This article introduces a distributed system, called wireless proxy, to mitigate the effects of user mobility over streaming services on IEEE 802.11 wireless LANs (WLANs). It argues that a handoff procedure totally controlled by the client, depending on client mobility and configuration, can have negative effects over streaming services. In this way, mobile clients that remain associated with their current access point (AP) in poor channel conditions, severely affect the performance of streaming services. The presented distributed system monitors client mobility and induces mobile client handoffs when channel conditions worsen. Also, the system compensates streaming client and server underestimations of channel conditions. The obtained improvements using wireless proxy are experimentally tested using one of the most extended commercial streaming platforms and off-the-shelf WiFi devices. The main contribution of the developed system is that it works with unmodified IEEE 802.11 wireless NICs and APs, such as the ones widely deployed nowadays.
One of the most challenging issues of current 802.11 networks is the support of user mobility, mainly due to handoff latencies and performance anomalies. The reduction of the effects of user mobility over different types of services has been intensively researched previously. We can classify previous works in this field into three main groups: a first group that presents solutions based on configuration optimizations or technological modifications in IEEE 802.11 networks, a second group that analyzes streaming services performance over wireless LANs and a last group based on the development of systems or protocols capable of mitigating handoff latency effects maintaining current wireless technologies.