Updates for phones on an alternate carrier

[HoosierDaddy]

Ever have one of those questions that you need the answer before you know which forum to ask the question in? I don't know if this relates to the phone manufacturer, the carrier or the OS maker.

I've read conflicting descriptions about how updates to get to a phone and since that includes firmware and OS, there are likely multiple players involved.

Basically, I want to understand the ramifications of using a phone with a carrier that does not sell the phone. For the OS, will updates come directly from Microsoft, or from the phone manufacturer or from the carrier or is the customer completely on their own. And I would like to exclude Developer Preview from the equation because that may not always be an option.

Likewise for firmware updates which I have been lead to believe can be carrier specific, what is the process for a phone not sold by the carrier? I've read posts saying that if someone is using a T-Mobile branded phone on AT&T (for example), that firmware updates will come from T-Mobile. Others say firmware updates would come form the phone manufacturer.

So how does it all REALLY work?

And if the answer dictates this should be in a different forum, please move it there.

 

[anon(7817172)]

Carrier-branded phones receive OS and firmware updates from the carrier the phone is locked to. It's like this

Microsoft + Phone firmware > Carrier > You

Reason: Some carriers tend to modify some hardware of the phone to suit their needs (like network band support for example) and would therefore need to check for themselves first the update.

Whereas with unbranded phones:

Microsoft + Phone firmware > You

Unbranded phones don't have the carriers playing a role in the update. Unbranded phones are just how the manufacturers intended them.

If I'm wrong, then please correct me so, anyone.

 

[shmsnh]

Updates depend on the ROM on the phone. Phones which have a carrier-based ROM will get the updates from the carrier. Phones which have a country variant ROM will get the update from the device manufacturer.

 

[HoosierDaddy]

Carrier-branded phones receive OS and firmware updates from the carrier the phone is locked to. It's like this

Microsoft + Phone firmware > Carrier > You

Reason: Some carriers tend to modify some hardware of the phone to suit their needs (like network band support for example) and would therefore need to check for themselves first the update.

My understanding is if a phone is locked, it can't be used with a different carrier (ones piggybacking may be an exception). I asked about a phone being used on a DIFFERENT carrier than the one who sold the phone so an unlocked phone.

And you didn't mention which carrier you are talking about in your diagram, the carrier that sold the phone or the carrier the phone is being used with. I'm guessing you mean the selling carrier but then again I don't think the diagram applies to what I am asking since I'm talking about phones that have been moved to a different carrier and you seem to be talking about locked phones that are still on the carrier who originally sold the phone.

So still looking for the source of both the OS and firmware updates in the situation where a phone is being used on a different carrier than the one who sold it.

 

[HoosierDaddy]

Updates depend on the ROM on the phone. Phones which have a carrier-based ROM will get the updates from the carrier. Phones which have a country variant ROM will get the update from the device manufacturer.

How does one tell if the ROM is carrier based? If a phone was initially carrier locked does that mean it has a carrier ROM?

Are there ways to replace the ROM on any phone?

People are reporting issues with the 8.1 preview that are being blamed on the phone's firmware not yet being updated to work properly with 8.1. So part of my interest in all this is what happens if the original carrier abandons the phone and stops updating firmware? Is the phone owner basically screwed OR can they use firmware from the sane parts of the world where carriers aren't part of the equation. Not part of my original scenario but if someone buys a foreign 1520 to use on T-Mobile or AT&T are they better off in that they don't need firmware from AT&T or T-Mobile (who won't have any since T-Mobile doesn't sell the phone) or is the customer worse off because they can't get firmware from the carrier?

 

[anon(7817172)]

My understanding is if a phone is locked, it can't be used with a different carrier (ones piggybacking may be an exception). I asked about a phone being used on a DIFFERENT carrier than the one who sold the phone so an unlocked phone.

Sorry. Forgot the main question. Even if the phone gets unlocked, the phone's updates are still dependent on the original carrier approving it. Having the phone unlocked does not change the fact that the carrier modified the ROM and that the modified ROM, once the phone is unlocked, will be replaced by the international/unlocked one. Try removing the SIM on the once locked phone and turning it on. Go to settings > about. It will still say the locking carrier's name as it is their ROM running still on the phone.

So, yeah. Unlocked phones and using a different carrier won't mean updates are now passed on to your new carrier.

 

[anon(7817172)]

Are there ways to replace the ROM on any phone?

There's a way to change the ROM on the phone (well, for Nokia Lumia phones that I'm sure) and this completely bypasses carrier intervention.

 

[shmsnh]

If you see a carrier mentioned on either the about or extras+info pages, then it is safe to assume that your phone uses a carrier ROM, and any official updates you get will have to be approved by the carrier. The carrier in this instance is the carrier selling the phone, not the carrier providing your services.

It is possible to flash a different compatible ROM onto Lumia devices quite easily. Most people flash with a CV (country variant) ROM since these get updates directly from the manufacturer.

 

[HoosierDaddy]

There's a way to change the ROM on the phone (well, for Nokia Lumia phones that I'm sure) and this completely bypasses carrier intervention.

If you see a carrier mentioned on either the about or extras+info pages, then it is safe to assume that your phone uses a carrier ROM, and any official updates you get will have to be approved by the carrier. The carrier in this instance is the carrier selling the phone, not the carrier providing your services.

It is possible to flash a different compatible ROM onto Lumia devices quite easily. Most people flash with a CV (country variant) ROM since these get updates directly from the manufacturer.

Awesome. I'll look into changing to a CV ROM on any phones I have or will have. Based on the hassle my wife went thru to get her T-Mobile unlock code, I want to eliminate interactions with carriers to the extent possible. And if that means giving up any carrier specific apps/features I've ever heard of to date, such as T-Mobile's WiFi calling, it will be worth it.

I'm still a little fuzzy (no jokes) about where OS updates would come from if I change to a CV ROM. I mean other than getting them from Developer Preview. Would those still come from the carrier (that sold the phone or providing current service)?

 

[shmsnh]

Carriers usually do not sell phones with a CV ROM. Either way, any phone with a CV ROM will get updates from the manufacturer. Doesn't matter if it came like that or if you flashed a CV ROM onto the phone yourself.

 

[dlalonde]

That actually brings a question du my mind. Can you "unbrand" a phone? When you unlock a phone to change carriers, is it unbranded in the sense that you can get updates directly from Microsoft?

 

[anon(7817172)]

I'm still a little fuzzy (no jokes) about where OS updates would come from if I change to a CV ROM. I mean other than getting them from Developer Preview. Would those still come from the carrier (that sold the phone or providing current service)?

If the phone has a CV rom, updates come from manufacturers themselves. So OS updates will come from Microsoft directly. No more holdup by whatever carrier.

 

[anon(7817172)]

Awesome. I'll look into changing to a CV ROM on any phones I have or will have. Based on the hassle my wife went thru to get her T-Mobile unlock code, I want to eliminate interactions with carriers to the extent possible. And if that means giving up any carrier specific apps/features I've ever heard of to date, such as T-Mobile's WiFi calling, it will be worth it.

Can I just say that you would still need to contact your carrier for an unlock code even if you change the ROM to a CV one. Changing a locked phone's ROM to any ROM you want will ask the unlock code once the changing/flashing process finishes and you insert a SIM from a different carrier. Just heads-up ^^

 

[anon(7817172)]

That actually brings a question du my mind. Can you "unbrand" a phone? When you unlock a phone to change carriers, is it unbranded in the sense that you can get updates directly from Microsoft?

Having the phone unlocked doesn't change the carrier-modified ROM to the CV/unbranded ROM. You're just allowed to use a different SIM from a different carrier, that's all.

You would still have to flash a CV / unbranded ROM to the phone to get updates directly from Microsoft. That's when a phone is unbranded.

 

[HoosierDaddy]

Can I just say that you would still need to contact your carrier for an unlock code even if you change the ROM to a CV one. Changing a locked phone's ROM to any ROM you want will ask the unlock code once the changing/flashing process finishes and you insert a SIM from a different carrier. Just heads-up ^^

Absolutely. Good heads up for others reading the thread.

FWIW, all phones in my family are already unlocked. I unlock mine at the earliest point its free (40 days for my two T-Mobile phones).

 

[dlalonde]

Oh is that possible to do or is it just theorical?

 

[anon(7817172)]

Oh is that possible to do or is it just theorical?

Yeah. Done this to my phone I got from my carrier when I got an upgrade. Lots of people in this forum have done it to their phones to bypass carrier intervention in updates.

 

[dlalonde]

Yeah. Done this to my phone I got from my carrier when I got an upgrade. Lots of people in this forum have done it to their phones to bypass carrier intervention in updates.

Interesting! That's why I signed up as a dev actually. I will look around the forum see if I can find howto's ans such. Thanks!

 

[muvig]

Mine is CV UK but it doesn't get the updates immediately, i once queried this from Nokia but i didn't get a satisfactory response, i had the opinion that once the updates are out from Nokia we would be the first to get these updates but alas we would get them weeks well after some of those carrier branded phone had received the updates.

 

[tgp]

I'm still a little fuzzy (no jokes) about where OS updates would come from if I change to a CV ROM. I mean other than getting them from Developer Preview. Would those still come from the carrier (that sold the phone or providing current service)?

I have an AT&T (GoPhone) Lumia 520. I SIM unlocked it by getting the code, so I can use it on any GSM carrier. I then flashed a CV ROM on it. Now, other than the AT&T logo on the back cover, it's unbranded. I get official updates directly from Nokia, not from AT&T. The carrier makes no difference. The Developer Preview updates come the same way as any other WP. The only thing that matters to get updates is that it's online. In fact, I haven't had a SIM card in it for probably 6 months or more. Updates have come through Wifi (this is necessary anyways to download updates).

I hope this clearly answers your question!