Unidirectional links prove costly in wireless ad hoc networks

Most, of t,he routing algorithms for ad hoc net,works assume t,hat all wireless links are bidirect,ional. In realit,y, some links may be unidirect.ional. The presence of such links can jeopardize t,he performance of t,he existing dist,ance vect.or rout.ing algorit.hms. In this paper we show t,hat, dist.ance vector based rout,ing prot.ocols t,hat, account for unidirectional links will require nodes t.o exchange O(n2) informat.ion with each other, where n is t.he number of nodes in t,he nebwork. We also present. modifications to dist,ance vector based routing algorithms to make t,hem work in ad hoc netsworks wit.h unidirectional links.