Automatic Network Management for Mobile Devices.

Mobile devices increasingly find themselves immersed in a sea of potential wireless network connectivity. Our prior work [2] showed that, in urban areas, users encounter multiple 802.11 access points on virtually every scan. Not all of these are usable, however, and the connection quality provided by each varies widely with regard to bandwidth and latency to the network core, and with regard to allowed port traffic. Many devices now featuremultiple radios as well. Each of these is appropriate for different situations and tasks. For example, a user may subscribe to GPRS service as a fall-back, low bandwidth, high latency connection for times when 802.11 coverage is unavailable. Bluetooth and ZigBee (IEEE 802.14.5) radios are ideal for short range, low power, point-to-point communication between devices in a user's personal area network (PAN).