Method for signaling interaction in 5g space-ground integrated heterogeneous network architecture

A method of signaling interaction in 5G space-ground integrated heterogeneous network architecture, comprises the following steps:

• S1:
• one or more satellites or satellite instances register respective publicly available parameter sets for satellite discovery of them to a Network Repository Function (NRF) of a 5G core network with a Network Exposure Function (NEF) of the 5G core network;
• S2:
• when a 5G ground node base-station (gNB) is about to establish or update a connection with satellites, the 5G gNB obtains a parameter set from the NRF with one or more querying parameters, and selects at least one satellite or at least one satellite instance as at least one relay satellite by using a preset rule according to the parameter set obtained from the NRF, wherein, the parameter set is a subset or a full set of the respective publicly available parameter sets and comprises the publicly available parameter set registered to the NRF by the at least one satellite or at least one satellite instance among the one or more satellites or satellite instances;
• S3:
• in response to determining that access token service of the 5G core network is not enabled, the 5G gNB directly sends a service request to the selected relay satellite to initiate a process for establishing or updating a connection;
• or
• in response to determining that access token service of the 5G core network is enabled, the 5G gNB obtains an access token of the selected relay satellite from the NRF and sends a service request carrying the access token to the selected relay satellite, so to proceed to step S4;
• S4:
• the selected relay satellite receives the service request carrying the access token sent by the 5G gNB, and verifies validity of the service request from the 5G gNB with the access token;
• wherein, the satellite instance refers to a virtualized identifier associated with functions of a satellite in the case that the satellite supports network functions virtualization.