Output and delay processes in a slotted ALOHA multichannel packet radio network with capture

The author presents the moment generating functions for the output process, packet interdeparture time, packet delay and number of packets successfully transmitted in parallel in a slotted ALOHA multichannel system with power capture. The author calculates the averages and higher moments of these performance measures by differentiating the moment generating functions and numerically compares the systems with and without power capture. The system consists of a fine population of N station both fixed and mobile. N stations are divided into L different capture groups and access a set of parallel M channels to transmit their packets. Capture effect means that a packet transmitted by a station with a highest capture level can be received accurately, even when other packets in lower capture levels are simultaneously transmitted on the same channel and the same slot. Numerical results show that the capture effect improves such aspects of the system performance as average channel utilization and average packet delay