Performance comparison of slotted and unslotted DS/SSMA networks

Throughput and delay for both slotted and unslotted direct-sequence spread-spectrum multiple-access (DS/SSMA) packet radio networks are compared. In both systems, each user employs a newly chosen random signature sequence for each bit in a transmitted packet. Accurate packet success probabilities for both systems are computed using an improved Gaussian approximation technique. Average throughput and delay results are obtained for varying levels of block error correction. The slotted system is shown to have better performance than the unslotted system in all cases.<>