Access, mobility management and regulatory services are supported for satellite access to a 5G core network. A coverage area, e.g., a country or region, is divided into fixed virtual cells and fixed tracking areas. The UE receives configuration information for fixed cells and fixed tracking areas associated with a serving PLMN. The fixed cells and the fixed tracking areas are defined, independently of each other, as fixed geographic areas. A position of the UE is used to determine a fixed serving cell and/or fixed tracking area for the UE. A service operation for the UE is enabled for the serving PLMN based on the fixed serving cell or the fixed tracking area. A fixed cell may be associated with an overlapping fixed tracking area by assigning a color code to the tracking area and appending the color code to an ID for the fixed cell.

Disclosed are techniques for wireless communication using satellite access to a wireless network, where a wireless cell supported by a satellite is moving or temporarily fixed. In an aspect, a radio access network (RAN) entity or a user equipment (UE) provides, to a core network entity, an enhanced cell global identifier (CGI), where the enhanced CGI includes at least one field representing a location of the UE. Based on the enhanced CGI, the core network entity determines a location of the UE, and may provide a service to the UE based on the location. A core network may also provide an enhanced CGI to a RAN, e.g., to support wireless emergency alerting to UEs.

A multi-static synthetic aperture radar using beamformed illumination beams and multiple collection satellites is described. An illumination satellite may be in first orbit and multiple collection satellites may be in a second orbit. The illumination satellite may transmit beam signals (e.g., communication signals carrying modulated data to user terminals) from an antenna array to different beam coverage areas according to a beamforming matrix. Each of the collection satellites may receive reflections of the beam signals. The reflected signals received at the collection satellites may be processed according to the beam signals and beamforming matrix used to transmit the beam signals to obtain an image of a geographical area. In some cases, the collection satellites may relay the received signals for processing via the illumination satellite.

Described herein are systems, methods, media, and devices for generating a satellite program for contacting satellites. In some embodiments, data including one or more targets for accessing a satellite constellation is obtained. Based on the data, a set of representations may be generated and candidate satellite constellation access programs may be determined based on the set of representations. For each program, a first score may be computed for each target to obtain a first set of scores, and a second score may be computed for each first score of the first set of scores to obtain a second set of scores. A satellite constellation access program may be selected from the candidate satellite access programs based on the second set of second scores.

A time division multiple access frame structure includes a signal transmission section allocated for transmitting reference signals from a plurality of ground reference stations; a relay section for relaying the transmitted reference signals by a plurality of aeronautical satellite relay stations selected by a central station; and a data transmission section for data transmission of the central station, the plurality of ground reference stations, or the plurality of aeronautical satellite relay stations, wherein the signal transmission section, the relay section, and the data transmission section are time division multiplexed with each other.

Various arrangements are presented for using an estimated timing advance for user equipment communications. A location of an instance of user equipment may be determined. An estimated distance between the user equipment and a communication satellite may be determined using the determined location of the user equipment and an estimated satellite location. An estimated timing offset using the calculated estimated distance may be determined. An uplink data frame may be transmitted by the user equipment to the satellite such that a timing of transmission of the uplink data frame is based on the calculated estimated timing offset.

A method for calculating a position of a mobile device relative to a selected reference station of a plurality of reference stations, the method comprising: receiving satellite signal measurements associated with a first reference station; receiving location signals from a plurality of satellites; tracking a baseline between the mobile device and the first reference station using the satellite signal measurements associated with the first reference station and the location signals to provide the position of the mobile device relative to the first reference station; sending a handover request, the handover request comprising the current position of the mobile device; receiving a handover message comprising integer ambiguities for a baseline between the first reference station and the second reference station; initialising tracking of a baseline between the mobile device and the second reference station using the integer ambiguities of the handover message; receiving satellite signal measurements associated with the second reference station; and tracking the baseline between the mobile device and the second reference station using the satellite signal measurements associated with the second reference station and the location signals to provide the position of the mobile device relative to the second reference station.

In one embodiment of the present disclosure, a satellite communication system includes a satellite constellation including a plurality of satellites in non-geosynchronous orbit (non-GEO), wherein at least some of the plurality of satellites travel in a first orbital path at a first inclination, and an end point terminal having an earth-based geographic location, the end point terminal having an antenna system defining a field of regard for communicating with the satellite constellation, wherein the field of regard is a limited field of regard, wherein the field of regard is tilted from a non-tilted position to a tilted position, and wherein the tilt angle of the tilted position is a function of the latitude of the geographic location.

A time division multiple access frame structure includes a signal transmission section allocated for transmitting reference signals from a plurality of ground reference stations; a relay section for relaying the transmitted reference signals by a plurality of aeronautical satellite relay stations selected by a central station; and a data transmission section for data transmission of the central station, the plurality of ground reference stations, or the plurality of aeronautical satellite relay stations, wherein the signal transmission section, the relay section, and the data transmission section are time division multiplexed with each other.

The disclosure relates in some aspects to location reporting and paging for satellite communication. In one aspect, the disclosure relates to a user terminal (UT) sending a message to report information about the UT's location. A threshold may be used to control whether (e.g., when) the UT reports its location. The location information may be used to enforce area (e.g., country) restrictions for the UT. In one aspect, the disclosure relates to forwarding paging messages between network access controllers. For example, a network access controller that is not able to page a UT may forward a paging message to another network access controller. In one aspect, the disclosure relates to a list of paging areas that indicates where a UT need not perform a paging area update.