One of the most speculated things these days among Windows fans is when the official rollout for Windows 10 Mobile will begin for Windows Phone 8.1 devices. Many have considered using the Insider Program as a solution but have opted to wait for the "official firmware".

After all, just about every update that Lumias have received were bundled with firmware. Windows Phone 8.1 was bundled with firmware called Lumia Cyan. Windows Phone 8.1 Update 1 was bundled with Lumia Denim.

Windows 10 Mobile will be bundled with no such firmware. Lumia Denim will become Lumia Windows 10 in name only.

This is not to say that Windows Phone 8.1 devices will not receive any firmware updates. They're just going to come separately. In fact, there may even be some devices that get a firmware update at the same time as the Windows 10 Mobile update. It will just arrive as two separate updates.

A Microsoft spokesperson issued the following statement to Neowin:

For existing 8.1 devices, Win10 update is going to be only SW update, but in order to fix few issue, there will be FW updates for some devices which are still based on 8.1 SW before they can receive Win10 update. Right now we have not communicated what 8.1 devices will get updated and when but please have the latest SW on all your 8.1 in preparation of win 10

This isn't an entirely new strategy. We've seen it before with the Microsoft Lumia 950 and 950 XL where firmware updates and software updates are delivered separately.

So what's changed?

The difference between now and then is that Lumias are first party hardware now. Back in ancient times (early 2014), Microsoft would release a software update, it would get passed on to the OEMs, who would in turn build a firmware update on top of it, it would get passed on to the carriers, who would test it and update their software, and then it would get passed on to the user.

Today, the middlemen are entirely cut out. There is no Nokia to build firmware on top of the update and carriers won't need to approve it (once the device is upgraded to Windows 10 Mobile). Firmware, however, will continue to require carrier approval.

Preview for Developers and the Windows Insider Program

When users were waiting for Windows Phone 8.1 (or other updates of its time), they had the Preview for Developers program, a program that allowed users to get the software update but not the Lumia Cyan firmware. Microsoft discontinued the Preview for Developer program in favor of the Windows Insider Program.

Of course, there was a fundamental difference between the two programs. Preview for Developers gave the user RTM software while the Insider Program delivers beta and even alpha software.

Luckily, Microsoft introduced the Release Preview ring.

Windows 10 Mobile is available

Make no mistake, Windows 10 Mobile is not in beta. Anybody that works for Microsoft will tell you that. There are four Lumias on the market and a few third party devices running the OS without any ties to the Insider Program. One could go on for hours about the issues that it might have, but it doesn't change the fact that the OS is already on the market.

Build 10586.0 was the RTM build of Windows 10 Mobile. It was the build that was released to manufacturing, even if Microsoft was the first manufacturer. Every 10586 build since has been an update to that.

The Release Preview ring will bring users early access to build 10586.xxx updates. It's not going to deliver Redstone builds until Redstone has been delivered through the Production ring.

In other words, if you've been waiting for the Windows 10 Mobile update, you can get it right now through the Windows Insider Program. Since users will now also receive firmware updates while being enrolled in the program, users aren't missing out on anything.

Assuming that build 10586.107 is the build that gets released to Windows Phone 8.1 devices (as it looks like it will be), the Release Preview ring will deliver the exact same update to your device as the "official" update would. If another cumulative update comes out between now and then, you'll receive that too.

The bottom line

Windows Phone 8.1 devices will continue to receive firmware updates, albeit separately from software updates.

The Windows 10 Mobile upgrade for Windows Phone 8.1 users will require carrier approval.

Going forward, Windows 10 Mobile updates will not require carrier approval. Firmware updates will continue to require carrier approval.

There is no evidence of which Windows Phone 8.1 devices will receive firmware updates nor when.

Windows 10 Mobile is RTM. While not having rolled out to Windows Phone 8.1 devices through the Production ring, it is installed on public hardware.

Windows Phone 8.1 users can use the Release Preview ring of the Windows Insider Program to get the same update that they would receive through the Production ring.

Once upgraded through the Release Preview ring, they can continue to receive early access to cumulative updates or they can switch to the Production ring, which will still not require carrier approval.

Which Insider Preview ring have you enrolled in, if any? Are you still looking forward to Windows 10 Mobile? Let us know in the comments!