> > Why can't we have VoIP phones with built-in GPS receivers and a > > Because GPS doesn't work indoors.
GPS works anywhere where the satellite signals can be detected. http://www.u-blox.com/technology/supersense.html Obviously, signals get weaker when they have to pass through solid materials like building walls. But people are already working on more sensitive receivers. But, leaving that aside, if the IP phone has a battery inside it and if it can record previous GPS locations and if you move the phone outside to a new location, then it could remember the last GPS detectable location and use that when it connects to the net again. --Michael Dillon P.S. assuming that phones like this come on the market, we might see the following exchange on a web forum somewhere... Q. Hi. My ACME VoIP Phone is complaining that it can't provide E-911 service. I reset it, pulled the plug, but nothing helps. A. Do you live in an apartment building? Q. Yeah, why? What difference does that make? A. Trust me. Unplug the phone, take it outside and walk to the nearest major intersection. Cross all 4 streets at the intersection, walking around until you get back to where you first arrived at the intersection. Then go home, plug in your ACME VoIP Phone and try again. Q. WOW! It worked! I can't believe it. Now I have a new problem. I told my friends how I fixed the phone and now they all think I'm smoking strange substances. A. Well, you win some, and you lose some. :-)