On Link Layer Policies of Data Forwarding Over Wireless Relays

Abstract:  For wireless/mobile ad hoc networks, researchers have developed many routing protocols. A typical problem setting is such that a packet of data is routed from a source to a destination without a prior knowledge of any existing route. To deal with unknown existing route, local flooding is required for each hop of the packet. Such an approach is appropriate for establishing a new route or forwarding infrequent data packets. However, for large volume data transmissions, the above approach is very inefficient. We believe that for many applications, mobile ad hoc networks must allow large volume data transmissions (in many separate packets) within a short period of time. For such applications, data forwarding policy should be based on a pre-established route. However, to combat random fluctuations of link qualities between nodes in dynamic environment, data forwarding policy should also exploit the spatial diversity of distributed nodes in a given route. It is from this perspective that we propose and analyze a one-to-many (1/M) data forwarding policy where each packet transmitted from a node is destined to multiple receiving nodes, and the node that receives the packet successfully and has the highest ranking becomes the next transmitting node. All nodes involved belong to a pre-established route, but the dynamic nature of each transmitting node of a packet makes the 1/M policy superior to the conventional one-to-one (1/1) policy for networks where transmission power dominates processing power.