A method for signalling demand in many-user digital loops

An analysis of digital loop capacity requirements is conducted and methods of signaling demand are considered. It is shown that in systems designed for infrequent loss dramatic improvements are possible if more than one user may signal demand at once in an interfering, but nondestructive, manner. A theorem which is related to the separating ability of Mod-2 addition is presented. It is found that for demand-assigned communication with messages of telex length or less, signaling of demand in a digital loop requires a significant fraction of the total bit rate.