  The area of mobile ad hoc networking has received considerable attention of
the research community in recent years. These networks have gained immense
popularity primarily due to their infrastructure-less mode of operation which
makes them a suitable candidate for deployment in emergency scenarios like
relief operation, battlefield etc., where either the pre-existing
infrastructure is totally damaged or it is not possible to establish a new
infrastructure quickly. However, MANETs are constrained due to the limited
transmission range of the mobile nodes which reduces the total coverage area.
Sometimes the infrastructure-less ad hoc network may be combined with a fixed
network to form a hybrid network which can cover a wider area with the
advantage of having less fixed infrastructure. In such a combined network, for
transferring data, we need base stations which act as gateways between the
wired and wireless domains. Due to the hybrid nature of these networks, routing
is considered a challenging task. Several routing protocols have been proposed
and tested under various traffic conditions. However, the simulations of such
routing protocols usually do not consider the hybrid network scenario. In this
work we have carried out a systematic performance study of the two prominent
routing protocols: Destination Sequenced Distance Vector Routing (DSDV) and
Dynamic Source Routing (DSR) protocols in the hybrid networking environment. We
have analyzed the performance differentials on the basis of three metrics -
packet delivery fraction, average end-to-end delay and normalized routing load
under varying pause time with different number of sources using NS2 based
simulation.
