Wireless mesh networks are communication networks possessing radio nodes with mesh organization structure. They are expected to be widely employed by personal, local, campus and metropolitan area applications. Most of the needed components for the deployment of WMNs; such as ad-hoc network routing protocols, wireless security protocols, IEEE 802.11 MAC protocol are already available, while there are problems sourced from various protocol layers. These problems restrict WMNs from serving their potential. The purpose of this work is to evaluate the WMN routing mechanisms with respect to several performance indicators and to determine the routing protocols, which maintain scalable, robust and efficient operation. The performance of B.A.T.M.A.N (Better Approach to Mobile Ad-hoc Networking) protocol is compared to conventional AODV and OLSR protocols in addition to an experimental wireless MPLS routing mechanism (LWMPLS). The OMNeT++ simulation environment helps to determine the performance of routing mechanisms throughout our tests. The simulation results point out that B.A.T.M.A.N protocol performs stable routing in networks with varying link qualities or failing nodes. It has low packet loss rate even when it is employed in environments with extremely high thermal noise, therefore B.A.T.M.A.N is foreseen to become one of the most popular routing mechanisms of WMNs.