Just as a data point, before blue-tooth car sets were ubiquitous, at least one of the Israeli providers (Pelephone) used to offer this very service on it’s CDMA network – you’d get two handsets, once for your car, one handheld, which had the same number but different MSNs. They didn’t ring together, but first the Car Phone rang, then the Handheld, then it went to voice mail.
I’m pretty sure they couldn’t, and certainly wouldn’t, allow stringing three phones together (although they probably could if you were willing to forgo voice mail)
I know that some businesses were allowed to string together a pair of handhelds in this manner, so that if the primary recipient couldn’t answer, a backup could. This could be used by SOHO businesses like plumbers, electricians etc…
Not exactly what the OP wanted, though – the phones wouldn’t ring together. This did however neatly dispose of the “two phones on different towers” problem.
It’s a geek novelty. I was intrigued by the idea of building one as a project in my free time (there are instructions on the website) and showed my wife. She thought it was cool and wanted one, but with school and looking for a job and such I never got around to making it. So I ended up just buying one for her. I’ll dig up one of my mom’s old rotaries eventually to convert myself.
We both are kind of old-timey in some ways and thought it would be neat to have a loud bell ringer go off in the grocery store or someplace and pull out an old rotary phone and answer it. It’s a head turner and it does fit in her purse. It’s a pain in the ass to dial 10 digit numbers every time you want to make a call though, which is why we wanted to see if we could make both of them work at the same time.
And thanks for all the answers, guys. I learned a lot about cellular networks from this thread. I think we’re just going to buy a prepaid SIM card and hand out both numbers to people so they can either call the cell or the rotary. Not ideal but easy enough.
With copper wire land lines, you can go to the phone punch-down block and jumper/cross-connect the lines together. I don’t know if the phone company would do this if requested. Probably.
I’m surprised no one has popped in yet to mention that this service , usually called Multi Sim have been available in Europe and Asia For a number of years.
They are usually offered as a perk for Business Customers or people on more expensive plans who want the ability to have multiple phones which they can use without having the hassle of changing SIM’s as those customers are more likely to have more expensive unsubsidised or unlocked phones…
On my Carrier here in Egypt, Vodafone, they offer the service for a One time charge of LE100 (US$18) and a Monthly Charge of LE 50 (US$9) for two Additional SIM’s which I can pop into different Handsets from which all their services (Voice, SMS, Data) are available. My other carriers in the UK also offer this service as does the Carrier I use in India.
Back to the OP’s question, it’s usually a Carrier Supported Service, and is often reserved for business customers so even normal CS or in store personal may not be aware of it if it is available. Still it may be possible to check by searching for the term “Multi SIM” and your carrier to find out if it is available.