Abstract: We analyze the performance of Binary Exponential Backoff (BEB) algorithm under the slotted ALOHA protocol: whenever a node`s message which tries to reserve a channel is involved in a collision for the nth time, it chooses one of the next 2 n frames with equal probability and attempts the reservation again. We derive the expected access delay and throughput, which is defined as the expected number of messages that reserve a channel in a frame. A numerical study is performed to exemplify our method