Abstract:
A .Mobile. Ad. Hoc. Network. (MANET) consists. of. a. group. of. autonomous nodes
communicating in an infrastructure-less environment. MANETs can configure
themselves on the go. Due to the aforementioned properties, MANETs are favored in
rescue and relief services and have varied military applications. MANETs can be
deployed anywhere, regardless of the topographical conditions. However, topography
plays a huge role in the network performance of mobile nodes. Network. Simulator. 2
(NS-2). is. the. most popular. simulation. tool. used by researchers for Ad hoc networks
performance analysis. Radio.Propagation. models. used. in simulations.greatly influence
the performance of.MANETs for both Line.of.Sight (LoS) .and .Non .Line .of .Sight
(NLoS).conditions. The existing propagation models in NS-2 are fairly simplistic and
don’t account for the effect of multiple intersections and/or obstacles. The Two Ray
Ground and the Free Space Path loss models yield unrealistic results for an Ad hoc
network scenario (i.e. no infrastructure). We have integrated Cost 231 muti-wall model
in NS-2 to provide a more sophisticated approach for indoor path loss evaluations. All
obstructions (i.e. walls) between the transmitter and the receiver are considered. The
individual material properties for all obstructions are also taken into account. We have
also analyzed the effect of group based and entity based mobility models such as
Manhattan Grid model, Random Waypoint, Gauss Markov and Reference Point Group
Mobility model. Different network performance.metrics. such. as. Packet. Delivery.
Ratio(PDR). and. mean Delay were evaluated with varying node densities. The network
performance degrades severely with the use of Cost 231 Multi-wall propagation model
and entity based mobility models.
