Non-terrestrial network communication method and apparatus

Abstract

The embodiments of the present application provide a non-terrestrial network communication method and an apparatus, which are applied to NTN scenarios. In the communication method, a network device can send a first message to terminals on the basis of an NTN store-and-forward mechanism, the first message being used for indicating that the network device located at a high-altitude platform such as a satellite does not cache downlink data of the terminals in the coverage area thereof, such that the terminals do not monitor paging messages or do not establish RRC connections, thus allowing the terminals to reduce power consumption in store-and-forward scenarios of NTN communication.

Description

Non-terrestrial network communication method and device

[0001] The present application claims priority to the Chinese Patent Application No. 202410573782.1, filed on May 9, 2024, entitled "Non-terrestrial network communication method and device", and the Chinese Patent Application No. 202411346174.3, filed on September 25, 2024, entitled "Non-terrestrial network communication method and device", the contents of which are incorporated herein by reference in their entirety. TECHNICAL FIELD

[0002] Embodiments of the present application relate to the technical field of non-terrestrial network communication, in particular to a non-terrestrial network communication method and device. BACKGROUND

[0003] Satellite network is a hot topic in today's world, and satellite communication technology has become mature, for example, non-terrestrial network (NTN) uses satellite on-board radio frequency network or network segment to realize communication, which can provide wider coverage, but terminal listening to satellite signals will consume high power consumption, therefore, for terminal devices in satellite coverage scenarios, how to save the power consumption of listening is a problem to be solved. SUMMARY

[0004] Embodiments of the present application provide a non-terrestrial network communication method and device, which can save power consumption of terminals in the store-and-forward scenario of NTN communication.

[0005] In a first aspect, a communication method is provided, applied to NTN communication, comprising,

[0006] receiving a first message, the first message containing at least one of the following information:

[0007] indicating that the first network device does not cache downlink data of terminals located in the first area; or,

[0008] indicating that the first network device caches downlink data of terminals located in the third area; or,

[0009] indicating the first group number of the terminals corresponding to the downlink data cached by the first network device;

[0010] the first network device is deployed on a satellite;

[0011] based on the first message, not listening to part or all of the paging messages of the first network device, or not establishing a first connection; or,

[0012] listening to a paging message of the first network device, or establishing a first connection based on the first message.

[0013] In the above scheme, the network device is deployed on a high altitude platform such as a satellite, and the first message is sent to indicate whether the network device on the current satellite buffers data of terminals in a coverage area. When the satellite can send the first message to the terminal, the service link must be in a connected state, and because in the store-and-forward scenario, the service link is connected, the feeder link must be disconnected. Therefore, the terminal can not listen to the paging message or not establish the first connection under appropriate conditions according to the situation, so as to save power consumption.

[0014] Optionally, the coverage area can be an area covered by the network device in a past period of time, an area to be covered by the network device in a future period of time, or an area being covered by the network device, and the period of time can be set.

[0015] In some possible implementation manners, the communication method further includes, based on the first message, performing one of the following actions:

[0016] when it is determined that the second area belongs to the subset of the first area, performing the action of not listening to part or all of the paging message of the first network device, or not establishing the first connection;

[0017] when it is determined that the second area does not belong to the subset of the first area, performing the action of listening to the paging message of the first network device, or establishing the first connection;

[0018] when it is determined that the second area overlaps with the third area, performing the action of listening to the paging message of the first network device, or establishing the first connection;

[0019] when it is determined that the second group number matches the first group number, performing the action of listening to the paging message of the first network device, or establishing the first connection;

[0020] when it is determined that the second group number does not match the first group number, performing the action of not listening to part or all of the paging message of the first network device, or not establishing the first connection;

[0021] when it is determined that the second area overlaps with the third area and the second group number matches the first group number, performing the action of listening to the paging message of the first network device, or establishing the first connection;

[0022] determining that the second area overlaps with the third area, but the second group ID does not match the first group ID, performing the not listening to part or all of the paging message of the first network device, or not establishing the first connection;

[0023] determining that the second area does not overlap with the third area, performing the not listening to part or all of the paging message of the first network device, or not establishing the first connection.

[0024] Optionally,

[0025] The first area includes:

[0026] at least one tracking area (Tracking Area) covered or served by the first network device, or an earth surface area, wherein the earth surface area is indicated by area information included in the first message;

[0027] The second area includes:

[0028] at least one of a tracking area in which the terminal is located, a plurality of tracking area sets including the tracking area, or a location in which the terminal is located.

[0029] Optionally, the earth surface area is determined by indicating a center point position by longitude and latitude, adding a radius distance to determine an area; or indicating a pre-agreed area; or determining a geometric shape area by indicating a plurality of point positions. Here, the area can be a tracking area corresponding to an earth surface area with or without cached data (which can include or exclude the boundary according to a preset).

[0030] Optionally, the first message includes at least one of the first area, the third area, or a first group ID of a terminal corresponding to cached downlink data.

[0031] In some possible implementation manners, the communication method further includes,

[0032] determining the second group ID based on the second message, or determining the second group ID based on a terminal identifier (UE ID).

[0033] That is, the group ID can be sent by the network device to the terminal, for example, in an access procedure or a tracking area update procedure, or can be determined by the terminal itself according to the terminal identifier or a pre-agreement.

[0034] In some possible implementation manners, the communication method further includes, before receiving the first message,

[0035] sending a third message, the third message requesting grouping, or indicating support for grouping;

[0036] receiving a second message, the second message comprising a second group number.

[0037] Optionally, the first message further comprises a duration, a start time of the duration being based on a first time and a first threshold, and an end time of the duration being based on a second time and a second threshold, wherein the first time is a time when the first network device is disconnected from the ground station link, and the second time is a time when the first network device resumes the ground station link; and the first threshold and the second threshold are preset time values, which can be 0 or not exist.

[0038] Optionally, the not listening to the part or all of the paging messages of the first network device comprises at least one of the following:

[0039] not listening to the paging messages of the first network device for data transmission;

[0040] not triggering connection establishment after listening to the paging messages of the first network device for data transmission;

[0041] listening to the paging only once or a limited number n of times within a system information modification period;

[0042] deactivating or suspending an access stratum (AS) layer.

[0043] Optionally, the establishing the first connection comprises at least one of the following:

[0044] initiating a registration procedure, or initiating an RRC connection establishment procedure, or initiating an RRC connection resume procedure.

[0045] Optionally, the not establishing the first connection comprises at least one of the following:

[0046] not initiating a registration procedure, or not initiating an RRC connection establishment procedure, or not initiating an RRC connection resume procedure.

[0047] In a second aspect, a communication method is provided, which is applied to NTN communication, and comprises the following steps:

[0048] sending a first message, the first message comprising at least one of the following information:

[0049] indicating that there is no downlink data of a terminal located in a first area buffered; or

[0050] indicating that there is downlink data of a terminal located in a third area buffered; or

[0051] indicating a first group number of a terminal corresponding to the buffered downlink data;

[0052] indicate the terminal not to listen to part or all of the paging message, or not to establish the first connection based on the first message; or

[0053] indicate the terminal to listen to the paging message, or to establish the first connection based on the first message.

[0054] In the above scheme, the network device is deployed on a high-altitude platform such as a satellite, and the network device can send a first message to indicate whether the network device on the current satellite has buffered data for terminals in the coverage area. When the satellite can send the first message to the terminal, the service link must be in a connected state, and because in the store-and-forward scenario, the service link is connected, the feeder link must be disconnected. Therefore, the network device does not have new data arriving at the network device on the satellite within a period of time when the network device sends the first message, and thus the network device can instruct the terminal not to listen to the paging message or not to establish the first connection in appropriate cases. Thus, the purpose of saving power consumption is achieved.

[0055] Optionally, the first area and the third area are both coverage areas of the network device. The coverage area can be an area covered by the network device in the past period of time, an area to be covered by the network device in the future period of time, or an area being covered by the network device. The period of time can be set. Here, coverage can also be understood as providing service.

[0056] In some possible implementation manners, the communication method further includes:

[0057] based on the first message, including instructing the terminal to perform one of the following actions:

[0058] when the second area belongs to the subset of the first area, instructing the terminal not to listen to part or all of the paging message, or not to establish the first connection;

[0059] when the second area does not belong to the subset of the first area, instructing the terminal to listen to the paging message, or to establish the first connection;

[0060] when the second area overlaps the third area, instructing the terminal to listen to the paging message, or to establish the first connection;

[0061] when the second group number matches the first group number, instructing the terminal to listen to the paging message of the first network device, or to establish the first connection;

[0062] when the second group number does not match the first group number, instructing the terminal not to listen to part or all of the paging message, or not to establish the first connection;

[0063] when the second area overlaps the third area and the second group number matches the first group number, instructing the terminal to listen to the paging message, or to establish the first connection;

[0064] when the second area overlaps with the third area but the second group ID does not match the first group ID, instructing not to listen to part or all of the paging message or not to establish the first connection;

[0065] when the second area does not overlap with the third area, instructing not to listen to part or all of the paging message or not to establish the first connection.

[0066] Optionally,

[0067] The first area includes:

[0068] at least one tracking area or a region on the earth's surface, where the region on the earth's surface is indicated by area information included in the first message.

[0069] The second area includes:

[0070] at least one of a tracking area where the terminal is located, a set of multiple tracking areas including the tracking area, or a location where the terminal is located.

[0071] Optionally, the region on the earth's surface is determined by indicating a center point position by longitude and latitude, adding a radius distance to determine a region, or indicating a plurality of point positions to determine a geometric shape region. Here, the region can be a region on the earth's surface corresponding to a tracking area with or without cached data (which can include or exclude a boundary according to a preset).

[0072] Optionally, the first message includes at least one of the first area, the third area, or a first group ID of the terminal corresponding to cached downlink data.

[0073] In some possible implementation manners, the communication method further includes,

[0074] indicating the second group ID based on the second message.

[0075] That is, the group ID can be sent by the network device to the terminal, for example, in an access procedure or a tracking area update procedure, or can be determined by the terminal itself according to a terminal identifier or a pre-agreement.

[0076] For the first area and the second area, the matching relationship therebetween can also be understood as a relationship such as association or equality.

[0077] In some possible implementation manners, the communication method further includes, before sending the first message,

[0078] receiving a third message, the third message requesting grouping of the terminal or indicating that the terminal supports grouping;

[0079] sending a second message, the second message including a second group number.

[0080] Optionally, the first message further includes a duration, a start time of the duration being based on a first time and a first threshold, and an end time of the duration being based on a second time and a second threshold, wherein the first time is a time when the link with the ground station is disconnected, the second time is a time when the link with the ground station is resumed, and the first threshold and the second threshold are preset time values, which can be 0 or not exist.

[0081] Optionally, the not listening to part or all of the paging messages includes at least one of the following:

[0082] not listening to a paging message of the first network device for data transmission;

[0083] not triggering connection establishment after listening to the paging message of the first network device for data transmission;

[0084] listening to the paging message only once or a limited number n of times within a system information modification period;

[0085] deactivating or suspending an access stratum (AS) layer.

[0086] Optionally, the establishing the first connection includes at least one of the following:

[0087] initiating a registration procedure, or initiating an RRC connection establishment procedure, or initiating an RRC connection resume procedure.

[0088] Optionally, the not establishing the first connection includes at least one of the following:

[0089] not initiating a registration procedure, or not initiating an RRC connection establishment procedure, or not initiating an RRC connection resume procedure.

[0090] In a third aspect, an electronic device is provided, which has the functions of any of the above aspects. The functions can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions. For example, a transceiving module or unit, a processing module or unit, an obtaining module or unit, etc.

[0091] In a fourth aspect, an embodiment of the present application provides a communication device, including a memory and a processor, the memory being used to store a computer program, and the processor being used to invoke the computer program to make the communication device execute the communication method of any of the above aspects.

[0092] In a fifth aspect, an embodiment of the present application provides a chip system, the chip system comprising a processor coupled with a memory, the processor executing a computer program stored in the memory to implement the communication method of any one of the above aspects.

[0093] The chip system can be a single chip or a chip module composed of multiple chips.

[0094] In a sixth aspect, an embodiment of the present application provides a computer readable storage medium having stored thereon a computer program, the computer program being executed by a processor to implement the communication method of any one of the above aspects.

[0095] In a seventh aspect, an embodiment of the present application provides a computer program product, when the computer program product is run on a communication device, causing the communication device to execute the communication method of any one of the above aspects.

[0096] It can be understood that the beneficial effects of the above third aspect to seventh aspect can be referred to the related description of the above aspects, which will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0097] FIG. 1(a) is a schematic diagram of area coverage provided by an embodiment of the present application.

[0098] FIG. 1(b) is a schematic diagram of another area coverage provided by an embodiment of the present application.

[0099] FIG. 2(a) is an LTE paging flowchart provided by an embodiment of the present application.

[0100] FIG. 2(b) is an NR paging flowchart provided by an embodiment of the present application.

[0101] FIG. 2(c) is an RRC connection establishment flowchart provided by an embodiment of the present application.

[0102] FIG. 2(d) is an RRC connection resume flowchart provided by an embodiment of the present application.

[0103] FIG. 2(e) is another RRC connection resume flowchart provided by an embodiment of the present application.

[0104] FIG. 3(a) is a schematic diagram of an NTN store-and-forward scenario provided by an embodiment of the present application.

[0105] FIG. 3(b) is another schematic diagram of an NTN store-and-forward scenario provided by an embodiment of the present application.

[0106] FIG. 4(a) is still another schematic diagram of an NTN store-and-forward scenario provided by an embodiment of the present application.

[0107] FIG. 4(b) is another schematic diagram of the NTN store-and-forward scenario according to an embodiment of the present application.

[0108] FIG. 5 is another schematic diagram of the area coverage according to an embodiment of the present application.

[0109] FIG. 6 is another schematic diagram of the area coverage according to an embodiment of the present application.

[0110] FIG. 7 is a schematic diagram of a communication apparatus according to an embodiment of the present application.

[0111] FIG. 8 is a schematic diagram of another communication apparatus according to an embodiment of the present application. DETAILED DESCRIPTION

[0112] The technical solutions in the embodiments of the present application will be described below with reference to the drawings.

[0113] The technical solutions in the embodiments of the present application can be applied to various communication systems, such as a long term evolution (LTE) system, a long term evolution-advanced (LTE-A) system, an LTE frequency division duplex (FDD) system, an LTE time division duplex (TDD) system, a universal mobile telecommunications system (UMTS) system, a worldwide interoperability for microwave access (WiMAX) communication system, a next generation communication system (for example, a fifth generation (5G) communication system), a converged system of multiple access systems, or an evolved system, three application scenarios of a 5G mobile communication system, that is, enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), and enhanced machine type communication (eMTC), or a new communication system to be developed in the future. The technical solutions provided in the present application can also be applied to a future communication system, such as a sixth generation mobile communication system. The present application is not limited in this regard.

[0114] The technical solutions provided in the application can also be applied to machine type communication (MTC), long term evolution-machine (LTE-M), device-to device (D2D) network, machine to machine (M2M) network, internet of things (IoT) network or other network. The IoT network may, for example, include a vehicle network. In the vehicle network system, the communication mode is collectively referred to as vehicle to X (V2X, X can represent any thing), for example, the V2X can include vehicle to vehicle (V2V) communication, vehicle to infrastructure (V2I) communication, vehicle to pedestrian (V2P) communication or vehicle to network (V2N) communication, etc.

[0115] The network device in the embodiment of the application can also be referred to as a (radio) access network device ((R)AN). The (R)AN can manage radio resources, provide access services for a terminal device, and complete forwarding of terminal device data between the terminal device and a core network. The (R)AN can also be understood as a base station in the network, which is a device deployed in a wireless access network to provide wireless communication functions for a mobile station (MS).

[0116] Exemplarily, the access network device in the embodiments of the present application can be any kind of communication device with wireless transceiving function for communicating with the terminal device. The access network device includes but is not limited to: an evolved Node B (eNB), a radio network controller (RNC), a Node B (NB), a base station controller (BSC), a base transceiver station (BTS), a home evolved NodeB (HeNB) or a home Node B (HNB), a baseband unit (BBU), an access point (AP) in a wireless fidelity (WiFi) system, a wireless relay node, a wireless backhaul node, a transmission point (TP) or a transmission and reception point (TRP), and the like, and can also be a gNB or a TP in a 5G, such as a NR system, a base station of a 5G system, one or a group of antenna panels (including multiple antenna panels), or a network node constituting a gNB or a transmission point, such as a baseband unit (BBU) or a distributed unit (DU). It can be understood that all or part of the functions of the access network device in the present application can also be implemented by software functions running on hardware, or by virtualized functions instantiated on a platform (such as a cloud platform).

[0117] In addition, in a network structure, the access network device can include a centralized unit (CU) node, or a distributed unit (DU) node, or a RAN device including the CU node and the DU node. The RAN device including the CU node and the DU node splits the protocol layers of the gNB in the NR system, and the functions of part of the protocol layers are placed in the CU for centralized control, and the rest or all of the protocol layers are distributed in the DU, which is controlled by the CU. The centralized unit CU can also be divided into a control plane (CU-CP) and a user plane (CU-UP). The CU-CP is responsible for the control plane function, mainly including the RRC and the PDCP corresponding to the control plane, i.e. PDCP-C. The PDCP-C is mainly responsible for the encryption and decryption of the control plane data, the integrity protection, the data transmission, etc. The CU-UP is responsible for the user plane function, mainly including the SDAP and the PDCP corresponding to the user plane, i.e. PDCP-U. The SDAP is mainly responsible for processing the data of the core network and mapping the flow to the bearer. The PDCP-U is mainly responsible for the encryption and decryption of the data plane, the integrity protection, the header compression, the sequence number maintenance, the data transmission, etc. The CU-CP and the CU-UP are connected through the E1 interface. The CU-CP represents the gNB to connect with the core network through the NG interface. The control plane of the F1 interface, i.e. F1-C, is connected with the DU. The CU-UP is connected with the DU through the user plane of the F1 interface, i.e. F1-U. Of course, there is also a possible implementation that the PDCP-C is also in the CU-UP. The RAN device can be responsible for the functions of the radio resource management, the quality of service (QoS) management, the data compression and encryption, etc. on the air interface. The AN device provides access services for the terminal device, and then completes the forwarding of the control signals and the user data between the terminal device and the core network.

[0118] The terminal device in the embodiments of the present application can also be referred to as a user equipment (UE), a terminal, an access terminal, a user unit, a user station, a mobile station, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a wireless communication device, a user agent or a user apparatus. The terminal in the embodiments of the present application can be a mobile phone, a tablet computer, a computer with wireless transceiver function, a virtual reality (VR) terminal, an augmented reality (AR) terminal, a wireless terminal in industrial control, a wireless terminal in self driving, a wireless terminal in remote medical, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, an in-vehicle device, a wearable device, a terminal in a 5G network or a terminal in a future evolution network, etc.

[0119] Among them, the wearable device can also be called a wearable smart device, which is a general term for devices that can be designed and developed by applying wearable technology to daily wear, such as glasses, gloves, watches, clothing and shoes, etc. The wearable device is a portable device that can be directly worn on the body or integrated into the user's clothes or accessories. The wearable device is not only a hardware device, but also a powerful function realized through software support and data interaction, cloud interaction. The general wearable smart device includes full function, large size, and can realize complete or partial functions without relying on a smart phone, such as smart watches or smart glasses, etc., and focuses on a certain application function and needs to cooperate with other devices such as a smart phone, such as various smart wristbands, smart jewelry, etc. for monitoring vital signs.

[0120] In the embodiments of the present application, the communication device for realizing the function of the network device can be a network device, a network device with base station part function, or a device capable of supporting the network device to realize the function, such as a chip system, which can be installed in the network device.

[0121] Non-Terrestrial Network (NTN) refers to a network or network segment using satellite, unmanned aerial system (UAS) platform or high-altitude platform RF (Radio Frequency). Among them, the most typical non-terrestrial network is to provide communication services through satellites.

[0122] Satellite communication has the advantages of wide coverage, long communication distance, high reliability, great flexibility and high throughput, especially it is not affected by geographical environment, climate conditions and natural disasters, and has good development prospects. At present, satellite communication has been widely used in aviation communication, maritime communication, military communication and other fields. Introducing satellites into the future 5th-Generation (5G) mobile network can provide communication services for areas that are difficult to cover by traditional ground networks, such as oceans, forests, etc., and can also enhance the reliability of 5G communication, such as providing more stable and high-quality communication services for trains, airplanes and users on these vehicles, and can also provide more data transmission resources to support a larger number of connections. Thanks to the concept of "anytime, anywhere" communication today, the status of satellite communication networks will further improve in the future.

[0123] Generally speaking, the higher the orbit of the satellite, the larger the coverage area, but the longer the communication delay. Generally, the orbit of the satellite can be divided into low earth orbit (LEO), medium earth orbit (MEO) and geostationary orbit (GEO) according to the height. Non-Geosynchronous orbit (NGSO) includes low earth orbit with an altitude of about 300 kilometers to 1500 kilometers and medium earth orbit with an altitude of about 7000 kilometers to 25000 kilometers. NTN cells are divided into fixed cells (or stationary cells), quasi-fixed cells and mobile cells.

[0124] Fixed cell refers to a beam or cell or satellite that fixedly covers a geographical area. For example, a geosynchronous orbit satellite can provide a fixed cell.

[0125] Quasi-Earth fixed: also can be referred to as quasi-fixed cell, beam or cell or satellite covers a geographical area in a limited time, covers a different geographical area in another time (for example, the case of NGSO (Non-Geosynchronous orbit, non-geosynchronous orbit) satellite generates steerable beams), as shown in FIG. 1(a); satellite 1 is in different positions on the orbit at T1, T2, T3 time, but satellite 1 can always cover the geographical area 1 in the possible range (for example, to the earth's back of the relative geographical area 1, it is impossible to provide service due to angle problem) by adjusting the angle of the antenna or the posture of the satellite.

[0126] Earth moving: the coverage area of the beam or cell or satellite slides on the earth's surface (for example, the case of NGSO satellite generates fixed or non-steerable beams), as shown in FIG. 1(b). Satellite 1 is in different positions on the orbit at T1, T2, T3 time, respectively, due to the change of position, the three time respectively corresponds to cover three different geographical areas 1, 2, 3. It is easy to understand that the three geographical areas can be continuous and intersected.

[0127] It is also possible to combine the above, the purpose is to cover some population or business hot area.

[0128] One scenario applicable to the present application is called Mobile Terminated Data Transport (MT), which specifically refers to the process of the core network (CN) receiving downlink data of a non-connected terminal and sending the downlink data to the terminal. The process involves paging the terminal by the core network, after paging the terminal, the terminal re-accesses the network, and the core network sends data to the terminal. Since the core network elements involved in the LTE protocol and the NR protocol are different, according to whether the terminal accesses the 4G core network or the 5G core network, the MT data transmission process will have some differences.

[0129] As shown in FIG. 2(a), for the paging procedure of 4G, after the SGW receives the downlink data of the terminal sent by the network side, and the terminal is not in the connected state, the SGW triggers the sending of a downlink data notification message to the MME. The MME replies to the S-GW with a Downlink Data Notification Ack message to confirm the receipt of the downlink data notification. At the same time, the MME sends a paging message to each base station belonging to the tracking area where the terminal last camped, which can contain terminal paging identification, TAI (Tracking Area Identity, tracking area identification) information, etc. TAI is used to uniquely identify a tracking area (in the NTN scenario, the tracking area can also be a fixed area on the surface of the earth). TAI can contain PLMN and TAC (Tracking Area Code, tracking area code). For example, the last tracking area where the terminal last camped is saved by the MME is tracking area 1 and tracking area 2, wherein tracking area 1 corresponds to base station 1 and tracking area 2 corresponds to base station 2, then the MME needs to send the paging message of the terminal to base station 1 and base station 2. The base station can determine the occasion for sending the paging and the terminal to be paged according to the paging message of the MME, and the base station sends a paging message containing terminal identification information. The terminal can calculate the time of the paging occasion (PO) according to its own identification IMSI (international mobile subscriber identity) to listen to the paging, and the terminal detects the paging PDCCH (containing paging DCI) in the PO time. The base station can contain paging messages for multiple terminals in one Paging message, and each terminal will have a separate PagingRecord.

[0130] When the terminal detects paging PDCCH in PO, it will receive paging PDSCH at the location scheduled by the paging PDCCH. The paging PDSCH contains one or more paging records, each of which contains at least one UE ID, which is used to indicate the specific terminal being paged. The UE ID can include the international mobile subscriber identity (IMSI) or 5G-S-Temporary Mobile Subscriber Identity (5G-S-TMSI). If the ue-Identity contained in the PagingRecord matches one of the terminal identifiers assigned by the upper or higher layer, the terminal can confirm that it is paged, thereby triggering the RRC connection establishment process or the RRC connection recovery process. Or if the ue-Identity contained in the PagingRecord matches one of the terminal identifiers assigned by the upper or higher layer, the ue-Identity is forwarded to the higher layer, which in response triggers the RRC connection establishment process or the RRC connection recovery process. This is also called MT data transmission process triggered by downlink service data.

[0131] As shown in FIG. 2(b), for the paging procedure of 5G, there is downlink data of a terminal in the non-connected state. According to the NR protocol, the downlink data can be selected to be buffered in the UPF, or can also not be buffered in the UPF. The UPF uses the downlink data notification message (Downlink Data Notification) of step 2a to notify the SMF, and the SMF uses the UE reachability request message (Namf_MT_EnableUEReachability Request) of step 2c to notify the AMF that there is downlink data. Subsequently, the AMF sends a paging message (Paging) to each base station belonging to the tracking area registered by the terminal in step 3. The paging message can contain terminal paging identification, TAI (Tracking Area Identity) information, etc. The TAI is used to uniquely identify a tracking area. The TAI can contain a PLMN and a TAC (Tracking Area Code). If the tracking areas registered by the terminal saved by the AMF are tracking area 1 and tracking area 2, tracking area 1 corresponds to base station 1, and tracking area 2 corresponds to base station 2, then the AMF needs to send a paging message to base station 1 and base station 2. The base station can determine the occasion for sending the paging and the terminal to be paged according to the paging message of the AMF, and then the base station sends a paging message containing terminal identification information. Similar to 4G, the terminal can calculate the time of the occurrence of the paging occasion (PO) for listening to paging according to its own identification 5G-S-TMSI. The terminal detects the paging PDCCH (containing paging DCI) in the PO time. The base station can contain paging messages for multiple terminals in one paging message, and each terminal will have a separate PagingRecord.

[0132] For the procedure of MT data transmission of NR, if the paging PDCCH indicates that the scheduling information is paging message, the UE will receive the paging PDSCH at the location scheduled by the paging PDCCH. The paging PDSCH contains one or more paging records, each of which contains at least one UE ID, which is used to indicate the specific terminal being paged. If the ue-Identity contained in the PagingRecord matches one of the terminal identifiers assigned by the upper layer or high layer, the terminal can confirm that it is paged, thereby triggering the RRC connection establishment process or the RRC connection recovery process. Or if the ue-Identity contained in the PagingRecord matches one of the terminal identifiers assigned by the upper layer or high layer, the ue-Identity is forwarded to the high layer, and the high layer triggers the RRC connection establishment process or the RRC connection recovery process in response.

[0133] As shown in Figure 2(c), it is the RRC connection establishment process. 1. The UE sends an RRC connection establishment request to the base station, which contains UE identification information. Optionally, the RRC connection establishment request can also contain RRC connection establishment reason information, which indicates that the UE requests to establish an RRC connection to receive store-and-forward data. 2. The base station sends an RRC connection establishment message to the UE, which contains radio resource configuration information (MAC layer and or physical layer configuration information). 3. The UE sends an RRC connection establishment completion message to the base station, which is used to confirm that the RRC connection establishment is successfully completed.

[0134] As shown in Fig. 2(d), it is a RRC connection resume procedure. 1. UE sends a RRC connection resume request to the base station. The RRC connection resume request contains a resume ID (for base station connecting 4G core network) or I-RNTI (for base station connecting 5G core network). (I-RNTI, Inactive RNTI, Inactive state wireless network temporary identifier). Optionally, it contains RRC connection resume cause information, which indicates that the UE requests to resume RRC connection is to receive store-and-forward data. 2a. The base station sends a RRC connection resume message to the UE, which is used to resume RRC connection. If the base station cannot resume the UE context or cannot obtain the UE context from other base stations, the base station sends a RRC connection setup message to the UE. 3a. The UE sends a RRC connection resume complete message to the base station, which is used to confirm that the RRC connection resume is successfully completed. Wherein, if after step 1, the message sent by the base station is not the RRC connection resume message, as shown in Fig. 2(e), 2b. The UE receives the RRC connection setup message, then 3b. The UE sends the RRC connection setup complete message. That is, the RRC connection resume request has different subsequent procedures.

[0135] In addition, there is also a system-level paging mechanism, in which the base station can indicate the change of system information and / or provide ETWS (Earthquake and Tsunami Warning System) notification or CMAS (Commercial Mobile Alert Service) notification in such paging message. Such paging message is different from the paging message generated by the ordinary downlink data of the terminal, which is initiated to all terminals within the coverage of the base station, and all terminals also listen and receive such paging message, which is also called as the broadcast paging belonging to the system level. In some cases, there will be a situation such as the change of base station system information, at this time, the terminal needs to obtain the required changed system message or ETWS, CMAS notification indication information through the system-level paging message.

[0136] Currently, NTN needs to support the store-and-forward scenario, which specifically refers to that the service link and the feeder link (feeder link) cannot exist at the same time, and the satellite has the function of a base station or part of the base station (here, the satellite is used to unify the description, and in fact, it can also be a variety of devices such as unmanned aerial vehicles, high-altitude platforms, etc. in the NTN scenario, and the like throughout the text). As shown in FIG. 3(a) and FIG. 3(b), when the satellite 1 runs on the orbit, at T1 moment, the service link with the terminal is disconnected, and the feeder link with the ground station is connected. At T2 moment, the service link with the terminal is connected, and the feeder link with the ground station is disconnected. The system during T1-T2 is the typical scenario of NTN store-and-forward scenario, that is, in the store-and-forward scenario, the core network-base station-terminal path necessary for traditional wireless transmission is not always in an end-to-end open state. In simple terms, when the core network-base station has a link (feeder link is connected), the base station-terminal has no link (service link is disconnected); and when the base station-terminal has a link (service link is connected), the core network-base station has no link (feeder link is disconnected). For the particularity of the link in the store-and-forward scenario, when the service link is disconnected and the feeder link is connected, the satellite will buffer the downlink data to be sent to the terminal, and when the service link between the base station and the terminal is connected, the base station pages the terminal and sends the downlink data after the terminal re-connects. In NTN communication, the terminal needs to communicate with the satellite, and the power consumption is significantly higher than that in ordinary ground communication scenarios. The high power consumption of the terminal in the NTN scenario has been a problem that people expect to solve. By analyzing the characteristics of the store-and-forward scenario, if the satellite base station does not receive the downlink data of the terminal during the time when the feeder link is connected, then during the time when the service link of the terminal is connected, there is also no downlink data of the terminal, because according to the foregoing description, the service link and the feeder link cannot be in an open state at the same time, which means that during the time when the service link of the terminal is connected, the feeder link is disconnected, and there is no downlink data. Based on this, the power consumption can be reduced by reducing the terminal monitoring paging time, and the specific embodiments involved in the present application are as follows.

[0137] As shown in FIG. 4(a), the satellite 1 will disconnect the feeder link after T1 moment, at this time, the satellite 1 has no buffered downlink data, to T2 moment as shown in FIG. 4(b), the satellite re-acquires the feeder link. That is, during T1-T2, there is no buffered data in at least one area covered by the base station on the satellite 1. In this case, the system flow includes:

[0138] S101, the satellite 1 (base station) sends indication information indicating that the satellite 1 has no buffered data, or indicating that there is no stored downlink data. Or it can also indicate that the satellite 1 has buffered data / stored downlink data.

[0139] Optionally, the area here is at least one tracking area covered or served by the satellite 1, or at least one earth surface area covered or served.

[0140] Optionally, the indication information can indicate all tracking areas covered or served, or all earth surface areas covered or served. In this case, further optionally, the indication information can not carry the area information, and by default indicates all areas, or indicates all areas by a flag bit.

[0141] Optionally, the indication information can be sent in a unicast or broadcast manner, and all terminals in the area covered or served by the satellite 1 are expected to receive the prompt information.

[0142] In the NTN, there are various satellite architectures, and for these different architectures, the following cases exist.

[0143] a) Only base station satellite: optimize transmission for control plane (CP) and user plane (UP), data is stored in the base station, that is, in the satellite 1, in this case, the base station determines that there is no buffered downlink data;

[0144] b) Base station and partial MME / AMF or entire MME / AMF satellite:

[0145] i. CP optimized transmission, downlink data to MME / AMF, MME / AMF informs the base station that there is no buffered downlink data;

[0146] ii. UP optimized transmission, downlink data to base station, base station determines that there is no buffered downlink data;

[0147] c) Base station and (partial) core network CN satellite:

[0148] i. CP optimized transmission, downlink data in S-GW / UPF, S-GW indicates to the base station through MME, UPF indicates to the base station through AMF, or S-GW / UPF directly indicates to the base station that there is no buffered downlink data;

[0149] ii. UP optimized transmission, downlink data in S-GW / UPF, S-GW indicates to the base station through MME, UPF indicates to the base station through AMF, or S-GW / UPF directly indicates to the base station that there is no buffered downlink data.

[0150] Optionally, the coverage area indicated by the indication information can be an area covered by the satellite 1 in the past period of time, an area to be covered in the future period of time, or an area being covered, and the above-mentioned time period can be set.

[0151] S102, after receiving the indication information, the terminal in the coverage area of satellite 1 determines that satellite 1 has no downlink data of the terminal, and the terminal stops listening to the paging message of satellite 1, and enters a mode of not listening to the paging message. Or the terminal does not listen to the paging message of satellite 1 for data transmission, or the terminal does not listen to the paging message of satellite 1 and / or does not receive downlink data, or satellite 1 selects not to send a system paging message in this case. Or the terminal does not establish an RRC connection, for example, does not initiate a registration process, does not initiate an RRC connection establishment process, does not initiate an RRC connection recovery process, and does not initiate an attach process.

[0152] Specifically, the terminal not listening to the paging message can have the following execution modes, which can also be called a paging message listening mode:

[0153] a) After receiving the indication information, the terminal determines that satellite 1 has no downlink data of the terminal, and the terminal only listens to the paging message once in the system information modification period, or a preset limited number n (n is a positive integer), and the terminal does not listen to the paging message at other paging occasions in the system information modification period. Correspondingly, the base station can make the system information modification period as long as possible to make the terminal save power consumption as much as possible.

[0154] b) After receiving the indication information, the terminal determines that satellite 1 has no downlink data of the terminal, and the terminal can deactivate or suspend the access stratum (AS). The terminal can save the configuration information related to the AS layer; or keep all running timers continue to run, but do not perform any idle mode tasks, such as measurement. The timer here includes a terminal location information validity timer (the expiration of the timer can be considered as the terminal location information invalid or inaccurate); also includes a satellite ephemeris information or satellite auxiliary information validity timer (the expiration of the timer can be considered as the satellite auxiliary information invalid or inaccurate); or does not trigger the connection establishment / random access process after listening to the paging message for data transmission; or stops all paging listening; or keeps the running timer at the same time but does not perform idle mode tasks. At least one of the above. The terminal performs all idle mode tasks before or after (preset time) the satellite 1 or the service cell of satellite 1 stops covering / stops serving. Or the terminal has uplink data to execute all idle mode tasks.

[0155] In another possible case, the system process includes:

[0156] S201, satellite 1 sends indication information, indicating that part or all of the areas covered or served by the base station on satellite 1 have buffered data, and the indicated area is called the third area.

[0157] Optionally, the third area here is at least one tracking area covered or served by satellite 1, or part or all of the earth surface area covered or served.

[0158] Optionally, the area indication information indicates that there is data in the tracking area currently broadcasted by the base station on satellite 1.

[0159] Optionally, when the area indicates an earth surface area, it can be determined by indicating the center point position by using latitude and longitude, plus the radius distance to determine an area; or indicating a pre-agreed area; or determining a geometric shape area by indicating multiple point positions. The area here is the earth surface area corresponding to the tracking area with data.

[0160] Optionally, the area can also indicate the first area, which has no cached data, at this time, the indication information includes at least one of the first area and the third area.

[0161] In NTN, there are many different satellite architectures, and for these different architectures, the following cases exist.

[0162] a) Only base station satellite: optimize transmission for CP and UP, data is stored in the base station, that is, in satellite 1 (all data to the base station at T1, feeder link disconnected at T1), in this case, the base station can determine the tracking area corresponding to the terminal to which the data is to be sent;

[0163] b) Base station and part of MME / AMF or entire MME / AMF satellite:

[0164] i. CP optimized transmission, all data to MME / AMF at T1, MME / AMF informs the base station of the tracking area where the terminal corresponding to the data in [T1, T2] time is located;

[0165] ii. UP optimized transmission, all data to the base station at T1, MME / AMF knows the tracking area corresponding to the data, MME / AMF informs the base station of the tracking area where the terminal corresponding to the data in [T1, T2] time is located.

[0166] c) If the base station and (part of) the core network CN are satellite:

[0167] i. CP optimized transmission, all data in S-GW / UPF at T1, S-GW through MME, UPF through AMF to indicate to the base station, or S-GW / UPF directly to the base station to indicate the tracking area where the terminal corresponding to the data in [T1, T2] time is located;

[0168] ii. UP optimization transmission, all data in S-GW / UPF at T1 moment, S-GW indicates to base station through MME, UPF indicates to base station through AMF, or S-GW / UPF directly indicates to base station that there is data corresponding to the terminal in the tracking area within [T1, T2] time.

[0169] Optionally, the indication information can also include a duration, which is based on the [T1, T2] time data notified by the MME / AMF, can be in the form of [T1±t1, T2±t2], t1 and t2 are preset time values, used to flexibly adjust the duration window.

[0170] S202, based on the area information in the indication information, the terminal:

[0171] When it is determined that the area where the terminal is located does not belong to the first area subset, the terminal executes the following operations: monitoring the paging message of satellite 1, or establishing an RRC connection, for example, initiating a registration process, initiating an RRC connection establishment process, initiating an RRC connection recovery process, and initiating an attachment process (the same below);

[0172] When it is determined that the area where the terminal is located belongs to the first area subset, the terminal executes the following operations: not monitoring part or all of the paging message of satellite 1, or not establishing an RRC connection, for example, not initiating a registration process, not initiating an RRC connection establishment process, not initiating an RRC connection recovery process, and not initiating an attachment process (the same below);

[0173] When it is determined that the area where the terminal is located overlaps with the third area, the terminal executes the following operations: monitoring the paging message of satellite 1, or establishing an RRC connection;

[0174] When it is determined that the area where the terminal is located does not overlap with the third area, the terminal executes the following operations: not monitoring part or all of the paging message of satellite 1, or not establishing an RRC connection.

[0175] Optionally, when the area information is an earth surface area, the terminal determines the following according to its own position information:

[0176] When it is determined that the area where the terminal is located does not belong to the first area, the terminal executes the following operations: monitoring the paging message of satellite 1, or establishing an RRC connection;

[0177] When it is determined that the area where the terminal is located belongs to the first area, the terminal executes the following operations: not monitoring part or all of the paging message of satellite 1, or not establishing an RRC connection;

[0178] When it is determined that the area where the terminal is located belongs to the third area, the terminal executes the following operations: monitoring the paging message of satellite 1, or establishing an RRC connection;

[0179] When it is determined that the area where the terminal is located does not belong to the third area, the terminal executes the following operations: not monitoring part or all of the paging message of satellite 1, or not establishing an RRC connection.

[0180] When the area information in the indication information is tracking area information (as at least one tracking area, it can be considered that one tracking area set is indicated), because the terminal can save one or more tracking areas, when the terminal in the tracking area covered by satellite 1 receives the indication information, if one of the tracking areas saved by the terminal is indicated to have data (one tracking area belongs to (∈) the third area), the terminal listens to the paging message of satellite 1, or establishes an RRC connection; and if all the saved areas are not indicated to have no data (all the saved tracking areas do not belong to the third area), the terminal does not listen to the paging message of satellite 1, or does not establish an RRC connection.

[0181] Optionally, when the earth surface area indication is used, the terminal can also determine whether it is in the earth surface area indicated by the terminal through its own position information (which can include or not include the boundary according to the preset).

[0182] Specifically, the terminal can have the following execution modes when it does not listen to the paging message, which can also be called the paging message listening mode:

[0183] a) After the terminal receives the indication information, it is determined that satellite 1 has no downlink data of the terminal, and the terminal only listens to the paging message once in the system information modification period, or a preset limited number of times n (n is a positive integer), and the terminal does not listen to the paging message at other paging occasions in the system information modification period. Correspondingly, the base station can make the system information modification period as long as possible to make the terminal save power as much as possible.

[0184] b) After the terminal receives the indication information, it is determined that satellite 1 has no downlink data of the terminal, and the terminal enters the paging message listening mode. The terminal can deactivate or suspend the access stratum (AS). The terminal can save the configuration information related to the AS layer; or keep all running timers continue to run, but do not perform any idle mode tasks, such as measurement, etc. The timers here include a terminal position information validity timer (the expiration of the timer can be considered as the terminal position information being invalid or inaccurate); also includes a satellite ephemeris information or satellite assistance information validity timer (the expiration of the timer can be considered as the satellite assistance information being invalid or inaccurate); or does not trigger the connection establishment / random access process after listening to the paging message for data transmission; or stops all paging listening; or keeps the running timer at the same time but does not perform the idle mode task. The terminal performs all idle mode tasks before or after the satellite 1 or the service cell of satellite 1 stops covering / stops serving (preset time). Or the terminal has uplink data to be executed, and performs all idle mode tasks.

[0185] To further illustrate, as shown in Figure 5, at T1.5 in the time [T1, T2], the satellite covers the tracking areas TACm-1 and TACm. At this time, the satellite only caches data 1, which is to be sent to UE1 in TACm. Satellite 1 sends indication information indicating that TACm-1 has no data and TACm has data;

[0186] The tracking area information saved by UE1 is TACm, so UE1 judges according to the indication information of satellite 1 that it needs to listen to the paging message or establish an RRC connection to receive the downlink data;

[0187] The tracking area information saved by UE2 is TACm-1, so UE2 judges according to the indication information of satellite 1 that it does not need to receive the downlink data, i.e. does not need to listen to the paging message or establish an RRC connection, and directly sets to the mode of not listening to the paging message.

[0188] Optionally, satellite 1 can also explicitly indicate the area information without data. At this time, the terminal needs to perform the opposite processing of the above-mentioned logic when judging, i.e. when the terminal is in the area associated with the area indicated by the indication information, it does not listen or does not establish an RRC connection, and when the terminal is not in the area associated with the area indicated by the indication information, it listens or establishes an RRC connection.

[0189] Further optionally, the indication information can also indicate that satellite 1 has cached downlink data of the terminal in area 1 and does not have cached downlink data of the terminal in area 2. At this time, the terminal can compare the first area and the third area respectively and judge according to the above-mentioned logic whether it needs to listen to the paging message or whether it needs to establish an RRC connection.

[0190] In another possible case, the system flow includes:

[0191] S301, satellite 1 (base station) sends indication information indicating the group ID (referred to as the first group ID) of the terminal corresponding to the stored / cached data.

[0192] Optionally, it can also indicate that part or all of the areas covered or served by the current base station on satellite 1 have cached data, and the indicated area is referred to as the third area.

[0193] Optionally, it can also indicate that part or all of the areas covered or served by the current base station on satellite 1 have no cached data, and the indicated area is referred to as the first area.

[0194] Further optionally, it can also indicate that the tracking area of the current system message broadcast by the base station has data.

[0195] The terminal groupID is assigned to the terminal by the core network control. Specifically, the MME / AMF may configure a terminal groupID for the terminal. In preceding procedures, such as the access procedure, the terminal requests packets from the MME / AMF or instructs the terminal to support packets; the MME / AMF configures and sends the groupID to the terminal. Optionally, the MME / AMF may also send the groupID to the base station (or send it to the base station in a subsequent procedure). Specifically, the groupID can be numbered 1, 2, 3, 4…n, divided into n groups, used to distinguish terminals within the coverage / service area.

[0196] Optionally, regarding the method by which the terminal obtains the groupID number, in addition to MME / AMF indication, the base station and the terminal can also determine the groupID number based on the terminal's UE ID (and / or the total number of groupIDs based on the UE ID), or by determining the subgroup ID number of the groupID. The base station can send the total number of groupIDs to the terminal, or agree on the ID number in advance with the core network and the terminal.

[0197] The UE ID here can be either IMSI or 5G-S-TMSI. The core network can determine and configure the groupID using methods such as IMSI mod X or 5G-S-TMSI mod X. X can be any preset integer; mod is a modulo operation.

[0198] In NTN, there are several different uplink architectures, and the following situations apply to these different architectures.

[0199] a) Base station only: Optimized transmission for CP and UP, data is stored at the base station, i.e., stored on satellite 1 (all data arrives at the base station at time T1, i.e., the feeder link is disconnected at time T1). In this case, the base station can determine the tracking area corresponding to the terminal to which the data is to be sent. The MME / AMF needs to send the groupID of the terminal corresponding to the data to the base station (or send it to the base station in advance). If the groupID is determined based on the UE ID, the base station can determine it itself and does not need to send the groupID separately.

[0200] b) Base station and part or all of the MME / AMF are uploaded to satellite:

[0201] i. CP optimized transmission: all data at time T1 is sent to MME / AMF, and MME / AMF notifies the base station of the tracking area and groupID corresponding to the [T1,T2] time data (or sends it to the base station in advance);

[0202] ii. UP optimization transmission, all data to the base station at T1 time, but the MME / AMF knows the tracking area corresponding to the data, and the MME / AMF informs the base station of the tracking area corresponding to the data in the [T1, T2] time and the groupID (or sent to the base station in advance; or according to the UE ID, the base station determines itself);

[0203] c) Base station and (part of) core network CN star:

[0204] i. CP optimization transmission, all data in S-GW / UPF at T1 time, S-GW through MME, UPF through AMF to indicate to the base station, or S-GW / UPF directly to the base station Indicate the tracking area and groupID of the data in [T1, T2] time (or sent to the base station in advance); If it is based on UE ID to determine groupID, the base station can determine itself, and does not need to send groupID additionally;

[0205] ii. UP optimization transmission, all data in S-GW / UPF at T1 time, S-GW through MME, UPF through AMF to indicate to the base station, or S-GW / UPF directly to the base station Indicate the tracking area and groupID of the data in [T1, T2] time (or sent to the base station in advance); If it is based on UE ID to determine groupID, the base station can determine itself, and does not need to send groupID additionally.

[0206] Optionally, the indication information can also include the duration, which is based on the [T1, T2] time data notified by the MME / AMF, and can be in the form of [T1±t1, T2±t2], t1 and t2 are preset time values, used to flexibly adjust the duration window, such as adjusting value 0, which is the actual duration.

[0207] S302, after the terminal receives the sent indication information, judges in combination with its own group number (referred to as the second group number),

[0208] determining that the second group number matches the first group number, listening to the paging message of satellite 1, or establishing an RRC connection with satellite 1;

[0209] determining that the second group number does not match the first group number, not listening to part or all of the paging message of satellite 1, or not establishing an RRC connection with satellite 1;

[0210] determining that the area where it is located overlaps with the third area, and the second group number matches the first group number, listening to the paging message of satellite 1, or establishing an RRC connection with satellite 1;

[0211] If it is determined that the region where the terminal is located overlaps with the third region, but the second group number does not match the first group number, the terminal does not listen to part or all of the paging message of satellite 1, or does not establish an RRC connection with satellite 1.

[0212] Optionally, when the region information is a region on the earth's surface, the terminal determines, according to its own position information, that:

[0213] If it is determined that the second group number matches the first group number, the terminal listens to the paging message of satellite 1, or establishes an RRC connection with satellite 1.

[0214] If it is determined that the second group number does not match the first group number, the terminal does not listen to part or all of the paging message of satellite 1, or does not establish an RRC connection with satellite 1.

[0215] If it is determined that the region where the terminal is located belongs to the third region, and the second group number matches the first group number, the terminal listens to the paging message of satellite 1, or establishes an RRC connection with satellite 1.

[0216] If it is determined that the region where the terminal is located belongs to the third region, but the second group number does not match the first group number, the terminal does not listen to part or all of the paging message of satellite 1, or does not establish an RRC connection with satellite 1.

[0217] The judgment of the region information is the same as that described in S202 above.

[0218] For further illustration, as shown in FIG. 6, at T1.5 in the time [T1, T2], satellite covers tracking areas TACm-1 and TACm. At this time, satellite 1 only buffers data 1, which is to be sent to UE1 in TACm. Satellite 1 sends indication information indicating that TACm-1 has no data and TACm has data, and in the indication information, the group ID of the terminal corresponding to the data is sent: group ID1.

[0219] If the tracking area information saved by UE1 is TACm, and the group ID saved by UE1 is group ID1, then UE1 tracks the indication information sent by satellite 1, and the tracking area and the group ID are matched at the same time, so UE1 judges that it needs to listen to the paging message or establish an RRC connection to receive the downlink data.

[0220] If the tracking area information saved by UE2 is TACm, and the group ID saved by UE1 is group ID2, then UE2 tracks the indication information sent by satellite 1, and the tracking area and the group ID are not matched at the same time, so UE2 judges that it does not need to receive the downlink data or establish an RRC connection, and directly sets the mode to not listen to the paging message.

[0221] Optionally, the satellite 1 can also explicitly indicate the groupID and / or region information without data. In this case, the terminal needs to perform the opposite process as the above-mentioned logic when making a judgment, that is, for example, when the groupID of the terminal and the region in which it is located match the indication information, it means that there is no data, and the terminal can not listen or establish an RRC connection; when any one does not match, it means that there is data, and the terminal needs to listen or establish an RRC connection.

[0222] Further optionally, in addition to the group, the indication information can also indicate that the satellite 1 has buffered downlink data of the terminal located in the region 1 and that the satellite 1 has no buffered downlink data of the terminal in the region 2. At this time, the terminal can compare the region 1 and the region 2 respectively and determine whether to listen to the paging message or whether to establish an RRC connection according to the above-mentioned logic.

[0223] FIG. 7 is a schematic block diagram of a communication apparatus provided by an embodiment of the present application. As shown in FIG. 7, the communication apparatus 700 can include a processing unit 710 and a communication unit 720. The communication unit 720 can implement corresponding communication functions, which can be internal communication of the communication apparatus 700 or communication between the communication apparatus 700 and other apparatuses; the processing unit 710 can implement corresponding processing functions. The communication unit 720 can also be referred to as a communication interface or a transceiver unit. Optionally, the communication apparatus 700 can also include a storage unit, which can be used to store instructions and / or data, and the processing unit 710 can read the instructions and / or data in the storage unit to enable the apparatus to implement the foregoing method embodiments.

[0224] In a possible design, the communication apparatus 700 can be a terminal device in the above-mentioned communication method, and can also be a module or a chip applied to the terminal device. The communication apparatus 700 can be used to execute the steps or processes performed by the terminal device in the above-mentioned method embodiments. Optionally, the communication apparatus 700 can be a network device in the above-mentioned communication method, and can also be a module or a chip applied to the network device. The communication apparatus 700 can be used to execute the steps or processes performed by the network device in the above-mentioned communication method embodiments.

[0225] For the steps or processes performed by each unit in the communication apparatus 700, reference can be made to the above-mentioned method embodiments, and details are not described herein.

[0226] It should be understood that the "units" in the communication apparatus 700 can be implemented by hardware, or implemented by software, or implemented by the hardware executing the corresponding software. For example, the "units" can refer to an application specific integrated circuit (ASIC), an electronic circuit, a processor (for example, a shared processor, a dedicated processor, or a group processor, etc.) and a memory for executing one or more software or firmware programs, a combination logic circuit, and / or other suitable components supporting the described functions. For another example, the communication unit 720 can be replaced by a transceiver circuit (for example, which can include a receiving circuit and a transmitting circuit), and the processing unit 710 can be replaced by a processor or a processing circuit.

[0227] FIG. 8 shows a schematic block diagram of another communication apparatus 800 provided by the embodiments of the present application. The communication apparatus 800 can be a terminal device or a network device, or a chip, a chip system, or a processor, etc. supporting the terminal device or the network device to implement the above method. The apparatus can be used to implement the method described in the above method embodiments, and the details can be referred to the description in the above method embodiments.

[0228] The communication apparatus 800 can include one or more processors 810, which can also be referred to as processing units, and can implement certain control functions. The processor 810 can be a general purpose processor or a special purpose processor, etc. For example, it can be a baseband processor or a central processing unit. The baseband processor can be used to process communication protocols and communication data, and the central processing unit can be used to control the communication apparatus (for example, a base station, a baseband chip, a user chip, a DU or a CU, etc.), execute software programs, and process data of the software programs.

[0229] In an optional design, the processor 810 can also store instructions and / or data, which can be executed by the processor 810, so that the communication apparatus 800 performs the method described in the above method embodiments. Optionally, the processing unit 710 in the communication apparatus 700 can be the processor 810.

[0230] In another optional design, the communication apparatus 800 can include a communication interface 820 for implementing receiving and transmitting functions. For example, the communication interface 820 can be a transceiver circuit, an interface, an interface circuit, or a transceiver, etc. The transceiver circuit, the interface, the interface circuit, or the transceiver for implementing the receiving and transmitting functions can be separate or integrated together. The above transceiver circuit, interface, interface circuit, or transceiver can be used for reading and writing of codes / data, or the above transceiver circuit, interface, interface circuit, or transceiver can be used for transmission or transfer of signals. Optionally, the communication unit 720 in the communication apparatus 700 can be the communication interface 820.

[0231] Optionally, the communication device 800 can include one or more memories 830, which can store instructions that can be executed by the processor 810, so that the communication device 800 performs the methods described in the above method embodiments. Optionally, the memory 830 can also store data. Optionally, the processor 810 can also store instructions and / or data. The processor 810 and the memory 830 can be separately arranged, or integrated together.

[0232] Those skilled in the art can understand that, for the convenience of description, FIG. 8 only shows one memory and one processor. In an actual communication device, there can be multiple processors and memories. The memory can also be referred to as a storage medium or a storage device, and the embodiments of the present application do not limit this.

[0233] For example, the processor can include a baseband processor and a central processor, the baseband processor is mainly used for processing communication protocols and communication data, and the central processor is mainly used for controlling the entire terminal device, executing software programs, and processing data of the software programs. The processor in FIG. 8 integrates the functions of the baseband processor and the central processor. Those skilled in the art can understand that the baseband processor and the central processor can also be independent processors, which are interconnected through a bus or the like. Those skilled in the art can understand that the terminal device can include multiple baseband processors to adapt to different network modes, and the terminal device can include multiple central processors to enhance its processing capability. Various components of the terminal device can be connected through various buses. The baseband processor can also be referred to as a baseband processing circuit or a baseband processing chip. The central processor can also be referred to as a central processing circuit or a central processing chip. The function of processing communication protocols and communication data can be built into the processor, or stored in the form of software programs in the storage unit, and the processor executes the software programs to realize the baseband processing function.

[0234] It should be understood that, in a possible design, the steps in the method embodiments provided by the present application can be completed by integrated logic circuits of hardware in the processor or instructions in the form of software. The steps of the method disclosed in combination with the embodiments of the present application can be directly embodied as hardware processor execution, or executed by a combination of hardware and software modules in the processor. The software module can be located in a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an electrically erasable programmable memory, a register, or other mature storage media in the art. The storage medium is located in the memory, and the processor reads the information in the memory and combines the hardware to complete the steps of the above method. To avoid repetition, it will not be described in detail here.

[0235] It should be noted that the processor in the embodiments of the present application can be an integrated circuit chip with a signal processing capability. In the implementation process, the steps of the above method embodiments can be completed by an integrated logic circuit or an instruction in the form of software in the processor. The processor described above can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. The disclosed methods, steps and logic block diagrams in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor or the like. The steps of the method disclosed in conjunction with the embodiments of the present application can be directly embodied as a hardware code processor for execution, or a combination of hardware and software modules in the code processor for execution. The software module can be located in a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register or other mature storage medium in the art. The storage medium is located in the storage, and the processor reads the information in the storage, and combines the hardware to complete the steps of the above method.

[0236] It can be understood that the memory in the embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically EPROM (EEPROM) or a flash memory. The volatile memory can be a random access memory (RAM) used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced SDRAM (ESDRAM), synchlink DRAM (SLDRAM) and direct rambus RAM (DR RAM). It should be noted that the memory of the system and method described herein is intended to include but not limited to these and any other suitable types of memory.

[0237] The present application also provides a computer program product, which comprises computer program codes, when the computer program codes are run on a computer, the computer is caused to perform each step or procedure performed by the terminal device or the network device in any of the above method embodiments.

[0238] The present application also provides a computer readable storage medium, which stores program codes, when the program codes are run on a computer, the computer is caused to perform each step or procedure performed by the terminal device or the network device in any of the above method embodiments.

[0239] The present application also provides a communication apparatus, which comprises a processor and an interface for sending and / or receiving signals, so that the processor performs each step or procedure performed by the terminal device or the network device in any of the above method embodiments.

[0240] The present application also provides a communication system, which comprises a terminal device and a network device.

[0241] Each of the above apparatus embodiments and method embodiments corresponds completely, and the corresponding steps are performed by the corresponding modules or units, for example, the steps of receiving or sending in the method embodiments are performed by the communication unit or the communication interface, and the other steps except sending and receiving can be performed by the processing unit or the processor.

[0242] In the embodiments of the present application, each term and English abbreviation is an exemplary example given for convenience of description, which should not constitute any limitation to the present application. The present application does not exclude the possibility of defining other terms capable of achieving the same or similar functions in the existing or future protocols.

[0243] The terms "component", "module", "system", and the like used in the present specification are used to represent computer-related entities, hardware, combinations of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and / or a computer. By way of illustration, both an application running on a computing device and the computing device can be a component. One or more components can reside within a process and / or thread of execution, and a component can be localized on one computer and / or distributed between two or more computers. In addition, these components can execute from various computer readable media having various data structures stored thereon. The components can communicate by way of local and / or remote processes such as in accordance with a signal having one or more data packets (e.g., data from one component interacting with another component in a local system, distributed system, and / or across a network such as the Internet with other systems via the signal), by way of the data packets, and / or by way of other signals in the various embodiments.

[0244] Those of skill in the art would understand that the various illustrative logical blocks and steps described in connection with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or combinations of both. The disclosure is not limited to implementations set forth herein for the sake of providing an overall understanding of architectures, suitability, and alternatives thereof. Those of skill would further understand that the functionality of various illustrative logical blocks and steps can be carried out by one or more electrical circuits, microprocessors, or gate arrays designed with source or object code, by a programmed computer, or by a combination thereof. Such functionality can be carried out in various ways, depending inter alia on the particular application for which the disclosure is employed, the design choices, and available technology. Skilled artisans can employ a variety of different approaches to implement the described functionality, and all combinations of these approaches are contemplated.

[0245] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the system, device and unit described above can be based on the corresponding processes in the foregoing method embodiments, which will not be repeated here.

[0246] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the device embodiments described above are merely illustrative, for example, the division of the units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interfaces, devices or units, and can be electrical, mechanical or other forms.

[0247] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiment.

[0248] In addition, the functional units in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit.

[0249] In the above embodiments, the functions of the various functional units can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented by software, the software can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions (programs). When the computer program instructions (programs) are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are wholly or partially generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another, for example, the computer instructions can be transferred from one website, computer, server or data center to another via wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) manner. The computer-readable storage medium can be any available medium accessible by a computer or a data storage device such as a server, data center, etc. integrated with one or more available media. The available media can be magnetic media (for example, floppy disk, hard disk, magnetic tape), optical media (for example, DVD), or semiconductor media (for example, solid state disk (SSD)) and the like.

[0250] The functions, if implemented in the form of software functional units and sold or used as independent products, can be stored in a computer-readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the parts that make contributions to the prior art or parts of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0251] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A communication method applied to NTN communication, characterized in that, The method comprises, receiving a first message, the first message containing at least one of the following information: indicating that the first network device does not cache downlink data of a terminal located in a first area; or, indicating that the first network device caches downlink data of a terminal located in a third area; or, indicating that the first group number of the terminal corresponding to the downlink data cached by the first network device; The first network device is deployed on a satellite; based on the first message, not listening to part or all of the paging messages of the first network device, or not establishing a first connection; or, based on the first message, listening to the paging messages of the first network device, or establishing a first connection, or resuming a first connection.

2. The method of claim 1, wherein, Based on the first message, one of the following actions is performed: when it is determined that the second area belongs to the subset of the first area, not listening to part or all of the paging messages of the first network device, or not establishing a first connection; when it is determined that the second area does not belong to the subset of the first area, listening to the paging messages of the first network device, or establishing a first connection, or resuming a first connection; when it is determined that the second area overlaps with the third area, listening to the paging messages of the first network device, or establishing a first connection, or resuming a first connection; when it is determined that the second group number matches the first group number, listening to the paging messages of the first network device, or establishing a first connection, or resuming a first connection; when it is determined that the second group number does not match the first group number, not listening to part or all of the paging messages of the first network device, or not establishing a first connection; when it is determined that the second area overlaps with the third area and the second group number matches the first group number, listening to the paging messages of the first network device, or establishing a first connection, or resuming a first connection; when it is determined that the second area overlaps with the third area but the second group number does not match the first group number, not listening to part or all of the paging messages of the first network device, or not establishing a first connection; when it is determined that the second area does not overlap with the third area, not listening to part or all of the paging messages of the first network device, or not establishing a first connection.

3. The method of claim 2, wherein: the first area and the third area comprise: at least one tracking area (TA) covered or served by the first network device, or a region on the earth's surface, wherein the region on the earth's surface is indicated by area information included in the first message; the second area comprises: a tracking area in which the terminal is located, or a plurality of tracking areas including the tracking area, or at least one of the locations in which the terminal is located.

4. The method of claim 3, wherein, The area information included in the first message comprises: indicating the position of the center point with latitude and longitude, and determining a region with a radius distance; a pre-agreed region; or a geometric shape region determined by a plurality of point positions; wherein, according to a preset, the area information includes or does not include a boundary.

5. The method of claim 2, wherein, determining the second group number based on the received second message, or determining the second group number based on a terminal identity (UE ID).

6. The method of claim 5, wherein, before receiving the first message, sending a third message, the third message requesting grouping, or indicating that grouping is supported; receiving the second message, the second message including the second group number.

7. The method of claim 1, wherein, the first message further includes a duration, a start time of the duration being based on a first time and a first threshold, and an end time of the duration being based on a second time and a second threshold, wherein the first time is a time when the first network device is disconnected from a ground station link, the second time is a time when the first network device resumes the ground station link, and the first threshold and the second threshold are preset time values.

8. The method according to any one of claims 1 to 7, characterized in that, the not listening to part or all of the paging messages of the first network device includes at least one of the following: not listening to the paging messages of the first network device for data transmission; not triggering connection establishment after listening to the paging messages of the first network device for data transmission; listening to the paging only once or a limited number n of times within a system information modification period; deactivating or suspending an access stratum (AS).

9. The method of claim 1, wherein, the establishing the first connection further includes initiating a first connection establishment procedure, and the resuming the first connection further includes initiating a first connection resumption procedure.

10. The method of claim 1, wherein, the first connection includes a radio resource control (RRC) connection.

11. A communication method applied to NTN communication, characterized in that, the method includes, sending a first message, the first message including at least one of the following information: indicating that there is no buffered downlink data for a terminal located in a first region; or indicating that there is buffered downlink data for a terminal located in a third region; or indicating a first group number of a terminal corresponding to the buffered downlink data; based on the first message, indicating that the terminal does not listen to part or all of the paging messages, or does not establish the first connection; or based on the first message, indicating that the terminal listens to the paging messages, or establishes the first connection, or resumes the first connection.

12. The method of claim 11, wherein, based on the first message, including indicating that the terminal performs one of the following actions: when the second region belongs to the subset of the first region, indicating that the terminal does not listen to part or all of the paging messages, or does not establish the first connection; when the second region does not belong to the subset of the first region, indicating that the terminal listens to the paging messages, or establishes the first connection, or resumes the first connection; when the second region overlaps with the third region, indicating that the terminal listens to the paging messages, or establishes the first connection, or resumes the first connection; when the second group number matches the first group number, indicating that the terminal listens to the paging messages of the first network device, or establishes the first connection, or resumes the first connection; when the second group number does not match the first group number, indicating that the terminal does not listen to part or all of the paging messages, or does not establish the first connection; when the second region overlaps with the third region and the second group number matches the first group number, indicating that the terminal listens to the paging messages, or establishes the first connection, or resumes the first connection; when the second area overlaps with the third area but the second group number does not match the first group number, instructing not to monitor part or all of the paging message or not to establish the first connection; when the second area does not overlap with the third area, instructing not to monitor part or all of the paging message or not to establish the first connection.

13. The method of claim 12, wherein the first area comprises: at least one tracking area (TA) covered or served by the first network device, or a region on the earth surface, wherein the region on the earth surface is indicated by region information included in the first message; the second area comprises: a TA in which the terminal is located, or a set of TAs including the TA, or at least one of the locations in which the terminal is located. the region information included in the first message comprises:

14. The method of claim 13, wherein, a region determined by a center point position indicated by longitude and latitude and a radius distance; a pre-agreed region; or a geometric shape region determined by a plurality of point positions; wherein the region information includes or does not include a boundary according to a preset.

15. The method of claim 12, wherein the second group number is indicated based on the second message sent. before the first message is sent, a third message is received, the third message being used to request grouping of the terminal or indicating that the terminal supports grouping; 16. The method of claim 15, wherein, a second message is sent, the second message including the second group number. the first message further includes a duration, a start time of the duration being based on a first time and a first threshold value, and an end time of the duration being based on a second time and a second threshold value, wherein the first time is a time when the link with the ground station is disconnected, the second time is a time when the link with the ground station is resumed, and the first threshold value and the second threshold value are preset time values. the not monitoring part or all of the paging message or the not establishing the first connection comprises at least one of:

17. The method of claim 11, wherein, not monitoring a paging message for data transmission from the first network device; 18. The method of any of claims 11-17, wherein, not triggering connection establishment after monitoring the paging message for data transmission from the first network device; monitoring the paging only once or a limited number of times n within a system information modification period; deactivating or suspending an AS layer. the establishing the first connection further comprises initiating a procedure for establishing the first connection, and the resuming the first connection further comprises initiating a procedure for resuming the first connection. the first connection comprises a radio resource control (RRC) connection.

19. The method of claim 11, wherein, include units or modules for performing the method of any one of claims 1 to 10, 11 to 20.

20. The method of claim 11, wherein, include a processor connected with a memory, the memory being used to store a computer program, and the processor being used to execute the computer program stored in the memory to cause the chip to perform the communication method of any one of claims 1 to 10, 11 to 20.

21. An electronic device, comprising: include:

22. A chip, characterized by ​ 23. An electronic device, comprising: ​ A processor coupled with a memory for storing a program or instructions that, when executed by the processor, cause the electronic device to perform the method of any of claims 1-10, 11-20.

24. A computer readable storage medium having stored thereon a computer program or instructions, characterized in that, The computer program or instructions, when executed, cause a computer to perform the method of any of claims 1-10, 11-20.

25. A computer program product comprising computer program code in said computer program product, characterised in that, The computer program code, when running on a computer, causes the computer to implement the method of any of claims 1-10, 11-20.

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