Issue link: https://read.dmtmag.com/i/91181
T he first 911 call in the United States was made in 1968 in Haleyville, Ala., on an old-fashioned rotary-dial telephone similar to that in Figure 1. Since then, massive advances in the way people communicate have forced the once-pioneering 911 system to evolve. These changes can be categorized as follows: A major change over the past two decades has been the penetration of wireless technol- ogy so much that mobile phones now are ubiquitous. The other major technological change is the availability of high-accuracy location technologies to assist in locating mobile emergency callers. Perhaps the most impactful changes are the ways in which people communicate, the devices they use and the environments in which they use these devices. Mandates and other regulations enforced by the Federal Communications Commission (FCC) impacted telecommunications providers, tech- nology vendors and, ultimately, end users. These three factors have combined to create 911 scenarios that the first emergency callers in Alabama in 1968 could hardly imagine. All Location Methods Not Equal The mobile geo-location industry emerged in the late 1990s, following the first FCC E911 mandate. A vari- ety of low-, medium- and high-accuracy performance location technologies emerged as a result of the man- date. However, only the high-accuracy solutions were deployed by operators for meeting the FCC mandate. Location-accuracy performance and reliability require- ments vary by the type of application they serve, driv- ing the selection of the appropriate location solution from the following: - receiver chipsets to be included in the caller's mobile is increasing due to widespread adoption of smart- phones, the technology isn't ubiquitous from a global - tions), such as suburban and rural areas, but are chal- lenged in dense urban (urban canyons) and especially indoor environments where most calls originate from. - on predictions or models of the radio environment against which it performs an algorithmic comparison of the measurements to determine a best-match estima- tion of the device location. target, resulting in possible life-threatening situations O CT OB E R .C O M 27