GPS based distributed routing algorithms for wireless networks

Recently, several fully distributed (localized) GPS based routing protocols for a Mobile Ad hoc NETwork (MANET) were reported in literature. They are variations of directional (DIR) routing methods, in which node A (the source or intermediate node) transmits a message m to several neighbors whose direction is closest to the direction of D. We also found an older, MFR (most forward progress within radius) method. We propose a new location based GEographic DIstance Routing (GEDIR) algorithm. When node A wants to send m to node D, it forwards m to it’s neighbor C which is closest to D among all neighbors of A. The same procedure is repeated until D, if possible, is eventually reached. 2-hop GEDIR, DIR, and MFR methods are also suggested, in which node A selects the best candidate node C among its 1-hop and 2-hop neighbors according to the corresponding criterion (distance, direction, and progress, respectively) and forwards m to its best 1-hop neighbor among joint neighbors of A and C. These basic and 2-hop methods do not require nodes to memorize past message traffic. We propose flooding GEDIR, DIR and MFR methods, intended to guarantee the message delivery at the expense of MANET' s partial flooding. Further, we introduce three variants of multiple path c-GEDIR, c-DIR and c-MFR methods, in which m is initially sent to c best neighbors according to corresponding criterion, and afterwards, on intermediate nodes, it is forwarded to only the best neighbor. They provide multiple paths with minimal flooding effects. We show that the directional routing methods are not loop-free, while the GEDIR and MFR methods are inherently loop free. The simulation experiments with static random unit graphs show that GEDIR and MFR have similar success rates, with hop counts that are near the performance of the shortest path algorithm, while DIR method has comparable success rate but worse hop count. Further, the performance of DIR method worsened when 2-hop neighbors were taken into account, while 2-hop GEDIR and MFR have improved their performance. Flooding GEDIR and MFR methods are the first distributed methods (other than full flooding) that guarantee the delivery, and are shown to have low flooding rates. Disjoint multiple path methods are shown to provide high success rates and small hop counts for small values of c.