Honest question here: How can it uses the cell towers to figure things out if there is no data plan to ask someone? Does it have a list of all cell towers in it somewhere? I would think that it would need to communicate with someone about it after getting tower info from the towers
Sorry, I don't know how this stuff works On Feb 5, 2010, at 6:44 AM, Neil Laubenthal wrote: > Assisted GPS does not require a data plan or cell connectivity to work . . > .assisted GPS means that the GPS chip uses cell tower info as a starting > point to get a fix. Without it . . .the GPS receiver must do a great deal > more analysis of the orbital ephemeris of the satellites before I can > determine where it is. > > My iPhone gets a fix just fine with 3G and data disabled. Note though . . > .that putting the iPhone in airplane mode is not the same . . .that disables > the radio entirely which means that the receiver is turned off as well. > > If you've got a GPS in your car . . .ever notice how it gets a fix much > faster if it is in the same location as it was when you turned it off > compared to turning it off in say Jacksonville when you turned in the rental > car . . .and carrying it in your pocket to Atlanta and turning it on in your > next rental car? Takes much longer in the second case . . .the receiver > attempts to use it's last known location as an assist just like it does with > cell towers. If they aren't available, or the last known position is hosed . > . .the receiver is forced to listen a lot longer to the info the satellite is > transmitting before it has enough data to find itself. > > On Feb 4, 2010, at 3:59 PM, objectwerks inc wrote: > >> >> >> Of course, that begs the question of whether the GPS works without a data >> plan. It is billed as some sort of assisted GPS that is built into the G3 >> comms chip. I think on the iPhone that the GPS gets seeded by a cell tower >> triangulation first. Don't know the details. > > > ----------------------------------------------- > There are only three kinds of stress; your basic nuclear stress, cooking > stress, and A$$hole stress. The key to their relationship is Jello. > > neil > > > _______________________________________________ MacOSX-talk mailing list [email protected] http://www.omnigroup.com/mailman/listinfo/macosx-talk
