Router selfishness in community wireless mesh networks: Cross-layer benefits and harms

In community wireless mesh (CWM) networks following the IEEE 802.11s standard, wireless nodes combine the functionality of a client application host and a transit packet router. Not being subjected to tight administrative control, CWM nodes may act selfishly by refusing to forward transit packets along (selected) established routes or to participate in the route creation process. Unlike in a mobile ad hoc network (MANET), a CWM node is typically connected to mains electricity, hence unconcerned about energy expenditure; the only rational (as distinct from malicious) motivation behind selfish behavior is then to prevent the incoming transit traffic from competing with the source traffic and thereby achieve a higher source throughput. We examine through simulation the benefits and harms of selfish behavior with a cross-layer view and relate them to the router density, selfish routers´ location and details of their behavior. We find many conclusions and intuitions valid in MANET environments incorrect in CWMs.