att_abstract={{Operators of 3G data networks need to distinguish the performance
of each geographic area in their 3G networks to
detect and resolve localized network problems. This is because
the quality of the �last mile� radio link between 3G
base stations and end-user devices is a crucial factor in the
end-to-end performance that each user experiences. It is relatively
straightforward to measure the performance of all IP
traffic in the 3G network from a small number of vantage
points in the core network. However, the location information
available about each mobile device (e.g., the cell sector
that it is in) is often too stale to be accurate because
of user mobility. Moreover, it is impractical to collect fine grained
location information about all mobile devices on an
on-going basis in large 3G networks. Thus, it is not practical
to accurately assign IP performance measurements to
fine-grained geographic regions of the 3G network using off the-
shelf components. Fortunately, previous studies have observed
that human mobility patterns are very predictable. In
this paper, we exploit this predictability to develop a novel
clustering algorithm that accurately assigns IP performance
measurements to fine-grained geographic regions. At the
GGSNs, we can either localize a subscriber into only 4 cell
sectors with the accuracy of 70% over 5 consecutive days
based on a one-day snapshot of fine-grained 3GPP events,
or increase the accuracy 20% through lightweight handover
statistics hourly collected. We present results from a prototype
in a real 3G network that shows our clustering provides
more accurate performance localization results than existing
approaches. Our results also shed light on the mobility patterns
of 3G devices.}},
	att_authors={ag1971, jp935w},
	att_copyright_notice={{(c) ACM, 2011. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in ACM Mobisys Conference {{, 2011-06-27}}.}},
	att_tags={umts, location accuracy, cellular networks},
	author={Qiang Xu and Alexandre Gerber and Z. Morley Mao and Jeffrey Pang},
	institution={{in Proc. of ACM MobiSys}},
	title={{AccuLoc: Practical Localization of Performance Measurements in 3G Networks}},