Mobility Management & Route Optimization issues for Wireless Networks are presented in detail. IP-based Networks, PSTN-based Networks and ATM-based Networks backbones have been considered for developing mobility management technique. In IP-based backbone network, a route optimization scheme is proposed to improve the performance of Mobile IP having some apparent drawbacks like triangular routing problem, home agent overloading etc. An encapsulation at one- level up in the hierarchy is performed to improve the handoff delay and the simulation is carried out on NS-2 simulator. In PSTN-based backbone networks, a protocol is proposed and an analytical modeling is carried out where the location registration can be finished prior to the arrival of a MT at the new network to support the inter-system roaming. For an ATM-based backbone network, a design and prototyping of a mobility support ATM network is proposed to improve the handoff time, cell loss and call setup time. Further, an improved mobile location management for wireless ATM networks is proposed and analyzed to improve the performance in terms of number of hops required for location managements.