Rising to the FCC challenge
By the year 2001, the location of the mobile station must be provided to the Public Safety Answering Point (PSAP) in two dimensions (x,y), accurate within a radius of 125 meters in 67% of, all cases.
For a mix of reasons - including opportunism, fortuitous architecture, and industry vision - some companies are stepping up to the challenge of Docket 94-102, companies like The Associated Group, CML Technologies, Plant Equipment, and SCC Communications Corp.
Plant Equipment, a longtime supplier of telephony and 9-1-1 products, recently evaluated its 9-1-1 product line in light of wireless integration issues. The company believes that existing users of the Modular ANI/ALI Retrieval System (MAARS) will be able to comply with Phase I of the rules by installing a software upgrade.
Phase I requires wireless carriers to transmit 9-1-1 emergency calls to a PSAP identifying both calling mobile unit (ANI) and cell site or cell site sector. The emergency caller must transmit a mobile identification number or its equivalent and the local 9-1-1 district must request ANI transmission from the wireless carriers. Phase I compliance is required by 1998.
Phase II requires wireless carriers to relay an emergency caller's number, allow PSAP attendants to redial the caller in case of disconnection, and relay the location of the base station or cell site receiving the 9-1-1 call.
'We have the system to meet the new standards through simple migration architecture,' says John K. Fuller, Plant Equipment's vice president of marketing. Users will achieve Phase II compliance by migrating to MAARS-View or VESTA platforms.
CML Technologies has been testing wireless call solutions since early 1994 and offers two solutions for wireless call identification: the Signaling Interface Router (SIR) and ANI Message Integrator (AMI).
The SIR receives wireless call data from the Mobile Telephone Switching Office (MTSO), converts the data to standard eight-digit ANI, selectively routes the call to an appropriate PSAP, and sends location information via a separate data stream to the address locator information (ALI) database. AMI software receives the wireless location and call-back number from the SIR and sends it to a PSAP when the ALI query is made.
SCC Communications Corp. has been a key participant in wireless integration testing. The company has developed a product called 9-1-1 Connect that enables PSAPs to receive wireless 9-1-1 calls using existing premise equipment and networks. It also allows wireless carriers to offer 9-1-1 service with standard wireless data and network interfaces.
Lou Stilp, vice president and general manager of The Associated Group, invented and patented Time Difference of Arrival (TDOA) in 1994. This technology forms the core of the company's TruePosition automatic location system for wireless subscribers. True-Position is a passive overlay system that complements existing cellular and PCS network architectures.
Consisting of four major subsystems - Signal Collection System (SCS), TDOA Location Processor (TLP), Application Processor (AP) and Network Operations Center (NOC) - the system doesn't require any changes to premise equipment, and only minimal cell site modification.
Stilp worries about the dynamics of providing wireless location information. Wireless networks are substantially different from their wireline counterparts. Cellular operators continually tune their networks to improve transmission quality, adjusting antenna coverage as new cell sites come on line. The newer PCS infrastructure is even more volatile.
Every addition of a base station or cell site, every negligible turn of an antenna, affects the positioning information forwarded to TruePosition and other wireless position locating systems.
Eric Sorensen, product marketing manager at SCC, is concerned about the volatility of the wireless network, too. He notes that a 5% adjustment in antenna attitude moves its coverage area several degrees, more than enough to produce location errors.
Kent Sander, a veteran of Ericsson Radio Systems and The Associated Group's new president and chief operating officer, says cellular carriers are taking 'very seriously' the integration of wireless calling into the emergency services environment. They have 'stepped up to do what's necessary,' he believes.
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|Comment:||FCC issues Docket 94-102 rules for basic 9-1-1 and wireless services|
|Date:||May 1, 1997|
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