Noncooperative Routing with Cooperative Diversity

Routing in wireless networks confronts more diverse and more rapidly varying characteristics associated with wireless links. Several recent protocols have tried to exploit cooperative diversity to deal with these channel characteristics, but they suffer from large overhead costs due to the need for collaboration among candidate nodes of next hop. We propose a novel routing protocol that is able to realize cooperative diversity without exchanging information among candidate nodes. Our protocol divides the routing decision between the transmitter and the receivers: the transmitter decides the direction and an angle spread to broadcast the packet; each receiver, without communicating each other, decides whether to start a timer whose duration depends on the strength of the channel state information. The node with shortest timer transmits first and thus becomes the transmitter for the next hop. Thus, a multi-hop route is found in a noncooperative way where the communication overhead is minimal, and we show that cooperative diversity is collected. The performance characteristics and design parameters of this protocol are first theoretically analyzed, and then examined in a realistic network setting through simulations.