The effect of capture on performance of multichannel slotted ALOHA systems

The author presents an exact analysis to evaluate the effect of capture on the multichannel slotted ALOHA protocol. The author derives the probabilities of the successful transmission. These probabilities are used to calculate the throughputs, average packet delays for both IFT (immediate-first-transmission) and delayed-first-transmission protocols and numerically compare the performance of the systems with and without capture. Numerical results show that when a quantitative capture restriction u is considered, in a multichannel system having a fixed total bandwidth, depending on parameter u and channel number M, an improved system performance such as the average channel utilization and average packet delay can be obtained