iPhone 4S GLONASS

One of the first things I noticed when I looked up the specs for the new iPhone's baseband chip is that it supported GLONASS, Russia's GNSS (Global Navigation Satellite System). Now, just because the baseband supports it doesn't mean the device does. The baseband also supports UMTS Band IV (T-Mobile 3G/4G) yet the iPhone 4S does not. It looked like GLONASS was the same situation.

Until today, someone noticed Apple now lists GLONASS support on their Tech Specs page. GLONASS is similar to the US Air Force GPS system. There are some minor differences, but accuracy, availability, etc is similar for most of the world (and actually MUCH better on GLONASS at extreme northern latitudes, part of Russia's interest in the system). The GLONASS constellation was just completed weeks ago, bringing it up to full design availability. GLONASS on the iPhone (or any other GNSS receiver) serves as a backup/alternative to GPS.

GPS is ran by the US Air Force and is such a key part of our national and international infrastructure, that if the US were to shut it down for some reason, the political situation would be so dire that you'd have far bigger concerns than your iPhone not getting a position fix. But a backup is still useful. Have you ever been in the forest? Sometimes when it's dense it's HARD to get a GPS lock, you have to see three satellites (ideally more) through the clearings. GLONASS support gives the iPhone 4S another GNSS system to use for a position fix, and while I don't know how Apple's implementation works (and no one likely ever will), there is the potential for it to be a simultaneous search where which ever system can calculate a position fix first wins. It could even potentially use both systems for better accuracy.

This minor change is major. It should mean better, more accurate position fixes quicker by giving the iPhone one more high-accuracy source for a position fix. The basic operating principles of GLONASS are the same. You still need to see relatively low-powered satellites. Wi-Fi and cell sites will still be used for indoor position fixes. But, more than anything, the magic in this is the availability of a cheap, mass-market GLONASS receiver in a phone. The newest Garmin eTrex units also support GLONASS. And that's where the real magic of GLONASS will be. Better, more accurate fixes in even more remote places thanks to the powerful combination of two GNSS systems. Plus the symbolic lack of dependence on a military operated system (GLONASS is a project of the Russian space agency, not their military. GPS is a project of the US Air Force)