Communications, Engineering and Design

Articles

The slow, slow pace of E911
Wed, 07/31/2002 - 8:00pm
Jeffrey Krauss, E911 Elucidator and President of Telecommunications and Technology Policy

Krauss
By Jeffrey Krauss,
E911 Elucidator
and President of Telecommunications
and Technology Policy
Did you think anything could be slower than the rollout of HDTV? What about the rollout of E911 mobile location service? The FCC began a proceeding in 1994 to promote this capability, but public safety agencies are still unable to determine where you are when you call 911 on your cellphone.

The idea is straightforward. When you call 911 from your wireline phone, there is an automatic database lookup of your location, which then appears on the screen in front of the public safety calltaker. The FCC adopted a rule in 1996 that required cellular operators to provide the same kind of location information when you call 911 from a cellphone. The FCC's 1996 decision gave the industry five years to implement this Enhanced 911 (E911) capability.

There are basically two technological approaches that have been developed to determine the cellular handset location. One uses signals from Global Positioning System (GPS) satellites; the other uses only terrestrial signals. The FCC gave the operators the freedom to choose either approach.

An approach that simply incorporates a GPS receiver in a cellphone handset isn't good enough, because GPS signals are easily blocked by buildings, so the network must be modified to broadcast "assistance" signals to help handsets lock onto the satellite signals. The roughly 130 million cellphones in use in the U.S. today do not have GPS capability (with a few recent exceptions). The FCC originally required operators that chose the GPS approach to have GPS handsets on the market by October 2001, and by June 30, 2002, at least 50 percent of all new handsets activated were to be GPS-capable. And they were required to implement the network changes needed to broadcast the "assistance" signals during 2001.

The operators were unable to meet the FCC timetable, so they requested additional time, which the FCC granted. Verizon, for example, finally made its network changes in Rhode Island and in some rural Virginia communities in April 2002. And the first GPS-capable handsets are supposedly now on the market. Sprint PCS claims to have sold more than 700,000! But just try to buy one. The wireless operators that have chosen GPS, like Verizon and Sprint PCS, have been very careful to conceal from the public just which handsets have the new capability!

In addition, there are two approaches that rely solely on terrestrial signals to locate the handset that calls 911. One, called Time Difference of Arrival (TDOA), uses signals from the handsets that are received at multiple receiver locations. The network control center calculates the handset location based on the times that these signals are received. The other, called Enhanced Observed Time Difference (E-OTD), uses signals from fixed network transmitter sites that are received by the handset, which then calculates its location. Because of the complex signal processing needed to combat multipath reflections, and the greater horsepower found in the network control center compared to the handset, TDOA is expected to be more accurate than E-OTD. Moreover, just like the GPS approach, only newly designed handsets will work with E-OTD. But none of these E-OTD-capable handsets are on the market yet, and won't be until late this year.

The cellular carriers that have chosen GPS and E-OTD have not met the FCC deadlines. They blame the equipment vendors, of course. But the FCC isn't buying that story. The FCC recently assessed a fine of $2.2 million against AT&T Wireless for missing the deadline and breaking promises it made for deploying E-OTD technology on its GSM networks. The law allows the FCC to assess a fine of $120,000 per day for violations, with a maximum of $1.2 million per violation, but the FCC came up with three separate violations and finally decided that $2.2 million was a nice round number. Separately, the FCC fined AT&T Wireless $100,000 for missing the deadlines on its TDMA networks. A $100,000 fine was also imposed on Cingular Wireless, and the FCC has other investigations underway.

Why are the cellular operators dragging their feet? They see the deployment of E911 location capability as a government-imposed tax with no countervailing revenue. (Sounds just like the broadcasters' view of HDTV.) That's wrong, of course. In Europe, where there is not yet any government requirement to determine the location of a 112 caller, the mobile phone operators are viewing location-based services as a potential revenue bonanza. These new revenue-producing services include commercial assistance services (roadside assistance for drivers; tracking stolen cars, lost children and disabled people; commercial tracking and tracing of shipments, etc.) and value-added services (location-based billing, location-based information services, etc.). A shopping mall could, for example, make a deal with the cellular operators for free calling if you are calling from within the mall.

Every time a new technology is presented to the FCC, it takes longer than expected to deploy. Usually, that's because the FCC's rules themselves act as barriers, while the vendors are frustrated by the delays. This case is just the opposite. The FCC is promoting the new technology, the vendors are creating the barriers, and it's the public that is frustrated. And unlike HDTV, in this case, lives are at stake.

Have a comment? Contact Jeff via e-mail at: jkrauss@cpcug.org

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