[Galaxy Note II General] Jade Eyed Wolf:
[UPDATE:] Confirmed to work!

Without going into too much detail here (you can check out the full post in the AT&T Note II dev section here), my theory described below does in fact work as I postulated. However, it doesn't seem to work when using PC Odin (Mobile Odin may be a different story).

The basic process goes something like this though:

1. Download CWM/TWRP flashable stock N7105 firmware here.

2. Download the AT&T/Rogers modem from here.

3. Use custom recovery to flash the N7105 firmware. Confirmed to work with TWRP and CWM.

4. Flash the modem.

5. Profit!

[/UPDATE]

So, correct me if I'm wrong, but my understanding of the differences between the international N7100 and the AT&T Note 2 (whatever model number that ends up being), is that the AT&T version has an LTE modem compatible with 700/1700 mhz LTE, but apart from that, the rest of the device is exactly the same as the international version. In other words, they are both Exynos devices with separate LTE chips, unlike the first generation where the international unlocked Note was an Exynos device, and the AT&T version was a Qualcomm device for LTE compatibility.

So, with that in mind, what's the betting that the international firmware is 100% compatible with the AT&T Note 2 (minus the modem)? Kinda like how the original Galaxy Tab 7" international firmware was 100% compatible with AT&T's re-branded Galaxy Tab.

So, what I'm really hoping is possible, is to be able to flash the firmware for the International/Unlocked Note 2 (no AT&T bloatware, plus quicker updates), and then flash the modem.bin from the AT&T firmware (so that LTE will work). Best of all worlds! International firmware AND LTE?

Normally I buy imports, because they're usually better in general. However, if what I mention above is possible, I wouldn't really mind owning an AT&T branded Note 2, while rocking an international/unlocked frankenfirmware.

What do you guys think? Is this a sound theory? Or am I just hoping for the impossible...

Ultimately, I'm just looking forward to the day that OEM's begin making unlocked multi-band LTE devices with compatibility for both Europe and America/Canada (and Asia). But that may never happen... :P

EDIT: The following is a response from another thread which more clearly illustrates what I hope we can accomplish here.

I'm not sure yet. That's why I started that other thread. It's my theory and hope that you can flash international firmware onto (some) of the domestic North American Note 2's (including Canadian versions).

Just as an example, and I think I may have briefly touched on this in the other thread, take a look at the original Galaxy Tab (7 inch).

The international version of that device, available everywhere else around the world, was able to function as a GSM phone right out of the box.

The domestic carrier versions of the same device did not offer phone functionality at all, and were basically locked down, pay-as-you-go only, data-only, worthless (but expensive) pieces of crap! Unfortunately, if you had a CDMA version (Sprint, Verizon, US Cellular, etc.), you were totally out of luck, because the chipsets were different (or at least the modem firmware), and not compatible with the international firmware. However, the GSM US models were an exception, especially the AT&T version, and here's why:

With the very slight exception of the T-Mobile version (which used a custom UMTS modem for its own 1700mhz AWS band), the North American GSM Galaxy Tab's had -exactly- the same hardware, transistor for transistor. As such, if you bought an AT&T branded Tab (as I did), and you didn't like your carrier dictating to you what features you could or couldn't have on your device (which I didn't), you could give them a big fat middle finger by simply flashing the international firmware in all its unlocked feature-full glory.

With the T-Mobile version, it was slightly different due to the custom modem. If you simply flashed the international firmware and just left it at that, phone functionality would work fine, but you wouldn't have 3G functionality (because the international firmware didn't support 1700mhz AWS), so you'd be stuck on EDGE. However, if you wanted 3G, all you had to do was use Mobile Odin to flash the T-Mobile specific modem.bin, and off you went (minus working phone functionality). You had to flip flop between two modems, depending on your needs, but it was an OK workaround.

So anyway, this all gets me back to the Note 2 of today. As I mention in the other thread, seeing as how the North American Note 2's are almost identical to their international counterparts, with the major exceptions being the radio hardware and modem firmware, shouldn't it then be possible to get international firmware working on a domestic version?

The first step would be to see if you could even flash international firmware onto a domestic Note 2 and get the thing to even boot up.

Assuming that's possible, and say you have limited cellular functionality (if any at all!), with perhaps only WiFi working or something, then the next step would be to extract the modem.bin from the carrier-specific firmware, and then flash that over the international firmware.

Hopefully, theoretically, that should get you up and running!

So to break it down, here's what I would plan to do:

WARNING!!! The following is just an idea for an experiment! Unless you know what you are doing, and are curious about testing this for yourself, DO NOT perform these steps unless you want a nice new brick!

I plan to use an AT&T Note 2 due to the fact that it bears the closest hardware resemblance to the international N7105. The only difference between the two, afaik, are the LTE radios and firmware.

1. Obtain firmware image of AT&T Note 2, probably from somewhere like Sammobile.

2. Extract modem.bin from carrier firmware and create CWM flashable .zip

3. Use Odin to flash stock N7105 international firmware.

4. Assuming step 3 works, and you're able to boot up fully, it's likely that most (if not all) wireless connectivity will not be working. WiFi might still work. So, if we make it to this step, the next step would be use the Note 2 Toolkit to root and flash CWM recovery.

5. Once CWM is installed, flash the custom .zip with the AT&T modem.bin inside of it.

6. Assuming this all works, profit! You now have an international N7105 Note 2, with all the development support of the international community, no AT&T bloatware, and working domestic LTE!

At least, that's the hope...

Please, developers, I'd like your input on this if you think this seems legit, or if it's even possible.