3GPP LTE traffic offloading onto WiFi Direct

Mobile network operators are struggling to handle the rapidly increasing amounts of data traffic on their networks. As a result, 3GPP is currently investigating possible scenarios for device-to-device (D2D) offloading in LTE networks. However, it remains unclear what kinds of gains can be expected from in-band D2D solutions. By comparison, the already available WiFi Direct D2D technology enables offloading onto unlicensed bands at data rates generally higher than infrastructure cellular links. In this paper¹, we study the performance of WiFi Direct as a prominent technology for D2D communications in urban environments. We also discuss some of the potential performance gains for WiFi Direct communications in the presence of 3GPP LTE network-level management. Our extensive simulation study of LTE traffic offloading onto WiFi Direct covers a range of D2D loads and interference levels. We focus on the case where the D2D overlay network is assisted by the cellular infrastructure network; or more specifically, where the cellular network supplies its clients with service discovery information to facilitate the establishment of D2D sessions.