I'm nowhere near this location!
This morning I tried to use my iphone map function to check the distance between 2 points for milage and drive time. Imagine my surprise when my ‘current location’ was shown to be 117 miles from where I actually was! The ‘wrong’ location was near where I used to live when I purchased both the phone and my original Micro-Cell box. (I’m now on my 2nd, box).
For those who don’t know, the ATT Micro Cell is a device you can purchase that acts like a mini cellular tower in your home. It connects to AT&T’s network via your existing broadband Internet service (such as DSL or cable) and is designed to support up to four simultaneous users. You receive improved cellular signal performance for both voice calls and data. The technology is generally know as Femtocell and several cell phone carriers have deployed it.
A little investigation revealed that the iphone uses a combination of cell phone tower triangulation AND the GPS receiver to lock on to your location, especially if your GPS signal is low because your iPhone can’t “see” the sky. I understand that it is called aGPS or assisted GPS. The only available 3G cell phone signal in my very rural home comes from my Micro-Cell box.
Some quick internet reading suggested that my iphone was relying on the 3G signal from the Micro-Cell to fix its location. To prove the theory I went into Settings on the iphone and turned 3G off. Next I went back to the map, and sure enough, after a minute or so it found my true location once the GPS locked on.
This is how far between the 2 locations
This is my real location
Turn off 3G in settings.
Admittedly this post is a little bit of “stating the obvious”. If you don’t have a good GPS fix then the iPhone uses what it has at its disposal to get as close as it can. However, and this was the “teachable moment” for me, if a Micro Cell or other Femtocell is in use then , based on my experience, you can probably disregard the ‘current location’ result entirely . I wonder if the Micro Cell was using the known location of the internet server that it is connected to?
Regarding my experience with the Micro Cell, it has been less than pleasant. As discussed in the Wikipedia article, when the Micro Cell uses the existing DSL backhaul connection it must share the home bandwidth with all the other services such as email, web browsing and gaming. This leads to frequent disconnections of the Micro Cell and loss of 3G coverage. The 3G LED will blink while the service is lost. It may recover in minutes, or it can take hours or even an entire day. For me, this happens at least once per day often when nobody is even using the DSL. An outage once per week would be bad enough but daily outages are unacceptable and I am looking for an alternative solution. ATT tech supports best suggestion was to swap the box which didn’t improve the situation.
//Jon
Tags: AT&T, 3G, GPS, Micro Cell, Femtocell
Wow! I just installed WPtouch on this blog as a test. I think I’ll keep it, and install a few more.
My trusty Treo 650 died last month so I succumbed to the iphone hype and purchased the 3GS. There has been plenty written about the pro’s and con’s of the iphone line, so I won’t add to that fodder. I do want to express my disappointment about the battery life and share my solution.
