METHOD AND APPARATUS FOR NETWORK ACCESS CONTROL WITH IMPLICIT RANGING AND DYNAMICALLY ASSIGNED TIME SLOTS

摘要

A time division multiple access protocol that prevents data collisions and that maximizes bandwidth utilization in a long distance communications network by performing implicit ranging and dynamic assignment of time slots. The propagation delay that would result when data travels from an end station to the hub is determined using an implicit ranging method. Time slots in a synchronization signal are assigned to end stations based upon the requests from end stations and the availability of time slots. Each end station is notified of its assigned time slot(s) and propagation delay and is provided with a timing signal which is the synchronization signal delayed by its propagation delay. Each end station then starts to transmit its data at the beginning of a time duration that is twice its propagation delay before the start of its assigned time slot(s) in its timing signal. Each end station transmits its data for the duration of its assigned time slot(s). The data from each of these end stations travels in a pipe-lined manner through the link toward the hub and arrives at the hub during the assigned time slots in the synchronization signal. Each time slot preferably includes a guard band during which no data is transmitted; the duration of the guard band can be minimized thus resulting in more efficient bandwidth utilization.