Add & Enable Edge in Lumia 900, under Cellular Settings

We all know how bad a mobile battery life performs over the high speed mobile network because of either low coverage, more usage etc. Now ever though Lumia has given the best performance for battery (which I have heard to last for 2 days on regular usage), if you want to enable Edge settings as an option when selecting “Highest Data Connection Speed”,  cubanaso  & Seed 2.0 at XDA has explained what has to be done.

• First you need to access the data field test utility menu by dialing ##DATA# or ##3282# the click the ….  on the main menu bar and choose settings.
• Now you will be able to choose settings between 2G or 3G or Automatic.
• Now hit back menu to get of this filed testing screen and you will loads of text as selectable items. Here you need to look for ToggleENS(REBOOT).
• This opens some kind of Tell Me like screen with option to Start and Stop. Try it for few seconds and then quit and reboot your phone.

After restart, you will see E or Edge as menu option for Highest connection speed along with 2G and 4G.  According to the forum user, Seed 2.0, he got a very high download speeds ~7000kbps with EDGE activated and registered. He also saw an option where it was possible to select and switch to network other than AT & T, like Maritime networks which gave ~12000kbps on 4G.

Mobility Digest has nice screenshot and bit of analysis done at their post which I highly recommend you to read and track as they will best testing how long the batter lasts with Edge mode next month.

• Note : In the second step you have option to change the polling frequency and limit sms storage options which you can try for fun and see what happens. 
•  At&T considers 4g as LTE.