In a wireless communication system that includes a base station, a plurality of relay stations that are moving, and a plurality of terminal stations in a service area, and performs downlink multiple access from the base station to each of the plurality of terminal stations via one or more relay stations of the plurality of relay stations, the base station includes a downlink multiple access unit configured to identify a relay station of the plurality of relay stations transmitting a signal receivable in the service area based on positions of the plurality of relay stations, frequency multiplex-transmit a data signal in a different frequency band to each of the plurality of terminal stations via the relay station, and spatial multiplex-transmit a data signal to a terminal station of the plurality of terminal stations supporting spatial multiplex transmission in a particular frequency band and via the plurality of relay stations.

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.

Systems and methods for supporting more flexible coverage areas and spatial capacity assignments using satellite communications systems are disclosed. A hub-spoke, bent-pipe satellite communications system includes: terminals; gateways; a controller for specifying data for controlling satellite operations in accordance with a frame definition including timeslots for a frame and defining an allocation of capacity between forward and return traffic; and a satellite including: pathways; at least one LNA, an output of which is for coupling to a pathway and to amplify uplink beam signals in accordance with the allocation; and at least one HPA, an input of which is for coupling to the pathway and to amplify downlink beam signals in accordance with the allocation, and wherein the frame definition specifies at least one pathway as a forward pathway for at least one timeslot and as a return pathway for at least one other timeslot in the frame.

A satellite provides communication between user terminals (UTs) and ground stations that connect to other networks, such as the Internet. Because the satellite is within range of many UTs at any given time, many UTs are in contention to use an uplink to send data to the satellite. Each satellite manages uplink contention by maintaining state data representative of the uplink resources allocated for use. As satellites move, handovers take place, transferring communication services from a first satellite to a second satellite. Before a handover, a first satellite sends state data to a UT. The second satellite is also informed about the UT. After the handover, the second satellite provides the UT with priority access to the uplink to send the state data to the second satellite. The second satellite uses the state data to resume management of the uplink, eliminating the need for time consuming link setup.

A system and method for beam switching by a User Terminal (UT). The method includes initiating a beam switch between an old beam and a new beam when the UT is disposed in an overlap area of the old beam and the new beam; duplicating over the new beam, at a Network Access Point (NAP), user traffic to the UT; and assigning a Time Division Multiplex Access (TDMA) allocation for the UT on the new beam, prior to an arrival of the UT on the new beam, where the user traffic traversing a satellite network remains uninterrupted during the beam switch and the NAP redirects user traffic for the UT via the old beam to the new beam.

An enhanced L-band Digital Aeronautical Communications System (LDACS) may include LDACS ground stations, and LDACS airborne stations configured to communicate with the LDACS ground stations. The enhanced LDACS may also include a Cloud-based network controller configured to allocate LDACS resources to the LDACS ground stations and the LDACS airborne stations based upon a number of LDACS airborne stations, respective flight paths of each LDACS airborne station, a respective type of each LDACS airborne station, and historical data on communication use for each LDACS airborne station.

The techniques disclosed herein feature a user equipment (UE), a base station, and methods for a UE and abase station. The UE comprises a transceiver which, in operation receives coverage area information indicating a coverage area of at least one candidate satellite beam relative to a satellite location of at least one satellite generating, respectively, the at least one candidate satellite beam; and circuitry which, in operation, determines, based on the received coverage area information, ephemeris data of the at least one satellite generating the at least one candidate satellite beam, and a location of the user equipment, a target satellite beam for switching out of the at least one candidate satellite beam and a switching timing for switching to the target satellite beam, and controls the transceiver to perform switching to the determined target satellite beam at the determined switching timing.

Satellites provide connectivity in remote and rural areas as well as providing applications and services elsewhere on earth and in space. Existing satellite networks will be increasingly augmented by ultra-dense deployments of interconnected satellites providing low Earth orbit (LEO) constellations. However, such satellites only offer short-term line-of-sight access requiring ongoing handovers during the duration of a terminal’s access. Accordingly, to exploit these LEO constellations the inventors have established methodologies exploiting distributed massive multiple-input multiple-output technology for a user terminal to be connected to a cluster of LEO satellites. Further, distributed joint power allocation and handover management techniques are outlined for improving the power allocation and handover management processes in a cross-layer manner such that enhanced network throughput and reduced handover rate are provided whilst taking into account quality-of-service demands of terminals and the power capabilities of the LEO satellites.

Systems and methods for supporting more flexible coverage areas and spatial capacity assignments using satellite communications systems are disclosed. A hub-spoke, bent-pipe satellite communications system includes: terminals; gateways; a controller for specifying data for controlling satellite operations in accordance with a frame definition including timeslots for a frame and defining an allocation of capacity between forward and return traffic. The satellite communications system may employ a satellite with a feed array assembly and may use on-board beamforming or ground-based beamforming. Beam hopping within timeslots of the frame may be used to provide coverage to different cells in different time periods. The flexible coverage areas may be provided using changes in satellite position, antenna patterns, or beam resource allocations.

A Low Earth Orbit (LEO) satellite system is provided. The LEO satellite system includes a plurality of user equipment (UEs), a plurality of LEO satellites, and a ground station. The ground station obtains the required resources of each UE and the remaining resources of each LEO satellite. Based on the required resource of each UE and the remaining resource of each LEO satellite, the ground station determines to perform a handover to at least one UE of the plurality of UEs.