Performance evaluation of selection schemes for offloading traffic to IEEE 802.11 hotspots

Offloading data traffic to IEEE 802.11 hotspots is one of the key techniques with which mobile operators aim at dealing with the increasing traffic demand of their users in cellular networks. Usually, these offloads are simply conducted once an end-device has WLAN connectivity. This paper identifies gains if the decisions for accommodating certain traffic flows in WLAN consider the characteristics of this technology, i.e., the suitability of traffic being offloaded in terms of occupation of the channel and MAC overhead as result of contention, interference, and fluctuating channels. The contribution of this work is twofold: A performance evaluation compares the novel scheme with common received-signal-strength-based decisions as well as with simpler randomized choices for offloading particular traffic flows. Our scheme shows substantial improvements over a broad range of factors. Lastly, the results identify operational points of the WLAN cell allowing operators to dynamically choose the mix of the offloaded traffic according to their requirements.