IT'S WRONG TO WISH ON SPACE HARDWARE... Why carriers may need to look for a non GPS solution to E911
by Nicki Hayes, October 4, 2001
Nicki Hayes, WDN's European correspondent shares her views on the FCC mandate regarding
Phase II e911 compliance and the passing of Monday's e911 mandate deadline.
Not one US carrier has met Monday's e911 mandate deadline. The main problem reported by these operators is the estimated $2 billion cost of implementing any of the currently promoted systems that rely on specialized hardware enhanced by the Global Positioning System (GPS) satellites. But cost is not the only concern related to GPS technology in the current climate. The availability of satellite networks for civilian use could also become an issue. Nicki Hayes, WDN's European correspondent investigates.
According to The Wall Street Journal, not one of the US's national wireless communication companies was in a position to meet the requirements of the e911 mandate's Monday deadline. The mandate from the Federal Communication Commission (FCC) requires wireless operators to be able to give approximate location of any mobile phone user who dials 911 (the number for emergency services in the US). The main issue reported by these operators is the estimated $2 billion cost of implementing any of the currently promoted systems that rely on specialized hardware enhanced by the Global Positioning System (GPS) satellites.
No doubt that members of the European Union's (EU's) Co-ordination Group on Access to Location Information by Emergency Services (CGALIES) is taking notes of these implementation problems. It is this group's task to facilitate consensus between all member state's players on the implementation details of the EU's equivalent mandate - e 112. The details of this regulatory package are due to be finalized by the end of the year, with final implementation scheduled for April 2003.
The issue of cost is crucial to cash strapped carriers everywhere and would certainly be a key barrier
for the implementation of such a mandate in Europe where many operators are still struggling to find ways to
off-set the cost of their 3G licenses. Such operators would be keen to find alternative lower cost solutions
than the currently promoted GPS based ones. Cost may not be the only factor influencing such a search either,
for while GPS based solutions are the best known they are not necessarily the best. Indeed, they have a number
of inherent weaknesses. For one, as the receiver needs to be on the satellite's line of sight, the technology
works less well in built-up areas and inside buildings. Also, in time of war GPS satellites take on a strategic
importance, and as has been reported in the UK press this week, it is not clear how the network will be affected
during such times. For instance, if these satellites were turned off to civilian use to prevent terrorist
exploitation, no alternative private network exists to take their place.
And, while there are several solutions, including Airbiquity and SnapTrack (see www.wirelessdevnet.com/channels/lbs/features/newsbite11.html) based on GPS,
which solve the "line of sight" issue, the network availability and cost issues still exist.
So, what are the alternatives?
Other alternatives exist in the form of TOA (time of arrival) solutions and Cell ID
(cell identification solutions). Cell ID solutions are only accurate to within 5 kilometers so are not
suitable for e911 purposes. TOA solutions measure the time a signal data is transmitted by the cellular
network to obtain a geographical position for the device that sent that signal. They are accurate to
within 100 meters and do not have the line of sight or network availability issues of GPS based systems. However they require costly infrastructure upgrades and network changes - costs for such upgrades vary from US$9,000 to US$30,000 per cell site. The US alone has 104,000 cell sites. It hardly calls for complex mathematics to work out that cost is also an issue here then!
Another alternative approach is triangulation. The principle is simple: by calculating the time taken for a signal to travel between a handset and several base stations, and the strength or weakness of the signal, one can fix a location to within 50 meters. Several companies produce the necessary software, including Cambridge Positioning Systems, CellPoint (see www.wirelessdevnet.com/news/2001/260/news11.html)
and Digital Earth Systems (see www.wirelessdevnet.com/news/2001/261/news1.html).
While triangulation does not solve the line of sight issue, it is not reliant on the availability of a government owned network of satellites, which may be turned-off from civilian use during times of war. Neither does it require huge expenditure on infrastructure upgrades nor network changes, as Jim McGeough, CEO of Digital Earth Systems who launched GeoMode(tm), a 100 per cent software based solution last month, explains:
"GeoMode is accurate to within 50 meters and does not require any infrastructure or network changes. The cost savings are significant, especially as the carrier implementing GeoMode does not have any capital expense for infrastructure or network upgrades. Infact, the GeoMode commercial model can be fee based on usage," he advised.
Cost is not the only advantage GeoMode offers. It can determine location within 30 seconds on GSM and 10 seconds on GPRS, which compares well to the 20-30 seconds of SnapTrak's and Cell-Loc's assisted GPS and blows the 15-20 minutes of pure GPS solutions and 60 seconds of TOA technology out of the arena. In addition it is very easy to use. The location capacity does not need activating when emergency calls are made, it automatically transmits the caller's location to the emergency dispatch center, and, according to McGeough, "It can be implemented today without any changes to wireless carrier's infrastructure, so we can start saving lives immediately."
McGeough also claims that lack of coverage due to line of sight requirements is not an issue with GeoMode's unique patented technology - GeoMode is based on a patented algorithm that analyzes the received signal strength from a mobile device, network data and signal arrival time. Using this information it fixes the position of the device in question:
"GeoMode works in buildings, in covered car parks and in wooded areas as long as there is a cellular signal received by the cell phone; that is the only requirement," he stated.
If the complex mathematics upon which GeoMode is based means that it really does work inside buildings, car parks and wooded areas, then Digital Earth Systems seems to have a killer application. Even if it doesn't, operators should be taking a look at it, if only as a temporary measure while we await news on the continuing availability of the world's space hardware for civilian use.
A response to the article from SnapTrack
Previous NewsByte... GETTING BACK ON THE WIRELESS TRACK
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For more on this see the WDN e911 Resource Page
About the author:
Nicki Hayes is a freelance writer and corporate communications consultant specialising in business to business internet issues. She has contributed editorial to a number of publications including Unstrung.com, Guardian Online, Financial Times, Banking & Financial Training, eAI Journal and Secure Computing. Nicki is also the European correspondent for The Wireless Developer Network. Nicki is based in Dublin, Ireland and also has a base in Cambridge, UK. Through her consultancy, Hayes-Singh Associates, she has access to a number of technical writers and PR consultants throughout Ireland and the UK.
About the WirelessDevNet (www.wirelessdevnet.com):
The Wireless Developer Network is an on-line community for information technology
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