On the capacity of multiple-terminal communication networks

A number of problems concerning the capacity of broadcast and multiple access channels are examined. Some results are obtained concerning the M(2N-1)-dimensional capacity region of an interference network that is utilized in a general way. Inner and outer bounds on the corresponding M-dimensional capacity region are obtained for discrete memoryless interference and linear superposition interference channels with additive white Gaussian noise (AWGN); the capacity region is determined in special cases. Results for the channel show that the capacity region does not decrease monotonically as the amount of interfering signal power at the receivers increases. The communication of digital data packets over a multiple-access channel with feedback was studied. It is shown that a previously proposed random time division (Aloha) technique often results in two statistically stable operating points for the system, one with efficient, fast communications and the other with low throughput and high delay. The analysis indicates that acceptable performance can be obtained even when the steady-state performance is very poor.