Capacity Region of ALOHA Protocol for Heterogeneous IoT Networks

In an Internet of Things (IoT) network, heterogeneous users with different priorities and service requirements will co-exist. This makes scheduling access to the shared communication medium a major challenge. To tackle this challenge, we consider the application of irregular repetition slotted ALOHA (IRSA), one of the best-performing random access protocols for homogeneous networks, for a heterogeneous multiclass IoT network. To this end, centralized and distributed implementations of the IRSA for multiclass IoT networks is proposed. Then, we focus on finding the network performance boundaries by studying the set of feasible throughput values for each class achieved via IRSA, called the capacity region. In addition to identifying the capacity region, the average and maximum delay of the users’ packet delivery for both centralized and distributed IRSA are investigated. Our throughput and delay analysis reveals that the performance of distributed IRSA achieves that for the centralized implementation as the number of users increases. Further, we use our capacity region analysis to find the optimal IRSA strategy that maximizes the weighted sum-throughput of the network.