An embodiment method includes determining, by first user equipment UE, first synchronization information, where the first synchronization information is used to indicate a priority of the first UE used as a synchronization source; and sending, by the first UE, the first synchronization information, so that second UE selects a synchronization source of the second UE according to the received first synchronization information.

A method and system for selectively using different gateways with a diverse terminal includes assigning a diverse channel set to each of a plurality of diverse terminals, and designating a primary gateway and a secondary gateway as either a home gateway or a foreign gateway for the each diverse terminal. During normal operations, link conditions for the channel between each diverse terminal and its home gateway are monitored. Diverse terminals can be reconfigured to communicate with a different their link conditions fall below a predetermined threshold.

A computer for a communications terminal includes a memory and a processor. The computer is programmed to identify a spectrum analysis test triggering event. The computer specifies a set of test parameters that include a test frequency range. The computer further sets a receiver to receive sequentially a plurality of signals. Each signal is received in one of a plurality of frequency bands within the frequency range. The computer measures, via the receiver, at least one characteristic of the signal received in each frequency band.

Various embodiments may provide a system for continuous two-way high-speed data transfer for satellites, such as Low Earth Orbit (LEO) based satellites and/or Medium Earth Orbit (MEO) based satellites.

In one implementation, a communications satellite includes a main antenna system and a communications controller. The main antenna system is configured to send communications to and receive communications from one or more terrestrial terminal devices. The communications controller has a memory storing a plurality of terminal attribute sets, each of which specifies attributes for communicating with a corresponding class of terrestrial terminal devices. The communications controller is configured to receive a terminal class identifier from an active terrestrial terminal device, identify, from among the stored terminal attribute sets, a particular terminal attribute set as corresponding to the terminal class identifier received from the active terrestrial terminal device, and control the communications satellite to communicate with the active terrestrial terminal device according to the attributes for communicating specified in the particular terminal attribute set identified as corresponding to the terminal class identifier received from the active terrestrial terminal device.

A very small aperture terminal (VSAT) installation tool is provided having the ability to measure cable loss along an interfacility link (IFL) between an outdoor unit and an indoor unit of the VSAT. Radio frequency (RF) signals can be transmitted from the indoor unit to the outdoor unit, where the RF signals are intercepted along the IFL prior to reaching the outdoor unit, and the output power is determined. The determined output power is compared to an expected output power at the indoor unit. The delta between the determined output power and the expected output power can be used to adjust the power of the indoor unit such that the outdoor unit can operate without reaching its compression point.

A system and method for networked geofencing includes identifying restricted areas in a service region, and defining a protective zone surrounding the restricted areas. A service availability map containing the protective zones is generated and broadcast within the service region. The positions of terminals on the service availability map are detected relative to the protective zones. Terminals inside the protective zones establish communication using a first frequency range, and terminals outside of the protective zones establish communication using either the first frequency range or a second frequency range.

A transmitter is set to time division multiple access (TDMA) mode and allocated a first TDMA channel. In the TDMA mode, the additional TDMA channels are allocated to and deallocated from the transmitter, according a traffic demand at the transmitter, until all TDMA channels are assigned and the traffic demand reaches a threshold, whereupon the transmitter is switched to a frequency division multiple access (FDMA) mode, and assigned an FDMA channel. In response to traffic levels, the transmitter is switched to larger bandwidth FDMA channels and, optionally, to a concurrent FDMA-TDMA mode having a large bandwidth FDMA channel in addition to a number of TDMA channels. Optionally, switching the transmitter among TDMA mode, FDMA mode, and concurrent FDMA-TDMA mode is based, at least in part, on QoS, or time of day, or user statistics, or combinations thereof.

Satellite communication methods and payloads are described. An imbalance in uplink and downlink availability may be mitigated through digitizing uplink spectrum, extracting guard band channels, and grouping the guard band channels to create a composite channel. The composite channel is converted to analog and RF up-converted, amplified, and multiplexed with other downlink analog channels before being transmitted to Earth. The guard bands may be from the same band of spectrum or different bands of spectrum, such as C band, Ka band, Ku band, etc. A satellite payload is described with dual output multiplexers having partially overlapping channels and a dual feed configuration. In one downlink implementation, unused regional band spectrum may be dynamically allocated to a spot beam. In one uplink implementation, regional band spectrum may be shared by a spot beam using spatial separation of the regional uplink location from the spot beam coverage area and digital cancellation techniques.

A Very Small Aperture Terminal (VSAT) and cellular system to provide backhaul satellite communications for a cellular base station are disclosed. The VSAT including an Evolved Packet Core (EPC) Core Network (CN) device; and a satellite modem connected to the EPC CN device and to communicate over a satellite link, wherein the EPC CN device manages communication of user traffic from the cellular base station to the satellite modem.