Enhancing ad hoc routing with dynamic virtual infrastructures

Several routing algorithms for mobile ad hoc networks (MANETs) have been proposed previously. With the exception of a few, these protocols (i) involve all nodes in the route management process, (ii) rely on the use of broadcast relays for route computation, and (iii) are primarily reactive in nature. Related work has shown that the capacity utilization in ad hoc networks decreases significantly when broadcast relays or "broadcast storms" are performed frequently. This effect is compounded when all nodes in the network take part in the route computation. We propose and study an approach based on overlaying a virtual infrastructure adaptation of the core, proposed by Sivakumar, Sinha and Bharghavan (see IEEE Journal on Selected Areas in Communications, vol.17, no.8, p.1454-65, 1999) on an ad hoc network and operating routing protocols over the infrastructure. The core enables routing protocols to use only a subset of nodes in the network for route management and avoid the use of broadcast relays. Using the ns-2 simulator we evaluate the performance of two ad hoc routing protocols, dynamic source routing (DSR) and ad hoc on demand distance vector (AODV), when they are operated over the core and compare their performance against those of their basic versions.