Time Division Multiple Access or TDMA is a method used to enable multiple earth stations or VSAT terminals to transmit intermittently on the same frequency, but with the timing of their transmissions so arranged that the bursts do not overlay when they arrive at the satellite but arrive in sequence and thus are all successfully received by the teleport hub modem burst demodulator.
The operation of TDMA requires an outlink control to all the remote sites which contains some control information. This outlink carrier also had a frame structure that provides accurate timing information for all the remote sites. The teleport hub equipment computer tells each VSAT site what particular time slot to use in the TDMA frame and this time plan information is broadcast to all sites periodically. The burst time plan may be fixed, so as to allocate each site a particular proportion of the total TDMA frame time or is may be dynamic, whereby the time slot allocated is adjusted in response to the traffic needs of each site