International Journal of Advanced Research in Computer and Communication Engineering (IJARCCE)
In the last years, the cellular communications system has evolved greatly, mainly moved by the increase of applications and user requirements. The growth of demand in this area is attributed to facilities and usability of services through cellular networks. Future wireless scenarios will be characterized by the coexistence of a variety of heterogeneous wireless access technologies. There will be complex protocol stacks, supporting a number of applications and services with different Quality-of-Service (QoS) demands and, in addition, requiring multi-mode terminal capabilities to access such networks.