Multi-Team Data Flow Optimization in Wireless Multi-Rate Multi-Hop Networks

In this article, we study the problem of join routing and scheduling of multi-team data flows multicasting in wireless multi-rate multi-hop networks with the objective of minimizing the time required to complete the transmission transactions. We prove in this paper that the optimal join routing and scheduling problem is NP-hard. Instead of trying to solve the optimization problem, we reformulate the problem into an intuitive form which provides intuitions to achieve optimal solution. Base on these observations, we propose a heuristic algorithm that locally optimally chooses multicast relays and multicast rates. The aim is to locally minimize the schedule time length within two-hop range so that the total transmission time approaches optimal. This algorithm explores multi-team multicast advantages as well as the multi-rate range tradeoffs. Simulations based on practical ISM band channel model and current IEEE802.11 standards´ parameters show superior of our proposed algorithm in approaching optimal solution.