A satellite signal relay system according to an embodiment of the inventive concept includes: a plurality of remote units configured to receive an analog satellite signal, to convert the analog satellite signal into a digital satellite signal, to generate a characteristic signal for the analog satellite signal, to generate a transmission frame based on the digital satellite signal and the characteristic signal, and to convert the transmission frame into an optical transmission frame; and a central unit configured to convert optical transmission frames received from the plurality of remote units into transmission frames through an optical transmission medium, respectively, to extract a digital satellite signal and a characteristic signal from each of the converted transmission frames, and to convert any one of the extracted digital satellite signals into an analog satellite signal based on the extracted characteristics signals.

Methods, systems, and apparatuses for providing layer-2 connectivity through a non-routed ground segment network, are described. A system includes a non-autonomous gateway in communication with a satellite configured to relay data packets. The non-autonomous gateway is configured to receive the data packets from the satellite at layer-1 (L1) of the OSI-model, generate a plurality of virtual tagging tuples within the layer-2 packet headers of the plurality of data packets. The non-autonomous gateway is further configured to transmit, at layer-2 (L2) of the OSI-model, the virtually tagged data packets. Each of the packets may include a virtual tagging tuple and an entity destination. The system further includes a L2 switch in communication with the non-autonomous gateway. The L2 switch may be configured to receive the data packets and transmit the data packets to the entity based on the virtual tuples associated with each of the data packets.

A satellite signal relay system according to an embodiment of the inventive concept includes: a plurality of remote units configured to receive an analog satellite signal, to convert the analog satellite signal into a digital satellite signal, to generate a characteristic signal for the analog satellite signal, to generate a transmission frame based on the digital satellite signal and the characteristic signal, and to convert the transmission frame into an optical transmission frame; and a central unit configured to convert optical transmission frames received from the plurality of remote units into transmission frames through an optical transmission medium, respectively, to extract a digital satellite signal and a characteristic signal from each of the converted transmission frames, and to convert any one of the extracted digital satellite signals into an analog satellite signal based on the extracted characteristics signals.

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.

Methods, systems, and apparatuses for providing layer-2 connectivity through a non-routed ground segment network, are described. A system includes a non-autonomous gateway in communication with a satellite configured to relay data packets. The non-autonomous gateway is configured to receive the data packets from the satellite at layer-1 (L1) of the OSI-model, generate a plurality of virtual tagging tuples within the layer-2 packet headers of the plurality of data packets. The non-autonomous gateway is further configured to transmit, at layer-2 (L2) of the OSI-model, the virtually tagged data packets. Each of the packets may include a virtual tagging tuple and an entity destination. The system further includes a L2 switch in communication with the non-autonomous gateway. The L2 switch may be configured to receive the data packets and transmit the data packets to the entity based on the virtual tuples associated with each of the data packets.

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.

A satellite signal relay system according to an embodiment of the inventive concept includes: a plurality of remote units configured to receive an analog satellite signal, to convert the analog satellite signal into a digital satellite signal, to generate a characteristic signal for the analog satellite signal, to generate a transmission frame based on the digital satellite signal and the characteristic signal, and to convert the transmission frame into an optical transmission frame; and a central unit configured to convert optical transmission frames received from the plurality of remote units into transmission frames through an optical transmission medium, respectively, to extract a digital satellite signal and a characteristic signal from each of the converted transmission frames, and to convert any one of the extracted digital satellite signals into an analog satellite signal based on the extracted characteristics signals.

In some embodiments, a disclosed method involves receiving, by a source gateway, a call request from a source user terminal for establishing a call with a destination user terminal. The method further involves determining, by a source client proxy of the source gateway, a capability related to a parameter(s) of the source user terminal and a capability related to a parameter(s) of the destination user terminal. Also, the method involves sending, by the source client proxy, a call capability offer to a destination gateway based on the determined capabilities. Additionally, the method involves determining, by a destination client proxy of the destination gateway, whether the destination user terminal can support the call capability offer. Also, the method involves sending, by the destination client proxy, a call initiation message to the destination user terminal, when the destination client proxy determines that the destination user terminal can support the call capability offer.

The use of UAV network cells may enable a wireless communication carrier to provide supplemental cellular network communication coverage to geographical areas. In some implementations, a first baseband processor of the UAV network cell may establish a first communication link with the ground network cell via a first antenna. The ground network cell may be connected to a core network of the wireless carrier network via a wired backhaul. Further, a second baseband processor of the UAV network cell may establish a second communication link with a user device via a second antenna. The first and second baseband processors may be communicatively coupled together. Accordingly, communication data may be routed between the user device and the core network through the first communication link and the second communication link.

Methods, systems, and apparatuses for providing layer-2 connectivity through a non-routed ground segment network, are described. A system includes a non-autonomous gateway in communication with a satellite configured to relay data packets. The non-autonomous gateway is configured to receive the data packets from the satellite at layer-1 (L1) of the OSI-model, generate a plurality of virtual tagging tuples within the layer-2 packet headers of the plurality of data packets. The non-autonomous gateway is further configured to transmit, at layer-2 (L2) of the OSI-model, the virtually tagged data packets. Each of the packets may include a virtual tagging tuple and an entity destination. The system further includes a L2 switch in communication with the non-autonomous gateway. The L2 switch may be configured to receive the data packets and transmit the data packets to the entity based on the virtual tuples associated with each of the data packets.