An Efficient Access Scheme for Variable Length Packets in Slotted ALOHA Channel

The slot division access method is suggested as an efficient method of transmitting variable length packets through Slotted ALOHA channel. Variable length packets are divided into two groups according to division parameter p, and synchronized their transmission at the beginning or at the end of a coming slot. By this method, the maximum throughput reached a value of 0.26. In addition, variable length packets are divided into four groups according to three division parameters ?, s and ?, and synchronized their transmission to two different slots. This method increased the throughput value to 0.35, and also showed an improvement in average delay performance. Finally, we proposed a contention access scheme by combining a reservation-slot to the aloha-slot, where we can expect an increase in throughput value and improved delay performance.