Wireless communications of today is moving from cellular networks towards more distributed, self-configuring ad hoc oriented networks. Wireless had a huge growth over the passing years, first with cellular phones (more than one billon users) and then wi-fi.The integration of mobile ad hoc networks into cellular wireless networks is with huge interest today. Due to the multiple hop functionalities offer by MANETs which give many advantages to cellular networks such as increase coverage, data rates, QoS performance in terms of call blocking probability, bit error rate, as well as QoS fairness for different users. The routing problems in heterogeneous network become popular researches nowadays. The heterogeneous network is the integration of ad hoc network in a cellular network.This thesis is about evaluation of the performance of some ad hoc routing protocols for the purpose of the integration of cellular network and MANET to extend coverage. Two routing protocol were chosen, AODV which is reactive Protocol (On-demand) and the DSDV a proactive protocol (table-driven). The throughput of the network was evaluated with respect to time, mobility and transmission range using a channel rate of 11 Mbps using two ray ground reflection model as the radio propagation model. The motive is also to propose a suitable MANETs routing protocol for wireless infrastructure and ad hoc networks integration in general. The system is more suitable for usage in rural areas where there is no many obstacles to cause fading of the radio signals before reaching the destination.