Cross-Layer Battle: Experimental Study of Cross-Layer Routing in a WMN Backbone

Over the last few years, cross-layer design in wireless networks has drawn the attention of the research community, given the potential gains of such a paradigm, especially in the case of routing. Due to the specificities of wireless links (e.g., interferences, collisions, and fading), one of the arguments frequently exposed is that only hop-count as a metric is not enough. To overcome this issue, researchers aimed at making the routing layer more aware of the peculiarities of the physical layer. In this paper, we focus on ad hoc routing protocols running in the backbone of a wireless mesh networks. We evaluate the real improvements that cross-layer can bring to routing stability when compared to the simple hop-count metric. We focus on the stability of routes and the persistence of the five most used routes. One of our main findings is that in many situations the hop-count metric outperforms the cross-layer metric in terms of route stability, loop occurrences, and broken routes.