Analysis of Half-Duplex Two-Node Slotted ALOHA Network With Asynchronous Traffic

Random access protocols play a key role in modern communication networks, e.g., IoT. Among them, slotted ALOHA is a simple and conventional protocol that is the basis of many newly proposed protocols. Despite the long history of research on slotted ALOHA, the exact analysis of the average delay is still in question as the performance of each node is coupled with the activity of other nodes. In this paper, we consider a network comprised of two half-duplex transmitter nodes with asynchronous arrival traffic. The nodes transmit their packets according to the slotted ALOHA protocol. We propose a new queueing theoretic model based on state-dependent queues to analyze the network. In addition, we derive the exact values of delay and stability region in the network. The numerical results demonstrate the accuracy of our proposed model.