Antenna on board each TDRS which allows the TDRS to provide return links to as many as five spacecraft simultaneously Each MA antenna has only one forward link capability
A methodology (FDMA, TDMA, CDMA) by which multiple users share access to a transmission channel Most modern systems accomplish this through "demand assignment" where the specific parameter (frequency, time slot, or code) is automatically assigned when a subscriber requires it
The simultaneous sharing of a common transmission bandwidth by multiple users In satellite communications, it usually refers to the shared use of one or more transponders by multiple earth stations