[LINK] Calculating A Mobile Phone User's Phyical Location

[Bernard Robertson-Dunn]

Patrick Corliss wrote:
 
> For those who are technically savvy about such things, how accurately
> can a mobile phone work out a person's physical location (assuming they
> are the one to use the phone)?  Is it possible to calculate a latitude
> and longtitude with any degree of accuracy using base stations?

http://www.ericsson.com/mobileinternet/offerings/location_enabler.shtml

<quote>
Description

Location Enablers will provide you with enhanced accuracy on coordinates
from your MPS and providing entering of personal context on selected
coordinates. These features integrate both location-based services and
personalized services. Applications are able to use the information (XML
based) from these enablers in order to achieve higher end user value.
Reach-U provides these features with PinPoint Mgine and Context Mgine, both
products operating commercially and successfully in GPRS environment. 

...

PinPoint Mgine

PinPoint delivers the coordinates for achieving accuracy of 100-500 meters
in urban areas and 1-2 km in rural areas. This accuracy is sufficient for
most commercial services.

... 

PinPoint Mgine improves accuracy up to 2 to 8 times in comparison to
current positioning systems. PinPoint features several categories of
functions for improving positioning accuracy and increasing usability of
the product. Included is an advanced algorithm for calculating the
positioning of mobile stations based on CGI+TA, modelled and measured GSM
network data.

• Enables most location based services today in GPS/GPRS networks
• Improves accuracy up to 2 to 8 times in comparison to current positioning
systems
• Saves large investments into positioning systems
• Proven, commercially operational technology

Context Mgine

Context Mgine creates adaptive personal context for position, the same
coordinate can have different meanings for different persons or one person
in different time ("home", "at work", "visiting") Personal context for the
user is which Handset used, service usage history. Objective context for
position Kista, Office instead of (3442452,2555324) and "near the beach"
instead of (2341244,21344325). Context-sensitive spatial search closest in
terms of meters is not closest in terms of time and speed of travel depends
on person and time. Context Mgine is used together with PinPoint

• Context describes the personal relation of the subscriber to the given
location, handset used and surrounding objects.
• Increases usage of location based services
• Gateway to context billing for boosting potential revenue
• Proven, commercially operational technology
</quote>

Note that GSM and GPRS use the same base stations, so this is technically
possible today.

-- 
I may not have gone where I intended to go, but I think I have ended up
where I intended to be. 
--Douglas Adams

Regards
brd

Bernard Robertson-Dunn
Sydney Australia
brd@austarmetro.com.au