In a method and apparatus for inter-satellite communications, transmissions between a satellite and neighboring satellites that share an orbital plane occur via an aft antenna or a forward antenna and transmissions between the satellite and neighboring satellites that do not share an orbital plane occur via the aft antenna or the forward antenna timed during orbital plane crossings. This occurs even if the total path length and number of links is higher than inter-satellite communications that use side-to-side transfers.

Some implementations of the disclosure relate to dynamic switching of a satellite inroute data path between a Time Division Multiple Access (TDMA) method and a Time Division Multiplexing (TDM) method. In one implementation, a method comprises: communicating, using a satellite terminal, over an inroute TDMA channel; determining, at the satellite terminal, based at least on an aggregate ingress traffic rate to the satellite terminal, to switch communications from the inroute TDMA channel to an inroute TDM channel; and after determining to switch communications, sending, from the satellite terminal to a Gateway Earth Station, a request to be allocated an inroute TDM channel.

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. Each LDACS airborne station may be configured to collect respective routing metrics, and each LDACS airborne station may be selectively operable as at least one of a host and client. The enhanced LDACS may also include a peer-to-peer server configured to establish a mesh network topology from the LDACS airborne stations based upon the routing metrics, and selectively operate each LDACS airborne station as at least one of the host and client.

Systems and methods implementing a satellite radio access network (SRAN) receiving a registration request from a user terminal (UT), determining a current tracking area (TA) of the UT, forwarding the registration request and the current TA to an access and mobility management function (AMF), and receiving a registration accept from the AMF that indicates a UT registration area. An implementation receives a UT page command from the AMF and, in response, determines a satellite beam for paging the UT, from among a plurality of satellite beams using the identifier of the current TA, and pages the UT on the satellite beam.

An enhanced L-band Digital Aeronautical Communications System (LDACS) may include LDACS ground stations; and Alternate Positioning, Navigation and Timing (A-PNT) beacon transmitters positioned on the ground; and LDACS airborne stations. The LDACS airborne station may be configured to communicate with the LDACS ground stations, and determine A-PNT information based upon the plurality of A-PNT beacon transmitters.

An Automatic Dependent Surveillance-Broadcast (ADS-B) device may include a controller and a radio frequency (RF) transmitter coupled thereto and configured to transmit flight identification data, and transmit flight position data at a coarse accuracy and a fine accuracy. The RF transmitter may be configured to operate at a frequency within the L-band Digital Aeronautical Communications System (LDACS) frequency band. For example, the controller may be configured to encapsulate the flight identification data and flight position data within a message for an LDACS.

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.

An enhanced L-band Digital Aeronautical Communications System (LDACS) may include cellular telephone ground stations, and LDACS ground stations. In addition, the enhanced LDACS may also include a plurality of LDACS airborne stations, each configured to selectively communicate with either a corresponding LDACS ground station or a corresponding cellular telephone ground station based upon an altitude of the LDACS airborne station.

An enhanced L-band Digital Aeronautical Communications System (LDACS) may include LDACS ground stations assigned to respective different ground communication networks; and LDACS airborne stations configured to communicate with selected ones of the LDACS ground stations based upon respective roaming agreements for the different ground communication networks. In addition, the system may include a network broker configured to authorize a connection between an LDACS airborne station and an LDACS ground station based upon a corresponding roaming agreement.

An enhanced L-band Digital Aeronautical Communications System (LDACS) may include LDACS ground stations, and LDACS airborne stations. Each LDACS airborne station may be configured to communicate with the LDACS ground stations using at least one cellular network security feature. For example, the at least one cellular network security feature may include a Long-Term Evolution (LTE) security feature.