Method and apparatus for determining system message re-searching mechanism

Abstract

A method for determining a system message re-searching mechanism, comprising: receiving a first system message from a satellite, and acquiring a second system message on the basis of an issuing mode of the first system message, the second system message being a modified version of the first system message, and the issuing mode being global issuing, regional issuing, wave-position group issuing or wave-position issuing. A system message re-searching criterion of a UE is determined on the basis of a system message issuing mode; this approach enables the UE to perceive a mode in which a network side issues a system message, and to establish a correspondence mechanism between system message issuing modes and re-searching criteria, and enables the UE to update a system message accurately and in a timely manner, thereby reducing the overhead caused by blind searching of system messages and improving the accuracy of mobility management or cell management.

Description

Method and apparatus for determining system message re-search mechanism TECHNICAL FIELD

[0001] The present application relates to the field of communication technology, and in particular to a method and apparatus for determining system message re-search mechanism. BACKGROUND

[0002] An NTN network refers to a network using radio frequency resources on a satellite (or unmanned aircraft system (UAS) platform, high altitude platform station (HAPS), etc.). Compared with a ground cellular network (such as a 5G mobile communication system), an NTN network has the characteristics of wide coverage, low latency, wide bandwidth, and low cost. Compared with a ground communication system, a satellite communication system has the significant characteristics of wider coverage, greater transmission loss, and faster movement speed. A general communication system needs to send system messages required for network access and network services to users through a broadcast beam, for indicating related configurations of network communication. In order to flexibly adapt to the needs of different areas and save signaling overhead, the network side can also configure system information of different granularities based on the coverage area of a beam, for example, configuring different system information for each beam, or configuring a group of system information for a group of beams, or configuring the same system information for beams in a region, and the like.

[0003] However, the prior art does not establish a corresponding relationship between different system message delivery granularities and re-search mechanisms. Further, the UE side is not aware of the specific granularity of the system message delivered by the network side. This misalignment of information causes the UE to be unable to determine which criteria to use to re-search the system message, and thus unable to timely and accurately update the system message. This misalignment of information can cause the system message to be updated in a timely and accurate manner, waste a large amount of overhead due to blind detection of the system message, and further cause the accuracy of mobility management and cell management to decrease. Therefore, how to improve the accuracy of mobility management and cell management is a problem that needs to be solved urgently. SUMMARY

[0004] In a first aspect, the embodiments of the present application provide a communication method, which can be applied to a terminal side, for example, a terminal or a communication module in the terminal, or a circuit or chip responsible for communication functions in the terminal (such as a Modem chip, also known as a baseband chip, or a System on Chip (SoC) chip or a System in Package (SIP) chip containing a modem core), for example, the terminal. In the method, the terminal receives a first system message from a satellite; according to the delivery mode of the first system message, a second system message is obtained, the second system message is a changed first system message, and the delivery mode is global delivery, regional delivery, wave position group delivery, or wave position delivery. It can also be understood that the terminal determines the re-search criterion of the system message according to the delivery mode of the first system message, re-searches the system message under the condition of meeting the re-search criterion, and obtains the changed first system message, i.e., the second system message. It can also be understood that the delivery mode of the first system message and the re-search criterion have a corresponding relationship, the terminal determines the re-search criterion of the system message according to the delivery mode of the first system message, re-searches the system message under the condition of meeting the re-search criterion, and obtains the changed first system message, i.e., the second system message. The corresponding relationship between the delivery mode of the first system message and the re-search criterion can be predefined or determined by the satellite and sent to the terminal, which is not limited in the present application. The first system message can be SIB1, OSI, or a combination of SIB1 and OSI, which is not limited in the present application. The second system message can be SIB1, OSI, or a combination of SIB1 and OSI, which is not limited in the present application. The global delivery can also be understood as delivering the same system message in the satellite coverage area or delivering the same system message in the satellite coverage cell. The regional delivery can also be understood as delivering the same system message in part of the satellite coverage area (such as the coverage edge area or other part of the area, which is not limited in the present application). The wave position group can include at least one wave position. For the description of the wave position, refer to the description in the satellite SSB beam in the specific implementation part (II). The wave position group delivery can also be understood as grouping the wave positions in the satellite coverage range and delivering the same system message in the same wave position group. As described in the satellite SSB beam in the specific implementation part (II), the SSB index has a one-to-one mapping relationship with the SSB beam, and each SSB beam covers a corresponding area, and each area corresponds to a wave position. Therefore, without special instructions, the wave position group in the embodiments of the present application can also be understood as a beam group, the wave position in the embodiments of the present application can also be understood as a beam, the wave position group delivery in the embodiments of the present application can also be understood as beam group delivery, and the wave position delivery in the embodiments of the present application can also be understood as beam delivery.

[0005] By the above method, the terminal receives a first system message from the satellite, and acquires a second system message changed from the first system message according to a delivery mode of the first system message, which is one of global delivery, regional delivery, beam group delivery, and beam delivery. The method enables the terminal to perceive the delivery mode of the first system message by the satellite, determine a re-search criterion corresponding to the delivery mode of the first system message, and then accurately and timely re-search the system message, thereby reducing the overhead caused by blind search of the system message and improving the accuracy of mobility management or cell management.

[0006] In combination with the first aspect, in some embodiments of the first aspect, the delivery mode is predefined, or the method further includes receiving first information, the first information being used to indicate the delivery mode.

[0007] In combination with the first aspect, in some embodiments of the first aspect, the acquiring the second system message according to the delivery mode of the first system message includes, when the delivery mode is the regional delivery, determining a first distance between the terminal and a reference position in a first region, the first region being a region where the first system message is delivered; and when the first distance is greater than a first distance threshold, acquiring the second system message.

[0008] In combination with the first aspect, in some embodiments of the first aspect, the acquiring the second system message according to the delivery mode of the first system message includes, when the delivery mode is the beam group delivery, determining a first synchronization signal block (SSB); and when the first SSB is different from SSBs corresponding to all beams included in a first beam group, acquiring the second system message, the first beam group being a beam group where the first system message is delivered.

[0009] In combination with the first aspect, in some embodiments of the first aspect, the acquiring the second system message according to the delivery mode of the first system message includes, when the delivery mode is the beam group delivery, determining a second SSB corresponding to a first beam; and when a second beam group does not include the first beam, acquiring the second system message, the second beam group being a beam group where the first system message is delivered.

[0010] In combination with the first aspect, in some embodiments of the first aspect, the acquiring the second system message according to the delivery mode of the first system message includes, when the delivery mode is the beam delivery, determining a third SSB in a first periodic time period; and when the third SSB is different from a fourth SSB, acquiring the second system message, the fourth SSB being an SSB in a periodic time period before the first periodic time period.

[0011] With reference to the first aspect, in some embodiments of the first aspect, the method further includes: receiving the first indication information when the first system message is globally distributed; and obtaining the second system message based on the first indication information.

[0012] In a second aspect, an embodiment of the present application provides a communication method. The method can be applied to a satellite side, for example, a satellite or a communication module in the satellite, or a circuit or chip responsible for communication function in the satellite (such as a Modem chip, also known as a baseband chip, or a System on Chip (SoC) chip or a System in Package (SIP) chip containing a modem core). In the method, the satellite sends a first system message to a terminal, and sends a second system message. The second system message is the first system message changed. The first system message can be SIB1, OSI, or a combination of SIB1 and OSI, which is not limited in the present application. The second system message can be SIB1, OSI, or a combination of SIB1 and OSI, which is not limited in the present application.

[0013] Through the above method, the terminal receives the first system message from the satellite, and obtains the second system message changed from the first system message according to the distribution mode of the first system message, which is global distribution, regional distribution, wave position group distribution, or wave position distribution. The method enables the terminal to perceive the distribution mode of the first system message sent by the satellite, determine the re-search criterion corresponding to the distribution mode of the first system message, and then accurately and timely re-search the system message, reduce the overhead caused by blind search of the system message, and improve the accuracy of mobility management or cell management.

[0014] In some embodiments of the second aspect, the method further comprises: sending first information, the first information being used to indicate a delivery mode of the first system message, the delivery mode being global delivery, regional delivery, wave position group delivery, or wave position delivery. The global delivery can also be understood as delivering the same system message in a satellite coverage area, or delivering the same system message in a cell covered by a satellite. The regional delivery can also be understood as delivering the same system message in a part of a satellite coverage area (e.g., an edge coverage area, or other part of the area, which is not limited in the present application). The wave position group can include at least one wave position. For the description of the wave position, refer to the description of the satellite SSB wave beam in the specific implementation part (II), which is not repeated here. The wave position group delivery can also be understood as grouping wave positions in a satellite coverage range, and delivering the same system message in the same wave position group. As described in the description of the satellite SSB wave beam in the specific implementation part (II), the SSB index and the SSB wave beam have a one-to-one mapping relationship, and each SSB wave beam covers a corresponding area, and each area corresponds to a wave position. Therefore, without special instructions, the wave position group in the embodiments of the present application can also be understood as a wave beam group, the wave position in the embodiments of the present application can also be understood as a wave beam, the wave position group delivery in the embodiments of the present application can also be understood as the wave beam group delivery, and the wave position delivery in the embodiments of the present application can also be understood as the wave beam delivery.

[0015] In some embodiments of the second aspect, the method further comprises: sending first indication information, the first indication information being used to indicate that the terminal acquires the second system message.

[0016] In the third aspect, the embodiments of the present application provide a device, which can implement the method in the first aspect, or any possible implementation manner of the first aspect. The device includes corresponding units or modules for performing the above method. The units or modules included in the device can be implemented by software and / or hardware. The device may, for example, be a terminal, a chip, a chip system, or a processor supporting the terminal to implement the above method, or a logic node, a logic module, or software capable of implementing all or part of the terminal functions.

[0017] In the fourth aspect, the embodiments of the present application provide a device, which can implement the method in the second aspect, or any possible implementation manner of the second aspect. The device includes corresponding units or modules for performing the above method. The units or modules included in the device can be implemented by software and / or hardware. The device may, for example, be a satellite device, a chip, a chip system, or a processor supporting the satellite device to implement the above method, or a logic node, a logic module, or software capable of implementing all or part of the satellite device functions.

[0018] In a fifth aspect, an embodiment of the present application provides an apparatus, comprising: a processor coupled with a memory, the memory being configured to store instructions which, when executed by the processor, cause the apparatus to implement the method in the first aspect or any possible implementation of the first aspect.

[0019] In a sixth aspect, an embodiment of the present application provides an apparatus, comprising: a processor coupled with a memory, the memory being configured to store instructions which, when executed by the processor, cause the apparatus to implement the method in the second aspect or any possible implementation of the second aspect.

[0020] In a seventh aspect, an embodiment of the present application provides a computer readable storage medium having stored thereon instructions which, when executed by a computer, cause the computer to perform the method in the first aspect or any possible implementation of the first aspect.

[0021] In an eighth aspect, an embodiment of the present application provides a computer readable storage medium having stored thereon instructions which, when executed by a computer, cause the computer to perform the method in the second aspect or any possible implementation of the second aspect.

[0022] In a ninth aspect, an embodiment of the present application provides a computer program product comprising computer program code which, when run on a computer, causes the computer to perform the method in the first aspect or any possible implementation of the first aspect.

[0023] In a tenth aspect, an embodiment of the present application provides a computer program product comprising computer program code which, when run on a computer, causes the computer to perform the method in the second aspect or any possible implementation of the second aspect.

[0024] In an eleventh aspect, an embodiment of the present application provides a chip, comprising: a processor coupled with a memory, the memory being configured to store instructions which, when executed by the processor, cause the chip to implement the method in the first aspect, the second aspect, any possible implementation of the first aspect, or any possible implementation of the second aspect.

[0025] In a twelfth aspect, an embodiment of the present application provides a communication system, comprising: the apparatus in the third aspect and the apparatus in the fourth aspect.

[0026] In a thirteenth aspect, an embodiment of the present application provides a communication system, comprising: the apparatus in the fifth aspect and the apparatus in the sixth aspect.

[0027] It can be understood that the beneficial effects of the features corresponding to the first aspect and the second aspect in the third aspect to the thirteenth aspect are described in the first aspect and the second aspect, and are not repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0028] FIG. 1 is a schematic diagram of a communication system to which embodiments provided by the present application are applied;

[0029] FIG. 2A is a schematic diagram of an NTN scenario based on transparent payload;

[0030] FIG. 2B is a schematic diagram of an NTN scenario based on regenerative payload;

[0031] FIG. 3A is a schematic diagram of a relationship between a satellite coverage and SSB beams;

[0032] FIG. 3B is a schematic diagram of an SSB pattern;

[0033] FIG. 3C is a schematic diagram of a mapping relationship between SSB beams and ground wave positions;

[0034] FIG. 4 is a schematic diagram of a communication method provided by an embodiment of the present application;

[0035] FIG. 5 is a schematic diagram of a structure of a terminal provided by an embodiment of the present application;

[0036] FIG. 6 is a schematic diagram of an apparatus provided by an embodiment of the present application;

[0037] FIG. 7 is a schematic diagram of another apparatus provided by an embodiment of the present application. DETAILED DESCRIPTION

[0038] The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0039] The terms “first”, “second”, “third”, and “fourth” and the like in the description and the claims of the present application and the accompanying drawings are used to distinguish different objects, and are not used to describe a particular order. In addition, the terms “include” and “have” and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device including a series of steps or units is not limited to the listed steps or units, but can optionally include other steps or units not listed, or can optionally include other steps or units inherent to the process, method, product, or device.

[0040] Reference herein to “an embodiment” means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily mutually exclusive of other embodiments. It is explicitly and implicitly understood by those skilled in the art that embodiments described herein can be combined with other embodiments.

[0041] As shown in FIG. 1, FIG. 1 is an architecture diagram of a communication system 100 provided by an embodiment of the present application. The communication system 100 can include at least one network device (110a, 110b, 110c), and can also include at least one terminal device (120a-120g). The network device and the terminal device can be connected to each other through wired or wireless means. FIG. 1 is only a schematic diagram, and the communication system can also include other network devices, such as wireless relay devices and wireless backhaul devices.

[0042] The network device provided by the embodiments of the present application can be an access network device, such as a base station, a Node B, an evolved Node B (eNodeB or eNB), a transmission reception point (TRP), a next generation Node B (gNB) in a 5th generation (5G) mobile communication system, an access network device in an open radio access network (O-RAN or open RAN), or a base station in a future mobile communication system, or an access node in a wireless fidelity (WiFi) system, etc. Alternatively, the network device can be a module or unit that completes part of the functions of the base station, for example, a central unit (CU), a distributed unit (DU), a CU control plane (CU-CP) module, or a CU user plane (CU-UP) module, etc. The network device can be a satellite (such as 110a in FIG. 1), or a macro base station (such as 110b in FIG. 1), and the access network device can also be a micro base station or an indoor station (such as 110c in FIG. 1), or a relay node or a donor node, etc. The specific technology and specific device form adopted by the access network device in the present application are not limited.

[0043] The terminal device provided by the embodiments of the present application can also be referred to as a terminal, including but not limited to a user equipment (UE), a mobile station, or a mobile terminal, etc. The terminal device can be widely applied to various scenarios for communication. The scenarios include but are not limited to at least one of the following scenarios: enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), massive machine-type communications (mMTC), device-to-device (D2D), vehicle to everything (V2X), machine-type communication (MTC), internet of things (IOT), virtual reality, augmented reality, industrial control, automatic driving, remote medical treatment, smart power grid, smart furniture, smart office, smart wear, smart transportation, or smart city, etc. The terminal device can be a mobile phone (such as the mobile phones 120a, 120d, and 120f in FIG. 1), a tablet computer, a computer with wireless transceiver function (such as the computer 120g in FIG. 1), a wearable device, a vehicle (such as 120b in FIG. 1), a drone, a helicopter, an airplane (such as 120c in FIG. 1), a ship, a robot, a mechanical arm, or a smart home device (such as the printer 120e in FIG. 1), etc. The present application does not limit the specific technology and specific device form of the terminal device.

[0044] The base station and / or the terminal device can be fixed in position or movable. The base station and / or the terminal device can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; or can be deployed on the water surface; or can be deployed on an airplane, a balloon, and a man-made satellite in the air. The present application does not limit the environment / scenario in which the base station and the terminal device are located. The base station and the terminal device can be deployed in the same or different environments / scenarios, for example, the base station and the terminal device are simultaneously deployed on land; or the base station is deployed on land and the terminal device is deployed on the water surface, etc., which will not be listed one by one.

[0045] The technical solutions of the embodiments of the present application can be applied to various communication systems, for example: long term evolution (LTE) system, 5G system or new radio (NR), non-terrestrial network (NTN), and future communication systems, etc. The present application does not limit this.

[0046] The following first introduces several concepts that can be involved in the present application.

[0047] (I) NTN network.

[0048] The NTN network refers to a network using radio frequency resources on a satellite (or unmanned aircraft system (UAS) platform, high altitude platform station (HAPS), etc.). Compared with a ground cellular network (such as a 5G mobile communication system), the NTN network has the characteristics of wide coverage, low latency, wide bandwidth, and low cost. As a supplement and extension of the ground network, the NTN network can achieve wide-area seamless coverage that cannot be achieved by wired telephone networks and ground mobile communication networks, effectively solving the problem of Internet access in areas where communication infrastructure is scarce. A large number of satellites are arranged in low earth orbits, and the round-trip transmission delay between data on the satellite and the ground terminal is greatly reduced to a low latency of tens of milliseconds. The use of high-frequency bands, multi-point beams, and frequency reuse significantly improves the communication capacity of the satellite and reduces the unit bandwidth cost, which can meet the demand for high information rate services. Compared with ground 5G base stations and submarine optical fiber cables and other communication infrastructure, NTN has a significant cost advantage. Modern small satellites have low development and manufacturing costs, and software-defined technology can further extend the on-orbit satellite service life. The NTN network can be used in global coverage (such as remote areas, ocean-going ships, etc.), emergency rescue (such as disaster monitoring, emergency communication), Internet of Things, high-speed mobile (such as high-speed rail, aircraft, etc.), and other scenarios.

[0049] The typical scenarios in which the NTN network provides terminal device access are transparent payload and regenerative payload. As shown in FIG. 2A, a schematic diagram of an NTN scenario based on a transparent payload, the transparent payload is a payload that changes the frequency carrier of the uplink radio frequency signal and filters and amplifies it before downlink transmission. Such a payload only has a radio frequency processing unit and does not have baseband demodulation, decoding, and other processing. Therefore, the signal waveform is unchanged and is repeated. As shown in FIG. 2B, a schematic diagram of an NTN scenario based on a regenerative payload, the regenerative payload is a payload that transforms and amplifies the uplink radio frequency (RF) signal before downlink transmission. The transformation of the signal refers to digital processing, which can include demodulation, decoding, re-encoding, re-modulation, and / or filtering. This is actually equivalent to having all or part of the base station function on the satellite (or UAS platform, HAPS, etc.).

[0050] In some possible implementation manners, the NTN network described above can have the following elements:

[0051] (1) There is one or more gateway stations (Gateway) connecting NTN network and common data network (common data network).

[0052] (2) Feeder link: wireless link between gateway and satellite (or UAS platform).

[0053] (3) Service link: wireless link between terminal device and satellite (or UAS platform).

[0054] (4) Satellite (or UAS platform) can realize transparent load and regenerative load.

[0055] (5) Whether the satellite constellation has inter-satellite link (ISL) is optional. Inter-satellite link requires satellite to be regenerative load (i.e. if there is inter-satellite link, satellite must be regenerative load). ISL can work in RF frequency or optical waveband.

[0056] (6) Terminal device is served by satellite (or UAS platform, HAPS, etc.) within the target service area.

[0057] (B) Satellite synchronization signal and physical broadcast channel (PBCH) block (synchronization signal and PBCH block, SSB) beam.

[0058] Compared with ground communication system, satellite communication system has the characteristics of wider coverage, larger transmission loss and faster moving speed. Unlike the ground system, which can cover the service range of a single base station with a maximum of 8 SSBs (applicable to Frequency Range 1 (FR1)) or 64 SSBs (applicable to Frequency Range 2 (FR2)), the satellite communication system needs a large number of SSB beams, which may reach hundreds or even thousands.

[0059] As shown in FIG. 3A, FIG. 3A is a schematic diagram of the relationship between satellite coverage and SSB beams, the satellite implements seamless coverage through N SSB beams, the value of N is related to the orbital height of the satellite and / or the beam width. Taking a satellite communication system with an orbital height of 600 km as an example, the service range of a single satellite can reach hundreds of thousands of square kilometers. In order to overcome the path loss caused by the transmission distance and ensure the quality of communication services, the satellite generally uses a large-scale antenna array to provide higher array gain, but at the same time, the main lobe of the beam is narrower. For example, the coverage radius of a 3dB beam width is only a few dozen kilometers, and the coverage area is about a few hundred square kilometers. Using narrow beams to complete seamless coverage of the service range of a single satellite requires thousands of beams. Further, even if the beam is processed to a certain extent, in order to ensure the gain level, it also needs to use hundreds of beams to achieve coverage. When the scanning beam reaches hundreds of times, the time of a complete scan is about a few hundred milliseconds.

[0060] Taking that the satellite transmits 256 SSB beams as an example, according to the configuration of the NR protocol in FR1, for a subcarrier spacing (SCS) of 30 kHz, the satellite transmits 8 SSBs in the first 2 ms of every 20 ms, and the overall transmission mode of the 256 SSB beams can be as shown in FIG. 3B, wherein SFN represents system frame number (SFN), 1 slot represents 1 time slot, 256 SSBs are divided into 32 groups in total, 8 SSBs for one group, one group lasts for 20 ms, and 256 SSBs last for 640 ms in total. In each group, the first 2 ms contains SSBs, and the remaining 18 ms can transmit normal data.

[0061] Considering that the satellites fly in orbits and maintain a certain specific relative relationship between the orbits, when the coverage range of each satellite is a rectangle, seamless coverage of the overall constellation can be ensured. The terminal mainly performs mobility management and RRM measurement in the edge of the satellite coverage, i.e., in the overlapping area with the adjacent satellite. Taking a rectangular coverage as an example, the service range of the satellite is evenly divided into 256 rectangular areas, and each SSB beam covers a corresponding rectangular area, each area corresponds to a wave position, and all wave positions are assigned with non-repeating numbers. The size of each wave position can be set to be the same as the coverage size of the SSB beam, so as to facilitate periodic scanning of the satellite. The specific position and number of each wave position can be pre-stored in the satellite and the terminal chip, or periodically issued by the operation and control center and the core network. In a period of time, a satellite covers the same number of ground wave positions as the number of SSB beams, so there is a one-to-one mapping relationship between the SSB index and the SSB beam number. The arrangement pattern of the SSBs can be as shown in FIG. 3C, wherein the numbers in each rectangle can represent the SSB index corresponding to the beam covering the area, or the wave position index corresponding to the beam covering the area.

[0062] This mapping relationship can also be maintained by the operation and control center and injected to the satellite.

[0063] (Three) System message.

[0064] In addition to SSB, the general communication system also needs to send various network access and network service required system messages to users through broadcast beams, which are used to indicate the relevant configuration of network communication. The system message of NR can be divided into three types:

[0065] ·MIB: Master Information Block, main information block

[0066] ·SIB1: System Information Block 1, system message block 1

[0067] ·OSI: Other System Information, other system message

[0068] MIB is the system information that UE needs to obtain immediately after completing cell search and frequency / time synchronization. MIB is broadcast through PBCH, and PBCH and synchronization signal are combined together and collectively referred to as SSB. MIB is the system information that must be broadcast by the cell, because the first 4 parameters in MIB are required for the random access process.

[0069] After obtaining MIB, the next system message that UE must obtain is SIB1. There is no need to appear in SIB1 for the information already obtained in MIB. SIB1 is broadcast on the physical downlink shared channel (PDSCH), contains the access permission of the serving satellite, and defines the scheduling indication of OSI. It also indicates the unified configuration information of the serving satellite, including the uplink and downlink frequency points, the initial BWP, the SSB transmission period and the transmission index, etc.

[0070] In addition to SIB1, the remaining types of SIBs can be collectively referred to as OSI. OSI includes SIB2-SIB21. In the NTN scenario, the commonly used and slightly different OSI from the ground cell mainly includes SIB2 / 4 and SIB19.

[0071] SIB2 / 4 contains the relevant information of the same frequency / inter-frequency cell reselection, mainly including the frequency point, signal strength, serving satellite measurement window configuration, SSB-based measurement timing configuration (SMTC), and adjacent satellite measurement window configuration SMTC4, etc.

[0072] SIB19 is newly added in NTN scenario, which contains a lot of satellite assistance information of NTN access, mainly including satellite configuration (such as ephemeris, TA information, cell-level Koffset, epoch time, etc.), switching distance reference point and threshold, and adjacent satellite configuration, etc.

[0073] (iv) System message delivery method.

[0074] In the initial access process, the network side sends multiple SSBs and SIB1 corresponding to multiple SSBs. SIB1 is cell-level system information, and the contents carried by SIB1 associated with different SSB indexes are consistent.

[0075] For example, the UE under satellite coverage can receive SSB0, SSB1 and SSB2. According to the reference signal received power (RSRP) energy detection of SSB, the optimal beam SSB1 is selected, and the monitoring time slot of SIB1 is confirmed according to SSB index = 1, and SIB1 is monitored.

[0076] In the NR NTN protocol, the base station mainly uses different directional beams to scan time-sharing, broadcasts OSI to users, and delivers the configuration of the network side to each user. Specifically, OSI configures SI window through SI-SchedulingInfo in SIB1, and SI message includes which SIB, broadcasting / notBroadcasting type. When the UE needs a certain SIB, it needs to blind detect the physical downlink control channel (PDCCH) scrambled by system information radio network temporary identifier (SI-RNTI) in the SI window corresponding to the SI message corresponding to the SIB to receive the specific SI message.

[0077] In addition, in order to flexibly adapt to the needs of different areas and save signaling overhead, the network side can also configure system information of different granularity based on the beam coverage area, such as configuring different system information for each beam, or configuring a group of system information for a group of beams, or configuring the same system information for the beams in a region, etc.

[0078] (v) Network side paging notification system message update.

[0079] If the content of system information is updated, the network side needs to inform the UE to update the system information. The system information update mechanism of NR is carried out by paging. The UE in RRC idle state and RRC inactive state always monitors the paging opportunity belonging to itself. The UE in RRC connected state monitors all paging opportunities. If the network needs to update the system information related to public safety, the public warning system (PWS) flag will be included in the paging notification. This flag will make the UE immediately perform the system information acquisition process when receiving the system information update notification. Other system information is generally acquired in the next system information update period to keep time synchronization with the network. The system information update period is generally an integer multiple of the discontinuous reception (DRX) period.

[0080] The network side can configure system information of different granularities based on the beam coverage area, for example, different system information for each beam, or a group of beams, or the same system information for beams in a region, etc. Different system information delivery methods correspond to different system information re-search mechanisms. For example, when the network side delivers cell-level system information, i.e., global broadcast, the UE does not need to update the system information again after receiving a system message containing measurement configuration once, unless the network side initiates paging to the UE using paging resources; when the network side delivers beam-level system information, i.e., different system information for different beams, the UE needs to perform system information re-search when the beam changes. However, the prior art does not establish the correspondence between the system information delivery granularity and the re-search mechanism. Further, the UE side does not perceive the specific granularity of the system information delivered by the network side. This misalignment of information causes the UE to be unable to determine the criteria for re-searching the system information, and thus unable to update the system information in a timely and accurate manner. This misalignment of information can cause the system information to be updated in a timely or inaccurate manner, wasting a lot of overhead due to blind detection of system information, and further causing the accuracy of mobility management and cell management to decrease.

[0081] The present application proposes a communication method, in which the UE determines the criteria for re-searching the system information according to the delivery method of the system information, enables the UE to perceive the delivery method of the system information by the network side, establishes a set of corresponding mechanisms between the system information delivery method and the re-search criteria, and enables the UE to update the system information in a timely and accurate manner, reduces the overhead of blind search of system information, and improves the accuracy of mobility management or cell management.

[0082] FIG. 4 is an interaction diagram of a communication method 400 according to an embodiment of the present application. The method is exemplified in FIG. 4 by taking a satellite and a terminal as the execution subject of the interaction diagram, but the present application does not limit the execution subject of the interaction diagram. For example, the satellite in FIG. 4 can be a module (such as a chip, a chip system, or a processor) applied to the satellite, and can also be a logic node, a logic module, or software capable of implementing all or part of the functions of the satellite; the terminal in FIG. 4 can be a module (such as a chip, a chip system, or a processor) applied to the terminal to implement the method, and can also be a logic node, a logic module, or software capable of implementing all or part of the functions of the terminal. As shown in FIG. 4, the method 400 of the embodiment can include a 410 part and a 420 part.

[0083] The 410 part: the satellite sends a first system message to the terminal, and correspondingly, the terminal device receives the first system message from the satellite. The first system message can be SIB1, can also be OSI, or can be a combination of SIB1 and OSI, which is not limited by the present application.

[0084] 420 part: the terminal acquires the second system message according to the first system message issuing mode, the second system message is the changed first system message, and the issuing mode is global issuing, regional issuing, wave position group issuing or wave position issuing. It can also be understood that the terminal determines the re-search criterion of the system message according to the first system message issuing mode, re-searches the system message under the condition of meeting the re-search criterion, and acquires the changed first system message, i.e., the second system message. It can also be understood that the first system message issuing mode and the re-search criterion correspond to each other, the terminal determines the re-search criterion of the system message according to the first system message issuing mode, re-searches the system message under the condition of meeting the re-search criterion, and acquires the changed first system message, i.e., the second system message. The correspondence between the first system message issuing mode and the re-search criterion can be predefined or determined by the satellite and sent to the terminal, which is not limited in the application. The second system message can be SIB1, OSI or a combination of SIB1 and OSI, which is not limited in the application. The global issuing can also be understood as issuing the same system message in the satellite coverage area or in the satellite coverage cell. The regional issuing can also be understood as issuing the same system message in part of the satellite coverage area, such as the coverage edge area or other part of the area, which is not limited in the application. The wave position group can include at least one wave position. For the description of the wave position, refer to the description of the satellite SSB wave beam in (2). The wave position group issuing can also be understood as grouping the wave positions in the satellite coverage range and issuing the same system message in the same wave position group. For example, in FIG. 3C, wave positions 7, 8, 23 and 24 are divided into a wave position group X, and the satellite issues the same system message in the wave position group X. As described in (2) satellite SSB wave beam, the SSB index and the SSB wave beam have a one-to-one mapping relationship, and each SSB wave beam covers a corresponding area, and each area corresponds to a wave position. Therefore, if not otherwise specified, the wave position group in the embodiments of the application can also be understood as a wave beam group, the wave position in the embodiments of the application can also be understood as a wave beam, the wave position group issuing in the embodiments of the application can also be understood as wave beam group issuing, and the wave position issuing in the embodiments of the application can also be understood as wave beam issuing.

[0085] In method 400, the terminal receives the first system message from the satellite, and acquires the changed first system message, i.e., the second system message, according to the first system message issuing mode, which is global issuing, regional issuing, wave position group issuing or wave position issuing. The method enables the terminal to perceive the satellite first system message issuing mode, determine the re-search criterion corresponding to the first system message issuing mode, and accurately and timely re-search the system message, thereby reducing the overhead caused by blind searching of the system message and improving the accuracy of mobility management or cell management.

[0086] In the present application, "sending information to the terminal" can be understood as that the destination of the information is the terminal. It can include directly or indirectly sending information to the terminal. "Receiving information from the satellite" can be understood as that the source of the information is the satellite, and it can include directly or indirectly receiving information from the satellite. The information can be processed between the source and the destination of the information sending, for example, format change, etc., but the destination can understand the effective information from the source. Similar expressions in the present application can be understood similarly, and will not be repeated here.

[0087] In a possible implementation of the terminal obtaining the delivery mode of the first system message, the delivery mode is predefined. For example, the satellite and the terminal define the delivery mode of the system message as beam delivery, and then the terminal determines the re-search criterion corresponding to the beam delivery according to the beam delivery mode, re-searches the system message under the condition of meeting the re-search criterion, and obtains the changed system message.

[0088] In another possible implementation of the terminal obtaining the delivery mode of the first system message, the method 400 further includes that the satellite determines the first information and sends the first information to the terminal, and correspondingly, the terminal receives the first information from the satellite, and the first information is used to indicate the delivery mode. The first information can be carried on the MIB, or can be carried on the SIB1, or can be carried on the OSI, and the present application does not limit the specific form and the carrying mode of the first information. In a possible implementation, the first information is an empty signaling, the satellite sends the first information to the terminal when the terminal initially accesses, the first information indicates that the delivery mode of the system message is global delivery, area delivery, beam group delivery or beam delivery. After receiving the first information, the terminal identifies the delivery mode of the system message, determines the criterion of re-searching the system message according to the corresponding relationship between the delivery mode and the re-search criterion, and re-searches the system message under the condition of meeting the re-search criterion. The corresponding relationship between the delivery mode and the re-search criterion can be predefined, and the present application does not limit it.

[0089] For example, the satellite defines the signal element sib1-BroadcastConfig: sib1-BroadcastConfig ENUMERATED{Beam, Beam Group, Area, Cell} OPTIONAL,--Need R

[0090] The first information includes an information element sib1-BroadcastConfig, where the information element sib1-BroadcastConfig is used to indicate the delivery mode of the SIB1 message, and the sib1-BroadcastConfig can take values of Beam, Beam Group, Area or Cell, where the sib1-BroadcastConfig taking the value of Beam indicates that the delivery mode of the SIB1 message is beam position delivery, the sib1-BroadcastConfig taking the value of Beam Group indicates that the delivery mode of the SIB1 message is beam position group delivery, the sib1-BroadcastConfig taking the value of Area indicates that the delivery mode of the SIB1 message is area delivery, and the sib1-BroadcastConfig taking the value of Cell indicates that the delivery mode of the SIB1 message is global delivery.

[0091] The information element can indicate the delivery mode of the SIB1, and similarly, the satellite can also configure such information elements (such as sib2-BroadcastConfig, sib4-BroadcastConfig, etc.) for the OSI to indicate the delivery mode of the OSI. The definition of the indication information element about the delivery mode of the OSI is similar to the indication information element sib1-BroadcastConfig about the delivery mode of the SIB1, and will not be repeated here.

[0092] For another example, the satellite can also define the information element sib1-BroadcastConfig as follows:

[0093] sib1-BroadcastConfig::=SEQUENCE{

[0094] sib1-BeamSpecific ENUMERATED{enabled,disable} OPTIONAL,--NeedR

[0095] sib1-BeamGroupSpecific ENUMERATED{enabled,disable} OPTIONAL,--NeedR

[0096] sib1-AreaSpecific ENUMERATED{enabled,disable} OPTIONAL,--NeedR

[0097] sib1-CellSpecific ENUMERATED{enabled,disable} OPTIONAL,--NeedR}

[0098] The first information includes an information element sib1-BroadcastConfig::, wherein the information element sib1-BroadcastConfig:: is used to indicate the delivery mode of the SIB1 message, sib1-BeamSpecific is used to indicate the beam delivery system message, and when the value is enabled, it indicates that the delivery mode of the SIB1 message is beam delivery, and when the value is disable, it indicates that the delivery mode of the SIB1 message is not beam delivery; similarly, sib1-BeamGroupSpecific is used to indicate the beam group delivery SIB1, sib1-AreaSpecific is used to indicate the area delivery SIB1, and sib1-CellSpecific is used to indicate the global delivery SIB1, and the value mode of the information elements sib1-BeamGroupSpecific, sib1-AreaSpecific and sib1-CellSpecific is similar to sib1-BeamSpecific, which will not be described here. For example, the satellite defines the information element sib1-BroadcastConfig:: as follows:

[0099] sib1-BroadcastConfig:: = SEQUENCE {

[0100] sib1-BeamSpecific ENUMERATED { disable} OPTIONAL, -- Need R

[0101] sib1-BeamGroupSpecific ENUMERATED { disable} OPTIONAL, -- Need R

[0102] sib1-AreaSpecific ENUMERATED { enabled} OPTIONAL, -- Need R

[0103] sib1-CellSpecific ENUMERATED { disable} OPTIONAL, -- Need R

[0104] sib1-CellSpecific ENUMERATED { disable} OPTIONAL, -- Need R

[0105] The information element sib1-BroadcastConfig: can indicate the delivery mode of SIB1. Similarly, the satellite can also configure such information element (e.g., sib2-BroadcastConfig:, sib4-BroadcastConfig:, etc.) for OSI to indicate the delivery mode of OSI. The definition of the indication information element for the delivery mode of OSI is similar to the indication information element sib1-BroadcastConfig: for the delivery mode of SIB1, and will not be repeated here.

[0106] It can be understood that the above description of the information element sib1-BroadcastConfig and sib1-BroadcastConfig: is only an example of the first information indicating the delivery mode of the first system message. In the present application, the specific form of the first information indicating the delivery mode of the first system message is not limited.

[0107] The above-mentioned re-search criterion can be based on the optimal SSB determined by the terminal, can be based on the distance threshold of a certain reference position in the relative movement of the terminal and the satellite, or can be based on the paging notification sent by the satellite. The specific expansion and examples of the re-search mechanism are described in detail in the following content of the present application.

[0108] In one possible implementation of the above-mentioned re-search criterion, the re-search criterion can be predefined and built-in in the terminal. The terminal can determine the re-search criterion corresponding to the delivery mode of the system message according to the delivery mode of the system message, and re-search the system message when the re-search criterion condition is met.

[0109] In another possible implementation of the above-mentioned re-search criterion, the re-search criterion can also be determined by the satellite and sent to the terminal together with the system message. The terminal can obtain the re-search criterion of the system message when receiving the system message, and re-search the system message when the re-search criterion condition is met.

[0110] In a possible implementation of the method for obtaining the second system message according to the first system message, when the first system message is distributed in a region, the terminal determines a first distance between the terminal and a reference position in the first region, the first region being the region in which the first system message is distributed; and when the first distance is greater than a first distance threshold, the terminal obtains the second system message. The first region can be a part of the satellite coverage region, for example, a coverage edge region, without limitation. It can be understood that when the first system message is distributed in a region, the terminal can determine the first distance between the terminal and a reference position in the first region according to the position of the terminal. The reference position can be predefined, or can be determined by the satellite and sent to the terminal together with the system message, or can be determined by the satellite and sent to the terminal alone, without limitation. The reference position can be the center position of the first region, or can be any position in the first region, without limitation. After the terminal determines the first distance, the terminal determines whether the terminal moves out of the current region according to the size relationship between the first distance and the first distance threshold, and further determines whether the terminal needs to search for the first system message again to obtain the second system message. The first distance threshold can be predefined, or can be determined by the satellite and sent to the terminal. When the first region is a rectangle, determining the first distance between the terminal and the reference position in the first region can include determining a horizontal distance between the terminal and the reference position in the first region, and determining a vertical distance between the terminal and the reference position in the first region; and when the horizontal distance is greater than a first horizontal distance threshold, or when the vertical distance is greater than a first vertical distance threshold, the terminal searches for the first system message again to obtain the second system message. The shape of the first region is not limited, and it can be understood that the specific implementation of the method is different for different shapes of the first region. However, the scheme of determining whether the terminal needs to obtain the second system message according to the distance between the terminal and the reference position in the first region is substantially the same, and therefore, examples of other shapes of the first region are not described herein.

[0111] In another possible implementation of the method for obtaining the second system message according to the first system message, when the first system message is delivered in the form of the wave position group, a first synchronization signal block (SSB) is determined; when the first SSB is different from the SSBs corresponding to all the wave positions included in the first wave position group, the second system message is obtained, and the first wave position group is the wave position group in which the first system message is delivered. The first SSB can also be understood as the SSB determined by the terminal for data transmission. In a possible implementation of the method for determining the first SSB, the terminal determines the first SSB according to the RSRP measurement results of all the SSBs received by the terminal. The first SSB can be the SSB with the highest RSRP measurement result among all the SSBs received by the terminal, or can be any one of the SSBs with the RSRP measurement results greater than a first RSRP threshold value among all the SSBs received by the terminal, which is not limited in the present application. The first wave position group includes at least one wave position, and each wave position in the at least one wave position corresponds to an SSB. When the first SSB is different from the SSBs corresponding to all the wave positions included in the first wave position group, the first system message is re-searched to obtain the changed first system message, that is, the second system message. The first SSB is different from the SSBs corresponding to all the wave positions included in the first wave position group, which can also be understood as that the index of the first SSB is different from the indexes of the SSBs corresponding to all the wave positions included in the first wave position group.

[0112] In another possible implementation of the method for obtaining the second system message according to the first system message, when the first system message is delivered in the form of the wave position group, a second SSB is determined, and the second SSB corresponds to a first wave position; when the second wave position group does not include the first wave position, the second system message is obtained, and the second wave position group is the wave position group in which the first system message is delivered. The second SSB can also be understood as the SSB determined by the terminal for data transmission. In a possible implementation of the method for determining the second SSB, the terminal determines the second SSB according to the RSRP measurement results of all the SSBs received by the terminal. The second SSB can be the SSB with the highest RSRP measurement result among all the SSBs received by the terminal, or can be any one of the SSBs with the RSRP measurement results greater than a second RSRP threshold value among all the SSBs received by the terminal, which is not limited in the present application. The second wave position group includes at least one wave position, and the second SSB corresponds to the first wave position. When the second wave position group does not include the first wave position, the first system message is re-searched to obtain the changed first system message, that is, the second system message. The second wave position group does not include the first wave position, which can also be understood as that the index of the first wave position is different from the indexes of all the wave positions included in the second wave position group.

[0113] In another possible implementation of the method for obtaining the second system message according to the first system message, when the first system message is delivered in the form of the wave position, the third SSB in the first period is determined; when the third SSB and the fourth SSB are different, the second system message is obtained, and the fourth SSB is an SSB in a period before the first period. The third SSB can also be understood as an SSB determined by the terminal for data transmission in the first period. In a possible implementation of the method for determining the third SSB, the terminal determines the third SSB according to the RSRP measurement results of all the SSBs received by the terminal in the first period. The third SSB can be an SSB with the highest RSRP in the RSRP measurement results of all the SSBs received by the terminal, or can be any one of the SSBs with the RSRP measurement results greater than a third RSRP threshold, which is not limited in the present application. The fourth SSB can also be understood as an SSB determined by the terminal for data transmission in the second period, and the second period is a period before the first period. In a possible implementation of the method for determining the fourth SSB, the terminal determines the fourth SSB according to the RSRP measurement results of all the SSBs received by the terminal in the second period. The fourth SSB can be an SSB with the highest RSRP in the RSRP measurement results of all the SSBs received by the terminal, or can be any one of the SSBs with the RSRP measurement results greater than a fourth RSRP threshold, which is not limited in the present application. When the third SSB and the fourth SSB are different, the first system message is re-searched to obtain the changed first system message, i.e., the second system message. The third SSB and the fourth SSB can also be understood as different in that the index of the third SSB is different from the index of the fourth SSB. According to the foregoing description of the wave position, it can be understood that the third SSB corresponds to the third wave position, and the fourth SSB corresponds to the fourth wave position. The embodiment can further include: when the third wave position and the fourth wave position are different, the first system message is re-searched to obtain the changed first system message, i.e., the second system message. The third wave position and the fourth wave position can also be understood as different in that the index of the third wave position is different from the index of the fourth wave position.

[0114] In another possible implementation of the method for obtaining the second system message according to the first system message, when the first system message is delivered in a global manner, the first indication information is received; and the second system message is obtained based on the first indication information. The first indication information can be a paging message. When the content of the system message is updated, the satellite needs to send a paging message to notify the terminal to update the system message. The terminals in the RRC idle state and the RRC inactive state always monitor the paging message that belongs to themselves. The terminal in the RRC connected state monitors all the paging messages. If the network needs to update the system information related to public safety, the PWS flag will also be included in the first indication information. This flag will make the terminal immediately perform the system information acquisition process when the paging message is received. Other system information is generally acquired in the next system message update period, so as to keep the time synchronization with the network. The system message update period is generally an integer multiple of the DRX period.

[0115] In the different embodiments of the method for obtaining the second system message according to the first system message, it can be seen that the mechanism for triggering the acquisition of the changed first system message (i.e., the second system message) is different when the first system message is delivered in a wave bit manner, a wave bit group manner, a regional manner or a global manner. In other words, the triggering mechanism for re-searching the first system message is different for different first system message delivery manners. It can be understood that the essence of the above embodiments is that, for different system message delivery manners, the terminal can trigger the re-search of the system message according to the re-search mechanism corresponding to the delivery manner, so as to enable the terminal to update the system message in time and accurately, reduce the overhead of blind search of the system message, and improve the accuracy of mobility management or cell management. The above embodiments only give examples of the correspondence between different system message delivery manners and different re-search mechanisms, and the present application does not limit other combinations of system message delivery manners and re-search mechanisms. Examples are given below.

[0116] In a possible implementation of the method for obtaining the second system message according to the first system message issuing mode, when the issuing mode is the above-mentioned area issuing, the first indication information is received; and the second system message is obtained based on the first indication information. The first indication information can be a paging message. When the content of the system message is updated, the satellite needs to send a paging message to notify the terminal to update the system message. The terminals in the RRC idle state and the RRC inactive state always monitor the paging message belonging to themselves. The terminal in the RRC connected state monitors all the paging messages. If the network needs to update the system information related to public safety, the PWS flag will also be included in the first indication information, which will make the terminal immediately perform the system information obtaining process when receiving the paging message. Other system information is generally obtained in the next system message update period, so as to keep the time synchronization with the network. The system message update period is generally an integer multiple of the DRX period.

[0117] In another possible implementation of the method for obtaining the second system message according to the first system message, when the first system message is broadcast in the wave position group, the first distance between the terminal and the reference position in the first region is determined, the first region being the region where the first system message is broadcast; and when the first distance is greater than the first distance threshold, the second system message is obtained. The first region can be a part of the satellite coverage region, for example, the coverage edge region, without limitation. It can be understood that when the first system message is broadcast in the region, the terminal can determine the first distance between the terminal and the reference position in the first region according to the position of the terminal. The reference position can be predefined, determined by the satellite and sent to the terminal together with the system message, or determined by the satellite and sent to the terminal alone, without limitation. The reference position can be the center position of the first region or any position in the first region, without limitation. After the terminal determines the first distance, the terminal determines whether the terminal moves out of the current region according to the size relationship between the first distance and the first distance threshold, and further determines whether the first system message needs to be re-searched to obtain the second system message. The first distance threshold can be predefined or determined by the satellite and sent to the terminal. When the first region is rectangular, the first distance between the terminal and the reference position in the first region can include the horizontal distance between the terminal and the reference position in the first region and the vertical distance between the terminal and the reference position in the first region. When the horizontal distance is greater than the first horizontal distance threshold or when the vertical distance is greater than the first vertical distance threshold, the first system message is re-searched to obtain the second system message. The shape of the first region is not limited, and it can be understood that the specific implementation of the method is different for different shapes of the first region. However, the scheme for determining whether the second system message needs to be obtained according to the distance between the terminal position and the reference position in the first region is substantially the same. Therefore, examples of other shapes of the first region are not described herein.

[0118] In another possible implementation of the method for obtaining the second system message according to the first system message, when the first indication information is a paging message, the satellite sends the paging message to notify the terminal of the update of the system message when the content of the system message is updated. The terminals in the RRC idle state and the RRC inactive state always monitor the paging message belonging to themselves. The terminal in the RRC connected state monitors all the paging messages. If the network needs to update the system information related to public safety, the PWS flag is further included in the first indication information, which makes the terminal immediately perform the system information acquisition process when the paging message is received. Other system information is generally acquired in the next system information update period, so as to keep the time synchronization with the network. The system information update period is generally an integer multiple of the DRX period.

[0119] In another possible implementation of the method for obtaining the second system message according to the first system message, when the first system message is broadcast in the wave position, the first distance between the terminal and the reference position in the first region is determined, and the first region is the region where the first system message is broadcast. When the first distance is greater than the first distance threshold, the second system message is obtained. The first region is a part of the satellite coverage region, for example, the coverage edge region, which is not limited in the present application. It can be understood that when the first system message is broadcast in the region, the terminal can determine the first distance between the terminal and the reference position in the first region according to the position of the terminal. The reference position can be predefined, determined by the satellite and sent to the terminal together with the system message, or determined by the satellite and sent to the terminal separately, which is not limited in the present application. The reference position can be the center position of the first region or any position in the first region, which is not limited in the present application. After the terminal determines the first distance, the terminal determines whether the terminal moves out of the current region by comparing the first distance with the first distance threshold, and then determines whether the first system message needs to be re-searched to obtain the second system message. The first distance threshold can be predefined or determined by the satellite and sent to the terminal. In the case where the first region is a rectangle, the first distance between the terminal and the reference position in the first region can include the horizontal distance between the terminal and the reference position in the first region, and the vertical distance between the terminal and the reference position in the first region. When the horizontal distance is greater than the first horizontal distance threshold, or when the vertical distance is greater than the first vertical distance threshold, the first system message is re-searched to obtain the second system message. The shape of the first region is not limited in the present application. It can be understood that the specific implementation of the method is different for different shapes of the first region, but the scheme for determining whether the second system message needs to be obtained by the distance between the terminal position and the reference position in the first region is essentially the same. Therefore, the examples of other shapes of the first region are not described herein.

[0120] In another possible implementation of the method for obtaining the second system message according to the first system message, when the first indication information is a paging message, the satellite sends the paging message to notify the terminal of the update of the system message when the content of the system message is updated. The terminals in the RRC idle state and the RRC inactive state always monitor the paging message belonging to themselves. The terminal in the RRC connected state monitors all the paging messages. If the network needs to update the system information related to public safety, the PWS flag is further included in the first indication information, which makes the terminal immediately perform the system information acquisition process when the paging message is received. Other system information is generally acquired in the next system information update period, so as to keep the time synchronization with the network. The system information update period is generally an integer multiple of the DRX period.

[0121] It can be understood that the embodiments of the present application are not limited to the NTN scenario, and are also applicable to other communication scenarios. The satellite in the present application can also be a network device, which is not limited by the present application.

[0122] Corresponding to the method provided by the method embodiment, the present embodiment also provides a corresponding device, which includes a module for executing the corresponding modules of the above embodiments. The module can be software, hardware, or a combination of software and hardware.

[0123] FIG. 5 provides a structural schematic diagram of a terminal. The terminal can be applicable to the scenarios shown in FIG. 1, FIG. 2A or FIG. 2B. The terminal or the modules in the terminal can perform the method 400 and various possible implementations described above. For ease of illustration, FIG. 5 only shows the main modules of the terminal. As shown in FIG. 5, the terminal 500 includes a processor, a memory, a control circuit, an antenna and an input / output device. The processor is mainly used for processing communication protocols and communication data, controlling the entire terminal, executing software programs, and processing data of the software programs. The memory is mainly used for storing software programs and data. The radio frequency circuit is mainly used for conversion between baseband signals and radio frequency signals and processing of the radio frequency signals. The antenna is mainly used for receiving and transmitting radio frequency signals in the form of electromagnetic waves. The input / output device, such as a touch screen, a display screen, a keyboard, etc., is mainly used for receiving user input data and outputting data to the user.

[0124] When the terminal is powered on, the processor can read the software program in the storage unit, parse and execute the instructions of the software program, and process the data of the software program. When data needs to be transmitted wirelessly, the processor performs baseband processing on the data to be transmitted, and outputs the baseband signal to the radio frequency circuit. The radio frequency circuit processes the baseband signal to obtain a radio frequency signal and transmits the radio frequency signal in the form of an electromagnetic wave through the antenna. When data is transmitted to the terminal, the radio frequency circuit receives a radio frequency signal through the antenna. The radio frequency signal is further converted into a baseband signal, and the baseband signal is output to the processor. The processor converts the baseband signal into data and processes the data.

[0125] For ease of illustration, FIG. 5 only shows one memory and one processor. In an actual terminal, there can be multiple processors and memories. The memory can also be referred to as a storage medium or a storage device, and the like, and the embodiments of the present application do not limit this.

[0126] As an optional implementation, the processor can include a baseband processor and a central processor. The baseband processor is mainly used for processing communication protocols and communication data. 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. 5 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 interconnected through a bus or the like. Those skilled in the art can understand that the terminal can include multiple baseband processors to adapt to different network standards, and the terminal can include multiple central processors to enhance its processing capability. Various modules of the terminal 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 can be stored in the storage unit in the form of a software program, and the processor executes the software program to realize the baseband processing function.

[0127] In one example, the antenna and control circuit with transceiving function can be regarded as the transceiving unit 511 of the terminal 500, and the processor with processing function can be regarded as the processing unit 512 of the terminal 500. As shown in FIG. 5, the terminal 500 includes the transceiving unit 511 and the processing unit 512. The transceiving unit can also be referred to as a transceiver, a transceiver unit, or the like. Optionally, the device for realizing the receiving function in the transceiving unit 511 can be regarded as a receiving unit, and the device for realizing the sending function in the transceiving unit 511 can be regarded as a sending unit, that is, the transceiving unit 511 includes the receiving unit and the sending unit. Exemplarily, the receiving unit can also be referred to as a receiver, a receiving circuit, or the like, and the sending unit can be referred to as a transmitter, a transmitting circuit, or the like. Optionally, the receiving unit and the sending unit can be integrated into one unit, or can be multiple independent units. The receiving unit and the sending unit can be in one geographical location, or can be dispersed in multiple geographical locations.

[0128] As shown in FIG. 6, another embodiment of the present application provides a device 600. The device can be a terminal, or a module (for example, an integrated circuit, a chip, or the like) applied to the terminal. Alternatively, the device can be a satellite device, or a module (for example, an integrated circuit, a chip, or the like) applied to the satellite device, or a logic node, a logic module, or software capable of realizing all or part of the functions of the satellite device. The device can also be other communication modules. For example, the device 600 can realize the functions of the satellite in the method 400 and various possible embodiments, or the device 600 can realize the functions of the terminal in the method 400 and various possible embodiments. The device 600 can include an interface module 601 (or an interface unit) and a processing module 602 (or a processing unit), and can further include a storage module 603 (or a storage unit).

[0129] In a possible design, one or more of the modules in FIG. 6 can be implemented by one or more processors, or by one or more processors and memories; or by one or more processors and transceivers; or by one or more processors, memories, and transceivers, and the embodiments of the present application are not limited here. The processor, the memory, and the transceiver can be separately arranged, or integrated.

[0130] The apparatus has the functions of the terminal described in the embodiments of the present application, for example, the apparatus includes modules or units or means corresponding to the steps performed by the terminal described in the embodiments of the present application. The functions or units or means can be implemented by software or by hardware, or by a combination of hardware and software. Further details can be referred to the corresponding description in the foregoing method embodiments. Alternatively, the apparatus has the functions of the radio access network device described in the embodiments of the present application, for example, the apparatus includes modules or units or means corresponding to the steps performed by the radio access network device described in the embodiments of the present application. The functions or units or means can be implemented by software or by hardware, or by a combination of hardware and software. Further details can be referred to the corresponding description in the foregoing method embodiments.

[0131] In one possible design, the apparatus 600 includes an interface module 601 and a processing module 602. The apparatus 600 can be, for example, a terminal, or a module (e.g., a processor, a chip, or a chip system) applied to a terminal, or a logic node, a logic module, or software capable of implementing all or part of the functions of a terminal. The interface module 601 is configured to receive a first system message from a satellite. The processing module 602 is configured to control the apparatus to acquire a second system message according to a delivery manner of the first system message, where the second system message is a changed first system message, and the delivery manner is a global delivery, a regional delivery, a wave position group delivery, or a wave position delivery.

[0132] In one possible implementation of the apparatus 600, the delivery manner is predefined, or the interface module 601 is further configured to receive first information, where the first information is used to indicate the delivery manner.

[0133] In one possible implementation of the apparatus 600, the processing module 602 is configured to control the apparatus to acquire the second system message according to the delivery manner of the first system message, including: when the delivery manner is the regional delivery, the processing module 602 is configured to determine a first distance between the terminal and a reference location in a first region, where the first region is a region where the first system message is delivered; and when the first distance is greater than a first distance threshold, the processing module 602 is configured to control the apparatus to acquire the second system message.

[0134] In a possible implementation of the apparatus 600, the processing module 602 is configured to control the apparatus to acquire a second system message according to a manner of delivery of the first system message, including: when the manner of delivery is delivery of the first system message in a wave position group, the processing module 602 is configured to determine a first synchronization signal block (SSB); and when the first SSB is different from an SSB corresponding to all wave positions included in a first wave position group, the processing module 602 is configured to control the apparatus to acquire the second system message.

[0135] In a possible implementation of the apparatus 600, the processing module 602 is configured to control the apparatus to acquire a second system message according to a manner of delivery of the first system message, including: when the manner of delivery is delivery of the first system message in a wave position group, the processing module 602 is configured to determine a second SSB corresponding to a first wave position; and when a second wave position group does not include the first wave position, the processing module 602 is configured to control the apparatus to acquire the second system message, where the second wave position group is a wave position group in which the first system message is delivered.

[0136] In a possible implementation of the apparatus 600, the processing module 602 is configured to control the apparatus to acquire a second system message according to a manner of delivery of the first system message, including: when the manner of delivery is delivery of the first system message in a wave position, the processing module 602 is configured to determine a third SSB in a first periodic time period; and when the third SSB is different from a fourth SSB, the processing module 602 is configured to control the apparatus to acquire the second system message, where the fourth SSB is an SSB in a periodic time period before the first periodic time period.

[0137] In a possible implementation of the apparatus 600, the interface module 601 is further configured to receive first indication information, and the processing module 602 is configured to control the apparatus to acquire a second system message according to a manner of delivery of the first system message, including: when the manner of delivery is delivery of the first system message in a global scope, the processing module 602 is configured to control the apparatus to acquire the second system message based on the first indication information.

[0138] In a possible design, the apparatus 600 includes an interface module 601. The apparatus 600 can be a satellite device, or a module (for example, a processor, a chip, or a chip system) applied to a satellite device, or a logic node, a logic module, or software capable of implementing all or part of functions of a satellite device. The interface module 601 is configured to send a first system message to a terminal. The interface module 601 is further configured to send a second system message, where the second system message is a changed first system message.

[0139] In a possible implementation of the apparatus 600, the interface module 601 is further configured to send first information, where the first information is used to indicate a delivery mode of the first system message, and the delivery mode is one of a global delivery, a regional delivery, a wave position group delivery, or a wave position delivery.

[0140] In a possible implementation of the apparatus 600, the interface module 601 is further configured to send first indication information, where the first indication information is used to indicate that the terminal acquires the second system message.

[0141] It can be understood that the apparatus 600 and the beneficial effects of the various possible implementations correspond to the descriptions in the foregoing method embodiments or the summary, and thus will not be described here.

[0142] Optionally, the apparatus 600 can further include a storage module 603 configured to store data or instructions (which can also be referred to as codes or programs). The other modules can interact with or be coupled to the storage module 603 to implement corresponding methods or functions. For example, the processing module 602 can read the data or instructions in the storage module 603, so that the apparatus 600 implements the methods in the foregoing embodiments.

[0143] In one example, the modules in the apparatus can be one or more integrated circuits configured to implement the above methods, for example, one or more application specific integrated circuits (ASICs), or one or more digital singnal processors (DSPs), or one or more field programmable gate arrays (FPGAs), or a combination of at least two of these integrated circuit forms. In another example, when the modules in the apparatus can be implemented in the form of a processing element scheduler, the processing element can be a general-purpose processor, such as a central processing unit (CPU) or other processor that can invoke programs. In yet another example, these units can be integrated together in the form of a system-on-a-chip (SOC).

[0144] Referring to FIG. 7, an apparatus provided by the embodiments of the present application is shown, which can be used to implement the method 400 and various possible implementation manners. As shown in FIG. 7, the apparatus includes a processor 710 and an interface 730, where the processor 710 is coupled to the interface 730. The interface 730 is configured to communicate with other modules or devices. The interface 730 can be a transceiver or an input / output interface. The interface 730 can be, for example, an interface circuit. Optionally, the apparatus further includes a memory 720 configured to store instructions executed by the processor 710 or input data required by the processor 710 to execute instructions or data generated after the processor 710 executes instructions.

[0145] The method 400 and various possible implementation manners can be implemented by the processor 710 invoking programs or instructions stored in the memory 720. The memory 720 can be internal to the apparatus or external to the apparatus, which is not limited in the present application.

[0146] Optionally, the functions / implementation procedures of the interface module 601 and the processing module 602 in FIG. 6 can be implemented by the processor 710 in the apparatus shown in FIG. 7. Alternatively, the functions / implementation procedures of the processing module 602 in FIG. 6 can be implemented by the processor 710 in the apparatus shown in FIG. 7, and the functions / implementation procedures of the interface module 601 in FIG. 6 can be implemented by the interface 730 in the apparatus shown in FIG. 7. For example, the functions / implementation procedures of the interface module 601 can be implemented by the processor invoking programs or instructions in the memory to drive the interface 730.

[0147] When the apparatus is a chip applied to a terminal, the chip implements the functions of the terminal in the method embodiments. The chip receives information from other modules (such as a radio frequency module or an antenna) in the terminal, where the information is from other terminals or wireless access network devices; or the chip sends information to other modules (such as a radio frequency module or an antenna) in the terminal, where the information is sent by the terminal to other terminals or wireless access network devices.

[0148] When the apparatus is a chip applied to a satellite device, the chip implements the functions of the satellite device in the method embodiments. The chip receives information from other modules (such as a radio frequency module or an antenna) in the satellite device, where the information is from other satellite devices or terminals; or the chip sends information to other modules (such as a radio frequency module or an antenna) in the satellite device, where the information is sent by the satellite device to other satellite devices or terminals.

[0149] Those skilled in the art can understand that various numbers such as first, second, etc. involved in the present application are only for the convenience of description and do not limit the scope of the embodiments of the present application, nor represent the order of precedence. The "and / or" describes the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. The character " / " generally represents an "or" relationship between the front and rear associated objects. "At least one" means one or more. At least two means two or more. "At least one", "any one" or the like means any combination of these items, including any combination of single item or multiple items. For example, at least one of a, b, or c (one, kind) can represent a, b, c, a-b, a-c, b-c, or a-b-c, where a, b, and c can be single or multiple. "Multiple" means two or more, and other quantifiers are similar.

[0150] It should be understood that in various embodiments of the present application, the size of the sequence number of the above-mentioned processes does not mean the order of execution, and the execution order of the processes should be determined by their functions and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0151] In the above embodiments, all or part can be realized by software, hardware, firmware or any combination thereof. When realized by software, all or part can be realized in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present application are 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 website, computer, server or data center through wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) mode. The computer readable storage medium can be any available medium that can be accessed 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.

[0152] The steps of the methods described in the embodiments of the present application can be directly embedded in hardware, software units executed by a processor, or a combination of the two. The software units can be stored in a random access memory (RAM), a flash memory, a read-only memory (ROM), a register, a hard disk, a removable disk, or any other form of storage medium in the art. Illustratively, the storage medium can be connected to the processor, so that the processor can read information from the storage medium and write information to the storage medium. Alternatively, the storage medium can also be integrated into the processor. The processor and the storage medium can be disposed in an ASIC.

[0153] The present application also provides a computer readable medium having a computer program stored thereon, which, when executed by a computer, implements the functions of any of the method embodiments described above.

[0154] The present application also provides a computer program product, which, when executed by a computer, implements the functions of any of the method embodiments described above. Identical or similar parts among various embodiments of the present application can be mutually referred to. In the various embodiments of the present application, and in each of the implementation manners / implementation methods / realization methods of the various embodiments, the terms and / or descriptions are consistent and can be mutually referred to, unless otherwise specified and there is no logical conflict, and the technical features in different embodiments, and in each of the implementation manners / implementation methods / realization methods of the various embodiments can be combined to form new embodiments, implementation manners, implementation methods, or realization methods according to their inherent logical relationship. The above-described implementation manners of the present application do not constitute a limitation on the protection scope of the present application.

[0155] The above describes only the specific embodiments 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.

Claims

1. A communication method characterized by comprising: The method comprises: receiving a first system message from a satellite; obtaining a second system message according to a delivery mode of the first system message, the second system message being a changed first system message, and the delivery mode being global delivery, regional delivery, wave position group delivery or wave position delivery.

2. The method of claim 1, wherein, The delivery mode is predefined, or the method further comprises: receiving first information, the first information being used to indicate the delivery mode.

3. The method according to claim 1 or 2, characterized in that, The obtaining of the second system message according to the delivery mode of the first system message comprises: when the delivery mode is the regional delivery, determining a first distance between a terminal and a reference position in a first region, the first region being a region where the first system message is delivered. When the first distance is greater than a first distance threshold, the second system message is obtained.

4. The method according to claim 1 or 2, characterized in that, The obtaining of the second system message according to the delivery mode of the first system message comprises: when the delivery mode is the wave position group delivery, determining a first synchronization signal block (SSB); When the first SSB is different from SSBs corresponding to all wave positions included in a first wave position group, the second system message is obtained, the first wave position group being a wave position group where the first system message is delivered.

5. The method according to claim 1 or 2, characterized in that, The obtaining of the second system message according to the delivery mode of the first system message comprises: when the delivery mode is the wave position group delivery, determining a second SSB corresponding to a first wave position; When a second wave position group does not include the first wave position, the second system message is obtained, the second wave position group being a wave position group where the first system message is delivered.

6. The method of claim 1 or 2, wherein, The obtaining of the second system message according to the delivery mode of the first system message comprises: when the delivery mode is the wave position delivery, determining a third SSB in a first periodic time period; When the third SSB is different from a fourth SSB, the second system message is obtained, the fourth SSB being an SSB in a periodic time period before the first periodic time period.

7. The method according to claim 1 or 2, characterized in that, The obtaining of the second system message according to the delivery mode of the first system message comprises: when the delivery mode is the global delivery, receiving first indication information; Based on the first indication information, the second system message is obtained.

8. A communication device, characterized by The method comprises: an interface module and a processing module: The interface module is configured to receive a first system message from a satellite; The processing module is configured to control the device to obtain a second system message according to a delivery mode of the first system message, the second system message being a changed first system message, and the delivery mode being global delivery, regional delivery, wave position group delivery or wave position delivery.

9. The apparatus of claim 8, wherein, The delivery mode is predefined, or the interface module is further configured to receive first information, the first information being used to indicate the delivery mode.

10. The apparatus of claim 8 or 9, wherein, The processing module is configured to control the device to obtain the second system message according to the delivery mode of the first system message, comprising: when the delivery mode is the regional delivery, the processing module is configured to determine a first distance between a terminal and a reference position in a first region, the first region being a region where the first system message is delivered. When the first distance is greater than a first distance threshold, the processing module is configured to control the apparatus to acquire the second system message.

11. The apparatus of claim 8 or 9, wherein, The processing module is configured to control the apparatus to acquire the second system message according to a delivery manner of the first system message, including: When the delivery manner is the wave position group delivery, the processing module is configured to determine a first synchronization signal block (SSB); When the first SSB is different from SSBs corresponding to all wave positions included in a first wave position group, the processing module is configured to control the apparatus to acquire the second system message, the first wave position group being a wave position group in which the first system message is delivered.

12. The apparatus of claim 8 or 9, wherein, The processing module is configured to control the apparatus to acquire the second system message according to a delivery manner of the first system message, including: When the delivery manner is the wave position group delivery, the processing module is configured to determine a second SSB corresponding to a first wave position; When a second wave position group does not include the first wave position, the processing module is configured to control the apparatus to acquire the second system message, the second wave position group being a wave position group in which the first system message is delivered.

13. The apparatus of claim 8 or 9, wherein, The processing module is configured to control the apparatus to acquire the second system message according to a delivery manner of the first system message, including: When the delivery manner is the wave position delivery, the processing module is configured to determine a third SSB in a first periodic time period; When the third SSB is different from a fourth SSB, the processing module is configured to control the apparatus to acquire the second system message, the fourth SSB being an SSB in a periodic time period before the first periodic time period.

14. The apparatus of claim 8 or 9, wherein, The interface module is further configured to receive first indication information; The processing module is configured to control the apparatus to acquire the second system message according to a delivery manner of the first system message, including: When the delivery manner is the global delivery, the processing module is configured to control the apparatus to acquire the second system message based on the first indication information.

15. A computer-readable storage medium having stored thereon instructions, The instructions, when executed, cause the method of any one of claims 1-7 to be performed.

16. A computer program product, characterised in that, Computer program code that, when run, implements the method of any one of claims 1-7.

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