Protecting regular customer traffic from ad-hoc traffic in public WLAN hot-spots

Mobile devices may often use WLAN hot-spots to communicate directly with one another in a peer-to-peer fashion without having to authenticate (and pay) for Internet access. This ad-hoc-style communication may impede the performance of regular Internet users´ hot-spot experience. We present how LEDBAT (Low Extra Delay Background Transport) and its modified version, fLEDBAT, can be used as transport protocol between mobile devices in an infrastructure mode WLAN to reduce the impact on regular traffic. Although promising, the use of (f)LEDBAT may not solve all the problems arising from high-volume ad-hoc data traffic. Active queue management at the access point would do this but this would require controlling it. To overcome this, we complement LEDBAT by bundle admission control mechanisms based on the queueing delay and/or the number of active bundle transfers as alternative approaches. Both combined make device-to-device traffic yield to regular traffic, which we validate through extensive ns-2 simulations.