Distributed timely-throughput optimal scheduling for wireless networks

Recent advance in distributed scheduling algorithms mainly focuses on designing CSMA-type protocols to achieve maximum network throughput in a fully distributive manner. However, it is inherently difficult for distributed scheduling algorithms to promise high throughput while maintaining low delay. To encounter this, a new scheduling algorithm, namely timely-throughput optimal algorithm, is introduced, which distributively determines the optimal transmission times for network users so that the largest set of traffic rates of network users can be supported, while ensuring timely data delivery within hard deadlines. More specifically, the maximum network capacity region that timely-throughput optimal scheduling algorithms can achieve is first derived, which characterizes the closure of the set of all arrival rate vectors under which there exists an viable scheduling algorithm to guarantee that all network users can meet the delay deadlines. Then, a distributed scheduling algorithm is proposed, which allows every user to make optimal transmission decision locally based on its incoming traffic rate, virtual debts, and previous channel sensing results. Finally, it is proven that the proposed algorithm is timely-throughput optimal in the sense that it can guarantee reliable data delivery before deadlines as long as the incoming traffic rates are within the derived maximum network capacity region.