Analyzing the WiFi Access Probability in LTE-U/WiFi Coexistence Networks

Deploying the long-term evolution (LTE) system in unlicensed spectrum, which is also known as LTE-U, is an appealing technology for future cellular networks. However, the performance of legacy WiFi users will be degraded by the coexistence of LTE-U in the same unlicensed spectrum. In this paper, we investigate the WiFi access probability in a LTE-U and WiFi coexistence scenario where LTE-U users employ the listen- before-talk (LBT) protocols to access the channel. We derive the WiFi access probability expression as a function of the numbers of LTE-U and WiFi users. Numerical results show that the larger LTE-U CW size and offload users from LTE-U to WiFi, the better performance of WiFi access probability can be achieved. Our results provide a significant reference for admission control in LTE-U/WiFi coexistence networks.