Method and apparatus for indicating status variables of multicast traffic

Abstract

The embodiment of the application discloses a multicast service state variable indication method and device, and belongs to the communication technical field. The multicast service state variable indication method comprises the following steps: a sending end sends PDCP COUNT information to a receiving end; wherein the PDCP COUNT information comprises at least one of the following: a PDCP COUNT value, a PDCP HFN value, a PDCP HFN value and a SN value.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of communication, and particularly relates to a multicast service state variable indication method and device. BACKGROUND

[0002] In the related art, the user network universal interface (Uu) and the side link (SL) interface are only enabled with the security mechanism of the packet data convergence protocol (PDCP) layer for unicast transmission. For Uu multicast and SL groupcast / broadcast services, the security mechanism of the PDCP layer is not currently enabled, and the security of multicast transmission is low. SUMMARY

[0003] Embodiments of the present application provide a multicast service state variable indication method and device, which can solve the problem of low security caused by the fact that the multicast service does not enable the security mechanism of the PDCP layer.

[0004] In a first aspect, a multicast service state variable indication method is provided, including: a sending end sending PDCP COUNT information to a receiving end; wherein the PDCP COUNT information includes at least one of the following: a PDCP COUNT value, a PDCP HFN value, and a PDCP HFN value and a SN value.

[0005] In a second aspect, a multicast service state variable indication method is provided, including: a receiving end receiving PDCP COUNT information from a sending end; wherein the PDCP COUNT information includes at least one of the following: a PDCP COUNT value, a PDCP HFN value, and a PDCP HFN value and a SN value.

[0006] In a third aspect, a multicast service state variable indication device is provided, including: a sending module configured to send PDCP COUNT information to a receiving end; wherein the PDCP COUNT information includes at least one of the following: a PDCP COUNT value, a PDCP HFN value, and a PDCP HFN value and a SN value.

[0007] In a fourth aspect, a multicast service state variable indication device is provided, including: a receiving module configured to receive PDCP COUNT information from a sending end; wherein the PDCP COUNT information includes at least one of the following: a PDCP COUNT value, a PDCP HFN value, and a PDCP HFN value and a SN value.

[0008] In a fifth aspect, a terminal is provided, which comprises a processor, a memory, and a program or instructions stored in the memory and executable on the processor, and the program or instructions, when executed by the processor, implement the method according to the first aspect or the second aspect.

[0009] In a sixth aspect, a terminal is provided, which comprises a processor and a communication interface, the communication interface being configured to send PDCP COUNT information to a receiving terminal or receive PDCP COUNT information from a sending terminal, and the PDCP COUNT information comprises at least one of a PDCP COUNT value, a PDCP HFN value, and a PDCP HFN value and a SN value.

[0010] In a seventh aspect, a network-side device is provided, which comprises a processor, a memory, and a program or instructions stored in the memory and executable on the processor, and the program or instructions, when executed by the processor, implement the method according to the first aspect or the second aspect.

[0011] In an eighth aspect, a network-side device is provided, which comprises a processor and a communication interface, the communication interface being configured to send PDCP COUNT information to a receiving terminal or receive PDCP COUNT information from a sending terminal, and the PDCP COUNT information comprises at least one of a PDCP COUNT value, a PDCP HFN value, and a PDCP HFN value and a SN value.

[0012] In a ninth aspect, a readable storage medium is provided, which stores a program or instructions, and the program or instructions, when executed by a processor, implement the method according to the first aspect or the second aspect.

[0013] In a tenth aspect, a chip is provided, which comprises a processor and a communication interface, the communication interface being coupled to the processor, and the processor is configured to execute a program or instructions to implement the method according to the first aspect or the second aspect.

[0014] In an eleventh aspect, a computer program / program product is provided, which is stored in a non-transitory storage medium, and the program / program product is executed by at least one processor to implement the method according to the first aspect or the second aspect.

[0015] In the embodiments of the present application, the sending end sends PDCP COUNT information to the receiving end, the PDCP COUNT information including at least one of the following: a PDCP COUNT value, a PDCP HFN value, a PDCP HFN value and a SN value, so that the receiving end can obtain the PDCP COUNT value based on the PDCP COUNT information to decrypt, integrity verify and sort the data packets of the multicast service, and improve the security of the multicast service transmission. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a schematic diagram of a wireless communication system according to an embodiment of the present application;

[0017] Figure 2 is a schematic flow chart of a state variable indication method for a multicast service according to an embodiment of the present application;

[0018] Figure 3 is a schematic flow chart of a state variable indication method for a multicast service according to an embodiment of the present application;

[0019] Figure 4 is a structural schematic diagram of a state variable indication apparatus for a multicast service according to an embodiment of the present application;

[0020] Figure 5 is a structural schematic diagram of a state variable indication apparatus for a multicast service according to an embodiment of the present application;

[0021] Figure 6 is a structural schematic diagram of a communication device according to an embodiment of the present application;

[0022] Figure 7 is a structural schematic diagram of a terminal according to an embodiment of the present application;

[0023] Figure 8 is a structural schematic diagram of a network side device according to an embodiment of the present application. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be described clearly below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present application.

[0025] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first" and "second" are generally of the same class, not limited in number; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0026] It is worth noting that the technologies described in this application are not limited to Long Term Evolution (LTE) / LTE-Advanced (LTE-A) systems, but can 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 this application are often used interchangeably, and the described technologies can be used in the systems and radio technologies mentioned above, as well as in other systems and radio technologies. The following description describes New Radio (NR) systems for illustrative purposes, and NR terminology is used in most of the following description. These technologies can also be applied to applications beyond NR systems, such as 6th generation (6G) radio systems. th Generation 6G communication system.

[0027] Figure 1A schematic diagram of a wireless communication system to which embodiments of the present application can be applied is shown. The wireless communication system includes a terminal 11 and a network side device 12. The terminal 11 can also be referred to as a terminal device or a user terminal (User Equipment, UE). The terminal 11 can be a terminal side device such as a mobile phone, a tablet personal computer, a laptop computer, a personal digital assistant (PDA), a palm computer, a netbook, an ultra-mobile personal computer (UMPC), a mobile Internet device (MID), an augmented reality (AR) / virtual reality (VR) device, a robot, a wearable device, a vehicle-mounted device (VUE), a pedestrian terminal (PUE), a smart home (a home device with wireless communication function, such as a refrigerator, a television, a washing machine, or furniture, etc.), and the like. The wearable device includes a smart watch, a smart bracelet, a smart earphone, smart glasses, smart jewelry (a smart bracelet, a smart necklace, a smart ring, a smart necklace, a smart ankle bracelet, a smart ankle chain, etc.), a smart wristband, smart clothing, a game console, and the like. It should be noted that the specific type of the terminal 11 is not limited in the embodiments of the present application. The network side device 12 can be a base station or a core network. The base station can 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 next generation node B (gNB), a home node B, a home evolved node B, a WLAN access point, a WiFi node, a transmitting receiving point (TRP), or some other appropriate terminology in the art, as long as the same technical effect is achieved. The base station is not limited to a specific technical term, and it should be noted that only the base station in the NR system is taken as an example in the embodiments of the present application, but the specific type of the base station is not limited.

[0028] The multicast service state variable indication method and device provided by the embodiments of the present application will be described in detail below in combination with the accompanying drawings and some embodiments and application scenarios.

[0029] The various embodiments of the present application mainly include the following contents:

[0030] 1) The sending end sends Packet Data Convergence Protocol (PDCP) count (COUNT) information to the receiving end through a signaling process. The sending end can be a network-side device or a terminal, while the receiving end is generally a terminal. The signaling process can be a Uu Radio Resource Control (RRC) process or a secondary link RRC process. Upon receiving the PDCP COUNT information, the receiving end obtains the PDCP COUNT value, which it uses to assign or update its own state variables. It can also reply with a completion message to the sending end, ending the signaling process.

[0031] 2) The sending end carries PDCP COUNT information in the data packet. Since ordinary data packets only carry PDCP SN value, an additional indicator field can be set in the header of the data packet to indicate whether the data packet carries PDCP SN value or PDCPCOUNT information. The receiving end then parses the header according to the specified data packet format. After obtaining the PDCP COUNT value, the receiving end uses the PDCP COUNT value to assign or update its own status variables.

[0032] 3) The transmitting end carries PDCPCOUNT information through the Protocol Data Unit (PDU) process. After receiving the PDCP COUNT information, the receiving end obtains the PDCP COUNT value, which is used to assign or update its own state variables.

[0033] The aforementioned COUNT information can be sent during multicast establishment to initialize the receiving state variables; it can also be sent during multicast data transmission to update and synchronize the PDCP COUNT value of the data packet; or it can be sent based on a request or report from the receiving end. For example, the receiving end can actively request a COUNT synchronization process, or the receiving end can report a security error, such as an integrity verification failure.

[0034] like Figure 2 As shown in the figure, this application embodiment provides a multicast service status variable indication method 200. This method can be executed by the sending end. In other words, this method can be executed by software or hardware installed on the sending end. The method includes the following steps.

[0035] S202: The sending end sends PDCP COUNT information to the receiving end; wherein the PDCP COUNT information comprises at least one of the following: a PDCP COUNT value, a PDCP Hyper Frame Number (HFN) value, a PDCP HFN value, and a Sequence Number (SN) value.

[0036] The sending end mentioned in various embodiments of the present application can be a network side device, and correspondingly, the receiving end can be a terminal, and this example is applicable to multicast service transmission of a Uu interface; or, the sending end and the receiving end mentioned in various embodiments of the present application are both terminals, and this example is applicable to multicast / broadcast service transmission of a sidelink interface, wherein multicast and broadcast can be collectively referred to as multicast.

[0037] The PDCP COUNT information is used for the receiving end to obtain a PDCP COUNT value, so as to decrypt, integrity verify, and sort data packets of the multicast service, etc. The PDCP COUNT value can be 32 bits (bit), which can be divided into two parts, the low bits being a PDCP SN value and the high bits being a PDCP HFN value. The PDCP SN value is generally 12 bits or 18 bits, and the PDCP HFN value corresponds to the remaining 20 bits or 14 bits.

[0038] In this embodiment, after obtaining the PDCP COUNT value, the receiving end can also decrypt, integrity verify, and sort data packets of the multicast service, etc.; correspondingly, before sending the data packets, the sending end can also encrypt and sort the data packets of the multicast service through the PDCP COUNT value, so as to improve the security of the multicast service.

[0039] In this embodiment, the sending end sending the PDCP COUNT information to the receiving end can comprise at least one of the following: 1) when the multicast service is established, the sending end sends the PDCP COUNT information to the receiving end; 2) in the process of transmitting multicast data, the sending end sends the PDCP COUNT information to the receiving end; 3) based on feedback information of the receiving end, the sending end sends the PDCP COUNT information to the receiving end, for example, the receiving end finds that its security processing has a problem, such as integrity verification failure, etc.; or, the receiving end triggers reporting or requesting the PDCP COUNT information based on a certain number of data packets / timer, etc.

[0040] The method for indicating the state variable of the multicast service provided by the embodiments of the present application comprises: a sending end sending PDCP COUNT information to a receiving end, wherein the PDCP COUNT information comprises at least one of the following: a PDCP COUNT value, a PDCP HFN value, and a PDCP HFN value and a SN value. In this way, the receiving end can obtain the PDCP COUNT value based on the PDCP COUNT information, so as to decrypt, integrity verify, and sort the data packets of the multicast service, and improve the security of the multicast service transmission.

[0041] Meanwhile, the sending end can flexibly send the PDCP COUNT information as needed, ensures that the sending end and the receiving end have consistent understanding of the COUNT, so that the security operation and the sorting operation can be smoothly performed, improves the receiving performance on the basis of taking into account the resource efficiency, and avoids the deterioration of the receiving experience caused by the COUNT out-of-sync.

[0042] Optionally, the sending of the PDCP COUNT information by the sending end to the receiving end in the embodiments of the present application comprises at least one of the following 1) to 3).

[0043] 1) The sending end sends first signaling to the receiving end, wherein the first signaling comprises the PDCP COUNT information, and the first signaling comprises, for example, Radio Resource Control (RRC) signaling.

[0044] 2) The sending end sends first data packets to the receiving end, wherein the first data packets comprise the PDCP COUNT information. In this example, the PDCP COUNT information is carried in the data packets. For example, the sending end sends M normal data packets that do not carry the PDCP COUNT information, and then sends N first data packets that carry the PDCP COUNT information, wherein M and N are positive integers.

[0045] 3) The sending end sends a control Protocol Data Unit (PDU) to the receiving end, wherein the control PDU comprises the PDCP COUNT information. The control PDU can be a newly defined control PDU type for carrying the PDCP COUNT information.

[0046] The following will describe some implementation details of 1) to 3) in multiple examples.

[0047] In one example, the PDCP COUNT information can include at least one of the following when the sending end sends the first signaling or the control PDU to the receiving end: 1) PDCP COUNT information corresponding to the next data packet to be sent by the sending end; 2) PDCP COUNT information corresponding to the last data packet sent by the sending end; 3) PDCP COUNT information corresponding to the data packets sent by the sending end, which do not include the last data packet sent by the sending end; and 4) PDCP COUNT information corresponding to the data packets to be sent by the sending end in the future, which do not include the next data packet to be sent by the sending end.

[0048] In one example, the sending end sending the first data packet to the receiving end includes at least one of the following 1) to 4).

[0049] 1) The sending end sends N first data packets when it is determined that a new receiving end joins the multicast service reception; where N is a positive integer.

[0050] 2) The sending end sends N first data packets based on the number of sent data packets, for example, the sending end sends N first data packets carrying PDCP COUNT information after sending M normal data packets not carrying PDCP COUNT information; where M and N are positive integers.

[0051] 3) The sending end sends N first data packets based on the running of a timer, for example, the sending end sends N first data packets when the timer expires, and restarts the timer after sending N first data packets, where normal data packets not carrying PDCP COUNT information can be sent during the running of the timer; where N is a positive integer.

[0052] 4) The sending end sends N first data packets based on the feedback information of the receiving end, for example, the receiving end finds that its security processing has a problem, such as integrity verification failure, etc.; or the receiving end reports or requests PDCP COUNT information based on a certain number of data packets / timer triggering, etc.; where N is a positive integer.

[0053] In one example, the sending end sending the control PDU to the receiving end includes at least one of the following: 1) the sending end sending one control PDU when it is determined that a new receiving end joins the multicast service reception; 2) the sending end sending one control PDU based on the number of data packets sent; 3) the sending end sending one control PDU based on the running of a timer; and 4) the sending end sending one control PDU based on the feedback information of the receiving end. For details of this example, please refer to the description of the previous example.

[0054] In one example, when the sending end sends the first data packet or the control PDU to the receiving end, the sending end sending the PDCP COUNT information to the receiving end includes at least one of the following 1) and 2).

[0055] 1) the sending end sending the PDCP COUNT information to the receiving end on a point to multipoint (PTM) branch. In this example, the PDCP COUNT information can be received by multiple receiving ends.

[0056] 2) the sending end sending the PDCP COUNT information to the receiving end on a point to point (PTP) branch. In this example, it can not affect the normal receiving users, can indicate a small number of newly joined receiving ends to perform initialization operation, or update operation for individual requesting or reporting receiving ends, thereby avoiding the influence on other receiving ends.

[0057] In one example, the sending end sending the control PDU to the receiving end includes at least one of the following:

[0058] 1) if the radio link control (RLC) layer of the sending end is configured in an acknowledgement mode (AM), the sending end sends one control PDU to the receiving end.

[0059] 2) if the RLC layer of the sending end is configured in a non-acknowledgement mode (UM), the sending end sends the control PDU to the receiving end according to the medium access control (MAC) layer hybrid automatic repeat request (HARQ) feedback information, which is used to indicate whether the control PDU is correctly received by the receiving end.

[0060] Optionally, the sending end re-sends the control PDU to the receiving end in case that the sending end determines that the control PDU is not correctly received by the receiving end according to the MAC layer HARQ feedback information; or re-generates the control PDU and sends the re-generated control PDU.

[0061] 3) The sending end sends multiple control PDUs or sends the control PDU multiple times to the receiving end. In this case, the sending end PDCP layer can decide to send multiple control PDUs or send the control PDU multiple times to improve reliability.

[0062] In one example, the first data packet comprises packet format indication information, which is used to indicate a data packet format, and the data packet format comprises a format of the first data packet carrying the PDCP COUNT information or a format of a data packet carrying only SN value. Of course, the packet format indication information in this embodiment specifically indicates the format of the first data packet carrying the PDCP COUNT information.

[0063] In one example, the first data packet comprises PDU type indication information, which is used to indicate a data packet format, and the data packet format comprises a format of the first data packet carrying the PDCP COUNT information or a format of a data packet carrying only SN value. Of course, the PDU type indication information in this embodiment specifically indicates the format of the first data packet carrying the PDCP COUNT information.

[0064] In one example, the first data packet comprises first indication information and PDCP SN value, and the first indication information is used to indicate whether the PDCP COUNT information exists. Of course, the first indication information in this embodiment specifically indicates that the PDCP COUNT information is carried.

[0065] In one example, the control PDU comprises type indication information, which is used to indicate a control PDU type; and the control PDU type comprises one of the following: 1) a type of the control PDU comprising the PDCP COUNT information, 2) a PDCP status report type, a Robust Header Compression (ROHC) feedback type and an Ethernet Header Compression (EHC) feedback type. Of course, the type indication information in this embodiment specifically indicates the type of the control PDU comprising the PDCP COUNT information in 1).

[0066] To provide a multicast service state variable indication of the embodiments of the present application in detail, the following will be described in conjunction with several specific embodiments. Among them, embodiment one is mainly that the sending end carries PDCP COUNT information through the first signaling; embodiment two is that the sending end carries PDCP COUNT information through the first data packet; and embodiment three is that the sending end carries PDCP COUNT information through the control PDU.

[0067] Embodiment one

[0068] This embodiment introduces a method for the sending end to send L2 state variable information to the receiving end through a signaling process. The signaling process is generally an RRC process, which can be a dedicated RRC process or a multicast or broadcast RRC process. This embodiment first takes the dedicated RRC process sent by the base station to the UE as an example to illustrate the overall workflow.

[0069] In Uu multicast service reception, it is generally required that the UE enters the connected state to receive the service. After the UE enters the connected state, the UE can actively report the multicast service information that it is interested in, or the network side obtains the UE list of the multicast service that it is interested in from the core network, and judges that the UE is interested in the multicast service through the UE identifier used by the UE to access the list.

[0070] The network side sends the configuration information corresponding to the multicast service to the UE through dedicated signaling, such as group radio network temporary identity (G-RNTI), MRB configuration, L2 / L1 configuration, discontinuous reception (DRX) configuration, etc. Here, all MRBs or part of the MRBs of this multicast service can also carry the PDCP COUNT information corresponding to each MRB, because each MRB corresponds to a PDCP entity, and the COUNT value of each PDCP entity is independent. Therefore, for each MRB that needs to send the COUNT value, the following information or combination can be used.

[0071] 1) The COUNT value corresponding to the next data packet to be sent by the sending end.

[0072] 2) The HFN value and SN value corresponding to the next data packet to be sent by the sending end.

[0073] 3) The HFN value to be sent by the sending end next.

[0074] 4) The COUNT value corresponding to the last data packet sent by the sending end.

[0075] 5) The HFN value and SN value corresponding to the latest data packet sent out on the sending side.

[0076] 6) The HFN value corresponding to the latest data packet sent out on the sending side.

[0077] 7) The COUNT value corresponding to the data packet sent out or to be sent out in the future on the sending side.

[0078] 8) The HFN value and SN value corresponding to the data packet sent out or to be sent out in the future on the sending side.

[0079] 9) The HFN value corresponding to the data packet sent out or to be sent out in the future on the sending side.

[0080] The network side sends the configuration information and PDCP COUNT information to the UE through a dedicated RRC process, and after the UE receives the information, the UE establishes the corresponding MRB and L2 entity according to the configuration information, and initializes the receiving variable according to the PDCP COUNT information of each MRB.

[0081] When the PDCP COUNT value is directly received, the UE directly initializes the receiving side state variable using the PDCP COUNT value, for example:

[0082] 1) The next expected receiving variable RX_NEXT is initialized as COUNT+1.

[0083] 2) The next expected receiving variable RX_NEXT is initialized as COUNT.

[0084] 3) The first still waiting for reordering variable RX_DELIV not submitted to the upper layer is initialized as COUNT-0.5*receiving window size, and if the result of the subtraction is less than 0, RX_DELIV is directly equal to 0.

[0085] 4) The first still waiting for reordering variable RX_DELIV not submitted to the upper layer is initialized as COUNT+1.

[0086] 5) The first still waiting for reordering variable RX_DELIV not submitted to the upper layer is initialized as COUNT.

[0087] When the HFN+SN information is received, the above two values are combined as high and low bits to form a COUNT value, and the above process similar to receiving COUNT is performed.

[0088] When receiving the HFN value, it is needed to update the variables together with a received SN value, which can be the SN value carried by the first data packet received by the PDCP layer of the MRB, using the SN and HFN as the low bit and high bit of the COUNT value respectively to form a complete COUNT value, and then performing the above initialization process.

[0089] After the UE configuration is completed, a completion message can be returned to the network side. The receiving UE thereby uses the current receiving variables for subsequent receiving and data packet processing.

[0090] The above is a typical signaling notification of COUNT initialization information process, which is used to establish the initial value of the initial receiving variable for the receiving end. Similarly, the above signaling notification of COUNT information process can also be used in the data packet sending process, which is initiated by the sending end. Generally, it is based on a certain number of data packets or based on a timer, or the sending end sends based on the request of the receiving end. The receiving end can request or report based on its own receiving situation, COUNT value synchronization situation or security processing situation, for example, the receiving end finds that it has received N data packets exceeding the receiving window, or the receiving end finds that its security processing has a problem, such as integrity verification failure, or the receiving end triggers based on a certain number of data packets / timer, etc., to report or request.

[0091] In the process of data sending, the sending end uses RRC signaling to send the content of the COUNT information, which is still one of the above-mentioned various situations or combinations. After the receiving end receives the COUNT information, its processing is different from the initialization process. Since the receiving end has established the receiving state variable and the receiving window at this time, after receiving the COUNT information, there are mainly two large operation directions.

[0092] The first is to reset / rebuild / zero the receiving information and window of the receiving end, as well as the cache, that is, to reset all the existing receiving variables, clear the cached data, delete the reordering timer, and then reestablish new receiving state variables and windows according to the received COUNT information, and start receiving data again. The new method is the same as the above initialization of the receiving end.

[0093] The second is to update the receiving state variable information and window of the receiving end accordingly, and retain the cache data, etc., as follows: the received COUNT information (whether it is a direct COUNT value or an HFN and SN that can be combined into a COUNT value) is treated as a newly received data for receiving processing.

[0094] If the newly received COUNT value is less than RX_DELIV, it proves that this data has been reordered or delivered to upper layer.

[0095] If the newly received COUNT value is greater than or equal to RX_DELIV, less than RX_NEXT, it proves that this data is waiting for reordering or has not been delivered to upper layer.

[0096] If the newly received COUNT value is greater than or equal to RX_NEXT, it proves that this data has not been received or HFN out-of-sync has occurred, and the receiving variables need to be updated accordingly: 1) update RX_NEXT to COUNT+1; 2) if the difference between RX_NEXT and RX_DELIV is greater than the window size after the update, it proves that HFN out-of-sync has occurred, and RX_DELIV needs to be updated to COUNT-0.5*window size or RX_DELIV=COUNT or COUNT+1; all the data packets in the buffer smaller than RX_DELIV are cleared; the data between RX_DELIV and RX_NEXT is kept, and optionally, in the case that the two variables are not equal, a reordering timer is started.

[0097] If the above HFN out-of-sync does not occur, RX_DELIV and the buffer do not need to be updated; the subsequent packet receiving process continues.

[0098] The signaling process generally has a completion response, and after the receiving end completes the update process, it feeds back the completion to the sending end. Optionally, in the case of HFN out-of-sync, it can also explicitly indicate HFN out-of-sync or give specific information about HFN out-of-sync, such as 1-bit indication of whether HFN is out-of-sync or the difference between the HFN maintained by the receiving end and the HFN updated by the sending end (the calculation method is, for example, the HFN of the COUNT value carried in the signaling minus the value of the HFN part of the RX_DELIV variable originally maintained by the receiving end).

[0099] Embodiment Two

[0100] This embodiment gives a way of directly carrying COUNT information with data to achieve the initialization or update of the COUNT value.

[0101] In the related art PDCP data packet, the packet header carries an SN field, which is only 12 bits or 18 bits, and the SN field length is statically configurable. In order to carry the COUNT information in the PDCP data packet, the following data packet formats can be used:

[0102] The first way is to introduce a 1-bit packet format indication field. For example, when the field is 0, it represents a traditional data packet format carrying only SN. When the field is 1, it represents a new data packet format carrying COUNT. According to the indication field, the receiving end can parse the SN field or the COUNT field according to the correct data packet format. If it is the SN field, the traditional processing is performed. If it is the COUNT field, the new initialization or update operation process is performed.

[0103] The second way is to introduce a PDU type field with 3 bits or other lengths. For example, when the PDU type is 001, it represents a traditional data packet format carrying only SN. When the PDU type is 010, it represents a new data packet format carrying COUNT. According to the indication field, the receiving end can parse the SN field or the COUNT field according to the correct data packet format. If it is the SN field, the traditional processing is performed. If it is the COUNT field, the new initialization or update operation process is performed.

[0104] In the above two ways, the SN field and the COUNT field are distinguished. The third way is that the SN field is always carried, and the above two ways are similar to the indication of whether the HFN field appears. If the indication does not appear, the SN field is obtained by reading the header format. If the indication appears, the SN and HFN fields are obtained by reading the header format, and the COUNT value is composed, so that the COUNT value can be obtained, triggering the new initialization or update operation process.

[0105] Generally, the sending end can carry the COUNT information in the data packet in the following cases:

[0106] 1) When it is explicitly known that a new receiving end UE has just joined the multicast reception, the sending end sends N data packets carrying the COUNT value to help the newly joined UE establish the initialization of the reception state variable.

[0107] 2) The sending end sends N data packets carrying the COUNT value based on the number of sent data packets, for example, every M data packets, to maintain the existing UE to update the reception state variable and help the newly joined UE establish the initialization of the reception state variable.

[0108] 3) The sending end sends N data packets carrying the COUNT value based on a timer, for example, a periodic timer is started. When the timer expires, the N data packets carrying the COUNT value are sent to maintain the existing UE to update the reception state variable and help the newly joined UE establish the initialization of the reception state variable.

[0109] 4) The sender can also decide to send N packets with COUNT value based on the trigger from the receiver, such as the receiver requests COUNT value, or the receiver reports security operation exception / failure, to help the receiver update the receiving state variable, and help the newly joined receiver to establish the initialization of the receiving state variable.

[0110] Generally, the N packets with COUNT information can be selected by the sender from the upcoming packets, either consecutive N or non-consecutive N with certain interval, in special cases, the sender can also retransmit the already sent packets to carry the COUNT information.

[0111] The receiving behavior of the receiver is as follows:

[0112] When a newly joined multicast receiver UE has a newly established PDCP layer entity, for the received packets with COUNT value, the receiving state variable and window initialization operation is performed, the specific operation details refer to the initialization operation in embodiment one, and the received packets are also processed normally, such as determining whether to receive in order, whether to start the reordering timer, and whether to deliver to the upper layer.

[0113] For a UE that is already normally receiving multicast, its PDCP layer entity has already maintained the current receiving state variable and window, when receiving the packets with COUNT value, the receiving state variable and window initialization update operation is performed, the specific operation details refer to the initialization or update operation in embodiment one, and the received packets are also processed normally, such as determining whether to delete duplicates, whether to receive in order, whether to start the reordering timer, and whether to deliver to the upper layer.

[0114] In particular, the packets with COUNT information can be sent on the common PTM leg if it is desired to affect all multicast users, and all UEs receive and update.

[0115] If it is not desired to affect the normal receiving users, and it is necessary to initialize a small number of newly joined UEs or update individual requesting or reporting receiving UEs, the UE's dedicated PTP leg can also be used for transmission, so that only these UEs receive and perform initialization or update operation, avoiding affecting other UEs.

[0116] Embodiment three

[0117] This embodiment introduces a method of using L2 control PDU to carry COUNT information, to help the receiver establish receiving state initialization or update receiving state.

[0118] There are three ways for the existing PDCP control PDU: PDCP status report, ROHC feedback and EHC feedback. This embodiment can add a fourth, namely PDCP COUNT information, and the corresponding PDU type field can also have a new value to indicate the type of this control PDU. In addition to the type indication in the control PDU, it can also carry a 32-bit COUNT value. The setting of the COUNT value can refer to the setting of the COUNT value carried in the signaling in Embodiment 1.

[0119] For the receiving end, if it is a new UE that joins the multicast reception, the PDCP receiving end variable does not have an initial value, and the COUNT value in the received control PDU is used to initialize the receiving state variable. The initialization method is described in Embodiment 1. If it is a UE that is already receiving, the PDCP receiving end already has a state variable maintenance, and the COUNT value in the received control PDU can be reset and initialized, or updated. The related operation method is also described in Embodiment 1.

[0120] Generally, the sending end can send a control PDU to carry the COUNT value in the following cases:

[0121] 1) When it is explicitly known that a new receiving end UE has just joined the multicast reception, a control PDU carrying the COUNT value is sent to help the newly added UE establish the initialization of the receiving state variable.

[0122] 2) The sending end can send a control PDU carrying the COUNT value based on the number of sent data packets, for example, every M data packets, to maintain the existing UE to update the receiving state variable, and help the newly added UE to establish the initialization of the receiving state variable.

[0123] 3) The sending end can send a control PDU carrying the COUNT value based on a timer, for example, start a periodic timer, and send a control PDU carrying the COUNT value every time the timer expires, to maintain the existing UE to update the receiving state variable, and help the newly added UE to establish the initialization of the receiving state variable.

[0124] 4) The sending end can also send a control PDU carrying the COUNT value based on the trigger of the receiving end, for example, the receiving end requests the COUNT value, or the receiving end reports a security operation exception / failure, to help the requesting UE to update the receiving state variable, and help the newly added UE to establish the initialization of the receiving state variable.

[0125] In particular, the control PDU carries a COUNT value, if it is desired to act on all multicast users, it can be sent on a common PTM leg, all UEs receive and update.

[0126] If it is desired to initialize a small number of newly joined UEs or to update individual requesting or reporting UEs without affecting normally received users, a dedicated PTP leg for the UE can also be used for transmission, so that only these UEs receive and perform initialization or update operations, avoiding the impact on other UEs.

[0127] Generally, the control PDU can be sent once, and the underlying layer such as RLC or MAC can ensure the reliability of transmission, for example, if the RLC layer is configured as AM (usually only the PTP leg can be configured as AM mode), since AM does not allow packet loss, one transmission is sufficient.

[0128] If the RLC layer is configured as UM, the MAC HARQ feedback can be relied on to track whether it is correctly received, and in the case of incorrect reception, the control PDU is retransmitted or reorganized according to the latest state.

[0129] Alternatively, in the absence of underlying tracking of correct reception, the PDCP layer itself decides to send multiple or multiple control PDUs to improve reliability.

[0130] The above describes the state variable indication method of the multicast service according to the embodiments of the application in detail. Figure 2 The state variable indication method of the multicast service according to another embodiment of the application is described in detail below. Figure 3 It can be understood that the description of the receiving end is the same or similar to that of the sending end in the method shown in the description, and the relevant description is appropriately omitted to avoid repetition. Figure 2

[0131] Figure 3 The flowchart of the state variable indication method of the multicast service according to the embodiments of the application is shown, which can be applied to the receiving end. As shown in the flowchart, the method 300 includes the following steps. Figure 3

[0132] S302: The receiving end receives PDCP COUNT information from the sending end; wherein the PDCP COUNT information includes at least one of the following: PDCP COUNT value, PDCP HFN value, PDCP HFN value and SN value.

[0133] ​​The method for indicating the state variable of the multicast service provided by the embodiments of the present application comprises: receiving, by a receiving end, PDCP COUNT information from a sending end, wherein the PDCP COUNT information comprises at least one of the following: a PDCP COUNT value, a PDCP HFN value, a PDCP HFN value and a SN value, so that the receiving end can obtain the PDCP COUNT value based on the PDCP COUNT information to decrypt, integrity verify and sort the data packet of the multicast service, and improve the security of the multicast service transmission.

[0134] Optionally, as one embodiment, after the receiving end receives the PDCP COUNT information from the sending end, the method further comprises one of the following: 1) the receiving end obtains the PDCP COUNT value based on the PDCP COUNT information, and initializes a state variable using the PDCP COUNT value; 2) the receiving end obtains the PDCP COUNT value based on the PDCP COUNT information, and updates a state variable and a receiving window using the PDCP COUNT value.

[0135] Optionally, as one embodiment, the initialization of the state variable using the PDCP COUNT value comprises at least one of the following: 1) initializing RX_NEXT as the PDCP COUNT value plus 1; 2) initializing RX_NEXT as the PDCP COUNT value; 3) initializing RX_DELIV as the PDCP COUNT value minus 0.5*receiving window; wherein if the result of the PDCP COUNT value minus 0.5*receiving window is less than 0, RX_DELIV is equal to 0; 4) initializing RX_DELIV as the PDCP COUNT value plus 1; 5) initializing RX_DELIV as the PDCP COUNT value; wherein RX_NEXT represents a variable of the next expected receiving of the receiving end, and RX_DELIV represents a variable of the first still waiting for reordering in the receiving window of the receiving end which has not been delivered to the upper layer.

[0136] Optionally, as one embodiment, the PDCP COUNT information is received in the process of the transmission of the multicast data, and before the initialization of the state variable using the PDCP COUNT value, the method further comprises at least one of the following: resetting the state variable by the receiving end; clearing the buffered data; and deleting a reordering timer.

[0137] Optionally, as an embodiment, the updating the state variable using the PDCP COUNT value comprises: updating RX_NEXT to the PDCP COUNT value plus 1; if the difference between the updated RX_NEXT and RX_DELIV is greater than a receiving window, updating RX_DELIV to COUNT minus 0.5*receiving window; or, RX_DELIV is the PDCP COUNT value; or, RX_DELIV is the PDCP COUNT value plus 1; wherein RX_NEXT represents a variable of the next expected receiving of the receiving end, and RX_DELIV represents a variable of the first still waiting for reordering in the receiving window of the receiving end.

[0138] Optionally, as an embodiment, the method further comprises at least one of the following: 1) clearing the data packets less than RX_DELIV in the buffer, and keeping the data packets between RX_DELIV and RX_NEXT; 2) delivering the data packets less than RX_DELIV in the buffer to the upper layer in sequence, wherein the "in sequence" mentioned herein can be in the order of the PDCP COUNT value of the data packets from small to large; 3) starting a reordering timer when RX_DELIV and RX_NEXT are not equal.

[0139] It should be noted that the execution subject of the multicast service state variable indication method provided in the embodiments of the present application can be a multicast service state variable indication apparatus, or a control module in the multicast service state variable indication apparatus for executing the multicast service state variable indication method. In the embodiments of the present application, the multicast service state variable indication apparatus executes the multicast service state variable indication method as an example, and the multicast service state variable indication apparatus provided in the embodiments of the present application is described.

[0140] Figure 4 FIG. 4 is a structural schematic diagram of a multicast service state variable indication apparatus according to the embodiments of the present application, which can correspond to the sending end in other embodiments. As shown in FIG. 4, the apparatus 400 comprises the following modules. Figure 4

[0141] The sending module 402 can be used for sending PDCP COUNT information to the receiving end; wherein the PDCP COUNT information comprises at least one of the following: a PDCP COUNT value, a PDCP HFN value, a PDCP HFN value and a SN value.

[0142] Optionally, the apparatus 400 further comprises a processing module.

[0143] ​The embodiment of the application provides a multicast service state variable indication device, a sending module sends PDCP COUNT information to a receiving end, the PDCP COUNT information includes at least one of the following: a PDCP COUNT value, a PDCP HFN value, a PDCP HFN value and a SN value, so that the receiving end can obtain the PDCP COUNT value based on the PDCP COUNT information to decrypt, integrity verify and sort the data packet of the multicast service, and the security of the multicast service transmission is improved

[0144] Optionally, as one embodiment, the sending module 402 is configured to perform at least one of the following: sending the PDCP COUNT information to the receiving end when the multicast service is established; sending the PDCP COUNT information to the receiving end during transmission of the multicast data; and sending the PDCP COUNT information to the receiving end based on feedback information of the receiving end.

[0145] Optionally, as one embodiment, the device is a network side device, and the receiving end is a terminal; or both the device and the receiving end are terminals.

[0146] Optionally, as one embodiment, the sending module 402 is configured to perform at least one of the following: sending first signaling to the receiving end, wherein the first signaling includes the PDCP COUNT information; sending a first data packet to the receiving end, wherein the first data packet includes the PDCP COUNT information; and sending a control PDU to the receiving end, wherein the control PDU includes the PDCP COUNT information.

[0147] Optionally, as one embodiment, in the case of sending the first signaling or the control PDU to the receiving end, the PDCP COUNT information includes at least one of the following: 1) PDCP COUNT information corresponding to a next data packet to be sent; 2) PDCP COUNT information corresponding to a last data packet sent; 3) PDCP COUNT information corresponding to data packets that have been sent, wherein the data packets that have been sent do not include the last data packet sent; and 4) PDCP COUNT information corresponding to data packets to be sent in the future, wherein the data packets to be sent in the future do not include the next data packet to be sent.

[0148] Optionally, as one embodiment, the sending module 402 is configured to perform at least one of the following: 1) sending N first data packets in the case of determining that a new receiving end joins the multicast service reception; 2) sending N first data packets based on a number of data packets that have been sent; 3) sending N first data packets based on running of a timer; and 4) sending N first data packets based on feedback information of the receiving end; wherein N is a positive integer.

[0149] Optionally, as an embodiment, the sending module 402 is configured to send one of the control PDUs in at least one of the following manners: 1) in a case where it is determined that a new receiving end joins the multicast service reception; 2) based on the number of sent data packets; 3) based on the running state of a timer; and 4) based on feedback information of the receiving end.

[0150] Optionally, as an embodiment, in a case where the first data packet or the control PDU is sent to the receiving end, the sending module 402 is configured to send the PDCP COUNT information to the receiving end in at least one of the following manners: 1) on a point-to-multipoint (PTM) branch; and 2) on a point-to-point (PTP) branch.

[0151] Optionally, as an embodiment, the sending module 402 is configured to send one of the control PDUs to the receiving end in at least one of the following manners: 1) if a radio link control (RLC) layer of the apparatus is configured in an acknowledged mode (AM); 2) if the RLC layer of the apparatus is configured in an unacknowledged mode (UM) and based on hybrid automatic repeat request (HARQ) feedback information of a medium access control (MAC) layer, the HARQ feedback information being used to indicate whether the control PDU is correctly received by the receiving end; and 3) multiple times or multiple times.

[0152] Optionally, as an embodiment, the sending module 402 is configured to resend the control PDU to the receiving end or to resend the control PDU after being regenerated, in a case where it is determined that the control PDU is not correctly received by the receiving end based on the HARQ feedback information of the MAC layer.

[0153] Optionally, as an embodiment, the first data packet comprises packet format indication information, the packet format indication information being used to indicate a data packet format, the data packet format comprising a format of the first data packet carrying the PDCP COUNT information or a format of a data packet carrying only a sequence number (SN) value; or the first data packet comprises PDU type indication information, the PDU type indication information being used to indicate a data packet format, the data packet format comprising a format of the first data packet carrying the PDCP COUNT information or a format of a data packet carrying only a SN value; or the first data packet comprises first indication information and a PDCP SN value, the first indication information being used to indicate whether the PDCP COUNT information exists.

[0154] Optionally, as an embodiment, the control PDU includes type indication information, the type indication information being used to indicate a control PDU type; wherein the control PDU type includes one of the following: a type of the control PDU including the PDCP COUNT information, a PDCP status report type, an ROHC feedback type, and an EHC feedback type.

[0155] The apparatus 400 according to the embodiments of the present application can refer to the flow of the method 200 according to the embodiments of the present application, and each unit / module in the apparatus 400 and the above-mentioned other operations and / or functions are respectively used to implement the corresponding flow in the method 200 and achieve the same or equivalent technical effects, and for brevity, will not be repeated here.

[0156] The multicast service state variable indication apparatus in the embodiments of the present application can be an apparatus, an apparatus with an operating system, or an electronic device, and can also be a component in a terminal, an integrated circuit, or a chip. The apparatus or electronic device can be a mobile terminal or a non-mobile terminal. Illustratively, the mobile terminal can include, but is not limited to, the types of the terminal 11 listed above, and the non-mobile terminal can be a server, a network attached storage (NAS), a personal computer (PC), a television (TV), a teller machine, or a self-service machine, etc., and the embodiments of the present application are not limited specifically.

[0157] The multicast service state variable indication apparatus provided by the embodiments of the present application can implement each process of the method embodiments Figure 2 to Figure 3 and achieve the same technical effects, and for brevity, will not be repeated here.

[0158] Figure 5 is a structural schematic diagram of the multicast service state variable indication apparatus according to the embodiments of the present application, and the apparatus can correspond to the receiving end in other embodiments. As shown in Figure 5 , the apparatus 500 includes the following modules.

[0159] The receiving module 502 can be used to receive PDCP COUNT information from a sending end; wherein the PDCP COUNT information includes at least one of the following: a PDCP COUNT value, a PDCP HFN value, a PDCP HFN value, and a SN value.

[0160] Optionally, the apparatus 500 further includes a processing module.

[0161] The state variable indication device for multicast service provided by the embodiment of the present application receives PDCP COUNT information from a sending end, the PDCP COUNT information includes at least one of the following: PDCP COUNT value, PDCP HFN value, PDCP HFN value and SN value, so that the processing module can also obtain PDCP COUNT value based on the PDCP COUNT information to decrypt, integrity verify and sort the data packet of the multicast service and the like, thereby improving the security of the multicast service transmission.

[0162] Optionally, as one embodiment, the device further includes a processing module configured to perform one of the following: 1) obtaining PDCP COUNT value according to the PDCP COUNT information and initializing a state variable using the PDCP COUNT value; 2) obtaining PDCP COUNT value according to the PDCP COUNT information and updating a state variable and a receiving window using the PDCP COUNT value.

[0163] Optionally, as one embodiment, the processing module is configured to perform one of the following: 1) initializing RX_NEXT as the PDCP COUNT value plus 1; 2) initializing RX_NEXT as the PDCP COUNT value; 3) initializing RX_DELIV as the PDCP COUNT value minus 0.5*receiving window; wherein if the result of the PDCP COUNT value minus 0.5*receiving window is less than 0, RX_DELIV is equal to 0; 4) initializing RX_DELIV as the PDCP COUNT value plus 1; 5) initializing RX_DELIV as the PDCP COUNT value; wherein RX_NEXT represents a variable of the next expected receiving of the receiving end, and RX_DELIV represents a variable of the first still waiting for reordering and not submitting to high layer in the receiving window of the receiving end.

[0164] Optionally, as one embodiment, the PDCP COUNT information is received in the process of transmitting multicast data, and the processing module is further configured to perform at least one of the following: resetting the state variable; clearing the buffered data; and deleting a reordering timer.

[0165] Optionally, as an embodiment, the processing module is configured to: update RX_NEXT to the PDCP COUNT value plus 1; if the difference between the updated RX_NEXT and RX_DELIV is greater than the receiving window, update RX_DELIV to COUNT minus 0.5*receiving window; or, RX_DELIV is the PDCP COUNT value; or, RX_DELIV is the PDCP COUNT value plus 1; wherein RX_NEXT represents the next expected receiving variable of the receiving end, and RX_DELIV represents the first still waiting for reordering variable in the receiving window of the receiving end which has not delivered the upper layer.

[0166] Optionally, as an embodiment, the processing module is further configured to perform at least one of the following: 1) clear the data packets less than RX_DELIV in the buffer, and keep the data packets between RX_DELIV and RX_NEXT; 2) deliver the data packets less than RX_DELIV in the buffer to the upper layer in sequence; and 3) start a reordering timer when RX_DELIV and RX_NEXT are not equal.

[0167] The apparatus 500 according to the embodiments of the present application can refer to the flow of the method 300 according to the embodiments of the present application, and each unit / module in the apparatus 500 and the above-mentioned other operations and / or functions are respectively used to implement the corresponding flow in the method 300, and can achieve the same or equivalent technical effects. For the sake of brevity, they will not be described here again.

[0168] Optionally, as shown in Figure 6 The embodiments of the present application also provide a communication device 600, which includes a processor 601, a memory 602, and a program or instruction stored in the memory 602 and executable on the processor 601. For example, when the communication device 600 is a terminal, the program or instruction is executed by the processor 601 to implement each process of the above-mentioned multicast service state variable indication method embodiments, and can achieve the same technical effects. When the communication device 600 is a network side device, the program or instruction is executed by the processor 601 to implement each process of the above-mentioned multicast service state variable indication method embodiments, and can achieve the same technical effects. To avoid repetition, they will not be described here again.

[0169] The terminal provided in the embodiments of the present application also includes a processor and a communication interface, the communication interface is configured to send PDCP COUNT information to a receiving terminal, or receive PDCP COUNT information from a sending terminal, wherein the PDCP COUNT information includes at least one of a PDCP COUNT value, a PDCP HFN value, a PDCP HFN value and a SN value. The terminal embodiment corresponds to the terminal-side method embodiment described above, and each implementation process and implementation manner of the method embodiment can be applied to the terminal embodiment, and the same technical effects can be achieved. Specifically, Figure 7 A hardware structure diagram of a terminal according to an embodiment of the present application is shown in FIG. 7.

[0170] The terminal 700 includes, but is not limited to, at least part of the components such as a radio frequency unit 701, a network module 702, an audio output unit 703, an input unit 704, a sensor 705, a display unit 706, a user input unit 707, an interface unit 708, a memory 709, and a processor 710.

[0171] Those skilled in the art can understand that the terminal 700 can also include a power supply (such as a battery) for supplying power to each component, and the power supply can be logically connected to the processor 710 through a power management system, so as to realize functions such as management of charging, discharging and power consumption management through the power management system. Figure 7 The terminal structure shown in FIG. 7 does not constitute a limitation on the terminal, and the terminal can include more or fewer components than those shown in the figure, or combine certain components, or different component arrangements, which are not described here.

[0172] It should be understood that in the embodiments of the present application, the input unit 704 can include a graphics processing unit (GPU) 7041 and a microphone 7042, and the graphics processing unit 7041 processes image data of a still picture or a video obtained by an image capture device (such as a camera) in a video capture mode or an image capture mode. The display unit 706 can include a display panel 7061, which can be configured in the form of a liquid crystal display, an organic light emitting diode, etc. The user input unit 707 includes a touch panel 7071 and other input devices 7072. The touch panel 7071 is also called a touch screen. The touch panel 7071 can include a touch detection device and a touch controller. The other input devices 7072 can include, but are not limited to, a physical keyboard, function keys (such as volume control keys, on-off keys, etc.), trackballs, mice, joysticks, etc., which are not described here.

[0173] In the embodiments of the present application, the radio frequency unit 701 receives the downlink data from the network side device, and then sends the data to the processor 710 for processing. In addition, the radio frequency unit 701 sends the uplink data to the network side device. Generally, the radio frequency unit 701 includes, but is not limited to, an antenna, at least one amplifier, a transceiver, a coupler, a low noise amplifier, a duplexer, etc.

[0174] The memory 709 can be used to store software programs or instructions and various data. The memory 709 can mainly include a storage program or instruction area and a storage data area, wherein the storage program or instruction area can store an operating system, at least one application program or instruction required by a function (such as a sound playing function, an image playing function, etc.), etc. In addition, the memory 709 can include a high-speed random access memory, and can also include a non-transient memory, which can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. For example, at least one magnetic disk storage device, a flash memory device, or other non-transient solid-state memory device. In addition, the memory in the embodiments of the present application can be volatile or non-volatile.

[0175] The processor 710 can include one or more processing units; optionally, the processor 710 can integrate an application processor and a modem processor, wherein the application processor mainly processes an operating system, a user interface, and an application program or instruction, etc., and the modem processor mainly processes wireless communication, such as a baseband processor. It can be understood that the above-mentioned modem processor can also not be integrated into the processor 710.

[0176] The radio frequency unit 701 can be used to send PDCP COUNT information to a receiving end, or receive PDCP COUNT information from a sending end, wherein the PDCP COUNT information includes at least one of the following: a PDCP COUNT value, a PDCP HFN value, a PDCP HFN value, and a SN value.

[0177] The multicast service terminal provided by the embodiments of the present application receives or sends PDCP COUNT information from / to a sending terminal, the PDCP COUNT information including at least one of a PDCP COUNT value, a PDCP HFN value, and a PDCP HFN value and a SN value, so that the receiving terminal can obtain the PDCP COUNT value based on the PDCP COUNT information to decrypt, integrity verify, and sort data packets of the multicast service, and improve the security of multicast service transmission.

[0178] The terminal 700 provided by the embodiments of the present application can also implement each process of the above-mentioned multicast service state variable indication method embodiments, and achieve the same technical effects. To avoid repetition, details are not described herein.

[0179] The embodiments of the present application also provide a network side device including a processor and a communication interface, the communication interface being configured to send PDCP COUNT information to a receiving terminal or receive PDCP COUNT information from a sending terminal, wherein the PDCP COUNT information includes at least one of a PDCP COUNT value, a PDCP HFN value, and a PDCP HFN value and a SN value. The network side device embodiment corresponds to the above-mentioned network side device method embodiment, each implementation process and implementation manner of the above-mentioned method embodiment can be applied to the network side device embodiment, and the same technical effects can be achieved.

[0180] Specifically, the embodiments of the present application also provide a network side device. As shown in Figure 8 The network side device 800 includes an antenna 81, a radio frequency device 82, and a baseband device 83. The antenna 81 is connected to the radio frequency device 82. In the uplink direction, the radio frequency device 82 receives information through the antenna 81 and sends the received information to the baseband device 83 for processing. In the downlink direction, the baseband device 83 processes the information to be sent and sends it to the radio frequency device 82. The radio frequency device 82 processes the received information and sends it out through the antenna 81.

[0181] The above-mentioned frequency band processing device can be located in the baseband device 83. The method executed by the network side device in the above embodiments can be implemented in the baseband device 83, which includes a processor 84 and a memory 85.

[0182] The baseband device 83 may, for example, include at least one baseband board, which is provided with a plurality of chips, as shown in Figure 8 One of the chips is, for example, the processor 84, which is connected to the memory 85 to call programs in the memory 85 and execute the operations of the network side device shown in the above method embodiments.

[0183] The baseband device 83 can further include a network interface 86 for interacting information with the radio frequency device 82, which is, for example, a common public radio interface (CPRI).

[0184] Specifically, the network side device of the embodiment of the present application further includes instructions or programs stored on the memory 85 and executable on the processor 84, and the processor 84 invokes the instructions or programs in the memory 85 to execute the method shown by each module and achieve the same technical effects. To avoid repetition, the details are not described here. Figure 4 or Figure 5 The method executed by each module shown in the above embodiment achieves the same technical effects. To avoid repetition, the details are not described here.

[0185] The embodiment of the present application further provides a readable storage medium, which can be volatile or non-volatile, and can also be non-transient. The readable storage medium stores programs or instructions, which are executed by a processor to implement each process of the above-mentioned multicast service state variable indication method embodiment and achieve the same technical effects. To avoid repetition, the details are not described here.

[0186] The processor can be the processor in the terminal described in the above-mentioned embodiment. The readable storage medium includes a computer readable storage medium, such as a computer readable memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0187] The embodiment of the present application further provides a chip, which includes a processor and a communication interface. The communication interface is coupled with the processor. The processor is used to run programs or instructions to implement each process of the above-mentioned multicast service state variable indication method embodiment and achieve the same technical effects. To avoid repetition, the details are not described here.

[0188] It should be understood that the chip mentioned in the embodiment of the present application can also be referred to as a system chip, a system on chip, a chip system or a system on chip, etc.

[0189] The embodiment of the present application further provides a computer program product, which is stored in a non-transient readable storage medium. The computer program product is executed by at least one processor to implement each process of the above-mentioned multicast service state variable indication method embodiment and achieve the same technical effects. To avoid repetition, the details are not described here.

[0190] The embodiment of the present application further provides a communication device, which is configured to implement each process of the above-mentioned multicast service state variable indication method embodiment and achieve the same technical effects. To avoid repetition, the details are not described here.

[0191] It has to be noted that, as used herein, the terms "includes" and / or "contains", or any other tautological variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements is not limited to those elements, but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. In addition, it should be noted that the scope of the methods and apparatus of the embodiments are not limited by the order of the steps or processes, as some steps can occur in different orders and / or concurrently with one another; for example, described methods can occur in an order other than that described, and / or described methods can take place simultaneously or with other steps not expressly described herein. Furthermore, features described with respect to certain examples can be combined in other examples.

[0192] From the above description of the embodiments, it is apparent that the method of the above-mentioned embodiments can be realized by means of software plus necessary universal hardware platforms, and of course, can also be realized by hardware, but in many cases, the former is a better embodiment. Based on such understanding, the technical solutions of the present application can be embodied in the form of a computer software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes a plurality of instructions for making a terminal (which can be a mobile phone, computer, server, air conditioner, or network side device, etc.) execute the method described in each embodiment of the present application.

[0193] The embodiments of the present application are described above in conjunction with the drawings, but the present application is not limited to the above-described specific embodiments, and the above-described specific embodiments are merely illustrative, rather than limiting, and those of ordinary skill in the art can make many forms under the inspiration of the present application without departing from the scope of the present application and the scope of protection of the claims, which all belong to the protection of the present application.

Claims

1. A method for indicating state variables in a multicast service, characterized in that, include: The sending end sends the Packet Data Convergence Protocol (PDCP) COUNT information to the receiving end; The PDCP COUNT information includes at least one of the following: PDCP COUNT value, PDCP superframe number HFN value, PDCP HFN value, and sequence number SN value; The sending of PDCP COUNT information from the sending end to the receiving end includes: when the multicast service is established, the sending end sends PDCP COUNT information to the receiving end; The sending of PDCP COUNT information from the sending end to the receiving end includes: the sending end sending a first signaling message to the receiving end, the first signaling message including the PDCP COUNT information.

2. The method according to claim 1, characterized in that, The sending end to the receiving end of PDCP COUNT information includes at least one of the following: During the transmission of multicast data, the sending end sends PDCP COUNT information to the receiving end; Based on the feedback information from the receiving end, the sending end sends PDCP COUNT information to the receiving end.

3. The method according to claim 1, characterized in that, The sending end is a network-side device, and the receiving end is a terminal; or... Both the sending end and the receiving end are terminals.

4. The method according to any one of claims 1 to 3, characterized in that, The sending of PDCPCOUNT information from the sending end to the receiving end also includes at least one of the following: The sending end sends a first data packet to the receiving end, the first data packet including the PDCP COUNT information; The transmitting end sends a Control Protocol Data Unit (PDU) to the receiving end, and the control PDU includes the PDCP COUNT information.

5. The method according to claim 4, characterized in that, When the transmitting end sends the first signaling or the control PDU to the receiving end, the PDCP COUNT information includes at least one of the following: The PDCP COUNT information corresponding to the next data packet to be sent by the sending end; The PDCP COUNT information corresponding to the most recently sent data packet from the sending end; The PDCP COUNT information corresponding to the data packets already sent by the sending end, wherein the data packets already sent do not include the most recently sent data packet; The PDCP COUNT information corresponding to the data packets to be sent by the sending end in the future, wherein the data packets to be sent in the future do not include the next data packet to be sent.

6. The method according to claim 4, characterized in that, The sending end sends the first data packet to the receiving end, including at least one of the following: When the sending end determines that a new receiving end has joined the multicast service reception, it sends N of the first data packets; The sending end sends N first data packets based on the number of data packets already sent; The sending end sends N of the first data packets based on the running status of the timer; Based on the feedback information from the receiving end, the sending end sends N of the first data packets; Where N is a positive integer.

7. The method according to claim 4, characterized in that, The sending end to the receiving end of the control PDU includes at least one of the following: When the transmitting end determines that a new receiving end has joined the multicast service reception, it sends one control PDU. The sending end sends one control PDU based on the number of data packets that have been sent; The transmitting end sends one control PDU based on the timer's running status; The transmitting end sends one control PDU based on the feedback information from the receiving end.

8. The method according to claim 4, characterized in that, When the sending end sends the first data packet or the control PDU to the receiving end, the sending end sending PDCP COUNT information to the receiving end includes at least one of the following: The transmitting end sends PDCP COUNT information to the receiving end on the point-to-multipoint transmission (PTM) branch; The transmitting end sends PDCP COUNT information to the receiving end on the point-to-point transmission PTP branch.

9. The method according to claim 4, characterized in that, The sending end to the receiving end of the control PDU includes at least one of the following: If the Radio Link Control (RLC) layer of the transmitting end is configured in Acknowledgment Mode (AM), then the transmitting end sends a control PDU to the receiving end. If the RLC layer of the transmitting end is configured as unacknowledged mode (UM), the transmitting end sends the control PDU to the receiving end according to the hybrid automatic repeat request (HARQ) feedback information of the media access control (MAC) layer. The MAC layer HARQ feedback information is used to indicate whether the control PDU has been correctly received by the receiving end. The transmitting end sends multiple control PDUs to the receiving end, or sends the control PDUs multiple times.

10. The method according to claim 9, characterized in that, The transmitting end sends the control PDU to the receiving end according to the MAC layer HARQ feedback information, including: If the transmitting end determines, based on the MAC layer HARQ feedback information, that the control PDU has not been correctly received by the receiving end, it may retransmit the control PDU to the receiving end; or regenerate the control PDU and retransmit the regenerated control PDU.

11. The method according to claim 4, characterized in that, The first data packet includes packet format indication information, which indicates the data packet format. The data packet format may include the format of the first data packet carrying the PDCP COUNT information or the format of a data packet carrying only the SN value; or The first data packet includes PDU type indication information, which indicates the data packet format. The data packet format may include the format of the first data packet carrying the PDCP COUNT information or the format of a data packet carrying only the SN value; or The first data packet includes first indication information and a PDCP SN value, wherein the first indication information is used to indicate whether the PDCP COUNT information exists.

12. The method according to claim 4, characterized in that, The control PDU includes type indication information, which is used to indicate the type of the control PDU. The control PDU type includes one of the following: the control PDU type that includes the PDCP COUNT information, the PDCP status report type, the Robust Header Compression (ROHC) feedback type, and the Ethernet Header Compression (EHC) feedback type.

13. A method for indicating state variables in a multicast service, characterized in that, include: The receiving end receives PDCP COUNT information from the sending end; The PDCP COUNT information includes the PDCP COUNT value; The receiving end receiving PDCP COUNT information from the sending end includes: the receiving end receiving a first signaling sent by the sending end, the first signaling including the PDCP COUNT information; The PDCP COUNT information is sent by the sending end to the receiving end when the multicast service is established; After the receiving end receives the PDCP COUNT information from the sending end, the method further includes: the receiving end obtains the PDCP COUNT value according to the PDCP COUNT information, and initializes the state variable using the PDCP COUNT value; The initialization of the state variable using the PDCP COUNT value includes: initializing RX_DELIV to the PDCPCOUNT value; wherein RX_DELIV represents the first variable in the receiver window that is still waiting for reordering and has not been submitted to the higher layer.

14. The method according to claim 13, characterized in that, The PDCP COUNT information also includes at least one of the following: PDCP HFN value, PDCP HFN value and SN value.

15. The method according to claim 13, characterized in that, After the receiving end receives the PDCPCOUNT information from the sending end, the method further includes: The receiving end obtains the PDCP COUNT value based on the PDCP COUNT information, and uses the PDCP COUNT value to update the status variables and the receiving window.

16. The method according to claim 13, characterized in that, The initialization of the state variables using the PDCP COUNT value also includes one of the following: Initialize RX_NEXT to the PDCP COUNT value plus 1; Initialize RX_NEXT to the PDCP COUNT value; RX_DELIV is initialized to the PDCP COUNT value minus 0.5 * the receive window; wherein, if the result of the PDCP COUNT value minus 0.5 * the receive window is less than 0, then RX_DELIV equals 0; Initialize RX_DELIV to the PDCP COUNT value plus 1; Wherein, RX_NEXT represents the next variable that the receiver expects to receive, and RX_DELIV represents the first variable in the receiver window that is still waiting to be reordered and not yet submitted to the higher layer.

17. The method according to claim 15, characterized in that, The step of updating the state variable using the PDCP COUNT value includes: Update RX_NEXT to the PDCP COUNT value plus 1; If the difference between the updated RX_NEXT and RX_DELIV is greater than the receive window, then update RX_DELIV to PDCPCOUNT minus 0.5 * receive window; or, RX_DELIV to the PDCP COUNT value; or, RX_DELIV to the PDCPCOUNT value plus 1. Wherein, RX_NEXT represents the next variable that the receiver expects to receive, and RX_DELIV represents the first variable in the receiver window that is still waiting to be reordered and not yet submitted to the higher layer.

18. The method according to claim 17, characterized in that, The method further includes at least one of the following: Clear packets in the buffer that are smaller than RX_DELIV, and keep packets that are between RX_DELIV and RX_NEXT; Deliver packets smaller than RX_DELIV in the buffer to the higher layer in order; If RX_DELIV and RX_NEXT are not equal, start the reordering timer.

19. A state variable indication device for a multicast service, characterized in that, include: The sending module is used to send PDCP COUNT information to the receiving end; The PDCP COUNT information includes at least one of the following: PDCP COUNT value, PDCP HFN value, PDCP HFN value, and SN value; The sending module is used to send PDCP COUNT information to the receiving end when the multicast service is established. The sending module is further configured to send a first signaling to the receiving end, the first signaling including the PDCP COUNT information.

20. The apparatus according to claim 19, characterized in that, The sending module is configured to perform at least one of the following: During the transmission of multicast data, PDCP COUNT information is sent to the receiving end; Based on the feedback information from the receiving end, PDCP COUNT information is sent to the receiving end.

21. The apparatus according to claim 19, characterized in that, The device is a network-side device, and the receiving end is a terminal; or... Both the device and the receiver are terminals.

22. The apparatus according to any one of claims 19 to 21, characterized in that, The sending module is also used for at least one of the following: Send a first data packet to the receiving end, the first data packet including the PDCP COUNT information; Send a control PDU to the receiving end, the control PDU including the PDCP COUNT information.

23. A state variable indication device for a multicast service, characterized in that, include: The receiving module is used to receive PDCP COUNT information from the sending end; The PDCP COUNT information includes the PDCP COUNT value; The receiving module is configured to: receive a first signaling sent by the sending end, wherein the first signaling includes the PDCPCOUNT information; The PDCP COUNT information is sent by the sending end to the receiving end when the multicast service is established; The device further includes a processing module for obtaining a PDCP COUNT value based on the PDCP COUNT information and initializing state variables using the PDCP COUNT value; The processing module is used to initialize RX_DELIV to the PDCP COUNT value; where RX_DELIV represents the first variable in the receiver window that is still waiting to be reordered and has not been submitted to the higher layer.

24. The apparatus according to claim 23, characterized in that, The PDCP COUNT information also includes at least one of the following: PDCP HFN value, PDCP HFN value and SN value.

25. The apparatus according to claim 23, characterized in that, The processing module is further configured to: The PDCP COUNT value is obtained based on the PDCP COUNT information, and the status variables and the receive window are updated using the PDCP COUNT value.

26. The apparatus according to claim 25, characterized in that, The processing module is used for one of the following: Initialize RX_NEXT to the PDCP COUNT value plus 1; Initialize RX_NEXT to the PDCP COUNT value; RX_DELIV is initialized to the PDCP COUNT value minus 0.5 * the receive window; wherein, if the result of the PDCP COUNT value minus 0.5 * the receive window is less than 0, then RX_DELIV equals 0; Initialize RX_DELIV to the PDCP COUNT value plus 1; Wherein, RX_NEXT represents the next variable that the receiver expects to receive, and RX_DELIV represents the first variable in the receiver window that is still waiting to be reordered and not yet submitted to the higher layer.

27. The apparatus according to claim 25, characterized in that, The processing module is used for: Update RX_NEXT to the PDCP COUNT value plus 1; If the difference between the updated RX_NEXT and RX_DELIV is greater than the receive window, then update RX_DELIV to COUNT minus 0.5 * receive window; or, RX_DELIV to the PDCP COUNT value; or, RX_DELIV to the PDCP COUNT value plus 1. Wherein, RX_NEXT represents the next variable that the receiver expects to receive, and RX_DELIV represents the first variable in the receiver window that is still waiting to be reordered and not yet submitted to the higher layer.

28. The apparatus according to claim 27, characterized in that, The processing module is also used for at least one of the following: Clear packets in the buffer that are smaller than RX_DELIV, and keep packets that are between RX_DELIV and RX_NEXT; Deliver packets smaller than RX_DELIV in the buffer to the higher layer in order; If RX_DELIV and RX_NEXT are not equal, start the reordering timer.

29. A terminal, characterized in that, It includes a processor, a memory, and a program or instructions stored in the memory and executable on the processor, wherein the program or instructions, when executed by the processor, implement the state variable indication method for multicast services as described in any one of claims 1 to 18.

30. A network-side device, characterized in that, It includes a processor, a memory, and a program or instructions stored in the memory and executable on the processor, wherein the program or instructions, when executed by the processor, implement the state variable indication method for multicast services as described in any one of claims 1 to 18.

31. A readable storage medium, characterized in that, The readable storage medium stores a program or instructions that, when executed by a processor, implement the multicast service state variable indication method as described in any one of claims 1 to 18.

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