On treating asymmetric links in backoff-based opportunistic routing: problem and solution

Abstract

In ad hoc networks, backoff-based opportunistic routing enables flexible forwarder selection based on a random backoff time. However, it assumes to require symmetry of each link due to the use of reverse path information. In this letter, we verify an asymmetric link problem based on their behavior and propose a solution to this problem. The proposed method confirms and ensures the destination reachability of each terminal based on link symmetry using a flag and restricts the acknowledgment procedure to avoid the problem. Finally, we examine the impact of asymmetric link use and the effectiveness of the proposed method by simulations.