« The Route | Main | A newbie writes... »

Assisted GPS

I've just had a Eureka moment! I've been testing out Nokia's Sports Tracker site using an N95 8GB phone and the included Sports Tracker software. To begin with the software was working brilliantly. It got a fix almost instantly and seemed very accurate. Lately, however, it's been a bit crap and if you look at the last few tracks, they only start somewhere randomly on my journey, and sometimes quit before I arrive.

I was puzzled by this until I realised I was switching different sim cards in and out of the phone and I was getting a good fix with O2 but a bad fix with T-Mobile which leads me to believe that Nokia has an Assisted GPS contract with O2, but possibly not with T-Mobile. Or maybe I have to use a specific T-Mobile APN or something.

As you can see, there is detailed technical testing and training involved in this event. Anyone out there encountered anything similar?

Comments (3)

Yanda [TypeKey Profile Page]:

Hmmm...

I got this response from Nokia:

"The AGPS uses a valid access point to connect to a specified Nokia server. The quality of the established connection impacts the speed with which the data is transferred back to the phone. However that data is only used for initialisation and then the phone relies on the GPS info which is obviously network independent."

which makes it a mystery why I get such a poor experience with my T-Mobile connection. Perhaps it's all in my head. More testing required.

Yanda [TypeKey Profile Page]:

D'oh!

Interestingly enough, this is a similar issue to something we'd noticed with N95s and video playback. Basically the settings for the Access Point aren't global. So when I switch SIMS I need to go into Tools -> Settings -> General -> Positioning -> Positioning Server and set the "Access Point" to whatever is relevant for the network I'm using.

Problem solved.

I've had similar issues with Sportstracker - it clocked me doing 145km/h going over Putney Bridge when I was trialing it in the summer. I get the impression that the GPS is a bit compromised by the need to not trash the battery with it.

Post a comment

(If you haven't left a comment here before, you may need to be approved by the site owner before your comment will appear. Until then, it won't appear on the entry. Thanks for waiting.)

Support Children in Need

About

This page contains a single entry from the blog posted on August 20, 2008 1:05 PM.

The previous post in this blog was The Route.

The next post in this blog is A newbie writes....

Many more can be found on the main index page or by looking through the archives.

Powered by
Movable Type 3.33