Patent Description:
In recent years, the information technology develops rapidly, and application of the technology is further affecting a development direction of the human society. An information communications network is also evolving from a fixed network to a mobile network, and from isolated ground and space networks to a space-ground integrated network. The space-ground integrated network is an important information infrastructure that extends human activities to the space, the high seas, and even the deep space. The space-ground integrated network can satisfy requirements of information technology development and transformation of economic and social development patterns, and is the emphasis, focus, and direction of development of the information technology, the information industry, the information network, and informatization.

Satellite communication is an important part of the space-ground integrated network. Standards organizations such as the 3rd Generation Partnership Project (3GPP, 3rd Generation Partnership Project) and the International Telecommunication Union (ITU, International Telecommunication Union) have successively carried out research and discussion on space-ground integrated satellite communications standards, which mainly focus on integration of existing <NUM> standards and satellite communications technologies, and define and analyze content such as an application scenario, a network structure, and a key technology of a <NUM> satellite network, to implement global coverage of the space-ground integrated network. Currently, the research has been initiated, and research on an integrated <NUM>-satellite architecture has been carried out. This application focuses on a coordinated satellite network technology in the integrated <NUM>-satellite architecture. The satellite communication has characteristics such as a long communication distance, a large coverage area, and flexible networking. In some important fields such as space communication, aeronautical communication, and military communication, the satellite communications technology plays an irreplaceable role. A satellite network can provide services for both fixed terminals and various mobile terminals.

To implement complete coverage of the earth's surface, satellite beams always evenly cover the earth's surface. However, due to population distribution, areas covered by different satellite beams differ greatly in quantities of users. <FIG> is a schematic diagram of satellite coverage areas. There are a large quantity of users in a densely populated land area (for example, a super-large city such as Beijing and Shanghai). For example, an area covered by a beam <NUM> (beam #<NUM>) of a satellite <NUM> has a large population density, a quantity of users of satellite communication has great potential, and communication load of the satellite <NUM> is very large or even exceeds a load capability. However, a sparsely populated area, for example, an area covered by a beam <NUM> (beam #<NUM>) of a satellite <NUM> or <NUM>, has a small population density. The coverage area is an area such as a sparsely populated city, a desert area, or even an ocean. Users of satellite communication are sparsely distributed, or even there is no user. Satellite resources are not fully utilized. Consequently, satellite resources in areas with sparse users are severely wasted, while satellite resources in areas with dense users may be severely insufficient and cannot provide access services. Currently, a common solution is to modify a pilot power to adjust a coverage area of a cell. However, modifying the pilot power affects a traffic volume supported by the cell. Another solution is mobility load balancing (MLB, Mobility Load Balancing), to be specific, adjusting a handover area by offsetting a handover cell measurement value. This method can only satisfy requirements of cell edge users and has limitations. Due to the huge difference in the quantities of users in different coverage areas, higher requirements are imposed on a coverage mode of the satellite beam.

<CIT> discloses systems and methods for opportunistic load balancing across one or more communication links supported by one or more base stations.

<CIT> relates to balancing beams in a multi-beam satellite communications network by identifying overloaded modulators / beams served by a first modulator, while maintaining traffic load on a second modulator below a load threshold.

This application provides satellite communication methods and a first network device of a core network, as defined in the appended set of claims, to coordinate a satellite beam to balance network load when the network load is relatively heavy, so as to improve satellite resource utilization.

To describe the technical solutions in embodiments of the present invention more clearly, the following briefly describes the accompanying drawings used in describing the background and the embodiments. It is clear that the accompanying drawings in the following descriptions show merely some embodiments of the present invention, and a person of ordinary skill in the art may still derive other drawings or embodiments based on these drawings or descriptions without creative efforts, without departing from the scope of the application as defined by the appended claims.

To make the objectives, technical solutions, and advantages of the present invention clearer and more comprehensible, the following further describes the present invention in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely used to explain the present invention, but are not intended to limit the present invention. It is clear that the described embodiments are merely some but not all of the embodiments of the present invention. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention, as defined by the appended set of claims.

To better understand a network architecture and a communication method for coordinated satellite communication disclosed in the embodiments of this application, an application scenario of the embodiments of this application is first described. Referring to <FIG>, a typical network architecture of a satellite communications system is first used as an example for description, and a network architecture for actual satellite communication is similar to this.

<FIG> is a schematic diagram of a typical network architecture of a satellite communications system. As shown in <FIG>, the satellite communications system <NUM> includes a terminal device <NUM>, satellite base stations <NUM>, a ground station <NUM>, a core network <NUM> (where the core network <NUM> mainly includes a user plane function UPF unit <NUM>, an access and mobility management function AMF unit <NUM>, a session management function SMF unit <NUM>, and a data network <NUM>). The terminal device <NUM> accesses a network through an air interface, to communicate with the satellite base station <NUM>. The satellite base station <NUM> is connected to the ground core network <NUM> through a radio link (an NG interface). In addition, there is also a radio link between the satellite base stations <NUM>, and signaling exchange and user data transmission between the satellite base stations are completed through an Xn interface. The network elements and interfaces shown in <FIG> are described as follows.

In this application, the terminal device <NUM> may be referred to as user equipment (UE), an access terminal, a subscriber unit, a subscriber station, a mobile station, a mobile console, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communications device, a user agent, or a user apparatus. The terminal device <NUM> may access a satellite network through the air interface and initiate a service such as a call or going online on the Internet, and may be a mobile device that supports a <NUM> new radio (NR, new radio). Typically, the terminal device <NUM> may be a mobile phone, a tablet computer, a portable notebook computer, a virtual/mixed/augmented reality device, a navigation device, a ground base station (for example, an eNB or a gNB), a ground station (ground station, GS), a session initiation protocol (Session Initiation Protocol, SIP) phone, a wireless local loop (Wireless Local Loop, WLL) station, a personal digital assistant (Personal Digital Assistant, PDA), a handheld device with a satellite communication function, a computing device, another processing device connected to a wireless modem, a vehicle-mounted device, a wearable device, a terminal device in a <NUM> network, a terminal device in a future evolved public land mobile network (Public Land Mobile Network, PLMN) or another future communications system, or the like.

The satellite base station <NUM> mainly provides a radio access service for the terminal device <NUM>, schedules a radio resource for the terminal device accessing the satellite base station, and provides a reliable radio transmission protocol, a data encryption protocol, and the like. The satellite base station is an artificial earth satellite, a high altitude aircraft, or the like that is used as a wireless communications base station, for example, an evolved base station (eNB) and a <NUM> base station (gNB). The satellite base station may be a geostationary earth orbit (geostationary earth orbit, GEO) satellite, may be a non-geostationary earth orbit (none-geostationary earth orbit, NGEO) such as a medium earth orbit (medium earth orbit, MEO) satellite or a low earth orbit (low earth orbit, LEO) satellite, may be a high altitude platform station (High Altitude Platform Station, HAPS), or the like.

In the embodiments of this application, the ground station (ground station) <NUM> is mainly responsible for forwarding signaling and service data between the satellite base station <NUM> and the core network <NUM>. The ground station is usually a ground device that is disposed on the earth's surface (including being disposed on a ship or an airplane) to perform artificial satellite communication. The ground station mainly includes a high-gain antenna system that can trace artificial satellites, a high-power microwave transmission system, a low-noise receiving system, a power supply system, and the like.

The core network (core network) <NUM> is mainly used for user access control, charging, mobility management, session management, user security authentication, a supplementary service, and the like. In the embodiments of this application, the core network <NUM> mainly includes the user plane function unit <NUM>, the access and mobility management function unit <NUM>, the session management function unit <NUM>, and the data network <NUM>. The core network <NUM> includes a plurality of function units, which may be classified as control plane function entities and data plane function entities. The access and mobility management function (AMF, Access and mobility function) unit <NUM> is a control plane function entity, and is responsible for user access management, security authentication, and mobility management. The session management function (SMF, Session Management Function) unit <NUM> is a control plane function entity, is responsible for session management, and is connected to the AMF. The user plane function (UPF, User Plane Function) unit <NUM> is a data plane function entity, and is responsible for functions such as user plane data transmission management, traffic statistics collection, and lawful interception. The data network <NUM> is a data plane function entity, and is connected to the UPF. The core network further includes other function units, but the function units are not listed one by one.

A first network device in this application is a device with a user plane function UPF unit or a similar function unit.

A second network device in this application is a device with an access and mobility management function AMF unit or a similar function unit. To better and more clearly describe the function units, in the embodiments of this application, the user plane function UPF unit is used to represent the first network device, and the mobility management function AMF unit is used to represent the second network device. This representation constitutes no substantive limitation on the embodiments of this application.

User equipment and the satellite base station may implement wireless communication based on air interface technologies such as 5th generation mobile communications system new radio (<NUM> NR, 5th generation mobile networks new radio), long term evolution (LTE, long term evolution), a global system for mobile communications (GSM, global system for mobile communication), and a universal mobile telecommunications system (UMTS, universal mobile telecommunications system). The Xn interface is an interface between the satellite base stations, and is mainly used for signaling interaction such as handover. The NG interface is an interface between the satellite base station and the ground station (the core network), and is mainly used to exchange signaling such as NAS signaling of the core network, and user service data.

<FIG> is a schematic diagram of a coordinated satellite communications architecture according to an embodiment of this application. The network architecture mainly includes satellite base stations <NUM> (Sat. #<NUM>, Sat. #<NUM>, and Sat. #<NUM>), terminal devices <NUM>, a ground station <NUM>, a user plane function UPF unit <NUM>, and an access and mobility management AMF unit <NUM>. In this embodiment of this application, three satellite base stations are used as examples. However, an actual quantity of satellite base stations is not limited to three, may be two or more, and may be determined based on an ephemeris (ephemeris) and a satellite load status. A coverage area set <NUM> of a satellite beam of the satellite base station Sat. #<NUM> is an area with dense users, and communication load of the satellite base station Sat. #<NUM> is heavy. A coverage area set <NUM> of a satellite beam of the satellite base station Sat. #<NUM> is an area with sparse users, and communication load of the satellite base station Sat. #<NUM> is light. A coverage area set <NUM> of a satellite beam of the satellite base station Sat. #<NUM> is a no man's area almost without users, and the satellite base station Sat. #<NUM> basically has no communication load. A radio link established between the satellite base station Sat. #<NUM> and the ground station <NUM> is denoted as a link <NUM>. Similarly, a radio link established between the satellite base station Sat. #<NUM> and the ground station <NUM> and a radio link established between the satellite base station Sat. #<NUM> and the ground station <NUM> are denoted as a link <NUM> and a link <NUM>. The ground station is mainly configured to forward signaling and service data between the satellite base station and a core network. The UPF is one of user plane function entities of the core network, and is responsible for data transmission and traffic statistics collection. A link established between the satellite base station Sat. #<NUM> and the core network (UPF) is also referred to as a link <NUM>. A link established between the satellite base station Sat. #<NUM> and the UPF and a link established between the satellite base station Sat. #<NUM> and the UPF are denoted as a link <NUM> and a link <NUM>.

<FIG> and <FIG> are a schematic flowchart of a coordinated satellite communication method according to an embodiment of this application. The method may be used in the network architecture shown in <FIG>. A UPF monitors a traffic between a satellite base station and a core network or an air interface resource allocated by a ground station, to determine a load status of the satellite base station. The UPF triggers, through a message, an AMF to adjust a communication resource of the satellite base station, to satisfy a communication requirement.

<NUM>: The user plane function (UPF) unit obtains traffics of a plurality of satellite communications links, or obtains air interface resources allocated by the ground station to a plurality of satellite base stations.

<NUM>: The UPF sends identifier information to the access and mobility management function (AMF) unit, where the identifier information indicates that a traffic of a satellite communications link reaches a specified threshold, or that an air interface resource allocated by the ground station to a satellite base station reaches a specified threshold.

<NUM>': The UPF sends a first message including the identifier information to the access and mobility management function (AMF) unit, where the first message includes the identifier information, a second cell identifier, and load information.

<NUM>: The AMF determines a to-be-linked satellite base station and a parameter of the to-be-linked satellite base station based on the first message.

<NUM>: The AMF sends a second message to the to-be-linked satellite base station, where the second message includes information about a generated beam of the to-be-linked satellite base station.

The parameter includes movement track information and communications protocol information. The movement track information includes an azimuth angle, an elevation angle, and a polarization angle of the to-be-linked satellite; and the communications protocol information includes a communication frequency and a communication power.

The information includes a direction, an angle, a frequency, and a power of the generated beam of the to-be-linked satellite base station.

In step <NUM>, specifically, the satellite communications links may be radio links between the satellite base stations and the ground station, may be communications links that are between the ground station and the user plane function (UPF) unit and that reflect the data traffics of the satellite base stations, or may be communications links between the satellite base stations and the core network. The traffic reflects load of each satellite base station.

Specifically, an air interface resource of the ground station is a frequency resource that can be allocated by the ground station to each satellite base station, and a load status of each satellite base station can be reflected by using the allocated air interface resource.

For example, in the network architecture shown in <FIG>, the UPF of the ground core network separately collects statistics on traffics of the link <NUM>, the link <NUM>, and the link <NUM> between the three satellite base stations (Sat. #<NUM>, Sat. #<NUM>, and Sat. #<NUM>) and the core network, to calculate a traffic <NUM>, a traffic <NUM>, and a traffic <NUM> in a pre-specified time interval, so as to determine load statuses of the three satellite base stations (Sat. #<NUM>, Sat. #<NUM>, and Sat. #<NUM>) based on the traffics in the pre-specified time interval. Alternatively, the UPF monitors air interface resources allocated by the ground station to the three satellite base stations, to determine load of each of the three satellite base stations (Sat. #<NUM>, Sat. #<NUM>, and Sat.

In step <NUM>, optionally, the trigger identifier information further indicates a cell corresponding to the satellite communications link whose traffic reaches the specified threshold, or a cell corresponding to the satellite base station whose air interface resource allocated by the ground station reaches the specified threshold. The trigger identifier information may carry an identifier (ID) of the cell or the satellite base station whose load reaches a specified threshold. In another feasible implementation solution, alternatively, the identifier (ID) of the cell or the satellite base station whose load reaches the specified threshold may be independently sent through a piece of identifier information.

Optionally, the UPF sends the first cell identifier to the AMF, where the first cell identifier is determined based on the satellite communications link whose traffic reaches the specified threshold, or is determined by the satellite base station whose air interface resource allocated by the ground station reaches the specified threshold.

Optionally, the UPF preconfigures a load threshold, where the threshold may be the specified threshold T1 of the traffic of the satellite link, or may be the specified threshold T2 of the air interface resource allocated by the ground station to each satellite. Optionally, the UPF creates a load threshold, where the load threshold is the threshold T1 that is specified for the traffic of the satellite communications link, or the threshold T2 that is specified for the air interface resource allocated to the satellite base station.

Further, if the traffic of the satellite communications link reaches the threshold T1, the UPF sends the trigger identifier information to the AMF.

Further, if the air interface resource allocated by the ground station to the satellite base station reaches the threshold T2, the UPF sends the trigger identifier information to the AMF.

In addition to determining, based on the pre-specified threshold, whether to trigger traffic warning information, the UPF may further create the threshold. This allows greater flexibility for the UPF.

Because the UPF monitors the traffics of the satellite communications links or the air interface resources allocated by the ground station, when the UPF detects that the traffic or the allocated air interface resource reaches the specified threshold, the UPF sends, to the AMF in a form of signaling, an identifier indicating that the specified threshold is reached. The signaling further includes a cell identifier (ID) corresponding to the traffic or the allocated air interface resource that reaches the specified threshold, and a traffic or an air interface resource allocation status of another link.

For example, in the network architecture shown in <FIG>, the traffic of the link <NUM> exceeds the specified threshold T1 from a moment, the UPF detects this event, and the UPF sends information to the AMF. The information includes an identifier indicating that the traffic of the link link <NUM> reaches the specified threshold, a cell identifier (ID) corresponding to the link, and the traffics or air interface resource allocation statuses of the other links.

In step <NUM>', the AMF further needs to determine a to-be-scheduled satellite beam based on a surrounding satellite resource in addition to the trigger identifier information. Therefore, an ID and load information of the surrounding satellite resource are need.

Optionally, the first message further includes the second cell identifier and the load information, the second cell identifier indicates a satellite base station around a satellite whose traffic reaches the specified threshold, and the load information indicates a traffic of a satellite communications link that is in the second cell identifier and whose traffic does not reach the specified threshold, or indicates an air interface resource allocated to a satellite base station that is in the second cell identifier and whose air interface resource does not reach the specified threshold.

Specifically, the second cell identifier is determined based on the satellite communications link whose traffic does not reach the specified threshold, or is determined by the satellite base station whose air interface resource allocated by the ground station does not reach the specified threshold. Optionally, the second cell identifier is determined based on a satellite ephemeris, and the load information is determined by a satellite base station corresponding to the satellite ephemeris.

In step <NUM>, the parameter that needs to be determined includes the azimuth angle, the elevation angle, and the polarization angle of the to-be-linked satellite, where the azimuth angle, the elevation angle, and the polarization angle of the to-be-linked satellite are an azimuth angle, an elevation angle, and a polarization angle of an antenna that receives a signal of the to-be-linked satellite.

Optionally, the AMF selects, as the to-be-linked satellite base station based on the satellite ephemeris, a satellite near the satellite base station whose traffic or allocated air interface resource reaches the specified threshold.

For example, in the network architecture shown in <FIG>, the traffic of the link link <NUM> exceeds the specified threshold T1, and the link link <NUM> corresponds to the satellite base station Sat. The AMF selects, based on the satellite ephemeris, the satellite base station Sat. #<NUM> that is relatively close to the satellite base station Sat. #<NUM> at the moment, as the to-be-linked satellite base station that assists in balancing communication load of the satellite base station Sat. The cell <NUM> covered by the beam of the satellite base station Sat. #<NUM> is an area with sparse users, and the satellite base station Sat. #<NUM> still has a redundant communication capability to bear more communication load. The AMF determines movement track information and communications protocol information of the satellite base station Sat. The movement track information includes an azimuth angle, an elevation angle, and a polarization angle of the satellite base station Sat. The communications protocol information includes information such as a frequency and a power of a satellite beam allocated by the satellite base station Sat. #<NUM> to the cell <NUM>. Optionally, in some cases, the AMF may also select the satellite base station Sat. #<NUM> as the to-be-linked satellite base station that assists in balancing the communication load of the satellite base station Sat.

After step <NUM>, optionally, the to-be-linked satellite base station generates the beam to cover a specified area (a heavy-load cell), and accepts access of a terminal device in the specified area.

For example, in the network architecture shown in <FIG>, the AMF sends information to the satellite base station Sat. #<NUM> through the ground station, to indicate the satellite base station Sat. #<NUM> to generate a beam to cover a specified area (an area in the cell <NUM>), and accept access of a terminal device in the area in the cell <NUM>. The information includes a direction and an angle of the generated beam of the satellite base station Sat. #<NUM>, a satellite communication frequency and power, and the like. Optionally, if the AMF selects the satellite base station Sat. #<NUM> as the to-be-linked satellite base station that assists in balancing the communication load of the satellite base station Sat. #<NUM>, the AMF sends information to the satellite base station Sat. #<NUM> through the ground station, to indicate the satellite base station Sat. #<NUM> to generate a beam to cover a specified area (an area in the cell <NUM>).

In another case, if the generated beam of the to-be-linked satellite base station still cannot satisfy the communication requirement of the cell, and the traffic of the satellite base station that originally covers the cell or the air interface resource allocated by the ground station to the satellite base station still reaches the specified threshold, the AMF may be triggered by a message again to allocate another satellite beam to assist the terminal device in the cell in accessing.

In this application, monitoring the traffic or the air interface resource means obtaining a status or information of the traffic or the allocated air interface resource. The two expressions may be interchanged, and this does not constitute an actual limitation on the solutions in the embodiments of this application.

This embodiment provides the network architecture and the communication method for coordinated satellite communication. The user plane function (UPF) unit monitors the traffics of the satellite communications links or the air interface resources allocated by the ground station. The UPF sends, to the access and mobility management function (AMF) unit, the information including the identifier indicating that the load reaches the threshold and the load status of the surrounding satellite. The AMF determines the to-be-linked satellite base station and the parameter of the to-be-linked satellite base station, and sends the information to the to-be-linked satellite base station. The to-be-linked satellite base station generates the beam to cover the specified area (the heavy-load cell), and accepts the access of the terminal device in the specified area. According to the network architecture and the communication method for coordinated satellite communication provided in this embodiment, the UPF monitors the traffic between the satellite base station and the core network or the air interface resource allocated by the ground station, to determine the load status of the satellite base station. The UPF triggers, through the message, the AMF to adjust the communication resource of the satellite base station, to satisfy the communication requirement. This solution uses characteristics such as a wide adjustable range of the satellite beam and different network resource utilization statuses of different coverage cells, to improve network resource utilization and provide a better access service for a terminal user.

<FIG> is a schematic flowchart of another coordinated satellite communication method according to an embodiment of this application. As shown in <FIG>, the method mainly relates to a satellite base station, a terminal device, and an access and mobility management function (AMF) unit. The AMF schedules, based on a population density and movement tracks of satellite base stations, a satellite around a heavy-load satellite base station to balance load.

<NUM>: The AMF obtains data, where the data carries population distribution information and movement track information of the satellite base stations.

<NUM>: The AMF determines a to-be-linked satellite base station and a parameter of the to-be-linked satellite base station based on the data.

<NUM>: The AMF sends a message to the to-be-linked satellite base station, where the message includes information about a generated beam of the to-be-linked satellite base station.

Optionally, the population distribution information may be a population distribution density table shown in Table <NUM> or may be in another form with a same effect. Levels are determined based on population distribution statuses in different geographical locations. Further, the population distribution information carries population distribution levels of different areas. In step <NUM>, if a population distribution level of a current cell reaches a specified threshold, the AMF determines the to-be-linked satellite base station and the parameter of the to-be-linked satellite base station based on the data.

Optionally, the parameter of the to-be-linked satellite base station includes a movement track parameter and a communications protocol, the movement track parameter includes an azimuth angle, an elevation angle, and a polarization angle for receiving a signal of the to-be-linked satellite base station, and the communications protocol includes a frequency and a power of the transmit beam of the to-be-linked satellite base station. From a specific implementation perspective, a movement track of the satellite is fixed, location information of the satellite at any moment may be obtained through calculation. Therefore, the movement track parameter of the satellite may be obtained through calculation, or may be obtained by querying an ephemeris.

Optionally, the message carries information about a direction, an angle, the frequency, and the power of the generated beam.

For example, ground areas may be classified into different levels such as A, B, C, and D, which correspond to population distribution densities: ≤<NUM> people per square kilometer, ≤<NUM>,<NUM> people per square kilometer, ≤<NUM>,<NUM> people per square kilometer, ≤<NUM>,<NUM> people per square kilometer, and the like. The population distribution density table is generated based on the foregoing level division and is stored in a network element node (for example, the AMF) of a core network. Alternatively, the ground areas may be directly classified based on each square kilometer, and the different ground areas are classified into population levels based on a population distribution density in each square kilometer.

<FIG> is a schematic diagram of adjusting a satellite beam based on a population distribution density table. <FIG> corresponds to Table <NUM>. As shown in <FIG>, an area A is a densely populated land area, for example, a geographical area of a large city such as Beijing, and a population distribution level of the area A is S; an area B is an area near an ocean, for example, a geographical area of a coastal city such as Qingdao, and a population distribution level of the area B is B; and an area C is a marine area, for example, a geographical area of an ocean area such as the Yellow Sea, and a population distribution level of the area C is A. At a moment T1 shown in <FIG>, a satellite beam of a satellite base station <NUM> (Sat. #<NUM>) covers the area A. Because the area A is a densely populated area, communication load of the satellite base station <NUM> (Sat. #<NUM>) is heavy, and a terminal user in the area A may not access a satellite network. A satellite beam of a satellite base station <NUM> (Sat. #<NUM>) covers the area B, the area B is a sparsely populated area, and communication load of the satellite base station <NUM> (Sat. #<NUM>) is light. In addition, the satellite base station <NUM> (Sat. #<NUM>) is close to the satellite base station <NUM> (Sat. #<NUM>), and the beam of the satellite base station <NUM> (Sat. #<NUM>) may cover a part or all of the area A. The satellite base station <NUM> (Sat. #<NUM>) generates, based on the information sent by the AMF, a beam to cover the part or all of the area A. Information such as a quantity of beams, a frequency and a power of the beam, and an angle of a satellite antenna is determined based on the information sent by the AMF. A terminal device in an area covered by both the satellite base station <NUM> (Sat. #<NUM>) and the satellite base station (Sat. #<NUM>) may access the satellite base station <NUM> (Sat. #<NUM>) or the satellite base station <NUM> (Sat. #<NUM>) based on a normal process.

Optionally, before the moment T1, the AMF sends the information to the light-load satellite base station <NUM> (Sat.

This embodiment provides the coordinated satellite communication method. The access and mobility management function (AMF) unit obtains the population distribution data and the movement track information of the satellite base stations. At a moment, the AMF sends the information to the to-be-linked satellite base station, where the information indicates the quantity of beams to be established by the to-be-linked satellite base station, the frequency and the power of the beam, the angle of the antenna, and the like. According to the coordinated satellite communication method provided in this embodiment, the satellite beam is coordinated based on the population distribution data, and beam coverage is performed on the densely populated area by scheduling an idle resource. This improves resource utilization of the satellite base station, optimizes configuration of satellite resources, and provides higher access capacity for the densely populated area, to satisfy a communication requirement of users in the densely populated area.

<FIG> is a schematic structural diagram of a first network device <NUM> according to an embodiment of this application, for example, a device with a user plane function UPF unit or a similar function unit. As shown in <FIG>, the first network device <NUM> includes:.

In some implementations, the trigger identifier information further indicates a cell corresponding to the satellite communications link whose traffic reaches the specified threshold, or a cell corresponding to the satellite base station whose air interface resource allocated by the ground station reaches the specified threshold.

Specifically, the second network device may be a device with an access and mobility management function AMF unit or a similar function unit.

Optionally, the sending unit <NUM> is further configured to send a first cell identifier to the second network device, where the first cell identifier is determined based on the satellite communications link whose traffic reaches the specified threshold, or is determined by the satellite base station whose air interface resource allocated by the ground station reaches the specified threshold.

Optionally, the sending unit <NUM> is further configured to send a second cell identifier and load information to the second network device, where the second cell identifier is determined based on a satellite communications link whose traffic does not reach the specified threshold, or is determined by a satellite base station whose air interface resource allocated by the ground station does not reach the specified threshold; and the load information indicates the traffic of the satellite communications link whose traffic does not reach the specified threshold, or indicates the air interface resource allocated to the satellite base station whose air interface resource does not reach the specified threshold.

Optionally, the sending unit <NUM> is further configured to send a second cell identifier and load information to the second network device, where the second cell identifier is determined based on a satellite ephemeris, and the load information is determined by a satellite base station corresponding to the satellite ephemeris.

Optionally, the first network device further includes: a creation unit <NUM>, configured to create a load threshold, where the load threshold is the threshold T1 that is specified for the traffic of the satellite communications link, or the threshold T2 that is specified for the air interface resource allocated to the satellite base station.

Optionally, if the traffic of the satellite communications link reaches the threshold T1, the first network device sends the trigger identifier information to the second network device.

Optionally, if the air interface resource allocated by the ground station to the satellite base station reaches the threshold T2, the first network device sends the identifier information to the second network device.

<FIG> is a schematic structural diagram of a second network device <NUM> not being part of the present invention, for example, a device with an access and mobility management function AMF unit or a similar function unit. As shown in <FIG>, the second network device <NUM> includes:.

The trigger identifier information indicates that a traffic of a satellite communications link reaches a specified threshold, or an air interface resource allocated by a ground station to a satellite base station reaches a specified threshold; and the load information indicates a traffic of a satellite communications link whose traffic does not reach the specified threshold, or indicates an air interface resource allocated to a satellite base station whose air interface resource does not reach the specified threshold.

Optionally, the trigger identifier information further indicates a cell corresponding to the satellite communications link whose traffic reaches the specified threshold, or a cell corresponding to the satellite base station whose air interface resource allocated by the ground station reaches the specified threshold.

Optionally, the first message includes a first cell identifier, and the first cell identifier is determined based on the satellite communications link whose traffic reaches the specified threshold, or is determined by the satellite base station whose air interface resource allocated by the ground station reaches the specified threshold.

Optionally, the second cell identifier is determined based on the satellite communications link whose traffic does not reach the specified threshold, or is determined by the satellite base station whose air interface resource allocated by the ground station does not reach the specified threshold.

Optionally, the second cell identifier is determined based on a satellite ephemeris, and the load information is determined by a satellite base station corresponding to the satellite ephemeris.

Optionally, the population distribution information carries population distribution levels of different areas.

Optionally, if a population distribution level of a current cell reaches a specified threshold, the processing unit determines the to-be-linked satellite base station and the parameter of the to-be-linked satellite base station based on the data.

In this application, some units (or components) of the first network device or the second network device may be implemented by using a hardware circuit, and some other units (or components) are implemented by using software, or all units (or components) may be implemented by using a hardware circuit, or all units (or components) are implemented by using software.

<FIG> is a schematic structural diagram of a first network device <NUM> not being part of the present invention. As shown in <FIG>, the first network device <NUM> is, for example, a device with a user plane function UPF unit or a similar function unit. The first network device <NUM> includes a processor <NUM> and a memory <NUM>. The memory <NUM> may be a memory (memory #<NUM>) independent of the processor or the network device, or may be a memory (memory #<NUM> or memory #<NUM>) inside the processor or the network device. The memory <NUM> may be a physically independent unit, or may be storage space, a network hard disk, or the like on a cloud server.

The memory <NUM> is configured to store a computer-readable instruction (or referred to as a computer program).

The processor <NUM> is configured to read the computer-readable instruction to implement the method provided in any one of the foregoing aspects related to the first network device and the implementations thereof.

Optionally, the memory <NUM> (memory #<NUM>) is located in the apparatus.

Optionally, the memory <NUM> (memory #<NUM>) is integrated with the processor.

Optionally, the memory <NUM> (memory #<NUM>) is located outside the apparatus.

Optionally, the first network device further includes a transceiver <NUM>, configured to receive and send data.

<FIG> is a schematic structural diagram of a second network device <NUM> not being part of the present invention. As shown in <FIG>, the second network device <NUM> is, for example, a device with an access and mobility management function AMF unit or a similar function unit. The second network device <NUM> includes a processor <NUM> and a memory <NUM>. The memory <NUM> may be a memory (memory #<NUM>) independent of the processor or the network device, or may be a memory (memory #<NUM> or memory #<NUM>) inside the processor or the network device. The memory <NUM> may be a physically independent unit, or may be storage space, a network hard disk, or the like on a cloud server.

The processor <NUM> is configured to read the computer-readable instruction to implement the method provided in any one of the foregoing aspects related to the second network device and the implementations thereof.

Optionally, the second network device further includes a transceiver <NUM>, configured to receive and send data.

In addition, the processor <NUM> or <NUM> may be a central processing unit, a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or another programmable logic device, a transistor logic device, a hardware component, or any combination thereof. The processor may implement or execute various example logical blocks, modules, and circuits described with reference to content disclosed in this application. Alternatively, the processor may be a combination of processors implementing a computing function, for example, a combination of one or more microprocessors or a combination of a digital signal processor and a microprocessor. In addition, the memory <NUM> or <NUM> may include a volatile memory (volatile memory), for example, a random access memory (random-access memory, RAM). The memory may alternatively include a non-volatile memory (non-volatile memory), for example, a flash memory (flash memory), a hard disk drive (hard disk drive, HDD), a solid-state drive (solid-state drive, SSD), a cloud storage (cloud storage), a network attached storage (NAS: network attached Storage), or a network drive (network drive). The memory may alternatively include a combination of memories of the foregoing types, or another medium or product in any form that has a storage function.

This application further provides a coordinated satellite communications system not being part of the present invention. The satellite communications system includes a ground station, a first network device, and a second network device. The first network device is the first network device described in the embodiment corresponding to <FIG>. The second network device is the second network device described in the embodiment corresponding to <FIG>. The ground station is usually a ground device that is disposed on the earth's surface (including being disposed on a ship or an airplane) to perform artificial satellite communication, and is mainly responsible for forwarding signaling and data between a satellite base station and a core network. The first network device may be a device with a user plane function UPF unit or a similar function unit, and the second network device may be a device with an access and mobility management function AMF unit or a similar function unit.

This application further provides a coordinated satellite communications system not being part of the present invention. The satellite communications system includes a ground station, a first network device, and a second network device. The first network device is the first network device corresponding to <FIG>. The second network device is the second network device corresponding to <FIG>. The ground station is usually a ground device that is disposed on the earth's surface (including being disposed on a ship or an airplane) to perform artificial satellite communication, and is mainly responsible for forwarding signaling and data between a satellite base station and a core network. The first network device may be a device with a user plane function UPF unit or a similar function unit, and the second network device may be a device with an access and mobility management function AMF unit or a similar function unit.

This application further provides a computer-readable medium not being part of the present invention. The computer-readable medium stores a computer program instruction. When the computer program instruction is executed by a computer, the method in any one of the foregoing embodiments is implemented.

This application further provides a computer program product not being part of the present invention. When the computer program product is executed by a computer, the method in any one of the foregoing embodiments is implemented.

A person of ordinary skill in the art may be aware that units, algorithms, and steps in the examples described with reference to the embodiments disclosed in this specification can be implemented by electronic hardware or a combination of computer software and electronic hardware. A person skilled in the art may use different methods to implement the described functions for each particular application, but it should not be considered that such an implementation goes beyond the scope of this application.

A person skilled in the art may clearly understand that, for the purpose of convenient and brief description, for a detailed working process of the system and apparatus described above, refer to a corresponding process in the foregoing method embodiments, and details are not described herein again.

For example, division into the units is merely logical function division and may be other division during actual implementation.

When the functions are implemented in a form of a software function unit and sold or used as an independent product, the functions may be stored in a computer-readable storage medium. Based on such an understanding, the technical solutions of this application essentially, or the part contributing to the current technology, or some of the technical solutions may be implemented in a form of a software product. The computer software product is stored in a storage medium, and includes several instructions for instructing a computer device (which may be a personal computer, a server, or a network device) to perform all or some of the steps of the methods described in the embodiments of this application.

Claim 1:
A satellite communication method, wherein the method comprises:
obtaining (S101), by a first network device (<NUM>) of a core network, traffic of a plurality of satellite communications links, or obtaining air interface resources allocated by a ground station (<NUM>) to a plurality of satellite base stations (<NUM>); and
sending (S102), by the first network device (<NUM>), identifier information to a second network device (<NUM>) of the core network, wherein the identifier information indicates that traffic of a satellite communications link reaches a specified threshold, or that an air interface resource allocated by the ground station (<NUM>) to a satellite base station (<NUM>) reaches a specified threshold,
wherein the first network device (<NUM>) of the core network is a data plane entity, and the second network device (<NUM>) of the core network is a control network entity.