Example communication methods and communication apparatus are described. One example method includes sending a first message by a first satellite to a second satellite. The first message includes information about a frequency reuse scheme. The information about the frequency reuse scheme includes basic unit information. The basic unit information includes central point locations and frequency information of at least N−1 beams. Herein, N is a frequency reuse factor of the first satellite. At least N−1 different pieces of frequency information exist in the frequency information that is of the at least N−1 beams and that is included in the basic unit information. In addition, N is a positive integer greater than or equal to 3.

Systems and methods for controlling satellites are provided. In one example embodiment, a computing system can obtain a request for image data. The request can be associated with a priority for acquiring the image data. The computing system can determine an availability of a plurality of satellites to acquire the image data based at least in part on the request. The computing system can select from among a plurality of communication pathways to transmit an image acquisition command to a satellite based at least in part on the request priority. The plurality of communication pathways can include a communication pathway via which the image acquisition command is indirectly communicated to the satellite via a geostationary satellite. The computing system can send the image acquisition command to the selected satellite via the selected communication pathway.

The present disclosure relates to a 5.sup.th generation (5G) or 6.sup.th generation (6G) communication system for supporting a data rate higher than a 4.sup.th generation (4G) communication system such as long term evolution (LTE). The present disclosure provides a satellite communication cell management apparatus for managing satellite communication cells of at least one satellite, the satellite communication cell management apparatus including a transceiver, and at least one processor, wherein the at least one processor is configured to connect the satellite communication cells to base stations (BSs), and update connections between the satellite communication cells and the BSs, according to a relative movement of the at least one satellite with respect to the ground.

The present disclosure relates, in part, to non-terrestrial communication systems, and in some embodiments to the integration of terrestrial and non-terrestrial communication systems. Non-terrestrial communication systems can provide a more flexible communication system with extended wireless coverage range and enhanced service quality compared to conventional communication systems.

Techniques are described to support call routing and location for a user equipment (UE) with satellite wireless access to a serving PLMN. The UE sends a Session Initiation Protocol (SIP) INVITE message to a network node, such as a P-CSCF, that includes an indication of satellite access for the UE. In response the network node sends a request to another network node for a cell ID for a fixed cell in which the UE is located. The fixed cell can be independent of satellite radio cells for the serving PLMN. The network node may receive the cell ID for the fixed cell and sends the SIP INVITE message to another network node (e.g., an E-CSCF or LRF) with the cell ID for the fixed cell. The other network node may use the cell ID to route the SIP INVITE message or obtain an approximate location of the UE.

Techniques are described to support call routing and location for a user equipment (UE) with satellite wireless access to a serving PLMN. The UE sends a Session Initiation Protocol (SIP) INVITE message to a network node, such as a P-CSCF, that includes an indication of satellite access for the UE. In response the network node sends a request to another network node for a cell ID for a fixed cell in which the UE is located. The fixed cell can be independent of satellite radio cells for the serving PLMN. The network node may receive the cell ID for the fixed cell and sends the SIP INVITE message to another network node (e.g., an E-CSCF or LRF) with the cell ID for the fixed cell. The other network node may use the cell ID to route the SIP INVITE message or obtain an approximate location of the UE.

This application discloses a random access preamble configuration method applicable to a satellite network and a communication apparatus. In the method, a random access preamble location offset and duration of a PRACH occasion can be flexibly configured based on features of a satellite system. The method includes: A receiving apparatus receives first indication information, where the first indication information includes indication information used to identify the random access preamble location offset at the physical random access channel PRACH occasion. The receiving apparatus transmits a random preamble based on the first indication information, where the random preamble includes a sequence part and a guard time. Because a communication distance is relatively long and a transmission delay difference between users is relatively large in a satellite communication system, time domain resources occupied by the PRACH occasion can be minimized by using this method.

In one embodiment of the present disclosure, a device for detecting a zone of communication between a user terminal and a satellite constellation including a plurality of satellites in non-geosynchronous (non-GEO) orbit includes one or more processors and memory. The memory stores instructions that, as a result of being executed by the one or more processors, cause the device to: determine a location of the device, wherein the location corresponds to a field of regard for detecting the zone of communication, and wherein the field of regard corresponds to an antenna aperture of the phased array antenna; evaluate a level of communication between the phased array antenna and the satellite constellation associated with the field of regard; and output, to a user of the device, an indication of the level of communication between the phased array antenna and the satellite constellation associated with the field of regard.

A high-altitude platform (HAP) node provides communication service during an emergency. The HAP node uses a first network to provide communication services for handling calls initiated by at least one user equipment (UE). The HAP node detects that an emergency disruption has occurred that prevents the use of the first network. In response to detecting the occurrence of the emergency disruption, a mobile terminal (MT) in the HAP node searches for a second network able to accept emergency calls. The HAP node determines whether the second network will handle all calls initiated by the at least one UE or only emergency calls generated by the at least one UE. The HAP node handles the calls based on the determining and through the use of the second network.

Systems and methods for controlling satellites are provided. In one example embodiment, a computing system can obtain a request for image data. The request can be associated with a priority for acquiring the image data. The computing system can determine an availability of a plurality of satellites to acquire the image data based at least in part on the request. The computing system can select from among a plurality of communication pathways to transmit an image acquisition command to a satellite based at least in part on the request priority. The plurality of communication pathways can include a communication pathway via which the image acquisition command is indirectly communicated to the satellite via a geostationary satellite. The computing system can send the image acquisition command to the selected satellite via the selected communication pathway.