Downlink Interoperability Model of LTE/Wi-Fi Integration/Coexistence with Performance Evaluation

The major concern of mobile operators is to improve the performance of the network by maximizing the capacity while maintaining proper utilization of the traffic in the network. Consequently, performance evaluation of the new generation of wireless mobile networks is a serious issue to be considered in future research in the uplink as well as in the downlink to meet the continuous demand for higher data rate, better utilization of network resources. For this purpose, an interoperability-integrated model in the downlink for both LTE and Wi-Fi technologies is proposed. Two virtual zones are assumed; a micro Wi-Fi free-unlicensed spectrum is in the inner zone, surrounded by a macro LTE licensed spectrum in the outer zone. The primary user data connections are served by the LTE outer zone, whereas the best-effort user data connections are served by Wi-Fi inner zone. Given an assumed maximum capacity of the whole cell, the call admission control algorithm is based on a minimum bit rate that should be satisfied by the request to be admitted to the cell. Besides, based on the type of service, a priority level is given to each service. The LTE zone serves higher priority requests, however, lower priority requests are forwarded by the LTE zone to be served by the Wi-Fi inner zone; hence, the balance of the traffic over the whole network will be achieved. The simulation results show that the proposed model of coexistence hurts LTE performance, however, the integration between both technologies has an advantage on the overall cell performance by maximizing the capacity network. Hence, the traffic is distributed between both technologies, and therefore, the load will be balanced all over the whole network.