So I had to post my thoughts on 2 things that has been a big debate for a while now; The “fact” that 3G needs 2 frequencies to operate correctly and the “fact” that European 2100mhz is different that US 2100mhz.
I know that challenging this idea is going to get me a lot of emails about how wrong I am but hear me out..

1. 3G needs 2 frequencies to operate correctly

The majority accepted concept is that you need 2 frequencies for 3G to operate on a phone. You need 1 frequency for uploading information to the tower and 1 for downloading. For example, AT&T’s 2 frequencies they own are 850mhz/1900mhz and T-Mobile’s 2 frequencies are 1700mhz/2100mhz. We’ll use T-Mobile’s frequencies for this example.
So we are told that 1700mhz is what the phone needs to receive data from the tower and 2100mhz is what is needed to upload date back to the tower (both are needed to have a 3G connection on any device). But I don’t think that is entirely correct.
The reason is that there are plentty of T-Mobile devices that ONLY have the 1700mhz frequency and NO 2100mhz frequency and they GET 3G JUST FINE. (The Samsung Behold for example, but you can look up the frequencies on a few other TMobile 3G devices to see this same pattern). So how can that statement be correct?
I believe that maybe T-Mobile is using 1700mhz for up AND down at the moment (as there is only a benefit to use 1 frequency for up and 1 for down if you need the extra bandwidth on the tower, and with so few 3G customers I don’t believe it is necessary in the first place), and they own the 2100 but haven’t employeed it yet. It may even be on the towers but T-Mobile’s network is blocking access to it at the moment).
Anyone have any other explanation for how 2100mhz is missing from some 3G TMobile devices and in others (probably in preparation for the 2100 release) and they all get 3G? (If you comment please site a reliable source for your information, let’s all debunk this together!)

2. 2100mhz Europe is different than 2100mhz US (And that is why unlocked European phones with 2100 frequency built in won’t work on T-Mobile’s 2100 3G frequency).

So the next natural thing to challenge after the 2 frequency concept would be the fact that 2100mhz European phones don’t pick up 3G on T-Mobile’s 2100mhz because there is a difference in the frequencies. Well, what if it wasn’t because the frequencies were different but because T-Mobile wasn’t transmitting 2100 AT ALL?! And we are just assuming that our unlocked phones aren’t working because the frequency is different. What if the unlocked phones started to work down the road once T-Mobile releases their 2100mhz network?!

What are your thoughts?! And if you post a comment, please site reliable sources in your comment to prove your point for or against this idea.

UPDATE! – So I spoke to Haykuro on the phone today (he is the one responsible for porting the HTC Hero ROM to G1 users via XDA-Developers.com before the Hero was even announced be HTC) and I began to tell him this revelation I had. He immediately began to do what I have always done when asked about 3G frequencies, he told me that I needed 2 frequencies to get 3G on a network. Then I showed him the spec sheet for the Behold and a few other T-Mobile phones that ONLY have 1700mhz in them and said, “Then explain that”. He replied, “Uhh… that’s really interesting”.
Long story short, he is now working on a G1 Application to monitor the data packets being sent and received and (more importantly) over what frequencies they are being sent on. If we can see that the G1 is ONLY using 1700 and not 2100, well I think that’s all the proof we’d need, no?
Will post our results/the program on here as soon as he’s done

Any thoughts guys?!