This research is the analysis of hybrid random-access systems which use a combination of multi-user coding and collision resolution algorithms to accommodate the bursty transmissions of many independent users on a single communications channel. The main idea is to avoid collisions among T or less simultaneous users by the use of multi-user codes and to resolve occasional collisions among more than T users by the use of a collision resolution algorithm. A gain in throughput and delay performance can thus be expected if close to T users transmit at the same time, but a penalty must be paid if only one user transmits because the symmetric code rate of almost all multi-user codes must be less than one for each individual user. One of the major goals of this research is to determine the properties which a multi-user code must possess such that the use of a hybrid random access system yields better overall performance than an uncoded random access system.
