The advancements in the telecoms industry have led to the emergence of many new technologies to meet communication requirements worldwide. Consumers have largely been using GSM, CDMA and WiFi. New developments have given birth to more robust communication systems including WiMax and LTE. Lay users are not aware of the technicalities, advantages and disadvantages of these technologies. Therefore, there is a state of great confusion among the users of this generation as to which technology is the best for them to use. Each of these technologies has pros and cons over one another. For example, LTE covers a large area and offers the highest speed, but the user has to pay for it; however, WiFi covers only hotspots but the use is free. Future heterogeneous networks (HetNets) will enable users to achieve seamless connectivity through vertical handovers while providing them the beneficial features of each technology. For HetNets many issues still need to be addressed. This paper explores some of the open problems and future trends related to the handovers in heterogeneous wireless networks. The dynamics with respect to handovers and the network load of cellular architecture in the coming era in the field of wireless communications are also presented. In addition, first a foundation is laid on the IEEE media independent handover and its importance and then the problem of load balancing and its impact on the realization of future HetNets is explained. Finally, an important problem during vertical handovers, known as the ping-pong effect is explained. The open problems for researchers have been identified for the aforementioned issues.
Mobility Modeling and Performance Evaluation of Heterogeneous Wireless Networks
