Two mobile phones - same number

Factual Questions
1

Why GSM wasn’t designed to support two phones with same number?

I mean it could be quite useful, at least for me - having one smartphone for normal use and another dumbphone with large battery when my main phone goes dead, both sharing the same number so if someone tries to reach me he doesn’t have to try multiple contacts…

Yes, I read that some companies provide two SIM cards with the same number, but using them is cumbersome to say the least - only one device can be turned on at the time, also you have to call special number to “activate” phone to allow it to receive calls - too much fiddling for my liking - I would just prefer to have them both ringing when I receive a call.

Which makes me believe it is a GSM limitation, and the solution provided is just a workaround.

So why is that? Did they just not think about it when they were developing GSM?

2

I don’t know if it’s a feature outside the GSM-specs, but for twin-SIM-cards in Norway both phones will ring at the same time.

3

Another workaround is a service like Google Voice (which is kinda in flux now, so I cannot really recommend it) which provides a single number that can ring multiple devices.

4

Call forwarding can serve this purpose. Also a spare battery would be lighter then carrying a second phone, even a recharge device/case if your phone has a non-removable battery.

5

Yes, Google voice or another call forwarding service is what you want:

https://www.google.com/search?q=call+forwarding+service

6

Damn, I’m dumb. I never heard (well, never knew it can work like that) about call forwarding.
Still, (at least with operators in my country) you have to pay for forwarded calls like it was you who were calling the second number (you people in US are used to paying for incoming calls, so I figure it wouldn’t matter much to you).

7

Almost nobody in the US pays for incoming calls.

8

There are so many prepaid and unlimited plans in the U.S. they don’t even track your minutes or bill you anymore.

9

Don’t we pay for it on cell phones?

10

Depends on how many minutes your carrier gives you. If they give you a block of minutes such as 450 or 600 or whatever a month and they bill you monthly, you pay for incoming calls. I’m on an unlimited plan I pay $45 a month for. Since I have unlimited minutes, it really doesn’t make a difference to me. I pay for service in advance every 30 days. I never see a bill. Whether a call is incoming or outgoing I don’t keep track and I don’t even know if my carrier does.

11

Well yeah, that’s unlimited.

12

So I technically don’t have incoming calls count as part of my minutes. I don’t consider that I’m paying for them. It’s like landline phone service. You don’t pay for incoming calls either.

13

I do. My landline is metered, through U-verse. I rarely use it, so I didn’t want to pay for unlimited calls. I may drop it.