On Mon, Jun 16, 2008 at 7:57 PM, Curt Sampson <cjs@cynic.net> wrote:
> On 2008-06-16 13:06 +0900 (Mon), Greg Conquest wrote:
>
>> In other words, I want to have unrestricted use of the GPS,
>> with that data going freely into google maps/google earth..., and the
>> connection being over WiFi. I don't want to pay anyone anything for
>> these features since they are all free.
>
> Perhaps you don't know this, but virtually all keitai GPS systems are
> not stand-alone, but get assistance from nearby cell-phone towers to
> find out where they are. So it's not free to the carrier when you use
> your GPS; it uses up some of their bandwidth.
I know that aGPS, and maybe eGPS, uses the cell phone signal to
roughly gauge location which then allows the regular GPS to get a lock
more quickly than without such preliminary location estimation. This
"feature" is not needed, though, for full GPS functioning. Even the
GPS augmentation (WAAS in North America, EGNOS in Europe and the
newly launched MSAS in Japan) which gives higher resolution location
entirely depends on the GPS chipset and GPS radio receivers -- no
cell phpone signal needed. So, when Japanese cell phone providers
*require* the use of a cell phone signal, it is almost entirely for
the purpose of generating a fee. The new shizensaigai (?)/hijou navi
(natural disaster GPS) feature touted on some GPS keitai makes this
clear. "Your keitai GPS system will work even if all the cell phone
towers are broken by an earthquake..." So, the function is out there
in the wild, even in "lock-down happy" Japan.
Greg
Received on Tue Jun 17 03:48:39 2008