Why do carrires have to modify the roms?

[dmorgan924]

So why does the finished rom have to be sent to carriers to be modified again? Cant just Samsung sent out the official say marshmallow update?

Whats the process, Android releases the rom, then Samsung edits it? or adds to it? then they send it to the carrier?

 

[El Presidente]

HTC released a good graphic on how the update process works -

http://www.htc.com/uk/go/htc-software-updates-process/

Carriers get a lot of clout as they can tell OEMS that if they don't put certain apps in there/tweak it a certain way, they won't be able to release it on their network. If someone like AT&T/Verizon in the US, EE in the UK or any major network anywhere doesn't get their way, that's a tonne of lost revenue for the manufacturer.

The networks (and manufacturers) put their own apps in there for commercial reasons. Verizon might make an extra $0.05 per phone if it has some sports app pre-installed. Doesn't sound much, but if a phone sells millions, it adds up. Those app makers might make up that money in ad revenue/IAPs.

 

[Hadron]

They don't have to technically, they choose to. The carriers add their own apps, services & branding. Some of is may be of use (eg. wifi calling apps), much of it is stuff to promote services nobody uses or apps that developers pay them to bundle.

The process is that Google release the base 0S, the manufacturer integrates it with the specific hardware & the necessary drivers for it (eg. building the kernel), adds their own UI customisation & apps, and then if you buy a carrier-branded device the carrier adds their stuff.

 

[codesplice]

Nice infographic, @El Presidente!

 

[kate]

In addition to the above, if you want stock Android with stock upgrades you can get a Nexus phone. Depending on your current phone model you might be able to root and put a custom ROM with stock Android on it.

 

[Thom]

Much (most?) of it was focused on pre-installed software running correctly.

In the past the changes were also "validated" using carrier-specific equipment to operate correctly and not permit some capabilities.

Carrier personnel also got"trained" on the changes during the process.

... Thom

 

[Guggy]

Because they love to piss off us "hackers" and "devs" with bloatware. (Sarcasm! :3)