On June 12, 1996 a Report and Order (CC Docket Number 94-102: RM-8143) was adopted by the FCC stating: "Not later than five years after the effective date of the rules adopted in this proceeding, covered carriers are required to achieve the capability to identify the latitude and longitude of a mobile unit making a 911 call within a radius of no more than 125 meters in 67% of all cases."

The reason behind the promulgation of the Report and Order is that the number of emergency calls from cellular phones has increased dramatically over the years, such that in Massachusetts alone there are 40,000 cellular 911 calls per month placed to the PSAP (Public Safety Access Point) in Framingham which is the point from which all cellular 911 calls are routed. According to th CTIA (Cellular Telecommunications Institute of. America), last year there were in 'excess of 18 million cellular 911 calls nationwide.

The problem is so severe that (according to Don Nagle, Chief of Telecommunications of the Commonwealth of Massachusetts) it takes an average of approximately 10 minutes to locate a cellular 911 caller, with an injured person expiring from a cut artery in as little as 8 minutes. The problem of identifying the location of E-911 callers is exacerbated by the fact that the individual may not be conscious, may not speak the English language, may be too hysterical to give adequate information to the dispatchers, or more likely, does not know where he/she is. In a panic situation, most E-911 callers have not a clue as to where they are within a town, much less the town that they are in.

The identification of the location of wireless transmissions in the past has most noticeably been carried out by the United States Coast Guard utilizing radio direction finding equipment for VHF radio transmissions. VHF RDF (Radio Direction Finding) techniques have been successful in the Coast Guard's carrying out of its responsibilities only if the transmission can be maintained long enough to get a fix, and then only if the VHF transmitter is within range of three "high-site" antennas.

With the advent of LORAN and GPS systems, boaters are increasingly able to report their location in terms of latitude and longitude through the readout of these devices to the Coast Guard stations receiving the calls. In addition, in 1985, Shakespeare produced a MayDay Mike radio, with automatic synthetic voice annunciation of the latitude and longitude (see Figure 1) . Simultaneously, a system called Digital Selective Calling or DSC was developed by Ross Engineering of Largo, Florida which digitally transmitted the latitude and longitude to Coast Guard stations.

From the marine point of view, the MayDay Mike system and the DSC systems provide the location of a stricken vessel through the transmission of latitude and longitude garnered locally from either LORAN or GPS receivers. The problem with Digital Selective Calling was the failure to deploy equipment making its utility questionable. The receivers cost initially in excess of $1500 and were not widely accepted by the boating public. As a result, according to Joe Hersey, Head of Telecommunications, USCG, a test program with the United States Coast Guard in Chicago resulted in fewer than three calls in the first month of operation.

With respect to the MayDay Mike System, VHF radio sales plummetted from 1.2 million in 1992 to less than 100,000 in 1995 due to saturation and the use of cellular phones by mariners.

- FIGURE 1-

In an attempt to identify the location of stricken individuals utilizing cellular phones, Pac-Tel developed its Teletrack system, a triangulation system in which the cellular phone location was identified through the utilization of a ranging technique and a transponder at the cell phone. Problems involved with the Teletrack system include an estimated imlplementation cost of $500K per cell site, along with a deployment time of approximately two years per community, making the system relatively expensive and neither universal nor quickly implementable.

Subsequent to Teletrack's deployment, Sanders Associates of Nashua, New Hampshire developed a time difference of arrival (TDOA) technique in which a data burst is received simultaneously at three cell sites. From the time difference of arrival of the data burst from the phone at each of the cell sites, the approximate location of the cellular telephone can be received. The approximate cost of the Sanders system is $90K per cell site and two years per community to implement.

A pure direction finding system was implemented by KSI of MacLain, Virginia at an approximate cost of $50K per cell site and 18 months per community to implement , with the position being acquired through the utilization of direction finding techniques, as opposed to time difference of arrival techniques (see Figure 2).

Most recently, the Associated Group has implemented a TDOA system, dubbed their True Position System. This system is presently being tested by the New Jersey State Police with participation from ComCast, MapInfo, On Target Mapping, Rockwell, Bell Atlantic, and the KML Group to ascertain location accuracy and cost of implementation. The estimated cost is $50K per cell site, but varies depending on the number of receivers (1-6) per cell site (see Figure 3).

As with any triangulation system, when the cell sites are in line, the lines between the towers and the cell phone come together at very shallow angles, reducing the accuracy with which position can be ascertained. Secondly, as with all triangulation systems , the coverage depends on towers being retrofitted with suitable antennas and infrastructure. For example, in Boston, there are 100 cell sites side (A, B) making the cost per side, even with the least expensive of the present systems, on the order of $5 - $10 million. This does not take into account PCS with two additional sides and many more cell sites. Moreover, the time to obtaining a fix can be as long as two minutes.

Bob Miller, New Jersey Office of Emergency Telecommunication Services, unequivocally states in his comments to the current FCC NPRM, that triangulation systems will cost New Jersey $100 million to implement. This is over $5 billion nationwide based on multiplying the $100 million figure by 50.

Also important is a civil liberties problem with all triangulation systems and that is the "big brother is watching you" problem, since the system is capable of locating the position of all cell phones, whether the individual wants to be found or not. Research shows that an individual wants to be found only when he/she wants to be found, where as cell phones are locatable 24 hours a day through the utilization of a triangulation system.

While triangulation systems suffer from infrastructure costs and deployment schedules, Global Position Satellites provide universal coverage, although non-operational in buildings. In order for GPS receivers to operate, the 40 watt spread spectrum signals from the 26 satellites must be receivable by the GPS receiver on a line-of-sight basis. It has been found that cloud cover, trees, and other blocking artifacts other than buildings seem to have very little effect on the receipt of these signals which are 20 dB down by the time they reach the earth's surface. In general, as many as 8-12 GPS satellites are visible from any particular point on the earth, with the result that manufacturers such as Motorola, Garmin, Trimble, Magellan, Rockwell, and others have provided 8-12 channel receivers for the receipt of the GPS signals. The satellites provide signals indicating their own position, e.g., ephemeris, and timing signals such that the GPS satellite receivers can derive range to each of these satellites from which the position is internally calculated by the GPS receiver.

One early system utilizing GPS information to provide a PSAP with the location of a stricken vehicle was developed by Navsys Corporation of Boulder, Colorado in which raw GPS data received by a GPS antenna mounted on the exterior of a car was transmitted to a central processing point provided by Navsys and the Department of Transportation for the State of Colorado to process the GPS information and to provide location to ISAP terminals within the State of Colorado. While the utilization of GPS-based location information proved adequate to locate the vehicles in question, the utilization of a central processing facility to process raw GPS data was found to be unwieldly, also limiting the portability of the system to other jurisdictions.

Noting the present development of miniaturized GPS multi-channel receivers, Motorola develoIped the Encore system for the location of vehicles initially implementing the system in Lincoln automobiles (see Figure 4). These systems were implemented through the utilization of a cellular phone coupled to the output of the Encore 8-channel GPS receiver, with the latitude and longitude location being modemed to Westinghouse in Irving, Texas for further discemination to the closest PSAP to the vehicle. The system was initially configured to provide the PSAP with the Vehicle Identification Number and position information only, with this information provided to the relevant PSAP by calling a back line at the PSAP.

Note, the initial Rescue system did not, however, provide voice communication between the stricken vehicle and the PSAP, a situation which has subsequently been corrected.

In an effort to ascertain back-up line telephone numbers, Westinghouse turned to the National Emergency Number Association or NENA for the provision of the telephone numbers of the local PSAPS. Presently, the accuracy of such PSAP numbers is at the 80% level, as there are some 7,000 PSAPS in the United States. The utility of modeming information to a central processing dispatch center such that as maintained by Westinghouse is that the amount of infrastructure to be provided at the PSAP can be limited.

Consumer acceptance of the Encore Rescue system is presently in question as the system is currently marketed. For instance, as of the date of this paper, the Rescue system is $1,500 per install, plus $100 per year monitoring fee, both amounts somewhat limiting sales.

In an effort to establish standards for E-911 signalling utilizing GPS receivers, in 1995 the Intelligent Vehicle Highway System (now ITS or Intelligent Transit System) under the direction of Dr. Christine Johnson, promulgated an operational test funded by the National Highway Public Safety Administration in which Calspan was the lead participant and which other participants included the Erie County Sheriff's Office, Cellular One, GM and AAA. The goal was to provide a system for determining not only the location of a stricken vehicle and time of crash, but also its change of velocity and direction of impact, its point of impact, the force of impact, and other details relating to the crash of the vehicle. The contract was let for $305 million, with the deployment in 1000 vehicles scheduled for early 1997.

As with any vehicle location. identifying system, there remains the question of the ability to provide location information for cell phone users who are not within a vehicle. It is estimated that there are now 40 million cellular telephone subscribers in the United States, with the cell phones being freely portable and with sales statistics indicating that less than 10% of the phones currently sold are for in-vehicle install. There is, therefore, a requirement for the ability to locate cellular E-911 callers outside of a vehicle, a task currently performed by the above-mentioned triangulation systems.

As an outgrowth of the MayDay Mike marine implementation for locating stricken vessels at sea, Tendler Cellular of Boston, Massachusetts has developed an integrated, portable, unitary cellular phone incorporating a GPS receiver, a GPS antenna, a chipset for decoding the latitude and longitude derivable from the GPS receiver, and a synthesized voice indicating location (see Figure 5). The salient features of the FoneFinder system are that it is instantly implementable with the provision of the cellular phone, universal in coverage, and can be made available by the carriers at the cost of a normal cell phone, plus $4 per month and a three-year no-cut contract. A block diagram of the system can be seen in Figure 6, with optional activations for car theft alarm, airbag deployment, man down, hijack and pager scenarios.

The utilization of synthesized voice to announce the latitude and longitude of the E-911 caller results in a virtually infrastructureless system in which, through the provision of electronic maps on CD-ROM at a cost of no more than $300 per terminal, operators at the PSAPS can obtain a bulls-eye on the electronic chart by merely listening to the latitude and longitude, typing it in and receiving the bulls-eye.

Testing of the FoneFinder system is currently planned by several carriers and by AirTouch in the Los Angeles County area. Moreover, since the FoneFinder also verbally anounces the caller's cell phone number, the requirement that the cell phone number be provided to the PSAP is automatically met. This solves a problem that had previously been addressed by providing Pseudo ANIs (referring to the telephone number of the receiving cell site) in a complicated infrastructure-intense system estimated to cost the PSAP on the order of .75 cents per minute to cover infrastructure costs.

On the other hand, the FoneFinder system simply announces in English through synthesized voice, the caller's telephone number or MIN.

The FoneFinder system thus provides an instantly deployable, universal and a "free to the public" system for solving an urgent public safety problem.