Smart Phone and Next Generation Mobile Computing

Mobile Application Challenges 417

7.1.4 Cellular Network Triangulation

For outdoor location sensing, aside from GPS, a cellular network

with a large number of fixed base stations is another excellent,

well-established infrastructure. In the case of distance triangulation

(lateration), the position of a cell phone can be determined by the

distances to three adjacent base stations. When angle triangulation is

used (angulation), two base stations are enough. In either case, loca-

tion information for the fixed base stations in the network is needed

in addition to distance measurements. The TOF of radio signals is

often used in cellular localization.

Cellular network-based location sensing solutions utilizing trian-

gulation techniques include cell ID, enhanced ...