Location Management in Sparse Ad Hoc Networks

Geometric routing using source–destination locations has been suggested as a scalable alternative to conventional routing approaches in mobile ad hoc networks. Prior studies have shown that the location of a destination can be found efficiently in large/dense ad hoc networks using intelligent location management schemes by recruiting nodes in specific unit regions of the terrain as location servers. In this work, we show that certain location management protocols that use a grid based approach suffer from the empty server region problem and that their performance can be seriously degraded with decreasing node density in sparse or irregular ad hoc networks. In order to tackle this problem, we introduce proxy based location management, a novel enhancement that can be used in conjunction with existing location management protocols to operate efficiently in sparse or irregular ad hoc networks. Extensive simulations show that proxy based location management combined with routing on an overlay graph constructed from the unit regions operates more effectively in sparse networks than SLURP/GPSR, an existing location management scheme and a geometric routing protocol that routes packets on a planar graph extracted from the unit disk