KALOHA: ike i ke ALOHA

A new family of channel-access schemes called KALOHA (for "Knowledge in ALOHA") is introduced. KALOHA consists of modifying the pure ALOHA protocol by endowing nodes with knowledge regarding the local times when packets and acknowledgments are received, and sharing estimates of channel utilization at the medium access control (MAC) layer. The only physical-layer feedback needed in KALOHA is the reception of correct data packets and their ACKs. A simple Markov-chain model is used to compare the throughput of KALOHA with ALOHA and slotted ALOHA. The analysis takes into account the amount of knowledge that nodes have and the effect of acknowledgments and turnaround latencies. The results demonstrate the benefits derived from using and sharing knowledge of channel utilization at the MAC layer. KALOHA is more stable than ALOHA and attains more than double the throughput of ALOHA, without the need for carrier sensing, requiring time slotting at the physical layer, or using other physical-layer mechanisms.