU may include K MAC SDUs, where K is a positive integer. The sixth MAC PDU may also include K MAC subheaders, which are the MAC subheaders of the K MAC SDUs, and each of the K MAC subheaders can correspond one-to-one with the K MAC SDUs. Optionally, the K MAC subheaders and the K MAC SDUs can form K MAC subPDUs. For example, one of the K MAC subheaders can form a MAC subPDU with the MAC SDU corresponding to that subheader, resulting in a total of K MAC subPDUs. Optionally, the K MAC subPDUs can be adjacent. For example, see [reference needed]. Figure 19 This is an example of the K MAC sub-PDUs.

[0322] Optionally, K can be predefined by the protocol or configured by the network device. For example, if configured by the network device, the network device can send second information to the UE, which can indicate K, and the UE can then execute S1801 according to the second information.

[0323] In this embodiment of the application, of the K MAC sub-headers, except for the third MAC sub-header, the remaining K-1 MAC sub-headers may not include the LCID or the DRB identifier. The third MAC sub-header is, for example, the MAC sub-header of the first MACSDU among the K MAC SDUs. Each of the K MAC SDUs corresponds to the same LCID or the same DRB.

[0324] In the traditional approach, each of the K MAC sub-headers includes a corresponding LCID. Since the LCIDs corresponding to the K MAC SDUs are the same, the LCIDs included in the K MAC sub-headers are identical. Therefore, in this embodiment, the K-1 MAC sub-headers can be made to exclude either the LCID or the DRB identifier. For the receiving end, based on the LCID or DRB identifier in the third MAC sub-header, it can be determined that each of the K MAC SDUs corresponds to the corresponding LCID or DRB.

[0325] The third MAC subheader may include the LCID corresponding to the K MAC SDUs, or the identifier of the DRB corresponding to the K MAC SDUs.

[0326] Alternatively, the third MAC subheader may not include the LCID or DRB identifier. For example, the UE can transmit the K MAC SDUs on the third resource, and the network device can receive the K MAC SDUs on the third resource; that is, the K MAC SDUs can be carried on the second resource. The third resource may correspond to an LCID, which could be the LCID corresponding to the RLC PDU included in the K MAC SDUs. For the receiving end, as long as the K MAC SDUs are received through the third resource, it can be determined that the K MAC SDUs correspond to the LCID. Therefore, the third MAC subheader may not include the LCID, or the third MAC subheader may not include any LCID.

[0327] Alternatively, the third resource may correspond to a DRB, which could be a DRB corresponding to at least one logical channel, and the at least one logical channel could be a logical channel corresponding to the RLC PDU included in the K MAC SDUs. For the receiving end, as long as the K MAC SDUs are received through the third resource, it can be determined that the K MAC SDUs correspond to the DRB. Therefore, the third MAC subheader may not include the DRB identifier, or the third MAC subheader may not include any DRB identifier. It is evident that, since the embodiments of this application correspond the transmission resources to LCIDs or DRBs, the MAC subheaders of the K MAC SDUs may all omit the LCID or DRB identifiers, thereby reducing the overhead of the MAC subheaders.

[0328] Optionally, each of the K MAC sub-headers may also include a length field, such as represented as "length," or may have other representations. This length field may indicate the length of the corresponding MAC SDU, or the length of the RoHC header included in the corresponding MAC SDU. For example, for any one of the K MAC sub-headers, the length field included in the MAC sub-header may indicate the length of the MAC SDU corresponding to that MAC sub-header, or the length of the RoHC header included in the MAC SDU corresponding to that MAC sub-header.

[0329] In traditional schemes, the length field within a MAC subheader can occupy one or two bytes. However, for voice data, the length of the MAC SDU carrying the voice data is relatively short, for example, no more than 128 bytes, and does not require many bits for indication. Based on the actual size of the voice data packet under low bitrate encoding, this application proposes that the number of bits occupied by the length field in any of the K MAC subheaders can be less than a third threshold to reduce the overhead of the MAC subheader. Optionally, the third threshold is 8 or 16, or it can be other values. Optionally, the number of bits occupied by different length fields in the K MAC subheaders can be the same. For example, if the number of bits occupied by different length fields in the K MAC subheaders is the same, this number of bits can be less than the third threshold. For example, this number of bits is, for instance, 7 bits, which can indicate a MAC SDU of up to 128 bytes. Since MAC subheaders can be byte-aligned, using 7 bits for the MAC SDU length indication, combined with the extended indication field E, allows one byte to be used to indicate the length of the MAC SDU, which is more convenient to implement. Alternatively, when the length of the MAC SDU can be further shortened, the number of bits can also be other values, such as 3, 4, etc., without restriction.

[0330] Optionally, the number of bits occupied by the length field in the MAC sub-header can be variable. The length field in the MAC sub-header can indicate the length of the MAC SDU or the length of the RoHC header included in the MAC SDU. Regardless of which it indicates, it includes the length of the RoHC header. The length of the RoHC header is related to RoHC compression. If the compression performance is good, the length of the RoHC header can be shorter, such as 1 byte or 3 bytes; if the compression performance is poor, the length of the RoHC header will be longer. That is, the length of the RoHC header is variable. It is evident that the length difference among multiple MAC SDUs transmitted by the MAC entity is mainly caused by RoHC header compression. Therefore, this application proposes that the number of bits occupied by the length field can also be variable. For example, if the RoHC header is short or the compression performance is good, the number of bits occupied by the length field in any of the K MAC SDUs can be less, for example, less than the fourth threshold, thereby further reducing the packet header overhead; or, if the RoHC header is long or the compression performance is poor, the number of bits occupied by the length field in any of the K MAC SDUs can be more, for example, greater than or equal to the fourth threshold, so that the length field can indicate the length of the MAC SDU or the length of the RoHC header.

[0331] For the length fields included in the MAC subheader of the MAC PDU generated by the UE, the number of bits occupied by different length fields can be the same or different. As a possible implementation, using several possible header lengths compressed from the RoHC header, for example, the number of bits occupied by each length field in a partial length field can be less, while the number of bits occupied by each length field in the remaining length fields can be more. For example, the RoHC header corresponding to the partial length field has better compression performance, while the RoHC header corresponding to the remaining length fields has poorer compression performance. Optionally, the number of bits occupied by each length field can be less than 11 bits. Optionally, MAC SDUs corresponding to length fields with different bit counts can not be included in the same MAC PDU; for example, the length fields in the same MAC PDU may occupy the same number of bits, and the length fields in different MAC PDUs may occupy the same or different numbers of bits. Alternatively, MAC SDUs corresponding to length fields with different bit counts can also be included in the same MAC PDU; for example, the length fields in the same MAC PDU may occupy the same or different numbers of bits.

[0332] Optionally, the MAC subheader may include first indication information, which indicates the number of bits occupied by the length field included in the MAC subheader. This first indication information may be represented as LS, or it may have other representations. Since the number of bits occupied by the length field is variable, it can be indicated by the first indication information, allowing the receiving end to clearly specify the number of bits occupied by the length field. The first indication information may occupy one or more bits, which may be newly added bits in the MAC subheader or existing bits in the MAC subheader. For example, if the first indication information occupies one bit, a "1" indicates that the number of bits occupied by the length field is less than the fourth threshold or that the length field is short, such as occupying 3 bits; a "0" indicates that the number of bits occupied by the length field is greater than or equal to the fourth threshold or that the length field is long, such as occupying 7 bits.

[0333] As mentioned earlier, the length field can indicate the length of the MAC SDU, or it can indicate the length of the RoHC header included in the MAC SDU. The content indicated by the length field can be predefined by the protocol, pre-configured by the network device, determined through negotiation between the UE and the network device, or it can be determined based on the first indication information. Taking the determination of the length field content based on the first indication information as an example: For instance, if the first indication information indicates that the number of bits occupied by the length field is less than the fourth threshold or that the length field is short, then the length field can indicate the length of the RoHC header; or, if the first indication information indicates that the number of bits occupied by the length field is greater than or equal to the fourth threshold or that the length field is long, then the length field can indicate the length of the RLC SDU. It is evident that there are many ways to determine the content indicated by the length field, making it quite flexible.

[0334] If the length field indicates the length of the MAC SDU, the receiving end (e.g., a network device) of the K MAC SDUs can determine the length of the K MAC SDUs based on the length fields included in the K MAC subheaders. Alternatively, if the length field indicates the length of the RoHC header included in the MAC SDU, the network device can determine the length of the K MAC SDUs based on the length fields included in the K MAC subheaders and the offset. For example, for any one of the K MAC SDUs, the network device can determine the length of the MAC SDU based on the length fields included in the MAC subheaders of the MAC SDU and the offset corresponding to the MAC SDU. The offset corresponding to the MAC SDU may include, for example, the length of the PDCP header, the length of the RLC header, and the length of the RoHC header included in the MAC SDU.

[0335] For reference Figure 20 This is an example of a MAC subheader. Figure 20 The left side shows the traditional MAC subheader, and the right side shows the MAC subheader provided in this embodiment. Taking the sixth MAC PDU, which includes two MAC SDUs, as an example, namely MAC SDU1 and MAC SDU2. The MAC subheader of MAC SDU1 includes a length field 1, and the MAC subheader of MAC SDU2 includes a length field 2. According to Figure 20 As shown in the right figure, the MAC subheader of MAC SDU2 does not include the LCID or DRB identifier, thus saving the overhead of the MAC subheader. Additionally... Figure 20 This example uses the MAC subheader of MAC SDU1, including the LCID. Figure 20 As shown in the left and right figures, the length fields 1 and 2 in this embodiment are shorter, while the length fields 1 and 2 in the traditional scheme are longer. Furthermore, some MAC sub-headers in this embodiment may not include the LCID and DRB identifiers, while in the traditional scheme, each MAC sub-header includes the LCID. The technical solution of this embodiment reduces the overhead of the MAC sub-header.

[0336] Can be referenced again Figure 21 This is another example of a MAC subheader. Figure 21 The left side shows the traditional MAC subheader, and the right side shows the MAC subheader provided in this embodiment. Taking the sixth MAC PDU, which includes two MAC SDUs, as an example, namely MAC SDU1 and MAC SDU2. The MAC subheader of MAC SDU1 includes a length field 1, and the MAC subheader of MAC SDU2 includes a length field 2. According to Figure 21 As shown in the right figure, the MAC subheader of MAC SDU2 does not include the LCID or DRB identifier, thus saving the overhead of the MAC subheader. Additionally... Figure 21 This example uses the MAC subheader of MAC SDU1, which does not include the LCID or DRB identifiers. Figure 21 As shown in the left and right figures, length fields 1 and 2 in this embodiment are shorter, while length fields 1 and 2 in the traditional scheme are longer. Furthermore, all MAC sub-headers in this embodiment may not include the LCID and DRB identifiers, whereas in the traditional scheme, each MAC sub-header includes the LCID. The technical solution of this embodiment reduces the overhead of the MAC sub-header.

[0337] Optionally, any one of the K MAC subheaders may also include a second field, which may indicate whether there is a next cascading MAC SDU with the same LCID or DRB. Figure 20 or Figure 21For example, "E" in the example represents the second field. A cascaded MAC SDU can be understood as a MAC SDU included within the same MAC PDU.

[0338] The second field can occupy one or more bits. These bits can be newly added bits within the MAC header, or they can be reused bits from the existing MAC header. In the scheme of reusing existing bits, for any one of the K MAC headers, the one or more bits occupied by the second field of that MAC header can optionally belong to, for example, the length field included in that MAC header. This can also be understood as reducing the length field included in the MAC header, and the resulting portion or all of the bits can be used as the second field. For example, for any MAC SDU, the length field in the MAC header of that MAC SDU originally occupies one byte, i.e., 8 bits. This length field can be reduced, for example, by one bit, so that the length field occupies 7 bits, reduced to one bit. This one bit can then be used as the second field; that is, the second field can occupy one bit. Figure 20 and Figure 21 This is used as an example. By reusing existing bits in the MAC header in the second field, it is not necessary to add new bits to the MAC header, which is beneficial for compatibility with existing technologies.

[0339] Optionally, the third resource can transmit MAC CEs in addition to MAC SDUs. The MAC CE and the K MAC SDUs are, for example, included in the sixth MAC PDU. The MAC CE also has a MAC subheader, for example called the fourth MAC subheader, and the fourth MAC subheader is not shortened; for example, the fourth MAC subheader may include MAC CE LCID, etc. Optionally, on the third resource, the MAC subheader of the MAC CE can be placed before the MAC subheader of the MAC SDU; for example, the fourth MAC subheader can be placed before the K MAC subheaders.

[0340] Optionally, each of the K MAC subheaders and the fourth MAC subheader may include second indication information. This second indication information may indicate that the MAC subheader containing the second indication information corresponds to a MAC CE or a MAC SDU. The second indication information may occupy one or more bits. Optionally, the second indication information may occupy one or more bits at the beginning of the MAC subheader, for example, the first bit within the MAC subheader.

[0341] Optionally, the second indication information included in any of the K MAC subheaders can be a first value, and the value of the second indication information included in the fourth MAC subheader can be a second value. The first value can indicate that the MAC subheader is a MAC subheader of a MAC SDU; the second value can indicate that the fourth MAC subheader is a MAC subheader of a MAC CE.

[0342] Taking the second indication information occupying one bit as an example, for instance, the first value is "1" and the second value is "0". Then, if the bit is "1", it indicates that the MAC subheader where the second indication information is currently located corresponds to the MAC SDU, or indicates that the MAC subheader where the second indication information is currently located is the MAC subheader of the MAC SDU; or, if the bit is "0", it indicates that the MAC subheader where the second indication information is currently located corresponds to the MAC CE, or indicates that the MAC subheader where the second indication information is currently located is the MAC subheader of the MAC CE.

[0343] In this embodiment, since the transmission resource can correspond to the identifier of LCID or DRB, the MAC subheader can be made to exclude the identifier of LCID or DRB, thereby reducing the overhead of the MAC subheader. Furthermore, if MAC CE and MAC SDU are transmitted on the same resource, the second indication information can be used to distinguish the MAC subheaders of these two types, thereby reducing the probability of incorrect identification by the receiver.

[0344] Figure 4 , Figure 7 , Figure 10 , Figure 11 , Figure 14 , Figure 17 , Figure 18 Any of the embodiments shown in the accompanying drawings can be applied individually, or any two or more embodiments can be applied in combination. For example, one combination includes that the UE can use one or more of the following to generate a MAC PDU: the UE's PDCP layer can adopt... Figure 7 or Figure 10 The embodiment shown reduces the packet header, and the UE's RLC layer can use... Figure 13 or Figure 14 The illustrated embodiment reduces the packet header, or the UE's MAC layer can adopt... Figure 4 , Figure 17 or Figure 18 The illustrated embodiment reduces the header size.

[0345] Figure 22 A schematic diagram of a device provided in an embodiment of this application is given. The communication device 2200 may be... Figure 4 , Figure 7 , Figure 10 , Figure 11 , Figure 14 , Figure 17 ,or Figure 18 The UE or its circuitry, as shown in any of the embodiments illustrated in the accompanying drawings, is used to implement the method corresponding to the UE in the above method embodiments. Alternatively, the communication device 2200 may be... Figure 4 , Figure 7 , Figure 10 , Figure 11 , Figure 14 , Figure 17 ,or Figure 18 The network device or circuit system of any of the embodiments shown in the accompanying drawings is used to implement the method corresponding to the network device in the above method embodiments. For example, one type of circuit system is a chip system.

[0346] The communication device 2200 includes at least one processor 2201. The processor 2201 can be used for internal processing within the device to implement certain control processing functions. Optionally, the processor 2201 includes instructions. Optionally, the processor 2201 can store data. Optionally, different processors can be independent devices, located in different physical locations, or located on different integrated circuits. Optionally, different processors can be integrated into one or more processors, for example, integrated on one or more integrated circuits.

[0347] Optionally, the communication device 2200 includes one or more memories 2203 for storing instructions. Optionally, the memories 2203 may also store data. The processor and the memories may be separate or integrated together.

[0348] Optionally, the communication device 2200 includes a communication line 2202 and at least one communication interface 2204. Since the memory 2203, communication line 2202, and communication interface 2204 are all optional, therefore... Figure 22 All are represented by dashed lines.

[0349] Optionally, the communication device 2200 may further include a transceiver and / or an antenna. The transceiver can be used to send information to or receive information from other devices. The transceiver may be referred to as a transceiver unit, transceiver circuit, input / output interface, etc., and is used to realize the transmission and reception functions of the communication device 2200 via the antenna. Optionally, the transceiver includes a transmitter and a receiver. For example, the transmitter can be used to generate a radio frequency (RF) signal from a baseband signal, and the receiver can be used to convert the RF signal back into a baseband signal.

[0350] Processor 2201 may include a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of programs according to the present application.

[0351] Communication line 2202 may include a path for transmitting information between the aforementioned components.

[0352] Communication interface 2204 uses any transceiver-like device for communicating with other devices or communication networks, such as Ethernet, radio access network (RAN), wireless local area network (WLAN), wired access network, etc.

[0353] Memory 2203 may be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited thereto. Memory 2203 may exist independently and be connected to processor 2201 via communication line 2202. Alternatively, memory 2203 may be integrated with processor 2201.

[0354] The memory 2203 stores computer execution instructions for implementing the scheme of this application, and its execution is controlled by the processor 2201. The processor 2201 executes the computer execution instructions stored in the memory 2203, thereby realizing... Figure 4 , Figure 7 , Figure 10 , Figure 11 , Figure 14 , Figure 17 ,or Figure 18The steps performed by the UE or network device in any of the embodiments shown in the accompanying drawings.

[0355] Optionally, the computer execution instructions in the embodiments of this application may also be referred to as application code, and the embodiments of this application do not specifically limit this.

[0356] In a specific implementation, as one example, the processor 2201 may include one or more CPUs, for example... Figure 22 CPU0 and CPU1 in the CPU.

[0357] In a specific implementation, as one example, the communication device 2200 may include multiple processors, for example... Figure 22 Processors 2201 and 2205 are mentioned in the text. Each of these processors can be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. Here, "processor" can refer to one or more devices, circuits, and / or processing cores used to process data (e.g., computer program instructions).

[0358] when Figure 22 When the device shown is a chip, such as a UE chip or a network device chip, the chip includes a processor 2201 (and may also include a processor 2205), a communication line 2202, and a communication interface 2204. Optionally, it may include a memory 2203. Specifically, the communication interface 2204 may be an input interface, pins, or circuits, etc. The memory 2203 may be a register, cache, etc. The processor 2201 and processor 2205 may be a general-purpose CPU, microprocessor, ASIC, or one or more integrated circuits for controlling the execution of a program that controls the communication method of any of the above embodiments.

[0359] This application embodiment can divide the device into functional modules according to the above method example. For example, each function can be divided into its own functional modules, or two or more functions can be integrated into one processing module. The integrated modules can be implemented in hardware or as software functional modules. The module division in this application embodiment is illustrative and only represents one logical functional division; in actual implementation, other division methods may be used. For example, in the case of dividing the device into functional modules corresponding to each function... Figure 23 This is a schematic diagram of an apparatus. The apparatus 2300 may be a UE or network device involved in the above-described method embodiments, or a chip in a UE or a chip in a network device. The apparatus 2300 includes a processing unit 2302 and a transceiver unit 2301.

[0360] It should be understood that the device 2300 can be used to implement the steps performed by the UE or network device in the communication method of the embodiments of this application, and the relevant features can be referred to above. Figure 4 , Figure 7 , Figure 10 , Figure 11 , Figure 14 , Figure 17 ,or Figure 18 The embodiments shown in any of the accompanying drawings will not be described in detail here.

[0361] Optional, Figure 23 The functions / implementation process of the transceiver unit 2301 and the processing unit 2302 can be obtained through Figure 22 The processor 2201 in the memory calls computer execution instructions stored in memory 2203 to implement the function. Alternatively, Figure 23 The function / implementation process of the processing unit 2302 in the middle can be achieved through Figure 22 The processor 2201 in the memory calls computer execution instructions stored in the memory 2203 to implement this. Figure 23 The function / implementation process of the transceiver unit 2301 can be obtained through Figure 22 It is implemented using the 2204 communication interface.

[0362] Optionally, when the device 2300 is a chip or circuit, the function / implementation process of the transceiver unit 2301 can also be implemented through pins or circuits. Optionally, the transceiver unit 2301 may include a transmitting unit and / or a receiving unit, whereby the transmitting unit implements the transmitting function and the receiving unit implements the receiving function; or, the transceiver unit 2301 may be an integral module capable of implementing both transmitting and / or receiving functions. Optionally, the transceiver unit 2301 can be implemented using a transceiver.

[0363] This application also provides a computer-readable storage medium storing a computer program or instructions that, when executed, implement the methods performed by the network device and / or UE in the aforementioned method embodiments. Thus, the functions described in the above embodiments can be implemented as software functional units and sold or used as independent products. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to it, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0364] This application also provides a computer program product comprising: computer program code, which, when run on a computer, causes the computer to perform the method executed by the network device and / or UE in any of the foregoing method embodiments.

[0365] This application also provides a processing apparatus, including a processor and an interface; the processor is used to execute the methods performed by the network device and / or UE involved in any of the above method embodiments.

[0366] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state disk (SSD)).

[0367] The various illustrative logic units and circuits described in the embodiments of this application can be implemented or operate the described functions using a general-purpose processor, digital signal processor (DSP), ASIC, field-programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof. The general-purpose processor can be a microprocessor; alternatively, it can be any conventional processor, controller, microcontroller, or state machine. The processor can also be implemented using a combination of computing devices, such as a digital signal processor and a microprocessor, multiple microprocessors, one or more microprocessors combined with a digital signal processor core, or any other similar configuration.

[0368] The steps of the methods or algorithms described in the embodiments of this application can be directly embedded in hardware, software units executed by a processor, or a combination of both. The software units can be stored in RAM, flash memory, ROM, erasable programmable read-only memory (EPROM), EEPROM, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium in the art. Exemplarily, the storage medium can be connected to the processor so that the processor can read information from the storage medium and write information to the storage medium. Optionally, the storage medium can also be integrated into the processor. The processor and storage medium can be disposed in an ASIC, which can be disposed in the terminal device. Optionally, the processor and storage medium can also be disposed in different components of the terminal device.

[0369] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0370] The contents of the various embodiments of this application can be referenced to each other. Unless otherwise specified or there is a logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0371] It is understood that in the embodiments of this application, the network device and / or UE may perform some or all of the steps in the embodiments of this application. These steps or operations are merely examples. In the embodiments of this application, other operations or variations of various operations may also be performed. Furthermore, the steps may be performed in different orders as presented in the embodiments of this application, and it is not necessary to perform all the operations in the embodiments of this application.

Claims

1. A communication method, characterized in that, The method includes: Send a fourth Media Access Control (MAC) Protocol Data Unit (PDU), the fourth MAC PDU including a first MAC Service Data Unit (SDU) and a first MAC subheader. The first MAC subheader is the MAC subheader of the first MAC SDU, wherein the first MAC SDU is carried on a first resource, the first resource corresponding to a Logical Channel Identifier (LCID) or a Data Radio Bearer, and the first MAC subheader does not include the LCID or the identifier of the Data Radio Bearer.

2. The method according to claim 1, characterized in that, The first MAC subheader includes the length information of the first MAC SDU.

3. The method according to claim 1 or 2, characterized in that, The fourth MAC PDU also includes a MAC control element CE and a second MAC sub-header, wherein the second MAC sub-header is the MAC sub-header of the MAC CE, wherein... The first MAC subheader includes indication information for indicating that the first MAC subheader is the MAC subheader of the MAC SDU; The second MAC subheader includes indication information for indicating that the second MAC subheader is the MAC CE.

4. A communication method, characterized in that, The method includes: The system receives a fourth Media Access Control (MAC) Protocol Data Unit (PDU), which includes a first MAC Service Data Unit (SDU) and a first MAC subheader. The first MAC subheader is the MAC subheader of the first MAC SDU. The first MAC SDU is carried on a first resource, which corresponds to a Logical Channel Identifier (LCID) or a Data Radio Bearer. The first MAC subheader does not include the LCID or the identifier of the Data Radio Bearer.

5. The method according to claim 4, characterized in that, The first MAC subheader includes the length information of the first MAC SDU.

6. The method according to claim 4 or 5, characterized in that, The fourth MAC PDU also includes a MAC CE and a second MAC subheader, wherein the second MAC subheader is the MAC subheader of the MAC CE, wherein... The first MAC subheader includes indication information for indicating that the first MAC subheader is the MAC subheader of the MAC SDU; The second MAC subheader includes indication information for indicating that the second MAC subheader is the MAC CE.

7. A communication device, characterized in that, The communication device includes a module for performing the method as described in any one of claims 1 to 3, or a module for performing the method as described in any one of claims 4 to 6.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store a computer program that, when run on a terminal or a chip in the terminal, causes the method as described in any one of claims 1 to 3 to be executed.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store a computer program that, when run on a network device or a chip in the network device, causes the method as described in any one of claims 4 to 6 to be executed.

10. A computer program product, characterized in that, The computer program product includes a computer program that, when run on a terminal or a chip in the terminal, causes the method as described in any one of claims 1 to 3 to be performed.

11. A computer program product, characterized in that, The computer program product includes a computer program that, when run on a network device or a chip in the network device, causes the method as described in any one of claims 4 to 6 to be performed.

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