Communication methods, devices, related equipment, and storage media

Abstract

The present disclosure provides a communication method, apparatus, satellite core network device, access network device, and storage medium. Among them, the method includes: a first satellite core network device receiving a first session establishment request transmitted from a first access network device, the first session establishment request being used to request to establish a session for a terminal and including at least an identifier of a first network slice; selecting a satellite serving the first network slice by using the location information and ephemeris information of the terminal; and establishing a session for the terminal by using the selected satellite.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims the priority of Chinese Patent Application No. 202210502155.X, filed in China on May 9, 2022, and all of its content is incorporated herein by reference. This disclosure relates to the field of communications, and in particular, to communication methods, devices, related equipment, and storage media.

Background Art

[0002] The satellite - terrestrial integrated network has a new and complex application scenario and complex and diverse service characteristics. By implementing the network slicing technology based on the integration of satellites and terrestrial areas, it is possible to efficiently organize network resources as needed for various service characteristics and form differentiated services for different users and different service scenarios. Currently, research on this technology in the satellite - terrestrial integrated network is still in its initial stage.

Summary of the Invention

Problems to be Solved by the Invention

[0003] To solve the problems in the related technology, embodiments of this disclosure provide a communication method, a device, related equipment, and a storage media.

Means for Solving the Problems

[0004] The technical solutions of the embodiments of this disclosure are realized as follows.

[0005] Embodiments of this disclosure provide a communication method applied to a first satellite core network device, the method comprising: receiving a first session establishment request transmitted from a first access network device, the first session establishment request being used to request to establish a session for a terminal and including at least an identifier of a first network slice; Using the location information and ephemeris information of the aforementioned terminal, select the satellite that will serve the first network slice, This includes establishing a session for the terminal using the selected satellite.

[0006] In the above embodiment, selecting a satellite to serve the first network slice using the location information and ephemeris information of the aforementioned terminal is: This includes selecting a satellite that the terminal accesses within one time period, in accordance with the terminal's location information and ephemeris information, and that supports the first network slice.

[0007] In the above embodiment, if the access time of the terminal exceeds the access time available from the selected satellite, the terminal re-selects a satellite that it accesses within one time period and that supports the first network slice, according to the terminal's location information and ephemeris information.

[0008] In the above embodiment, selecting the satellite that serves the first network slice described above is: This includes determining the satellite user plane function (UPF) and / or satellite operations platform that serve the first network slice.

[0009] In the above embodiment, the relationship between the network slice and the satellite is One network slice is supported by a single bearer on one satellite, One network slice is supported by one satellite, One satellite supports one network slice, At least one of the following conditions is met: a single satellite's multiple bearers support multiple network slices.

[0010] In the above configuration, the method is The method further includes determining the satellites that support the first network slice by utilizing a first mapping relationship which includes a mapping relationship between a network slice and a satellite bearer, and / or a second mapping relationship which includes a mapping relationship between a network slice and a satellite.

[0011] In the above configuration, the method is This further includes synchronizing the user information of the terminal with the terrestrial core network.

[0012] In the above embodiment, the user information includes: The location information of the aforementioned terminal, Subscribed network slice information and, Tracking Area (TA) related information, Related information on the Access and Mobility Management Function (AMF), It includes at least one of the following: Network Slice Selection Policy (NSSP).

[0013] In the above configuration, the method is Receiving a first registration request transmitted from the first access network device, which is a first registration request requesting registration for the terminal, The system further includes, after the registration of the terminal is successful, returning registration-related information to the first access network device, which includes the identifier of the configured network slice and the identifier of a network slice available in the area where the terminal is located.

[0014] In the above configuration, the method is The further includes transmitting context information of the terminal to the second satellite core network equipment.

[0015] In the above aspect, transmitting the context information of the terminal to the second satellite core network device includes transmitting the context information of the terminal to the second satellite core network device via an interface between the second satellite core network device and the terminal; transmitting the context information of the terminal to the second satellite core network device via the first access network device; and includes one of transmitting the context information of the terminal to the second satellite core network device sequentially via the first access network device and the second access network device.

[0016] Embodiments of the present disclosure further provide a communication method applicable to a first access network device, and the method includes receiving a second session establishment request transmitted from a terminal, where the second session establishment request is used to establish a session for the terminal and includes at least an identifier of a first network slice; selecting a first satellite core network device according to at least the location information of the terminal and the identifier of the first network slice; and transmitting a first session establishment request to the first satellite core network device, where the first session establishment request is used to request to establish a session for the terminal and includes at least an identifier of the first network slice.

[0017] In the above aspect, the method includes receiving a second registration request transmitted from the terminal, where the second registration request is used to request to register for the terminal; selecting the first satellite core network device for the terminal; and transmitting a first registration request to the first satellite core network device to request to register for the terminal. Receiving registration-related information returned from the first access network device, the registration-related information including an identifier of a configured network slice and an identifier of a network slice available in the area where the terminal is located; Further comprising selecting the first satellite core network device by at least using an identifier of a network slice available in the area where the terminal is located, location information of the terminal, and an identifier of the first network slice.

[0018] Embodiments of the present disclosure further provide a communication device provided in a first satellite core network device, the device comprising: A first receiving unit configured to receive a first session establishment request transmitted from a first access network device, the first session establishment request being used to request establishment of a session for a terminal and including at least an identifier of a first network slice; A first processing unit configured to select a satellite serving the first network slice by using location information and ephemeris information of the terminal, and establish a session for the terminal by using the selected satellite.

[0019] Embodiments of the present disclosure further provide a communication device provided in a first access network device, the device comprising: A second receiving unit configured to receive a second session establishment request transmitted from a terminal, the second session establishment request being used to request establishment of a session for the terminal and including at least an identifier of a first network slice; A second processing unit configured to select a first satellite core network device at least according to location information of the terminal and an identifier of the first network slice, and transmit a first session establishment request to the first satellite core network device, the first session establishment request being used to request establishment of a session for the terminal and including at least an identifier of a first network slice.

[0020] The embodiments of this disclosure are satellite core network equipment, A first communication interface for receiving a first session establishment request sent from a first access network device, which is used to request the establishment of a session for a terminal and includes at least the identifier of a first network slice, The satellite core network equipment further includes a first processor for selecting a satellite to serve the first network slice using the location information and ephemeris information of the terminal, and for establishing a session for the terminal using the selected satellite.

[0021] The embodiments of this disclosure are access network devices, A second communication interface for receiving a second session establishment request transmitted from a terminal, which is used to establish a session for the terminal and includes at least the identifier of a first network slice, and for transmitting a first session establishment request to the first satellite core network equipment, which is used to establish a session for the terminal and includes at least the identifier of a first network slice, The access network equipment further includes a second processor for selecting a first satellite core network device, at least according to the location information of the terminal and the identifier of the first network slice.

[0022] An embodiment of the present disclosure is a satellite core network device comprising a first processor and a first memory capable of storing a computer program that can run on the processor, The present invention further provides satellite core network equipment that, when the first processor is used to run the computer program, performs one of the steps of the satellite core network equipment side.

[0023] An embodiment of the present disclosure is an access network device including a second processor and a second memory capable of storing a computer program that can run on the processor, The present invention further provides an access network device that, when the second processor is used to run the computer program, performs one of the steps of the access network device side described above.

[0024] Embodiments of the present disclosure further provide a storage medium storing a computer program, wherein when the computer program is executed by a processor, a step of the method described in any one of the above-mentioned satellite core network equipment items is realized, or a step of the method described in any one of the above-mentioned access network equipment items is realized. [Effects of the Invention]

[0025] According to the communication method, apparatus, related equipment and storage medium of the embodiments of the present disclosure, a first access network device receives a second session establishment request transmitted from a terminal, which is used to establish a session for the terminal and includes at least the identifier of a first network slice, selects a first satellite core network device according to at least the location information of the terminal and the identifier of the first network slice, transmits a first session establishment request to the first satellite core network device, which is used to request that a session be established for the terminal and includes at least the identifier of a first network slice, the first satellite core network device uses the location information of the terminal and ephemeris information to select a satellite serving the first network slice, and uses the selected satellite to establish a session for the terminal. In embodiments of the embodiments of the present disclosure, the satellite core network can adjust the policy of satellites serving a given network slice instance in real time according to the ephemeris information and the location information of the terminal to select the optimal network connection mode, thereby meeting the resource isolation, quality assurance and service customization requirements of different application scenarios. [Brief explanation of the drawing]

[0026] [Figure 1] Figure 1 is a schematic flowchart of a communication method according to an embodiment of the present disclosure. [Figure 2] Figure 2 is a schematic diagram of the network structure according to an embodiment of the present disclosure. [Figure 3] Figure 3 is a schematic diagram illustrating the time-dependent changes of a satellite providing slicing services to a terminal according to an embodiment of the present disclosure. [Figure 4] Figure 4 is a schematic flowchart of another communication method according to an embodiment of the present disclosure. [Figure 5] Figure 5 is a schematic diagram of the processing flow of network slice data operations according to an application example of the present disclosure. [Figure 6] Figure 6 is a schematic diagram of the structure of a communication device according to an embodiment of the present disclosure. [Figure 7] Figure 7 is a schematic diagram of the structure of another communication device according to an embodiment of the present disclosure. [Figure 8] Figure 8 is a schematic diagram of the structure of satellite core network equipment according to an embodiment of the present disclosure. [Figure 9] Figure 9 is a schematic diagram of the structure of an access network device according to an embodiment of the present disclosure. [Figure 10] Figure 10 is a schematic diagram of the structure of a communication system according to an embodiment of the present disclosure. [Modes for carrying out the invention]

[0027] The present disclosure will be described in more detail below, in conjunction with the drawings and embodiments.

[0028] Regarding related technologies, the main methods employed for satellite-ground convergence networks include the following methods 1 to 3. Method 1 is satellite-transparent transmission, i.e., transparent transmission mode, in which the satellite only acts as a frequency converter and radio frequency device. Method 2 is a distributed base station, meaning the base station employs a centralized unit (CU)-distributed unit (DU) separation architecture, with only the DU deployed on the satellite, and is one of the regeneration modes. Method 3 involves deploying the entire base station to the satellite and is one of the regeneration modes.

[0029] On the other hand, related technologies address mobility management issues by employing a scenario where base stations are deployed on satellites (i.e., Method 2, regenerative transmission mode, which may also be called regenerative mode). In this method, satellites (e.g., non-geostationary orbit (NGSO) satellites) frequently change the ground stations they connect to and must notify the AMF of changes in the TA list they serve, resulting in a large amount of signaling on the N2 interface. To reduce the signaling overhead of the N2 interface, two extended fifth-generation (5G) network architectures have been proposed as solutions to reduce the impact of N2 interface signaling: Embodiment 1 employs a distributed AMF, specifically deploying a distributed AMF close to a ground station, with the local AMF handling N2 signaling. In this embodiment, the local AMF is a base station connected to it, and it is necessary to store the TA list served by the base station deployed on the satellite. Embodiment 2 involves employing an AMF agent, specifically deploying the AMF agent in a location close to the ground station, and the AMF agent is used to process N2 signaling and transmit N2 messages between the base station (gNB) and the AMF, and the AMF does not need to be modified.

[0030] As can be seen from the above description, the two embodiments described above either modify the ground AMF or add a ground AMF agent, and the satellite only actually provides access capabilities and cannot provide differentiated services for multiple application scenarios, and data operations still need to be returned to the ground core network for processing.

[0031] In embodiments of this disclosure, at least some of the functions of a core network are deployed on a satellite (hereinafter referred to as the satellite core network), and network slices (which may also be called slices) provide network isolation and assurance of the operational experience. The functions and advantages of the satellite core network are specifically represented in several aspects, namely, embodiments of the embodiments of this disclosure are applicable to the following scenarios. 1. In areas or regions where the deployment of 5G core networks (5GC) is difficult or costly, such as islands, open ocean, and mountainous areas, satellite core networks can reduce communication latency and signaling overhead, increase effective rates, and meet individual-centric needs. 2. The satellite core network can provide edge computing and the ability to keep data within its domain in areas such as islands, open ocean, and mountainous regions, meeting the needs of industrial internet, automotive networks, military facilities, and more. 3. The satellite core network enables satellite-based network slicing, thereby strengthening global resource scheduling and quality assurance for integrated space-ground networks. 4. In disaster scenarios and abnormal traffic peak scenarios, the satellite core network can provide disaster recovery backup and load sharing to the ground core network. 5. In countries / regions with underdeveloped terrestrial communication infrastructure and sparse populations, if local policies are supportive, international roaming and overseas operation services can be provided via a satellite core network.

[0032] In cases where the core network is deployed on satellites, ensuring satellite access while achieving network slice isolation and operational reliability still requires considering the issue of terminal mobility management. This issue may also be referred to as the mobility management issue for the area covered by the mobile satellite.

[0033] Based on this, in various embodiments of the present disclosure, the satellite core network adjusts the satellite policy serving a particular network slice instance in real time according to ephemeris information (such as the precise location of the satellite, satellite trajectory, and satellite connectivity capability) and the location of the terminal, thereby selecting the optimal network connectivity mode. In this way, it is possible to satisfy the resource isolation, quality assurance, and service customization requirements of different application scenarios (e.g., scenarios requiring network requirements such as latency, uplink and downlink bandwidth, deterministic transmission, and data not leaving the domain).

[0034] The embodiments of this disclosure provide a communication method applicable to the first satellite core network equipment, as shown in Figure 1, the method is Step 101 receives a first session establishment request sent from a first access network device, which is used to request the establishment of a session for a terminal and includes at least the identifier of a first network slice, Step 102 involves selecting a satellite to serve the first network slice using the location information and ephemeris information of the aforementioned terminal. The process includes step 103 of establishing a session for the terminal using the selected satellite.

[0035] In this context, "satellite core network equipment" refers to core network equipment deployed on a satellite. For example, an AMF (Automated Micronetwork Function) may be deployed on a satellite, and the core network equipment may include the AMF. However, the embodiments of this disclosure are not limited to this, and it is sufficient that the function is realized.

[0036] Access network equipment provides network access services to terminals, and may specifically be a base station, but the embodiments of this disclosure are not limited to this, as long as the function is realized.

[0037] In actual applications, the first access network equipment may be deployed on land or on satellite, but the embodiments of this disclosure are not limited to this.

[0038] The aforementioned terminal may also be referred to as User Equipment (UE) or user.

[0039] The identifier of the first network slice may include Single Network Slice Selection Assistance Information (S-NSSAI), but the embodiments of this disclosure are not limited thereto.

[0040] In actual applications, the first access network device needs to know the network slice composed of the first satellite core network device and the network slices available in the area where the terminal is located, in order to select the satellite core network device to access for the terminal.

[0041] Based on this, in one embodiment, before step 101, the method is Receiving a first registration request transmitted from the first access network device, which is a first registration request requesting registration for the terminal, After the registration of the terminal is successful, the system may further include returning registration-related information to the first access network device, which includes the identifier of the configured network slice and the identifier of a network slice available in the area where the terminal is located.

[0042] If the contract information of the terminal indicates that it is a satellite user, then the registration of the terminal is confirmed to be successful.

[0043] The network slice identifier may include Network Slice Selection Assistance Information (NSSAI), but the embodiments of this disclosure are not limited thereto.

[0044] In step 101, if the first access network receives a session establishment request from the terminal and determines that it has selected the satellite core network, it transmits the first session establishment request to the first satellite core network equipment. The first session establishment request may carry the first network slice and may also carry the terminal's location information.

[0045] In step 102, the first satellite core network equipment uses the terminal's location information and ephemeris information to determine the satellite serving the first network slice. In order to implement the embodiments of this disclosure, in actual applications, as shown in Figure 2, each satellite may be equipped with core network equipment functionality to perform at least steps 101 to 103, and each orbital satellite constellation (a constellation is formed by multiple satellites on the same orbital plane, and the multiple satellites are connected via satellite links to transmit the relevant information) may be equipped with core network equipment functionality to perform at least steps 101 to 103. Since the satellites orbit their respective orbits, i.e., the satellites are moving, after the terminal's location is determined, as shown in Figure 3, the service time of the network slice provided to the terminal by each orbital plane is limited. Therefore, this point must be taken into consideration when selecting a satellite for a particular network slice for the terminal.

[0046] Based on this, in one embodiment, the specific implementation of step 102 is as follows: The system may also include selecting satellites that the terminal accesses within one time period and that support the first network slice, based on the terminal's location information and ephemeris information.

[0047] In actual applications, the location information of the terminal may include the longitude and / or latitude information of the location where the terminal is located. In the embodiments of this disclosure, the terminal supports fixed connectivity (i.e., connectivity to a fixed network) and mobile connectivity (i.e., connectivity to a mobile network), and the location information of the terminal allows for the determination of information such as the fixed connectivity coverage status and mobile connectivity coverage status of the network at the location where the terminal is located.

[0048] According to the ephemeris information, the precise position of the satellite, its orbit, its satellite connectivity capabilities, etc., can be determined. In actual applications, when a satellite is registered and connected to the network, the corresponding ephemeris information may be configured in the first satellite core network equipment so that the equipment can access the ephemeris information.

[0049] In the embodiments of this disclosure, the terminal supports transmitting its location information to the core network (including the terrestrial core network and the satellite core network) when powered on or registered, and also supports updating its location information to the core network whether idle or connected.

[0050] The aforementioned time period can be understood as a single timer (which may be expressed as a Timer in English), and the time period can be set as needed. For example, since the time length covered by one TA by one satellite is typically 10 to 15 minutes, the time period may be set to 15 minutes, but the embodiments of this disclosure are not limited thereto.

[0051] In actual application, the first satellite core network equipment may select a satellite for the terminal in conjunction with factors such as the network slice supported by the satellite, the TA list and / or cell served by the first access network equipment, and the time period.

[0052] In the embodiments of this disclosure, the relationship between the network slice and the satellite is One network slice is supported by a single bearer on one satellite, One network slice is supported by one satellite, One satellite supports one network slice, At least one of the following conditions is met: a single satellite's multiple bearers support multiple network slices.

[0053] In actual applications, from the perspective of network slices, terminals in the same region may access multiple network slices, and one network slice may be supported by a single bearer of one satellite, or by one satellite. From the perspective of satellites, the same region may be covered by one or more satellites at the same time, and one satellite may support a single network slice, that is, one satellite may support one network slice, or it may support multiple network slices via multiple bearers.

[0054] In one embodiment, the first satellite core network device may determine the satellites that support the first network slice by utilizing a first mapping relationship which includes a mapping relationship between a network slice and a satellite bearer, and / or a second mapping relationship which includes a mapping relationship between a network slice and a satellite, thereby selecting the satellites that support the first network slice for the terminal.

[0055] Here, if the first satellite core network equipment determines that there are multiple candidate satellites, that is, if there are multiple satellites capable of supporting the first network slice at the location where the terminal is located, the first satellite core network equipment may, if necessary, select one satellite from the multiple candidate satellites. For example, it may preferentially select the satellite with the strongest signal strength, or select one satellite according to the satellite load, but the embodiments of this disclosure are not limited to this.

[0056] In the embodiments of this disclosure, if an orbiting satellite (i.e., a selected satellite) moves away from the area to which the terminal's location belongs, i.e., no longer covers the area to which the terminal's location belongs, the first network slice can be supported by orbiting satellites in other coverage areas. Therefore, if the terminal's access time exceeds the access time that can be provided by the satellite (i.e., the selected satellite moves away from the area to which the terminal's location belongs), a satellite switchover is necessary. In other words, if the terminal's access time exceeds the access time that can be provided by the selected satellite, the continuity of operations is ensured by re-selecting a satellite that the terminal accesses within one time period and that supports the first network slice, according to the terminal's location information and ephemeris information.

[0057] The ephemeris information represents the orbital parameters of the satellite, and by using the ephemeris information, it is possible to know the position that the satellite is expected to be at at regular intervals. The ephemeris information may also be called ephemeris data or ephemeris, but the embodiments of this disclosure are not limited thereto, and it is sufficient as long as the function is realized.

[0058] The selected satellite may deploy business processing functions, such as a Content Delivery Network (CDN), high-speed cache (Cache), and Mobile Edge Computing (MEC), to provide business services based on the first network slice to the terminal.

[0059] Based on this, in one embodiment, selecting the satellite that serves the above-mentioned first network slice is, This may also include determining the satellite UPF and / or satellite operations platform that serves the first network slice.

[0060] In this context, "satellite UPF" refers to the deployment of UPF on a satellite, and accordingly, "satellite operations platform" refers to the deployment of an operations platform on a satellite.

[0061] In actual applications, the first satellite core network equipment may, if necessary, determine the satellite UPF and / or satellite operations platform that serves the first network slice. For example, the satellite UPF and / or satellite operations platform that serves the first network slice may be determined according to the QoS requirements of the first network slice. However, the embodiments of this disclosure do not limit the specific process for determining the satellite UPF and / or satellite operations platform that serves the first network slice.

[0062] In actual applications, in order to ensure the continuity of the terminal's operations after the terminal moves, the first satellite core network equipment needs to synchronize the terminal's user information with the ground core network. In this way, if a ground core network providing slice services is selected after the terminal moves, the ground core network will be able to provide slice services in a timely manner.

[0063] Based on this, in one embodiment, the method is This may further include synchronizing the user information of the terminal with the terrestrial core network.

[0064] In one embodiment, the user information includes: The location information of the aforementioned terminal, Subscribed network slice information and, TA-related information, For example, AMF identifiers (e.g., IDs) and / or related AMF information such as AMF lists, At least one of the NSSPs may be included.

[0065] In actual applications, the first satellite core network equipment may further synchronize other information with the ground core network, such as timers for different satellites covering the same TA, i.e., the time length for covering the same TA; however, the embodiments of this disclosure are not limited to this.

[0066] In actual applications, the N14 interface may be extended so that the first satellite core network equipment synchronizes the relevant information with the ground core network via the N14 interface.

[0067] If, after the terminal moves, the first satellite core network equipment becomes unable to provide services to the terminal, a switchover of the satellite core network equipment will be necessary to ensure continuity of operations.

[0068] Based on this, in one embodiment, the method is This may further include transmitting context information from the terminal to the second satellite core network equipment.

[0069] In actual application, the first satellite core network device may directly transmit the terminal context information to the second satellite core network device via the interface between the first satellite core network device and the second satellite core network device, or, more precisely, the first satellite core network device may transmit the terminal context information to the second satellite core network device via the interface between it and the second satellite core network device. For example, by extending the N14 interface, the first satellite core network device may transmit the terminal context information to the second satellite core network device via the N14 interface.

[0070] Furthermore, the first satellite core network device may transmit the terminal context information to the second satellite core network device via the first access network device.

[0071] Furthermore, the first satellite core network equipment may sequentially transmit the context information of the terminal to the second satellite core network equipment via the first access network equipment and the second access network equipment.

[0072] The second access network equipment may be deployed on a satellite or on land, but the embodiments of this disclosure are not limited thereto.

[0073] In actual applications, it is possible to select one of the above transmission methods as needed to transmit contextual information from the terminal.

[0074] Accordingly, embodiments of this disclosure further provide a communication method applicable to a first access network device, as shown in Figure 4, the method is: Step 401 includes receiving a second session establishment request sent from a terminal, which is used to establish a session for the terminal and includes at least the identifier of a first network slice, Step 402 selects a first satellite core network device based at least on the location information of the terminal and the identifier of the first network slice, Step 403 includes sending a first session establishment request to the first satellite core network equipment, which is used to request that a session be established for a terminal and which includes at least an identifier of the first network slice.

[0075] In one embodiment, before performing step 401, the method is Receiving a second registration request transmitted from the aforementioned terminal, which is a second registration request requesting to register for the aforementioned terminal, Selecting the first satellite core network equipment for the aforementioned terminal, Sending a first registration request to the first satellite core network device to request registration for the terminal, The system may further include receiving registration-related information returned from the first access network device, which includes an identifier for a configured network slice and an identifier for a network slice available in the area where the terminal is located.

[0076] Accordingly, in step 402, the first access network device selects the first satellite core network device using at least the identifier of a network slice available in the area where the terminal is located, the location information of the terminal, and the identifier of the first network slice.

[0077] Of these, the second registration request will carry at least the identifier of the requested network slice (the identifier of the network slice supported by the terminal).

[0078] The first access network device may, if necessary, determine whether to select a satellite core network. If it determines that it is necessary to select a satellite core network, for example, if the satellite core network supports the first network slice of the terminal, its serving capacity is equivalent to that of the ground network, and the ground network is congested, it will determine to select the satellite core network. Furthermore, for example, if the terminal is located on a fishing vessel, it will determine to select the satellite core network, and then, if necessary, select satellite core network equipment to serve the terminal.

[0079] According to the communication method of the embodiment of the present disclosure, a first access network device receives a second session establishment request transmitted from a terminal, which is used to establish a session for the terminal and includes at least the identifier of a first network slice, selects a first satellite core network device according to at least the location information of the terminal and the identifier of the first network slice, and transmits a first session establishment request to the first satellite core network device, which is used to request that a session be established for the terminal and includes at least the identifier of a first network slice, the first satellite core network device uses the location information of the terminal and ephemeris information to select a satellite serving the first network slice, and uses the selected satellite to establish a session for the terminal. In embodiments of the present disclosure, the satellite core network can adjust the policy of satellites serving a given network slice instance in real time according to the ephemeris information and the location information of the terminal to select the optimal network connection mode, thereby meeting the resource isolation, quality assurance, and service customization requirements of different application scenarios.

[0080] The present disclosure will be described in more detail below, along with examples of its application.

[0081] In this application example, the AMF deployed on the satellite is referred to as satellite AMF (or satellite AMF) in the following description, the Unified Data Management (UDM) deployed on land is referred to as ground UDM, the AMF deployed on land is referred to as ground AMF, the Network Slice Selection Function (NSSF) deployed on land is referred to as ground NSSF, the Session Management Function (SMF) deployed on the satellite is referred to as satellite SMF, and the Radio Access Network (RAN) deployed on the satellite is referred to as satellite RAN.

[0082] In this application example, a single or multiple bearers for a multi-network slice policy are realized through a technology that allows the satellite core network to dynamically switch network slices.

[0083] The processing flow for network slice data operations in this application embodiment includes the following steps 500 to 509, as shown in Figure 5.

[0084] Step 500: This is a pre-configuration procedure in which you either pre-configure the NSSAI on the UE or configure the NSSAI on the network side (the configured NSSAI may be referred to as "Configured NSSAI" in English), and then perform Step 501. Here, the pre-configuration of NSSAI may include configuration using Over-the-Air Technology (OTA) and / or manual configuration. In other words, the method for allocating network slices is consistent with the procedure for allocating network slice identifiers under network management contracts in related technologies.

[0085] When a user contracts for slicing services, the S-NSSAI is stored or updated, and the network assigns a subscribed NSSAI (which may be expressed as "subscribed NSSAI" in English), which is then sent to the ground AMF via Ground Integrated Data Management (UDM). The ground NSSF stores slice instance information (including network slice instances (NSI), NSSAI, TA list, AMF list, etc.), and this slice instance information is used at least for AMF re-selection. The ground AMF exchanges real-time information with the satellite AMF via an extended N14 interface, and the messages transmitted mainly include user information (including UE location information, subscribed NSSAI, TA list, AMF list, UE NSSP, etc.). Also, when a user contracts, the user may be a satellite user.

[0086] Step 501: The UE initiates the registration request. Here, the requested NSSAI is carried in the registration request.

[0087] Step 502: After receiving the registration request, the Radio Access Network (RAN) (i.e., the first access network equipment mentioned above) selects the appropriate satellite AMF currently located in the UE's coverage area in accordance with the requested NSSAI. In the transmission network (TN), it is necessary to map the NSSAI to the corresponding Virtual Local Area Network (VLAN) identifier (ID) and find the appropriate bearer network channel to perform message transmission.

[0088] Step 503: Since the user of the UE is a satellite user, if the user information of the UE is available in the satellite AMF, it means that the registration of the UE was successful, and then step 504 is performed.

[0089] Step 504: The satellite AMF returns to the UE the configured NSSAI (i.e., all supported NSSAI) and allowed NSSAI (i.e., NSSAI available in the current domain and access status, i.e., NSSAI available in the domain where the UE is located), and then performs Step 505. If the RAN is a ground-based RAN, the satellite AMF sequentially returns the configured NSSAI and authorized NSSAI to the UE via the TN and RAN. On the other hand, if the RAN is a satellite-based RAN, the satellite AMF returns the configured NSSAI and authorized NSSAI to the UE via the RAN.

[0090] Step 505: After receiving the NSSAI returned from the satellite AMF, the terminal initiates a session establishment request and requests the establishment of a Protocol Data Unit (PDU) session. Here, the session establishment request carries the S-NSSAI of slice 1 corresponding to the application, which is a subset of the Allowed NSSAI.

[0091] Step 506: After receiving the session establishment request, the RAN selects the appropriate route according to the S-NSSAI of slice 1. Here, the RAN chooses whether to serve with satellite AMF or ground AMF (this step supports the RAN's AMF redirection technology). If you choose to serve with satellite AMF, perform step 507.

[0092] Step 507: After receiving the session establishment request, the satellite AMF selects the slice satellite that the current UE will access within one time period (T1) according to the UE's location and ephemeris information, and then performs Step 508. Specifically, the satellite AMF may select the satellite that the UE is currently accessing based on relevant information (e.g., NSI, NSSAI (i.e., slice 1), TA list, AMF List, timers where different satellites cover the same TA, etc.). If the UE's access time exceeds the access time available from the satellite, the system switches to the next satellite. In cases where multiple satellites provide overlapping coverage, users in the same area will be given priority access to the satellite with the strongest signal strength during the same time period. If the UE's communication continues, the connection with the satellite will be maintained until the satellite leaves its coverage area.

[0093] Step 508: The satellite AMF determines whether to process the business by the satellite CDN / Cache / MEC or return it to the ground AMF via the extended N14 interface or RAN to process the session corresponding to slice 1, by determining whether it can support the identifier of the network slice carried by the user (i.e., slice 1). Here, if the satellite AMF supports the identifier of the network slice, and it determines that the business will be processed by the satellite CDN / Cache / MEC, it invokes the corresponding QoS according to the identifier of the network slice currently being accessed, then the satellite SMF completes the identification of the corresponding satellite UPF and transmits it to the satellite CDN / Cache / MEC (i.e., the satellite business platform mentioned above) to process the business, and then executes step 509. On the other hand, if the satellite AMF does not support the identifier of the network slice, and it determines that the business will be processed by the ground AMF, the satellite AMF transparently transmits it to the ground AMF via the N14 interface or RAN to process the business.

[0094] Step 509: The satellite CDN / Cache / MEC returns a business processing response.

[0095] In the above process, data synchronization performed by the satellite AMF and ground AMF via the N14 interface may be understood as an update, and the data to be updated includes user information and timers where different satellites cover the same TA.

[0096] In the above process, if it is necessary to switch satellite AMFs, context information of the UE may be directly exchanged using the N14 interface between satellite AMFs, or an extended N2 interface may be established between the satellite RAN and the next satellite AMF to transmit the context information of the UE, or context information may be transmitted via the Xn interface over the link between RANs.

[0097] As can be seen from the above description, this application embodiment provides a mechanism for achieving network slice isolation and operational assurance under satellite access, realizing a parallel bearer for multi-slice policies by a technology in which the satellite core network dynamically switches network slices, that is, adjusting in real time the policy of one satellite in one orbital plane serving a certain network slice instance according to ephemeris information and the location of the UE. By adopting the embodiments of this disclosure, it is possible to meet the resource isolation, quality assurance, and service customization requirements of different elements and different application scenarios.

[0098] In order to realize the method for the first satellite core network equipment according to the embodiment of the present disclosure, the embodiment of the present disclosure further provides a communication device provided in the first satellite core network equipment, as shown in Figure 6, the device is A first receiving unit 601 for receiving a first session establishment request transmitted from a first access network device, which is used to request the establishment of a session for a terminal and includes at least an identifier of a first network slice, The system includes a first processing unit 602 for selecting a satellite to serve the first network slice using the location information and ephemeris information of the terminal, and for establishing a session for the terminal using the selected satellite.

[0099] In one embodiment, the first processing unit 602 is used to select a satellite that the terminal accesses within one time period and that supports the first network slice, according to the terminal's location information and ephemeris information.

[0100] In one embodiment, if the access time of the terminal exceeds the access time available from the selected satellite, the first processing unit 602 re-selects a satellite that the terminal accesses within one time period and that supports the first network slice, according to the terminal's location information and ephemeris information.

[0101] In one embodiment, the first processing unit 602 is used to determine the satellite UPF and / or satellite operations platform that serves the first network slice when determining the satellite that serves the first network slice.

[0102] In one embodiment, the relationship between the network slice and the satellite is One network slice is supported by a single bearer on one satellite, One network slice is supported by one satellite, One satellite supports one network slice, At least one of the following conditions is met: a single satellite's multiple bearers support multiple network slices.

[0103] In one embodiment, the first processing unit 602 is: A first mapping relationship, which includes the mapping relationship between the network slice and the satellite bearer, and / or a second mapping relationship, which includes the mapping relationship between the network slice and the satellite, are further used to determine the satellites that the first network slice supports.

[0104] In one embodiment, the first processing unit 602 is further used to synchronize the user information of the terminal with the terrestrial core network.

[0105] In one embodiment, the first receiving unit 601 is further used to receive a first registration request transmitted from the first access network device, which is a first registration request requesting registration for the terminal. After the registration of the terminal is successful, the first processing unit 602 is further used to return registration-related information to the first access network device, which includes the identifier of the configured network slice and the identifier of the network slice available in the area where the terminal is located.

[0106] In one embodiment, the first processing unit 602 is further used to transmit the context information of the terminal to the second satellite core network equipment.

[0107] In one embodiment, the first processing unit 602 is Transmitting context information of the terminal to the second satellite core network equipment via the interface with the second satellite core network equipment, Transmitting the context information of the terminal to the second satellite core network device via the first access network device, This device is used to transmit the context information of the terminal to the second satellite core network device in one of the following ways: sequentially transmitting the context information of the terminal to the second satellite core network device via the first access network device and the second access network device.

[0108] In actual applications, the first receiving unit 601 may be implemented by a communication interface in a communication device, and the first processing unit 602 may be implemented by a combination of a processor and a communication interface in a measuring device.

[0109] In order to implement the method on the first access network equipment side according to the embodiment of the present disclosure, the embodiment of the present disclosure further provides a communication device provided in the first access network equipment, as shown in Figure 7, the device is A second receiving unit 701 for receiving a second session establishment request sent from a terminal, which is used to establish a session for the terminal and includes at least an identifier of a first network slice, The system includes a second processing unit 702 for selecting a first satellite core network device based at least on the location information of the terminal and the identifier of the first network slice, and for sending a first session establishment request to the first satellite core network device, which is used to request the device to establish a session for the terminal and which includes at least the identifier of the first network slice.

[0110] In one embodiment, the second receiving unit 701 is used to receive a second registration request transmitted from the terminal, which is a second registration request requesting registration for the terminal, and to receive registration-related information returned from the first access network device, which includes an identifier for the configured network slice and an identifier for a network slice available in the area where the terminal is located. The second processing unit 702 is further used to select the first satellite core network equipment for the terminal and to send a first registration request to the first satellite core network equipment to request registration for the terminal, among which, The second processing unit 702 selects the first satellite core network equipment using at least the identifier of a network slice available in the area where the terminal is located, the location information of the terminal, and the identifier of the first network slice.

[0111] In actual applications, the second receiving unit 701 may be implemented by a communication interface in a communication device, and the second processing unit 702 may be implemented by a combination of a processor and a communication interface in a measuring device.

[0112] It should be explained that, while the above-described example of a communication device performing communication involved the division of each program module, in actual applications, the above processes may be assigned to different program modules as needed. That is, the internal structure of the device may be divided into different program modules to perform all or some of the processes described above. Furthermore, the communication device according to the above-described example belongs to the same concept as the communication method example, and for details of its specific implementation process, please refer to the method example, as it will not be repeated here.

[0113] Based on the hardware implementation of the above program module and in order to realize the method on the first satellite core network equipment side according to the embodiment of this disclosure, the embodiment of this disclosure further provides satellite core network equipment, as shown in Figure 8, the satellite core network equipment 800 is A first communication interface 801 that allows information exchange with first access network devices, A first processor connected to the first communication interface 801 so as to enable information exchange with the first access network equipment, and a first processor 802 for executing one or more methods according to the technical aspects of the first satellite core network equipment when running a computer program, It includes a first memory 803 in which the aforementioned computer program is stored.

[0114] Specifically, the first communication interface 801 is used to receive a first session establishment request transmitted from a first access network device, which is used to request the establishment of a session for a terminal, and which includes at least the identifier of a first network slice. The first processor 802 is used to select a satellite to serve the first network slice using the terminal's location information and ephemeris information, and to establish a session for the terminal using the selected satellite.

[0115] In one embodiment, the first processor 802 is used to select a satellite that the terminal accesses within one time period and that supports the first network slice, according to the terminal's location information and ephemeris information.

[0116] In one embodiment, if the access time of the terminal exceeds the access time available from the selected satellite, the first processor 802 re-selects a satellite that the terminal accesses within one time period and that supports the first network slice, according to the terminal's location information and ephemeris information.

[0117] In one embodiment, the first processor 802 is used to determine the satellite UPF and / or satellite operations platform that serves the first network slice when determining the satellite that serves the first network slice.

[0118] In one embodiment, the relationship between the network slice and the satellite is One network slice is supported by a single bearer on one satellite, One network slice is supported by one satellite, One satellite supports one network slice, At least one of the following conditions is met: a single satellite's multiple bearers support multiple network slices.

[0119] In one embodiment, the first processor 802 is: A first mapping relationship, which includes the mapping relationship between the network slice and the satellite bearer, and / or a second mapping relationship, which includes the mapping relationship between the network slice and the satellite, are further used to determine the satellites that the first network slice supports.

[0120] In one embodiment, the first processor 802 is further used to synchronize the user information of the terminal with the terrestrial core network via the first communication interface 801.

[0121] In one embodiment, the first communication interface 801 is further used to receive a first registration request transmitted from the first access network device, which is a first registration request requesting registration for the terminal. After the registration of the terminal is successful, the first processor 802 is further used to return registration-related information to the first access network device, which includes an identifier for the network slice configured via the first communication interface 801 and an identifier for the network slice available in the area where the terminal is located.

[0122] In one embodiment, the first processor 802 is further used to transmit context information of the terminal to the second satellite core network equipment via the first communication interface 801.

[0123] In one embodiment, the first processor 802 is Transmitting context information of the terminal to the second satellite core network equipment via the interface with the second satellite core network equipment, Transmitting the context information of the terminal to the second satellite core network device via the first access network device, This device is used to transmit the context information of the terminal to the second satellite core network device in one of the following ways: sequentially transmitting the context information of the terminal to the second satellite core network device via the first access network device and the second access network device.

[0124] What needs to be explained is that the specific processing steps of the first processor 802 and the first communication interface 801 can be understood by referring to the method described above.

[0125] Of course, in actual applications, each component within the satellite core network equipment 800 is connected via the bus system 804. Understandably, the bus system 804 is configured to enable communication between these components. In addition to the data bus, the bus system 804 includes a power bus, a control bus, and a status signal bus. However, for the sake of clarity, Figure 8 shows all the different buses as part of the bus system 804.

[0126] In embodiments of the present disclosure, the first memory 803 is configured to store various types of data to support the operation of the satellite core network equipment 800. Examples of this data include any computer programs to be operated on the satellite core network equipment 800.

[0127] The methods presented in the embodiments of this disclosure may be applied within or implemented by the first processor 802. The first processor 802 may be an integrated circuit chip having signal processing capabilities. In implementation, each step of the above method can be completed by an integrated logic circuit or a software command, which is hardware within the first processor 802. The first processor 802 described above may be a general-purpose processor, a digital signal processor (DSP), or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, etc. The first processor 802 can implement or execute each method, step and logic block diagram disclosed in the embodiments of this disclosure. The general-purpose processor may be a microprocessor or any common processor, etc. The combination of the steps in the methods disclosed in the embodiments of this disclosure may be completed as a direct implementation by execution by a hardware decoder processor, or by execution by a combination of hardware and software modules within a decoder processor. The software module may be located in a storage medium, which is located in the first memory 803. The first processor 802 reads the information in the first memory 803 and combines it with the hardware to complete the steps in the method described above.

[0128] In exemplary embodiments, the satellite core network equipment 800 may be implemented by one or more application-specific integrated circuits (ASICs), DSPs, programmable logic devices (PLDs), complex programmable logic devices (CPLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontroller units (MCUs), microprocessors, or other electronic components, and may be configured to perform the methods described above.

[0129] Based on the hardware implementation of the above program module and in order to realize the first access network device method according to the embodiment of this disclosure, the embodiment of this disclosure further provides an access network device, as shown in Figure 9, the access network device 900 is A second communication interface 901 that allows information exchange with the first satellite core network equipment, A second processor connected to the second communication interface 901 so as to enable information exchange with the first satellite core network equipment, and a second processor 902 for executing one or more technical methods on the first access network equipment side when running a computer program, It includes a second memory 903 in which the aforementioned computer program is stored.

[0130] Specifically, the second communication interface 901 receives a second session establishment request transmitted from a terminal, which is used to establish a session for the terminal and includes at least the identifier of the first network slice, and is used to transmit a first session establishment request to the first satellite core network equipment, which is used to establish a session for the terminal and includes at least the identifier of the first network slice. The second processor 902 is used to select the first satellite core network equipment, at least according to the location information of the terminal and the identifier of the first network slice.

[0131] In one embodiment, the second communication interface 901 is used to receive a second registration request transmitted from the terminal, which requests registration on behalf of the terminal, and to receive registration-related information returned from the first access network device, which includes an identifier for the configured network slice and an identifier for a network slice available in the area where the terminal is located. The second processor 902 is further used to select the first satellite core network equipment for the terminal and to send a first registration request to the first satellite core network equipment to request the second communication interface 901 to register for the terminal, among which, The second processor 902 selects the first satellite core network equipment using at least the identifier of a network slice available in the area where the terminal is located, the location information of the terminal, and the identifier of the first network slice.

[0132] What needs to be explained is that the specific processing steps of the second communication interface 901 and the second processor 902 can be understood by referring to the method described above.

[0133] Of course, in actual applications, each component within the access network device 900 is connected via the bus system 904. Understandably, the bus system 904 is configured to enable communication between these components. In addition to the data bus, the bus system 904 includes a power bus, a control bus, and a status signal bus. However, for the sake of clarity, Figure 9 shows all the different buses as the bus system 904.

[0134] In embodiments of this disclosure, the second memory 903 is configured to store various types of data to support the operation of the access network device 900. Examples of this data include any computer programs to be operated on the access network device 900.

[0135] The methods presented in the embodiments of this disclosure may be applied within or implemented by the second processor 902. The second processor 902 may be an integrated circuit chip having signal processing capabilities. In implementation, each step of the above method can be completed by an integrated logic circuit or a software command, which is hardware within the second processor 902. The second processor 902 described above may be a general-purpose processor, a DSP, or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, etc. The second processor 902 can implement or execute each method, step and logic block diagram disclosed in the embodiments of this disclosure. The general-purpose processor may be a microprocessor or any common processor, etc. The combination of the steps in the methods disclosed in the embodiments of this disclosure may be completed as a direct implementation by execution by a hardware decoder processor, or by execution by a combination of hardware and software modules within a decoder processor. The software module may be located in a storage medium, which is located in a second memory 903. The second processor 902 reads the information in the second memory 903 and combines it with its hardware to complete the steps in the method described above.

[0136] In exemplary embodiments, the access network device 900 may be implemented by one or more ASICs, DSPs, PLDs, CPLDs, FPGAs, general-purpose processors, controllers, MCUs, microprocessors, or other electronic components and configured to perform the methods described above.

[0137] Understandably, the memories (first memory 803, second memory 903) in the embodiments of this disclosure may be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. Among these, non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), ferromagnetic random access memory (FRAM®), flash memory, magnetic surface memory, optical disc, or compact disc read-only memory (CD-ROM), and magnetic surface memory may be magnetic disk memory or magnetic tape memory. Volatile memory may be random access memory (RAM) and may be used as an external high-speed cache.For example, various types of RAM are available, such as, but are not limited to, static random access memory (SRAM), synchronous static random access memory (SSRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synclink dynamic random access memory (SLDRAM), and direct memory bus random access memory (DRRAM). The memories described in the embodiments of this disclosure include, but are not limited to, these and any other suitable types of memory.

[0138] To implement the method according to the embodiments of the present disclosure, the embodiments of the present disclosure further provide a communication system, which, as shown in Figure 10, includes a first satellite core network device 1001 and a first access network device 1002.

[0139] The specific processing steps of the first satellite core network equipment 1001 and the first access network equipment 1002 have been described in detail above, so they will not be repeated here.

[0140] In exemplary embodiments, embodiments of the present disclosure further provide a storage medium, i.e., a computer storage medium, which is specifically a computer-readable storage medium and includes, for example, a first memory 803 storing a computer program, the computer program being executable by a first processor 802 of satellite core network equipment 800 so as to complete the steps described above in the method on the first satellite core network equipment side. Furthermore, for example, a second memory 903 storing a computer program is included, the computer program being executable by a second processor 902 of access network equipment 900 so as to complete the steps described above in the method on the first access network equipment side. The computer-readable storage medium may be a memory such as FRAM, ROM, PROM, EPROM, EEPROM, Flash Memory, surface-mount memory, optical disk, or CD-ROM.

[0141] It should be explained that terms like "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0142] Furthermore, the technical embodiments described in the embodiments of this disclosure can be combined in any way, as long as they do not contradict each other.

[0143] The foregoing describes only preferred embodiments of the present disclosure and is not intended to limit the scope of protection of this application.

Claims

1. A communication method applicable to the first satellite core network equipment, wherein the method is Receiving a first session establishment request sent from a first access network device, which is used to request the establishment of a session for a terminal, and which includes at least the identifier of the first network slice, Using the location information and ephemeris information of the aforementioned terminal, select the satellite that will serve the first network slice, A communication method comprising establishing a session for the terminal using a selected satellite.

2. Selecting a satellite to serve the first network slice using the location information and ephemeris information of the aforementioned terminal is: The method according to claim 1, comprising selecting a satellite that the terminal accesses within one time period and that supports the first network slice, according to the terminal's location information and ephemeris information.

3. The method according to claim 2, wherein if the access time of the terminal exceeds the access time available from the selected satellite, the terminal re-selects a satellite that it accesses within one time period and that supports the first network slice, according to the terminal's location information and ephemeris information.

4. Selecting the satellite to serve the first network slice is, The method according to claim 1, comprising determining a satellite user plane function (UPF) and / or satellite operations platform that serves the first network slice.

5. The connection between the network slice and the satellite is One network slice is supported by a single bearer on one satellite, One network slice is supported by one satellite, One satellite supporting one network slice, The method according to claim 1, wherein at least one of the following conditions is met: multiple bearers of a single satellite support multiple network slices.

6. The aforementioned method, The method according to claim 5, further comprising determining the satellites that support the first network slice by utilizing a first mapping relationship which includes a mapping relationship between a network slice and a satellite bearer, and / or a second mapping relationship which includes a mapping relationship between a network slice and a satellite.

7. The aforementioned method, The method according to claim 1, further comprising synchronizing the user information of the terminal with a terrestrial core network.

8. The user information includes: The location information of the aforementioned terminal, Subscribed network slice information and, Tracking area related information, Related information on access and mobility management functions (AMF), The method according to claim 7, comprising at least one of the following: a network slice selection policy (NSSP).

9. The aforementioned method, Receiving a first registration request transmitted from the first access network device, which is a first registration request requesting registration for the terminal, The method according to claim 1, further comprising, after the registration of the terminal is successful, returning registration-related information to the first access network device, which includes an identifier for the configured network slice and an identifier for a network slice available in the area where the terminal is located.

10. The aforementioned method, The method according to any one of claims 1 to 9, further comprising transmitting context information of the terminal to a second satellite core network device.

11. Transmitting the context information of the aforementioned terminal to the second satellite core network equipment is: Transmitting context information of the terminal to the second satellite core network equipment via the interface with the second satellite core network equipment, Transmitting the context information of the terminal to the second satellite core network device via the first access network device, The method according to claim 10, further comprising the steps of sequentially transmitting the context information of the terminal to the second satellite core network device via the first access network device and the second access network device.

12. A communication device installed in the first satellite core network equipment, wherein the device is A first receiving unit for receiving a first session establishment request sent from a first access network device, which is used to request the establishment of a session for a terminal and includes at least the identifier of a first network slice, A communication device comprising a first processing unit for selecting a satellite to serve the first network slice using the location information and ephemeris information of the terminal, and for establishing a session for the terminal using the selected satellite.

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