  A promising solution satisfying the industry's demand to have minimum
alterations in LTE for its operation in unlicensed spectrum is duty cycled
LTE-U scheme, which adopts discontinuous transmission to ensure fair
coexistence with 802.11 (Wi-Fi) WLANs. Even though the scheme guarantees to
maintain Wi-Fi network performance, the fairness among Wi-Fi users still
remains arcane. In this work, we present a practical scenario where LTE-U,
despite being discontinuous (by following an ON-OFF cycle), results in not only
unfair throughput distribution among Wi-Fi users but also causes degradation in
Wi-Fi APs downlink performance. This is due to the domination of few Wi-Fi
users who harness channel in both ON and OFF durations of LTE-U, namely
non-victim users over those who get access only in OFF duration, called victim
users. In this paper, we studied the performance of victim and non-victim Wi-Fi
users, and Wi-Fi AP while varying LTE-U ON duration (i.e., duty cycle). A
propitious scheme is proposed for WLANs, with regard to ease of implementation,
employing Point Coordination Function (PCF) mode of 802.11, promising fairness
among Wi-Fi users with improvement in the channel utilization of Wi-Fi network.
An analytical model is developed to demonstrate guaranteed improvement and
validate the simulation results.
