CN115379395A

CN115379395A - Transmission method, device, equipment and readable storage medium

Info

Publication number: CN115379395A
Application number: CN202110533050.6A
Authority: CN
Inventors: 孙军帅; 李娜; 张慧敏; 王莹莹; 赵芸; 刘光毅
Original assignee: China Mobile Communications Group Co Ltd; China Mobile Communications Ltd Research Institute
Current assignee: China Mobile Communications Group Co Ltd; China Mobile Communications Ltd Research Institute
Priority date: 2021-05-17
Filing date: 2021-05-17
Publication date: 2022-11-22
Also published as: WO2022242390A1

Abstract

The embodiment of the application provides a transmission method, a device, equipment and a readable storage medium, wherein the method comprises the following steps: the MAC layer of the sending end sends MBMS data through a scheduling function and/or a multiplexing function; and if the MAC layer of the sending end receives NACK transmitted by the MAC layer of the receiving end, the MAC layer of the sending end retransmits the MBMS data to the HARQ function of the MAC layer of the receiving end through the HARQ function.

Description

Transmission method, device, equipment and readable storage medium

Technical Field

The embodiment of the application relates to the technical field of communication, in particular to a transmission method, a transmission device, transmission equipment and a readable storage medium.

Background

Based on the Multimedia Broadcast Multicast Service (MBMS) scheme already defined in the fourth generation mobile communication technology (4G) standard, the current fifth generation mobile communication technology (5G) standard is discussing the technical trend of the MBMS scheme, wherein how to define the MBMS data feedback and retransmission flow is an urgent problem to be solved.

Disclosure of Invention

Embodiments of the present application provide a transmission method, an apparatus, a device, and a readable storage medium, which solve the problem of how to perform MBMS data feedback and retransmission.

In a first aspect, a transmission method is provided, including:

the MAC layer of the sending end sends the MBMS data through a scheduling function and/or a multiplexing function;

and if the MAC layer of the sending end receives NACK sent by the MAC layer of the receiving end, the MAC layer of the sending end retransmits the MBMS data to the HARQ function of the MAC layer of the receiving end through the HARQ function.

Optionally, after the MAC layer of the transmitting end transmits MBMS data through a scheduling function and/or a multiplexing function, the method further includes:

and the MAC layer of the sending end receives the ACK sent by the MAC layer of the receiving end through an HARQ function.

and the MAC layer of the sending end sends the MBMS data to the HARQ function of the MAC layer of the sending end.

Optionally, the scheduling function and/or multiplexing function of the MAC layer of the sending end directly sends the MBMS data to the HARQ function of the MAC layer of the sending end;

alternatively, the first and second liquid crystal display panels may be,

and the scheduling function and/or multiplexing function of the MAC layer of the sending end caches the MBMS data, and the HARQ function of the MAC layer of the sending end reads the MBMS data from the cache.

Optionally, the reading, by the HARQ function of the MAC layer of the sending end, the MBMS data from the buffer includes:

the HARQ function of the MAC layer of the sending end reads the MBMS data from the cache at regular time according to the sending mode of the PTM;

alternatively, the first and second electrodes may be,

and the HARQ function of the MAC layer of the sending end receives the notification message, and reads the MBMS data from the cache according to the notification message.

Optionally, the transmission mode of the PTM is configured through RRC signaling when HARQ is established or reconfigured.

Optionally, the cache is provided with a discard timer, and if the timer is overtime, the cache is emptied;

alternatively, the first and second liquid crystal display panels may be,

each HARQ function of the MAC layer of the sending end can only access the corresponding cache;

alternatively, the first and second electrodes may be,

multiple HARQ functions of the MAC layer at the transmitting end can access the same cache.

Optionally, the method further comprises:

the SDAP layer of the sending end maps MBMS data to be sent to different low layers for sending, and the low layers comprise one or more of the following items: PDCP layer, RLC layer and MAC layer.

Optionally, the method further comprises:

the SDAP layer of the sending end establishes or reconfigures a QoS Flow for bearing MBMS data to be sent;

the SDAP layer of the sending end selects a DRB of a lower layer;

and the SDAP layer of the sending end maps the QoS Flow for bearing the MBMS data to be sent to the DRB.

Optionally, the QoS Flow carrying the MBMS data to be transmitted is mapped to the DRB one to one.

Optionally, the QoS flows carrying MBMS data to be sent are mapped to one DRB.

Optionally, the format of the downlink SDAP PDU carrying MBMS data includes: a first field indicating an identity of a QoS Flow mapped to the same DRB.

Optionally, the QoS Flow carrying the MBMS data to be transmitted is mapped to a plurality of DRBs.

Optionally, the format of the downlink SDAP PDU carrying MBMS data includes: a second field indicating an identifier of a QoS Flow mapped to the same DRB;

alternatively, the first and second electrodes may be,

the downlink SDAP PDU format carrying the MBMS data does not comprise an SDAP PDU header;

alternatively, the first and second liquid crystal display panels may be,

the format of the downlink SDAP PDU for bearing the MBMS data comprises the following steps: a third field, configured to determine, by the receiving end, whether the downlink SDAP PDU has been received.

Optionally, the PDCP layer of the transmitting end directly transmits MBMS data to a lower layer of the PDCP layer.

Optionally, the RLC layer of the sending end performs MBMS data transmission in an unacknowledged mode.

In a second aspect, a transmission method is provided, including:

the MAC layer of the sending end receives MBMS data through a scheduling function and/or a multiplexing function;

if the MBMS data is received wrongly, the MAC layer of the sending end sends NACK through an HARQ function;

and the MAC layer of the sending end receives the MBMS data retransmitted by the MAC layer of the sending end through the HARQ function.

Optionally, the method further comprises:

and if the MBMS data is correctly received, the MAC layer of the sending end sends ACK through an HARQ function.

Optionally, the method further comprises:

the SDAP layer of the receiving end establishes or reconfigures the QoS Flow for bearing the MBMS data;

the SDAP layer of the receiving end selects DRBs of a lower layer, wherein the lower layer comprises one or more of the following items: a PDCP layer, an RLC layer and an MAC layer;

and the SDAP layer of the receiving end maps the QoS Flow carrying the MBMS data to the DRB.

Optionally, the QoS Flow carrying MBMS data is mapped one to the DRB.

Optionally, the plurality of QoS flows carrying MBMS data are mapped with one DRB.

Optionally, the format of the downlink SDAP PDU carrying the MBMS data includes: a first field indicating an identity of a QoS Flow mapped to the same DRB.

alternatively, the first and second electrodes may be,

alternatively, the first and second liquid crystal display panels may be,

the downlink SDAP PDU format for bearing the MBMS data comprises: a third field, configured to the receiving end to determine whether the downlink SDAP PDU has been received.

In a third aspect, a transmission apparatus is provided, including:

a sending module, configured to send MBMS data by a scheduling function and/or a multiplexing function through an MAC layer of a sending end;

and the retransmission module is used for retransmitting the MBMS data to the HARQ function of the MAC layer of the receiving end through the HARQ function if the MAC layer of the sending end receives the NACK sent by the MAC layer of the receiving end.

In a fourth aspect, a transmission apparatus is provided, including:

a receiving module, configured to receive, by an MAC layer of a sending end, MBMS data through a scheduling function and/or a multiplexing function;

a sending module, configured to send, if the MBMS data is received incorrectly, NACK by an MAC layer of the sending end through an HARQ function;

the receiving module is further configured to receive, by the MAC layer of the sending end, the MBMS data retransmitted by the MAC layer of the sending end through the HARQ function.

In a fifth aspect, a communication device is provided, which includes: a processor, a memory and a program stored on the memory and executable on the processor, which when executed by the processor, performs the steps of the method according to the first or second aspect.

A sixth aspect provides a readable storage medium having a program stored thereon, which when executed by a processor implements steps comprising a method according to the first or second aspect.

In the embodiment of the present application, by defining the HARQ function (such as an Adjoint HARQ function) and the SDAP function of the MAC layer, feedback and retransmission are realized in the MAC layer without performing ARQ feedback processing in the RLC layer and by following the HARQ, so that RRC signaling overhead is reduced, overhead and added system complexity that a new RLC functional body needs to be established on a network side and a terminal side are avoided, and fast and efficient MBMS data transmission with retransmission guarantee is realized.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the application. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

fig. 1 is a schematic diagram of a multicast/broadcast architecture of an RLC separate bearer;

fig. 2 is a schematic diagram of logical channel aggregation mode 1 (UM PTM + AM PTP);

FIG. 3 is a schematic diagram of logical channel aggregation mode 2 (AM PTM + AM PTP);

fig. 4 is one of the schematic diagrams of the downstream layer 2 structure;

fig. 5 is a second schematic diagram of the structure of the downlink layer 2;

fig. 6 is a schematic diagram of a model of two unacknowledged mode peer entities;

FIG. 7 is a diagram of a wireless communication system to which embodiments of the present application are applicable

Fig. 8 is a schematic diagram of a transmission method provided in an embodiment of the present application;

fig. 9 is a second schematic diagram of a transmission method according to an embodiment of the present application;

fig. 10 is a functional diagram of an overall MBMS scheme provided in an embodiment of the present application;

FIG. 11 is a diagram illustrating an SDAP data PDU format without an SDAP header according to an embodiment of the present application;

fig. 12 is one of schematic diagrams of DL SDAP PDU formats for carrying MBMS data according to an embodiment of the present application;

FIG. 13 is a second schematic diagram illustrating a DL SDAP PDU format for carrying MBMS data according to an embodiment of the present application;

fig. 14 is a schematic diagram of a transmission device according to an embodiment of the present application;

fig. 15 is a second schematic diagram of a transmission device according to an embodiment of the present application;

fig. 16 is a schematic diagram of a terminal provided in an embodiment of the present application;

fig. 17 is a schematic diagram of a network-side device according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some, but not all, embodiments of the present application. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without making any creative effort belong to the protection scope of the present application.

The terms "comprises," "comprising," or any other variation thereof, in the description and claims of this application are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements explicitly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus. Furthermore, the use of "and/or" in the specification and claims means that at least one of the connected objects, such as a and/or B, means that three cases, a alone, B alone, and both a and B, exist.

In the embodiments of the present application, words such as "exemplary" or "for example" are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "e.g.," is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word "exemplary" or "such as" is intended to present relevant concepts in a concrete fashion.

It is noted that the techniques described in the embodiments of the present application are not limited to Long Term Evolution (LTE)/LTE-Advanced (LTE-a) systems, but may also be used in other wireless communication systems, such as Code Division Multiple Access (CDMA), time Division Multiple Access (TDMA), frequency Division Multiple Access (FDMA), orthogonal Frequency Division Multiple Access (OFDMA), single-carrier Frequency Division Multiple Access (SC-FDMA), and other systems. The terms "system" and "network" in the embodiments of the present application are often used interchangeably, and the described techniques can be used for both the above-mentioned systems and radio technologies, as well as for other systems and radio technologies. However, the following description describes a New Radio (NR) system for purposes of example, and NR terminology is used in much of the description below, although the techniques may also be applied to applications other than NR system applications, such as 6th generation,6g communication systems.

To facilitate understanding of the embodiments of the present application, the following technical points are described below:

a Multimedia Broadcast Multicast Service (MBMS) Service includes a Multicast mode and a Broadcast mode, where the Multicast mode requires a user to sign a corresponding Multicast group, perform Service activation, and generate corresponding charging information. In the data transmission phase of broadcast mode service and multicast mode service, there are two modes for the MBMS service to transmit information between the network and the terminal: a Point-to-Multipoint (PTM) mode and a Point-to-Point (PTP) mode.

The PTP mode is to establish a point-to-point bearer for each terminal (e.g., user Equipment (UE)) in a cell, for example, an end-to-end transmission channel is established for the UE transmitting MBMS data;

by PTM mode is meant that a common transport channel is established in the cell to serve all UEs.

Multicast/broadcast technology enhancement schemes are studied in the related art, and the problems of focusing mainly include flexible switching of PTP and PTM, and the like.

Regarding the enhancement of multicast/broadcast technology, the current conference discussion mainly focuses on the way of Radio Link Control (RLC) separation, as shown in fig. 1, that is, a Packet Data Convergence Protocol (PDCP) at a transmitting end is used as an anchor point, and the RLC bearer separation respectively executes PTP and PTM procedures; with logical channel aggregation, the UE needs only one RLC receiving entity.

Also with respect to the aggregation of logical channels, there are two possible implementations discussed presently:

(1) Unacknowledged Mode (UM) PTM + Acknowledged Mode (AM) PTP, as shown in fig. 2.

PTM only supports UM mode, i.e. the multicast data can be flexibly selected PTM or PTP when transmitted for the first time. The UE feeds back the RLC status report through a Dedicated Traffic Channel (DTCH). And the AM RLC controls data to carry out data retransmission in a multicast mode.

(2) AM PTM + AM PTP, shown in FIG. 3

Both PTM and PTP support AM mode. Specifically, the UE shares the RLC status report fed back by the UL DTCH between two RLC entities, and the network can flexibly select whether to perform unicast retransmission by the DTCH or Multicast retransmission by a Multicast Traffic Channel (MTCH).

In the related Protocol of 5G, a Multimedia Broadcast Multicast Service (MBMS) is not defined, and a Service Data Attachment Protocol (SDAP) function is defined as follows: the main services and functions of the SDAP include:

-mapping between Quality of Service (QoS) flows and data radio bearers;

-marking the QoS Flow ID (QFI) in DL and UL packets.

If MBMS is reintroduced in the fifth generation mobile communication technology (5g), the SDAP functionality needs to be redefined, see fig. 4.

In the related protocol of the fourth generation mobile communication technology (4G), the MBMS has an independent scheduling and resource allocation manner, and there is no Hybrid Automatic Repeat reQuest (HARQ), that is, there is no feedback of an air interface, as shown in fig. 5.

In the related protocol, only UM RLC supports Multicast Traffic Channel (MTCH)/Multicast Control Channel (MCCH) channels of MBMS, but the transmission window length is 0, i.e. no ordering is required, and the transmission is completed:

the constant is used by the receiving UM RLC entity to define the SN of those UM mode transmitted Protocol Data Units (PDUs) (UMD PDUs) that can be received without causing the receive window to advance. UM _ Window _ Size =16 when a 5-bit SN is configured; UM _ Window _ Size =512 when 10-bit SN is configured; when the UM RLC entity is configured to be received for the MCCH, MTCH or STCH, UM _ Window _ Size =0, see fig. 6.

In the relevant protocols, the reception of MBMS is defined:

MCH transmissions may occur in subframes configured for MCCH or MTCH transmissions by upper layers. For each such subframe, the upper layer indicates whether a signaling MCS or a data MCS applies. The transmission of the MCH occurs in a set of subframes defined by the physical multicast channel configuration (PMCH-Config). MCH scheduling information a MAC control element is included in the first subframe allocated to the MCH within the MCH scheduling period to indicate the location of each MTCH and unused subframes on the MCH. If MCCH does not exist, the UE will assume that the first scheduled MTCH starts immediately after the MCCH or MCH scheduling information MAC control element, while the other scheduled MTCHs start immediately after the earliest preceding MTCH in the subframe. The location where the previous MTCH stopped. When the UE needs to receive MCH, the UE shall:

-attempt to decode TB on MCH;

-if the TB on MCH has been successfully decoded:

-demultiplexing the MAC PDUs and delivering the MAC SDUs to the upper layer.

In combination with the forms of MBMS that have been defined in the current standard, two types can be summarized:

1. in 4G, the MBMS is directly broadcast-transmitted by the base station — through the RLC UM mode of 0 window, the scheduling transmission is performed by using a Radio Resource Control (RRC) configured Radio Resource mode. Furthermore, the Medium Access Control (MAC) layer does not have HARQ, and does not need to perform reception feedback of an air interface.

2. At the time of 5G, it is currently desired to implement the receiving feedback of MBMS by introducing PTM transmission in RLC layer and by PTP feedback.

Based on the technical trends of the MBMS scheme already defined in the 4G standard and the MBMS scheme in question in the 5G standard, the MBMS defined in the 5G standard will have feedback and retransmission capabilities. However, as shown in fig. 2 and fig. 3, the introduction of an ARQ (Automatic Repeat-reQuest) function in the RLC layer complicates the processing mechanism of the MBMS, and each RLC Entity (RLC Entity) carrying MBMS transmission needs to configure one RLC AM Entity (RLC AM Entity) for feedback processing, although in order to reduce the complexity of implementation on the UE side, the scheme in fig. 2 and fig. 3 emphasizes that only one RLC AM Entity for receiving MBMS data is established on the UE side. However, in essence, RLC entities for MBMS transmission are respectively established on the network side and the terminal side through RRC signaling, a functional entity of RLC AM/UM PTM + AM PTP combination is established on the network side, and an RLC AM PTP functional entity is established on the terminal side. Meanwhile, in order to ensure that ARQ operates effectively, the network side needs to synchronize Sequence Number (SN) of RLC transmission packets between the RLC AM/UM PTM functional entity and AM PTP functional entities of different users.

Referring to fig. 7, a block diagram of a wireless communication system to which embodiments of the present application are applicable is shown. The wireless communication system includes a terminal 71 and a network-side device 72. Wherein, the terminal 71 may also be called as a terminal Device or a User Equipment (UE), the terminal 71 may be a Mobile phone, a Tablet Personal Computer (Tablet Personal Computer), a Laptop Computer (Laptop Computer) or a notebook Computer, a Personal Digital Assistant (PDA), a palmtop Computer, a netbook, an ultra-Mobile Personal Computer (UMPC), a Mobile Internet Device (MID), a Wearable Device (Wearable Device) or a Vehicle-mounted Device (Vehicle User Equipment, VUE), a Pedestrian terminal (Pedestrian User Equipment, PUE), and other terminal side devices, the Wearable Device includes: bracelets, earphones, glasses and the like. It should be noted that the embodiment of the present application does not limit the specific type of the terminal 71.

The network-side device 72 may be a Base Station or a core network, wherein the Base Station may be referred to as a node B, an evolved node B, an access point, a Base Transceiver Station (BTS), a radio Base Station, a radio Transceiver, a Basic Service Set (BSS), an Extended Service Set (ESS), a node B, an evolved node B (eNB), a home node B, a home evolved node B, a WLAN access point, a WiFi node, a TRP, or some other suitable terminology in the field, as long as the same technical effect is achieved, the Base Station is not limited to a specific technical vocabulary, and it should be noted that, in the embodiment of the present application, only the Base Station in the NR system is taken as an example, but the specific type of the Base Station is not limited.

Referring to fig. 8, an embodiment of the present application provides a transmission method, which includes: step 801 and step 802.

Step 801: the MAC layer of the sending end sends the MBMS data through a scheduling function and/or a multiplexing function;

step 802: if the MAC layer of the sending end receives a Negative-acknowledgement (NACK) sent by the MAC layer of the receiving end (e.g., via the HARQ function), the MAC layer of the sending end retransmits the MBMS data to the HARQ function of the MAC layer of the receiving end via the HARQ function.

The HARQ function herein may also be referred to as a HARQ function entity, HARQ related function or process.

The HARQ-related functions include one or more of: HARQ process function, feedback process function for reception and transmission of HARQ processes, function of different HARQ modes, mode function of different HARQ processes, and the like.

It is to be understood that the following description will take the HARQ function as an example of the accompanying HARQ function.

The accompanying HARQ function is dedicated to the PTP type transmission of MBMS service data (corresponding to the MCH channel). In fig. 4, the MBMS Scheduling and/or multiplexing (Multiplex) functions are responsible for PTM type transmission, with HARQ responsible for corresponding PTP reception and transmission.

When in sending: scheduling (MBMS Scheduling) and/or multiplexing (Multiplex) of PTM are carried out for broadcast transmission, and for one UE, if the MBMS data is correctly received, ACK is fed back or nothing is fed back through the accompanying HARQ function; if the MBMS data is received in error, NACK is carried out by the accompanying HARQ, then retransmission is carried out by the accompanying HARQ, the process is directly ended, and the 'process end' corresponds to three conditions: one transmission is successful; the second method is unsuccessful, and reaches the maximum sending times until the failure is discarded; and the three kinds of transmission are carried out for multiple times, but the maximum transmission times are not reached, and finally the transmission is successful.

And (3) during receiving: the UE receives and receives ACK/NACK feedback using the companion HARQ function.

The accompanying HARQ function may be a function added inside the existing HARQ function, and includes one of the following: the existing HARQ function adds a scheduling function aiming at the MBMS, a data transmission and feedback function and newly defines an HARQ Process (Process) aiming at the MBMS.

The HARQ-associated function may be a newly added function in parallel with the existing HARQ function, and when the user needs to transmit MBMS data, the HARQ-associated function is newly added (newly established or reconfigured). The HARQ-related function includes a scheduling function for MBMS data transmission, a data multiplexing function, an HARQ process, a corresponding transmission-feedback control function, and the like.

In an embodiment of the present application, after the MAC layer of the transmitting end transmits MBMS data through a scheduling function and/or a multiplexing function, the method further includes:

the MAC layer of the transmitting end receives (e.g., through the HARQ accompanying function) an Acknowledgement (ACK) sent by the MAC layer of the receiving end (e.g., through the HARQ accompanying function).

and the MAC layer of the sending end sends the MBMS data to the accompanying HARQ function of the MAC layer of the sending end.

In an embodiment of the present application, the scheduling function and/or multiplexing function of the MAC layer of the sending end does not buffer the MBMS data, and directly sends the MBMS data to an accompanying HARQ function of the MAC layer of the sending end;

alternatively, the first and second electrodes may be,

and the scheduling function and/or multiplexing function of the MAC layer of the sending end caches the MBMS data, and the accompanying HARQ function of the MAC layer of the sending end reads the MBMS data from the cache.

In an embodiment of the present application, the reading, by an accompanying HARQ function of an MAC layer of the sending end, the MBMS data from a buffer includes:

the accompanied HARQ function of the MAC layer of the sending end reads the MBMS data from the cache in a timing mode according to the sending mode of the PTM;

alternatively, the first and second electrodes may be,

and the accompanying HARQ function of the MAC layer of the sending end receives a notification message, and reads the MBMS data from the cache according to the notification message.

In one embodiment of the present application, the transmission mode of the PTM is configured by RRC signaling when the HARQ-accompanied is established or reconfigured.

In an embodiment of the present application, the cache is provided with a discard timer, and if the timer is over time, the cache is emptied;

alternatively, the first and second liquid crystal display panels may be,

each accompanying HARQ function of the MAC layer of the sending end can only access the corresponding cache;

alternatively, the first and second liquid crystal display panels may be,

the multiple accompanying HARQ functions of the MAC layer of the transmitting end can access the same cache.

In one embodiment of the present application, the method further comprises:

the SDAP layer of the sending end maps MBMS data to be sent to different low layers for sending, and the low layers comprise one or more of the following items: a Packet Data Convergence Protocol (PDCP) layer, an RLC layer, and an MAC layer.

In one embodiment of the present application, the method further comprises:

the SDAP layer of the transmitting end selects a Data Radio Bearer (DRB) of a lower layer;

In an embodiment of the present application, the QoS Flow for carrying MBMS data to be sent and the DRBs are mapped one to one.

In an embodiment of the present application, the QoS flows carrying MBMS data to be transmitted are mapped to one DRB.

In an embodiment of the present application, the downlink SDAP PDU format for carrying MBMS data includes: a first field indicating an identity of QoS Flow mapped onto the same DRB.

In an embodiment of the present application, the QoS Flow carrying MBMS data to be sent is mapped to a plurality of DRBs.

In an embodiment of the present application, the downlink SDAP PDU format for carrying MBMS data includes: a second field indicating an identifier of QoS Flow mapped to the same DRB;

alternatively, the first and second liquid crystal display panels may be,

alternatively, the first and second electrodes may be,

the downlink SDAP PDU format for bearing the MBMS data comprises: a third field, configured to determine, by the receiving end, whether the downlink SDAP PDU has been received.

In an embodiment of the present application, the PDCP layer of the transmitting end directly transmits MBMS data to a lower layer of the PDCP layer.

In an embodiment of the present application, the RLC layer of the transmitting end performs MBMS data transmission in an unacknowledged mode.

In the embodiment of the application, when the MAC layer solves PTM and PTP transmission (transmission and reception), the time delay is short, the control overhead is low, and for precise transmission (transmission and reception) of each UE, transmission (transmission and reception) and feedback are performed by HARQ, so that the overhead for transmitting ACK/NACK is the lowest. Only new function definition is needed to be carried out on the SDAP layer and the MAC layer, and the system overhead is small. The SDAP flexibly selects a low-layer channel, has no RRC signaling overhead, and can perform broadcast transmission (transmission and reception) as required.

Referring to fig. 9, an embodiment of the present application provides a transmission method, which includes: step 901 and step 902.

Step 901: the MAC layer of the sending end receives MBMS data through a scheduling function and/or a multiplexing function;

step 902: if the MBMS data is received wrongly, the MAC layer of the sending end sends NACK through the accompanying HARQ function;

step 903: and the MAC layer of the sending end receives the MBMS data retransmitted by the MAC layer of the sending end through the accompanying HARQ function.

In one embodiment of the present application, the method further comprises:

and if the MBMS data is correctly received, the MAC layer of the sending end sends ACK through an accompanying HARQ function.

In one embodiment of the present application, the method further comprises:

and the SDAP layer of the receiving end maps the QoS Flow for bearing the MBMS data to the DRB.

In an embodiment of the present application, the QoS Flow carrying the MBMS data is mapped to the DRB one to one.

In an embodiment of the present application, the plurality of QoS flows carrying MBMS data are mapped to one DRB.

In an embodiment of the present application, the format of the downlink SDAP PDU carrying MBMS data includes: a second field indicating an identifier of QoS Flow mapped to the same DRB;

alternatively, the first and second electrodes may be,

In the embodiment of the application, when the MAC layer solves PTM and PTP transmission (transmission and reception), the time delay is short, the control overhead is low, and for precise transmission (transmission and reception) of each UE, transmission (transmission and reception) and feedback are performed by HARQ, so that the overhead for transmitting ACK/NACK is the lowest. Only new function definition is needed to be carried out on the SDAP layer and the MAC layer, and the system overhead is small. The SDAP flexibly selects a lower layer channel, has no RRC signaling overhead, and can perform broadcast transmission (transmission and reception) as required.

Referring to fig. 10, a function definition for MBMS transmission is added at L2 (layer 2). The functions of "Qos flow", "PDU Distribution for add HARQ" and "add HARQ" are new functions. The newly added 5G system with the functions of 'segm', 'MBMS Scheduling' and 'Multiplexing' is a function borrowed from a 4G system (the innovation may be problematic).

1. With respect to SDAP layer

The data of the MBMS can be transmitted on different PDCP-RLC-MAC lower layer channels through mapping of the SDAP layer, as shown in fig. 10. The different PDCP-RLC-MAC lower layer channels may be channels of the same or different cells (cells). On the network side, the base stations can be on the same base station or different base stations; the same CU/DU of the same base station, or different CU/DU, or different DU of the same CU may be used. On the terminal side, the PDCP-RLC-MAC lower layer channel for different or same cells receives data and delivers the data to the SDAP layer.

Since the L2 function supporting the MBMS service is not defined in the 5G system. The transmission of MBMS service data is realized by defining new functions of SDAP and MAC layer.

For data point QoS Flows carrying MBMS service:

1. and receiving signaling configuration of RRC, and establishing/reconfiguring/deleting QoS Flow carrying MBMS data.

2. And selecting the low-layer DRB bearing. And carrying out low-layer DRB bearing selection according to RRC signaling configuration, or self monitoring, or system operation requirements.

3. And mapping the QoS flow carrying the MBMS data to the DRB. (Mapping between a QoS flow and a data radio bearer)

3.1. And the QoS Flow for bearing the MBMS data is mapped with the DRB one by one. Does not support reflective mapping (reflective mapping) function, simultaneously does not support the simultaneous mapping of a plurality of QoS flows to a DRB, and does not carry QFI (non-marking QoS Flow ID (QFI) in the volume DL and UL packets.)

The SDAP PDU format without SDAP header, which is defined in the current protocol, can satisfy the above data transmission requirement, and can also be transmitted by using the PDU format defined in FIG. 11, wherein the SDAP PDU only contains one data field and does not contain any SDAP header.

3.2. And carrying the QoS Flow of the MBMS data and the DRB many-to-one mapping. The reflective mapping (reflective mapping) function is not supported.

Referring to fig. 12, a Downlink (DL) SDAP PDU format for carrying MBMS data is illustrated.

Wherein, the first and the second end of the pipe are connected with each other,

(a) R Field (Reserved Field): length 1bit, set to 0, and the receiving end ignores the field after receiving the PDU.

(b) QFI Field (QFI Field): the length is less than or equal to 6bits, the length of QFI is not necessarily 6bits defined on the protocol, and can be 4bits, 2bits or even 1 bit. QFI is the ID of QoS Flow mapped to the same Data Radio Bearer (DRB).

3.3. The QoS Flow carrying MBMS data is mapped one-to-many with DRB (one SDAP functional entity is mapped to different PDCP-RLC-MAC lower layer channels as shown in fig. 10). The reflective mapping (reflective mapping) function is not supported.

May be transmitted using the SDAP PDU format of FIG. 12 or without the SDAP PDU header (as shown in FIG. 11).

Alternatively, the format of the SDAP PDU carrying the Duplicate Resolution Flag (DRF) may also be adopted, see fig. 13. To solve how the multiple reception identifies and discards duplicate MBMS packets (packets).

(b) QFI Field (QFI Field): the length is less than or equal to 6bits, the length of QFI is not necessarily 6bits defined on the protocol, and can be 4bits and 2bits, even 1 bit. QFI is the ID of QoS Flow mapped onto the same DRB (Data Radio Bearer).

The R and QFI fields may be fields selectable, and may or may not be carried. The configuration is carried out through RRC signaling, and the self-judgment can also be carried out through fields carried in the PDU.

If the judgment is self-made, the O field needs to be carried.

(c) And an O field: an optional field. Identify whether or not it carries QFI. For example, the ratio of 0: no QFI was carried; 1: carrying the QFI. Located in the first byte of the SDAP PDU. If QFI is present, it is within the same byte as QFI; if QFI is not present, it is within one byte with DRF.

(d) Duplicate Resolution Flag (DRF) field: to determine whether the PDU has been received. One definition that is commonly used is a Sequence Number (SN) sent for a packet, the length of which is an integer multiple of a whole byte, such as 8 bits, 16 bits, 24 bits (n 8, n is an integer), or 7 bits, 15 bits, 23 bits or other n 8-1 bits (n is an integer). The initial value is 0, and every time one PDU is sent, the DRF is added with 1, and then the cyclic addition is carried out.

After receiving a PDU, the receiving end judges whether the DRF of the PDU has been received, if so, the PDU is discarded, otherwise, the PDU is delivered to an upper layer after the processing is finished.

2. Regarding the PDCP layer:

and a transparent transmission PDCP protocol function layer, namely a data packet of the MBMS is subjected to any processing in a PDCP layer and is directly delivered to an upper layer of the PDCP or is sent to a lower layer of the PDCP.

3. Regarding the RLC layer:

the method has a segmentation function during transmission and a recombination function during reception.

The RLC layer performs reception and transmission of MBMS data using an Unacknowledged Mode (UM), without using an AM (Acknowledged Mode) Mode and an ARQ process.

When using RLC UM, both the sending and receiving windows may be closed, or the length may be set to 0, or not configured;

4. regarding the MAC layer:

two new functions are newly defined:

1. an Adjoint HARQ function (Adjoint HARQ);

the accompanying HARQ function is dedicated to the PTP type transmission of MBMS service data (corresponding to the MCH channel). In fig. 10, the MBMS Scheduling and/or multiplexing (Multiplex) functions are responsible for PTM type transmission, with HARQ responsible for corresponding PTP reception and transmission.

When in sending: scheduling (MBMS Scheduling) and/or multiplexing (Multiplex) of PTM are carried out broadcast transmission, and for one UE, if the MBMS data is correctly received, ACK is fed back or nothing is fed back by accompanying HARQ; if the MBMS data is received in error, NACK is carried out through the accompanying HARQ, then retransmission is carried out through the accompanying HARQ, and the process is directly finished, wherein the process is finished and corresponds to three conditions: one transmission is successful; the second method is unsuccessful, and reaches the maximum sending times until failure and discarding; and the three kinds of multi-time transmission do not reach the maximum transmission times, and finally the transmission is successful.

And (3) during receiving: the UE receives ACK/NACK feedback using companion HARQ.

MBMS MAC PDU distributes function to the accompanying HARQ;

when in sending: after broadcasting and transmitting each time the Scheduling (MBMS Scheduling) and/or multiplexing (Multiplex) body of the PTM, the MAC PDU transmitted this time is distributed to the accompanying HARQ function body of each UE in time.

The distribution mode may be that the Scheduling (MBMS Scheduling) and/or multiplexing (Multiplex) functions of the PTM do not buffer but directly distribute the accompanying HARQ to each UE; or temporary buffering, each accompanying HARQ sends a request to a Scheduling (MBMS Scheduling) and/or multiplexing (Multiplex) function of the PTM if retransmission is required, a Discard Timer (Discard Timer) is set, and the buffering is emptied when time out. A shared buffer can also be set, each accompanying HARQ can access the buffer, when PTM sends a data packet, each accompanying HARQ sends a notification message, and after receiving the notification message, the accompanying HARQ reads the data packet from the shared buffer; or the data is read from the buffer according to the sending mode (cycle length, starting point of cycle, sending starting subframe, etc.) of PTM with HARQ, in this case, the sending mode of PTM needs to be informed to each accompanying HARQ, because the sending mode of PTM is configured by RRC signaling, when the accompanying HARQ is established or reconfigured, the mode of PTM can be configured by RRC signaling.

And (3) during receiving: it is only necessary to have the HARQ accompanying function (PTP function), and the PTM function may not be provided.

Referring to fig. 14, an embodiment of the present application provides a transmission apparatus, which is applied to a sending end, where the apparatus 1400 includes:

a sending module 1401, configured to send MBMS data by using a scheduling function and/or a multiplexing function through an MAC layer at a sending end;

a retransmission module 1402, configured to, if the MAC layer of the sending end receives NACK sent by the MAC layer of the receiving end, retransmit the MBMS data to an accompanying HARQ function of the MAC layer of the receiving end through the accompanying HARQ function by the MAC layer of the sending end.

In this embodiment, the apparatus 1400 further includes:

and the receiving module is used for receiving the ACK sent by the MAC layer of the receiving end through the accompanying HARQ function by the MAC layer of the sending end.

In this embodiment of the present application, the sending module 1401 is further configured to send, by the MAC layer of the sending end, the MBMS data to an accompanying HARQ function of the MAC layer of the sending end.

In this embodiment of the present application, the sending module 1401 is further configured to directly send the MBMS data to an accompanying HARQ function of the MAC layer of the sending end by using a scheduling function and/or a multiplexing function of the MAC layer of the sending end;

alternatively, the first and second electrodes may be,

In this embodiment of the present application, the reading, from the buffer, the MBMS data by the HARQ accompanying function of the MAC layer of the sending end includes:

the accompanying HARQ function of the MAC layer of the sending end reads the MBMS data from the cache according to the sending mode timing of the PTM;

alternatively, the first and second electrodes may be,

In the embodiment of the present application, the transmission mode of the PTM is configured through RRC signaling when the HARQ is established or reconfigured.

In the embodiment of the application, the cache is provided with a discard timer, and if the timer is overtime, the cache can be emptied;

alternatively, the first and second electrodes may be,

In this embodiment of this application, the sending module 1401 is further configured to map, by the SDAP layer of the sending end, MBMS data to be sent to different lower layers for sending, where the lower layers include one or more of the following: PDCP layer, RLC layer and MAC layer.

In this embodiment, the apparatus 1400 further includes:

the mapping module is used for the SDAP layer of the sending end to establish or reconfigure the QoS Flow for bearing the MBMS data to be sent; the SDAP layer of the sending end selects a DRB of a lower layer; and the SDAP layer of the sending end maps the QoS Flow carrying the MBMS data to be sent to the DRB.

In this embodiment of the present application, the QoS Flow carrying the MBMS data to be sent and the DRBs are mapped one to one.

In this embodiment of the present application, the QoS flows carrying the MBMS data to be transmitted are mapped to one DRB.

In this embodiment of the present application, the format of the downlink SDAP PDU carrying MBMS data includes: a first field indicating an identity of a QoS Flow mapped to the same DRB.

In this embodiment, the QoS Flow carrying the MBMS data to be sent is mapped to a plurality of DRBs.

In this embodiment of the present application, the format of the downlink SDAP PDU carrying MBMS data includes: a second field indicating an identifier of a QoS Flow mapped to the same DRB;

alternatively, the first and second electrodes may be,

alternatively, the first and second liquid crystal display panels may be,

In this embodiment of this application, the sending module 1401 is further configured to send, by the PDCP layer of the sending end, the MBMS data directly to a lower layer of the PDCP layer.

In this embodiment of the application, the sending module 1401 is further configured to send, by the RLC layer of the sending end, the MBMS data in an unacknowledged mode.

Referring to fig. 15, an embodiment of the present application further provides a transmission apparatus, where the apparatus 1500 includes:

a receiving module 1501, configured to receive MBMS data by a scheduling function and/or a multiplexing function through an MAC layer of a transmitting end;

a sending module 1502, configured to send, if the MBMS data is received incorrectly, a NACK through an accompanying HARQ function by an MAC layer of the sending end;

the receiving module 1501 is further configured to receive, by the MAC layer of the sending end, the MBMS data retransmitted by the MAC layer of the sending end through the HARQ.

In this embodiment of the application, the sending module 1502 is further configured to send an ACK by the MAC layer of the sending end through an accompanying HARQ function if the MBMS data is correctly received.

In an embodiment of the present application, the apparatus 1500 further includes:

the mapping module is used for the SDAP layer of the receiving end to establish or reconfigure the QoS Flow carrying the MBMS data; the SDAP layer of the receiving end selects DRBs of a lower layer, wherein the lower layer comprises one or more of the following items: a PDCP layer, an RLC layer and an MAC layer; and the SDAP layer of the receiving end maps the QoS Flow carrying the MBMS data to the DRB.

In this embodiment, the QoS Flow carrying MBMS data is mapped to the DRB one to one.

In this embodiment, the QoS flows carrying MBMS data are mapped to one DRB.

In this embodiment of the present application, the QoS Flow carrying the MBMS data to be transmitted is mapped to the plurality of DRBs.

alternatively, the first and second liquid crystal display panels may be,

alternatively, the first and second electrodes may be,

The device provided in the embodiment of the present application can implement each process implemented in the method embodiment shown in fig. 9, and achieve the same technical effect, and is not described here again to avoid repetition.

Fig. 16 is a schematic diagram of a hardware structure of a terminal for implementing the embodiment of the present application, where the terminal 1600 includes, but is not limited to: radio frequency unit 1601, network module 1602, audio output unit 1603, input unit 1604, sensor 1605, display unit 1606, user input unit 1607, interface unit 1608, memory 1609, and processor 1610.

Those skilled in the art will appreciate that terminal 1600 may also include a power supply (e.g., a battery) for powering the various components, which may be logically coupled to processor 1610 via a power management system to perform the functions of managing charging, discharging, and power consumption via the power management system. The terminal structure shown in fig. 16 does not constitute a limitation of the terminal, and the terminal may include more or less components than those shown, or combine some components, or have a different arrangement of components, and will not be described again.

It should be understood that in the embodiment of the present application, the input Unit 1604 may include a Graphics Processing Unit (GPU) 16041 and a microphone 16042, and the Graphics processor 16041 processes image data of still pictures or videos obtained by an image capturing device (such as a camera) in a video capturing mode or an image capturing mode. The display unit 1606 may include a display panel 16061, and the display panel 16061 may be configured in the form of a liquid crystal display, an organic light emitting diode, or the like. The user input unit 1607 includes a touch panel 16071 and other input devices 16072. Touch panel 16071, also referred to as a touch screen. The touch panel 16071 may include two parts of a touch detection device and a touch controller. Other input devices 16072 may include, but are not limited to, a physical keyboard, function keys (e.g., volume control keys, switch keys, etc.), a trackball, a mouse, and a joystick, which are not described in detail herein.

In this embodiment, the radio frequency unit 1601 receives downlink data from a network device and then processes the downlink data in the processor 1610; in addition, the uplink data is sent to the network side equipment. Generally, the radio frequency unit 1601 includes, but is not limited to, an antenna, at least one amplifier, a transceiver, a coupler, a low noise amplifier, a duplexer, and the like.

The memory 1609 may be used to store software programs or instructions as well as various data. The memory 1609 may mainly include a stored program or instruction area and a stored data area, wherein the stored program or instruction area may store an operating system, application programs or instructions required for at least one function (such as a sound playing function, an image playing function, etc.), and the like. In addition, the Memory 1609 may include a high-speed random access Memory, and may also include a nonvolatile Memory, which may be a Read-Only Memory (ROM), a Programmable ROM (PROM), an Erasable Programmable PROM (EPROM), an Electrically Erasable Programmable ROM (EEPROM), or a flash Memory. Such as at least one magnetic disk storage device, flash memory device, or other non-volatile solid state storage device.

Processor 1610 may include one or more processing units; alternatively, the processor 810 may integrate an application processor, which primarily handles operating systems, user interfaces, and applications or instructions, etc., and a modem processor, which primarily handles wireless communications, such as a baseband processor. It is to be appreciated that the modem processor described above may not be integrated into processor 1610.

The terminal provided in the embodiment of the present application can implement each process implemented by the method embodiment shown in fig. 8, and achieve the same technical effect, and for avoiding repetition, details are not described here again.

Referring to fig. 17, fig. 17 is a structural diagram of a network side device according to an embodiment of the present invention, and as shown in fig. 17, a network side device 1700 includes: a processor 1701, a transceiver 1702, a memory 1703, and a bus interface, wherein:

in an embodiment of the present invention, the network-side device 1700 further includes: a program stored on the memory 903 and executable on the processor 1701, which when executed by the processor 1701, performs the steps of the embodiment shown in fig. 9.

In fig. 17, the bus architecture may include any number of interconnected buses and bridges, with one or more processors, represented by the processor 1701, and various circuits, represented by the memory 1703, specifically linked together. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further herein. The bus interface provides an interface. The transceiver 1702 may be a plurality of elements including a transmitter and a receiver that provide a means for communicating with various other apparatus over a transmission medium.

The processor 1701 is responsible for managing a bus architecture and general processing, and the memory 1703 may store data used by the processor 1701 in performing operations.

The network side device provided in the embodiment of the present application can implement each process implemented by the method embodiment shown in fig. 9, and achieve the same technical effect, and for avoiding repetition, details are not described here again.

An embodiment of the present application further provides a readable storage medium, where a program or an instruction is stored on the readable storage medium, and when the program or the instruction is executed by a processor, the program or the instruction implements each process of the method embodiment shown in fig. 8 or fig. 9, and can achieve the same technical effect, and in order to avoid repetition, details are not repeated here.

Wherein, the processor is the processor in the terminal described in the above embodiment. The readable storage medium includes a computer readable storage medium, such as a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and so on.

The steps of a method or algorithm described in connection with the disclosure herein may be embodied in hardware or may be embodied in software instructions executed by a processor. The software instructions may consist of corresponding software modules that may be stored in RAM, flash memory, ROM, EPROM, EEPROM, registers, hard disk, a removable hard disk, a compact disk, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium. Of course, the storage medium may also be integral to the processor. The processor and the storage medium may reside in an ASIC. In addition, the ASIC may be carried in a core network interface device. Of course, the processor and the storage medium may reside as discrete components in a core network interface device.

Those skilled in the art will recognize that in one or more of the examples described above, the functions described herein may be implemented in hardware, software, firmware, or any combination thereof. When implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a general purpose or special purpose computer.

The above-mentioned embodiments, objects, technical solutions and advantages of the present application are further described in detail, it should be understood that the above-mentioned embodiments are only examples of the present application, and are not intended to limit the scope of the present application, and any modifications, equivalent substitutions, improvements and the like made on the basis of the technical solutions of the present application should be included in the scope of the present application.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, embodiments of the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, embodiments of the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

Embodiments of the present application are described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

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

It will be apparent to those skilled in the art that various changes and modifications may be made in the embodiments of the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the embodiments of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to encompass such modifications and variations.

Claims

1. A method of transmission, comprising:

a Media Access Control (MAC) layer of a sending end sends Multimedia Broadcast Multicast Service (MBMS) data through a scheduling function and/or a multiplexing function;

and if the MAC layer of the sending end receives the negative acknowledgement NACK sent by the MAC layer of the receiving end, the MAC layer of the sending end retransmits the MBMS data to the HARQ function of the MAC layer of the receiving end through a hybrid automatic repeat request (HARQ) function.

2. The method as claimed in claim 1, wherein after the MAC layer of the transmitting end transmits the MBMS data through a scheduling function and/or a multiplexing function, the method further comprises:

and the MAC layer of the sending end receives the ACK sent by the MAC layer of the receiving end.

3. The method of claim 1, wherein after the MAC layer of the transmitting end transmits MBMS data through a scheduling function and/or a multiplexing function, the method further comprises:

4. The method of claim 3,

the scheduling function and/or multiplexing function of the MAC layer of the sending end directly sends the MBMS data to the HARQ function of the MAC layer of the sending end;

alternatively, the first and second electrodes may be,

5. The method of claim 4, wherein the reading of the MBMS data from the buffer by the HARQ function of the MAC layer of the transmitting end comprises:

the HARQ function of the MAC layer of the sending end reads the MBMS data from the cache in a timing mode according to the point-to-multipoint PTM sending mode;

alternatively, the first and second liquid crystal display panels may be,

6. The method according to claim 5, wherein the transmission mode of the PTM is configured by radio resource control, RRC, signaling when HARQ is established or reconfigured.

7. The method of claim 4, wherein the cache is provided with a discard timer, and wherein if the timer expires, the cache is emptied;

alternatively, the first and second electrodes may be,

multiple HARQ functions of the MAC layer of the sending end can access the same cache.

8. The method of claim 1, further comprising:

the service data adaptation protocol SDAP layer of the sending end maps MBMS data to be sent to different low layers for sending, and the low layers comprise one or more of the following items: PDCP layer, radio link control RLC layer and MAC layer.

9. The method of claim 8, further comprising:

the SDAP layer of the sending end establishes or reconfigures a QoS Flow carrying MBMS data to be sent;

the SDAP layer of the sending end selects a Data Radio Bearer (DRB) of a lower layer;

and the SDAP layer of the sending end maps one or more QoS flows for bearing MBMS data to be sent to the DRB.

10. The method of claim 9, wherein the QoS Flow carrying MBMS data to be transmitted is mapped one-to-one to the DRB.

11. The method of claim 9, wherein the plurality of QoS flows carrying MBMS data to be transmitted are mapped to one of the DRBs.

12. The method of claim 11, wherein the downlink service data adaptation protocol SDAP protocol data unit PDU format for carrying MBMS data comprises: a first field indicating an identity of QoS Flow mapped onto the same DRB.

13. The method of claim 9, wherein the one QoS Flow carrying MBMS data to be transmitted is mapped to a plurality of DRBs.

14. The method of claim 13,

the format of the downlink SDAP PDU for bearing the MBMS data comprises the following steps: a second field indicating an identifier of a QoS Flow mapped to the same DRB;

alternatively, the first and second liquid crystal display panels may be,

alternatively, the first and second electrodes may be,

15. The method of claim 1,

and the PDCP layer of the sending end directly sends the MBMS data to a lower layer of the PDCP layer.

16. The method of claim 1,

and the RLC layer of the sending end carries out MBMS data sending in an unacknowledged mode.

17. A method of transmission, comprising:

18. The method of claim 17, further comprising:

19. The method of claim 17, further comprising:

the SDAP layer of the receiving end establishes or reconfigures the QoS Flow carrying the MBMS data;

and the SDAP layer of the receiving end maps one or more QoS flows carrying MBMS data to the DRB.

20. The method of claim 19, wherein the QoS Flow carrying MBMS data is mapped one-to-one with the DRB.

21. The method of claim 19, wherein the plurality of QoS flows carrying MBMS data are mapped to one DRB.

22. The method of claim 21, wherein the downlink SDAP PDU format for carrying MBMS data comprises: a first field indicating an identity of QoS Flow mapped onto the same DRB.

23. The method of claim 19, wherein the one QoS Flow carrying MBMS data to be transmitted is mapped to a plurality of DRBs.

24. The method of claim 23,

the downlink SDAP PDU format for bearing the MBMS data comprises: a second field indicating an identifier of a QoS Flow mapped to the same DRB;

alternatively, the first and second electrodes may be,

25. A transmission apparatus, comprising:

a sending module, which is used for sending MBMS data by the MAC layer of the sending end through a scheduling function and/or a multiplexing function;

and the retransmission module is used for retransmitting the MBMS data to the HARQ function of the MAC layer of the receiving end through the HARQ function if the MAC layer of the sending end receives the NACK transmitted by the MAC layer of the receiving end.

26. A transmission apparatus, comprising:

the receiving module is used for receiving the MBMS data by the MAC layer of the sending end through a scheduling function and/or a multiplexing function;

27. A communication device, comprising: processor, memory and program stored on the memory and executable on the processor, which when executed by the processor implements the steps of the method according to any one of claims 1 to 24.

28. A readable storage medium, characterized in that the readable storage medium has stored thereon a program which, when being executed by a processor, carries out steps comprising a method according to any one of claims 1 to 24.