From the above spec Assisted GPS works with the cellular towers? Y/N
Assisted GPS uses available cell towers (and nearby Wifi hotspots) to get a faster lock on its position. The GPS/GLONASS receiver doesn't
need them, but it helps speed things up.
The idea is simple: GPS and GLONASS satellites are always moving. Cell phones are
often moving. It takes a while (sometimes minutes) for a positioning receiver to figure out the motion of the satellites, do the necessary math, and come up with a fix.
But cell towers are stationary, and *always* know their exact position. So if a cell phone with "Assisted GPS" capability has one or two cell towers with known location data nearby, it can use them as landmarks to cut down on the math and get a fix faster.
GLONASS is a Soviet --- Sorry Russian -- GPS equivalent - Suppose to be better than GPS and recently updated?
GLONASS is a Russian GPS equivalent. Currently it's about
as good as GPS. There was a time when Russia didn't really put any money into the GLONASS program, and for years they weren't replacing GLONASS satellites as they failed, causing the system to deteriorate badly.
More recently though, Russia's government suddenly decided the system was important again, and have spent a lot of money to rapidly launch new satellites and restore the system to full service.
In the chipset Apple uses, it's possible to combine GPS and GLONASS signals to improve accuracy. And that's one of the things the 5S does.
If I have cellular contact this will be the assisted GPS determination of my location? Y/N
Yes.
GLONASS is selected if cellular is not available?
Both GPS and GLONASS are always selected and usable, even without cellular.
Why did an american company... Sorry Irish company... pick GLONASS?
Because a while back, there was a law being proposed by Russia's government, where if you want to sell a smartphone with mapping/positioning capabilities in Russia, you would get charged a punitive 25% import tax if that system didn't have the ability to use GLONASS. In response to this, Qualcomm and other chipset makers baked-in the ability to use either GPS or GLONASS to help smartphone makers avoid this tariff.
Last I heard, the tariff idea had been dropped, but the chipsets were already designed and being made. The capability is there; why not use it?
In a strict definition the 5S does not use ANY american Global Positioning Satellites?
Wrong. The 5S uses both American and Russian satellites.
Think of it this way: the iPhone 5S has the ability to get location data from the following sources:
- GPS
- GLONASS
- Cell towers
- Nearby Wifi hotspots
The iPhone 5S is capable of using
any and all of these to get its location. The more options is has available to it, the more accurate the location data.
One last thing, and it could be a biggy: The
apps you use with Location Services (like Apple's Maps app) often require a data signal to retrieve a map on which to plot your position, either via WiFi or cellular. You can, as an alternative, purchase apps from the app store that store all these maps on your phone and don't require data, but they do cost some money, and will take up gigabytes of space on your phone.
If you don't have such an app, and don't have Wifi or a cellular data connection available, the GPS/GLONASS/Location Services system will deliver just a set of latitude and longitude coordinates, and you'll have to figure out what those coordinates mean on your own.
