GPS for 911 calls

Martin Lefkowitz lefko at
Wed Mar 7 18:36:20 CET 2007

It will be interesting to see how that pans out too.  My understanding
is that the CDMA systems started out trying this method and then wen't
to the idea of adding GPS HW.


> From: "Perry E. Metzger" <perry at> Harald Welte
> <laforge at> writes:
>>> >> Wireless Enhanced 911 for mobiles, including GPS or other
>>> >> radiolocation data, is a US standard. I don't know how the signaling
>>> >> works, but if you are selling a new phone in the US, it is mandatory
>>> >> that you comply.
>> >
>> > Please see
>> >
>> > "however. TDMA and GSM networks such as Cingular and T-Mobile use TDOA"
>> > which is location singulation based purely on the network.  No device
>> > support and no GPS needed for that.
> Ah, so the network does the work, not the phone. On CDMA I believe all
> the phones do the signaling.
> Perry

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