Abstract: The possibility of overload (saturation-lockup) condition of an ALPC satellite communication network is avoided by a scheme that grants network entry (allocates TWT power) to each link one at a time. As each link is granted entry into the network, the corresponding TWT probability density function is computed and then integrated to obtain a TWT cumulative distribution function. The required rain margin M.sub.r for a specified availability is determined from the cumulative margin. The computed margin M.sub.r is set equal to the initial satellite TWT operating point change (multiplicative factor) MR.sub.1 due to rain fade, MF.sub.1 =M.sub.r to ensure that network stability considerations and rain fades equally constrain network performance. This result is then used to compute the value of the corresponding multiplicative factor MF.sub.2.

Abstract: A mechanism for avoiding satellite transponder TWT saturation in an ALPC communication network detects the onset of a lockup condition through an avalanche detector. In response to avalanche detection, those links which have been identified as participating in a downlink fade have their ALPC attenuator settings placed at a minimum level, so that the operating point of the transponder TWT may be reduced below the avalanche threshold. Thereafter, as the fade recedes, those units whose ALPC attenuators have minimum power settings may be restored to normal operation. Because the orderwire which couples link quality data from a received terminal monitor unit to transmitter attenuator control units through the avalanche detection and recovery scheme may itself be impacted by a downlink fade, the foregoing scheme is augmented by a lockup detection and avoidance mechanism through which recovery from an actual lockup may take place.