[Loadstone] "bluetooht, supported, internal"?

Rob Melchers rob at loadstone-gps.com
Wed Oct 1 09:33:12 BST 2008


Assisted GPS (A-GPS) - Wikipedia

Conventional GPS has difficulty providing reliable positions in poor signal 
conditions. For example when surrounded by tall buildings (resulting in 
multipath), or when the satellite signals are weakened when a GPS device is 
indoors or under trees. Some newer receivers are better at handling these 
situations.

In addition, when first turned on in these conditions, some non-assisted 
GPS units may not be able to download the almanac and ephemeris information 
from the GPS satellites, rendering them unable to function until a clear 
signal can be received continuously for up to one minute.

An A-GPS receiver can address these problems in several ways, using an 
assistance server:

* The assistance server can locate the phone roughly by which cell site it 
is connected to on the cellular network.
* The assistance server has a good satellite signal, and lots of 
computation power, so it can compare fragmentary signals relayed to it by 
cell phones, with the satellite signal it receives directly, and then 
inform the cell phone or emergency services of the cell phone's position.
* It can supply orbital data for the GPS satellites to the cell phone, 
enabling the cell phone to lock to the satellites when it otherwise could 
not, and autonomously calculate its position.
* By having accurate, surveyed coordinates for the cell site towers, it can 
have better knowledge of ionospheric conditions and other errors affecting 
the GPS signal than the cell phone alone, enabling more precise calculation 
of position.

As an additional benefit, it can reduce both the amount of CPU and 
programming required for a GPS phone by offloading most of the work onto 
the assistance server.

A typical A-GPS-enabled cell phone will use an internet connection to 
contact the assistance server. Alternatively, it may use standard 
non-assisted GPS,
which is slower and less accurate, but does not lead to network charges for 
data traffic, which can be considerable.

At 10/1/2008, you wrote:
>Hello Shawn
>
> > Assisted gps is the internal receiver assisted with data from a
> > server.
>
>So this has no meaning for LS, I think? And I would have to activate
>just "internel" if I ever want to use it?
>
>Loadstone V. 0.70, Nokia N70
>
>--
>
>Regards
>
>Hanspeter Schaffner
>
>_______________________________________________
>Loadstone mailing list
>Loadstone at loadstone-gps.com
>http://www.loadstone-gps.com/mailman/listinfo/loadstone
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