[DBMandrake]

With news of O2 aggressively rolling out 3G on 900Mhz (many cities live already) and the likely-hood Vodafone will soon be following suit, I thought I'd post a little tech tip for you iPhone 4 users on how to determine whether your phone is using 2100Mhz or 900Mhz for the purposes of spotting 900Mhz 3G operation in the wild :)

Go into field test mode by dialling the number *3001#12345#* and pressing Call.

Once in field test go to UMTS Cell Environment->UMTS RR Info, and look for the field "Downlink Frequency".

There is a full list of channel numbers on this page:

http://en.wikipedia.org/wiki/UMTS_frequency_bands

But in summary:

* UMTS 2100 - Downlink will be between 10562 - 10838.

* UMTS 900 - Downlink will be between 2937 - 3088.

For example right at this moment my phone on Three is showing 10564 for downlink.

Sometimes this may show 65535 when idle which is invalid, but just wait a few seconds and it should change. Turning off wifi to cause a 3G data session to stay active may help.

Bear in mind that the phone can and will switch between them as necessary, so it could change in the middle of the test as you move the phone around. (The figures in the field test app update every 10 seconds or so)

Also, you have to be connected on 3G at the time of the test for any of the numbers to have meaning. If you're on GPRS or EDGE the diagnostic information will be invalid.

So all you iPhone 4 users with O2 and/or Vodafone SIM's, go at it :D

[Ben]

SureSignal just gives 65535 - how boring!

I'll definitely give this a try when I'm locked on to real 3G and see if I can see any signs of 3G900 on Vodafone. I'm quietly confident that they won't let O2 make too much hay out of this one, but it's entirely possible I would imagine that Vodafone's 3G kit is both older and more difficult to operate at 900MHz. It's also possible that Vodafone was intending to wait until the spectrum auctions before acting... they've lost all their aggression it seems.

If O2 suddenly surge to the forefront in 3G coverage and performance then one might say that their persistence in stalling their 3G rollout has paid off commercially. That said, I struggled plenty of times to get GSM from them, so they've work to do yet!

[hecatae]

any idea how to test on android for 900mhz 3G?

[DBMandrake]

Nope not directly, but if you search the internet for information on how to get into the field test mode and can find a field labelled Downlink Frequency, the same should apply.

[Ben]

10736 at the office. Even more boring! :D

Signal of -94 goes to -105 when death-gripped. Just a little bit of bonus info!

[Hands0n]

In Android do *#*#4636#*#* to get into Phone Info and scroll around the resulting page.

Be careful - you can make some quite subtle changes to the radio on this page - so note down the defaults before you actually change anything.

[hecatae]

that code does not work on the ZTE Blade

[Hands0n]

That is very strange - I just tried it on my CM7 RC4 Blade and it worked okay. Are you running a different ROM these days?

[hecatae]

I've updated my baseband to the libra platform, enabled 850mhz 3g and gsm, and enabled HSUPA, completely different partition layout and greater reception than previously.

heh, think we've hijacked this thread