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More info on GPS in general and the OpenMoko chip in particular.
Everybody who has used a modern GPS has used AGPS. It is usually called warm-start or hot-start. AGPS is purely a marketing term. To calculate the position a GPS chip needs:
* almanac = coarse position of satellites * ephemeris = precise positon of satellites
The almanac is broadcast in a loop of 12.5 minutes and valid for at least six weeks. The ephemeris is broadcast in a loop of 30 seconds and valid for ~2 hours.
Time is mostly irrelevant, as modern chips synchronise within a second with the satellites.
The receiver chipsets store this data in flash and load it from there onto the chip in order to _assist_ the hot or warm start.
AGPS now means to load the almanac and the ephemeris from elsewhere, i.e. via a network. For example for free from the american government: http://www.navcen.uscg.gov/gps/precise/default.htm
AGPS is a nice convenience yet the success and proper functioning of TomTom and Navigon PDAs shows that you don't need that at all.
It's worth noting that the GPS on the neo is sensitive enough to pick up GPS signals in buildings. If the spot you charge your neo happens to have a GPS signal, downloading the almanac from the satellites while it charges is essentially free, and takes no internet access at all. Do this daily, and you get most of the benefit of aGPS.
A 1: It is probably the same chipset as in ipaq hw6[59]15: http://wiki.xda-developers.com/index.php?pagename=SableGPS A 2: Should be Hammerhead.
A: See above, the important part is the GPS and not the assistance. Antenna is thus compulsory.
A: Can be anywhere on the net. Alternatively a service from the cellphone operators.
A: They use the low cost of their chip as selling point. Their website implies that this is a service that comes with the chip. I'd call it not very clever if they are going to charge you - it would change their image from lowcost to money grabber and the reverse engineering of their binary protocol would happen even faster.
Last but not least: Global Locate boasts itself to get a first fix in 8 sec without AGPS. The importance of AGPS depends whether the part of their website you are reading is targeted at cell phone operators, or not.
A: no. It's a broad term for many variants of GPS
A: As far as I understand it: yes. I will ask our GPS engineer to comment on those questions.
A: GPRS. so its up to you whether you want that extra traffic (and cost, unless you're flat) or not.
A: I am sure it's a quite fixed amount of
A: There are some numbers in the data sheet of our GPS chipset vendor, but that data sheet is closed. I will ask them to give us some document/numbers that we can publicize.
A: yes, it can be disabled through preferences.
A: yes. either you have enabled it in preferences or nor ;)
A: yes.
A: ?