Who is this “everyone” you speak of??
I think cell phones could handle it, or figure out how to in spite of technological issues, if there were a bunch of consumers who didn’t want their portable phone to be… portable anymore 
This would fit my definition of a very fringe service that they wouldn’t bother spending the time or money on.
Sure they can. As long as you can enter the duplicate data in the system without hiccupping, that might work. If all companies shared with all other companies all their data, sooner or later there would be a clash, and probably both phones will stop working. In a perfect system, they would share, but it’s possible that far-apart companies are separate enough to make it work. That’s something I don’t know enough about.
Why can’t the system keep a list of multiple ESNs for a single phone number? Why is it one-to-one? Why can’t the towers route calls to every ESN with that number, rather than only one?
I don’t mean in the same house, I mean “everywhere”. The docking station is not what I want. I want to call my wife and have both the mobile in her pocket and the rotary in her purse ring. I want them both to ring even if she leaves one at home. Analogous (but not completely) to how multiple wired phones can ring in my house when I’m called.
I think this would be a service that would be in high demand and I’m kind of curious why it hasn’t come up before. Wouldn’t Paris Hilton want a different fancy jewel-encrusted phone to go with each new outfit? Wouldn’t it be valuable to have a hands free car phone separate from one’s regular mobile?
Now, one hurdle I’ve just thought of is that in my home, if my wife and I pick up the phone in different parts of the house we can talk to each other for free. Obviously this would be undesirable to the providers in a long-distance situation. But wouldn’t that be easy to prevent?
It could, and I am reaching beyond my level of expertise, but my WAG is that it is due to the original concept in a database fashion. Think of how data is stored and looked up. A typical table would be:
Number........ESN
999 999-9996 0123456789ABC
999 999-9997 123456789ABCD
999 999-9998 234567890DCBA
999 999-9999 3456789ABCDEF
…etc. and there is a one-to-one correspondence between phone numbers and ESN. If you never need anything else, that’s a simple system. Allowing for a multiple correspondence requires a much different, more complex database and greater storage requirements. Considering the basic system was designed many years ago, I suspect storage space was expensive enough to be kept to a minimum.
When you are designing a system, you try to include forseen AND FREQUENT events, but not unusual ones. The system works for 99% of all customers, just not for you, and to handle the 1% might take excessive resources to accomodate.
Bluetooth accomplishes the car aspect. As for the rest, I am still not really convinced that people want multiple phones ringing when their cell phone is called. Nowadays, it’s an accessory that most people don’t keep more than 10 feet away from them at all times. As for the new phone for new tastes… that’s what faceplates were for. Now they’re viewed like a set of car keys. May clash with what you’re wearing, but kind of a PIA to have 10 sets of car keys with different types of keychains to go with your clothes. The styling of cell phones is certainly neutral and innocuous enough.
I don’t think the reason is as nefarious as you describe. I think part of the attraction of a cell phone is that when I ring one it rings to exactly one target. Either the target is there to answer me or they are not. I am uninterested in ringing two phones looking for Susie only to have Betsy answer Susie’s spare. That would be very annoying for me. Now how do I get hold of Susie to tell her Betsy picked up?
At home, it’s different. I want to be able to pick up the closest phone, and maybe that’s why cell phone dockers have a market. But anywhere else, I don’t get it. If you just want to use different devices, perhaps an easier mechanism to swap out SIMS would solve that problem, so I can use a different device for each pair of shoes. But even there I don’t see the high demand you do. I don’t see people buying lots of phones. We get used to how one device works and we keep stuff on it as well, including phone numbers and addresses and photos and so on. And the market has already figured out how to customize phones with things like decorative condoms.
For me, at least, it’s a step back to have a single number ring on multiple devices, except in certain specialized applications such as a central call paging in an entire response team–and those sorts of solutions already exist. In the cell phone world, one of the main drivers is that when I ring DrCube, only DrCube’s single device is rung. I’m not looking for some other location. That point-to-point target is a great convenience for me.
If you are asking why cellphones don’t act like wireless home phones, it’s for technological reasons. In spite of the apparent similarities (both are cordless and both are phones), they are quite different animals and work on completely different principles.
Isn’t there a security or privacy aspect? By attaching one number to one phone it makes it harder for others, especially unauthorized others, to get your calls.
Musicat’s explanations have been really good. I’ll add a piece of the answer to this last question.
If you allow a single phone number to ring several phones, it increases the system complexity quite a bit. Consider two mobile phones associated to the same phone number. The mobile phones might be on the same tower or they might be on opposite sides of the country. An incoming call to this phone number would have to ring both phones, wait for either to answer, and if neither does, go to voicemail. But there are a lot of devils in the details. If one phone answers, you have to signal the other phone to stop ringing. What if both phones answer? Who gets the call? How do you handle the ringing call if both phones are moving and handing off between towers? What about three or more phones? And who is the responsible network component to handle this additional logic?
It can be done – and it is on many systems. The system architecture for SIP VOIP supports this ‘forking’ functionality, but it is a pain. If the network planners consider this requirement to be rarely used, then it probably won’t be worth the additional effort.
I’ll mention a couple of other things related to points up-thread.
Since the OP is using a SIM, their network is GSM instead of CDMA. There are some minor differences.
As Musicat mentioned, only one CDMA phone can be registered at a time, so only one phone will receive calls at a time. However, both should be able to make outgoing calls since the phone will automatically register before placing the outgoing call. The phone that made the outgoing call would then be the phone to receive subsequent incoming calls. I don’t know if this is true on GSM; for some reason I think it is not exactly the same.
A CDMA system uses two identifiers: one for the phone device (ESN or MEID) and one for the phone number (I can’t remember this acronym MSN?). A GSM system uses three identifiers: one for the mobile phone (IMEI), one for the SIM (IMSI), and one for the phone number (MSISDN). The database associates these three numbers in order to route incoming calls.
Missed the edit window:
I forgot to mention: The reason why forking is easy on your home phones is because they all share the same circuit. The network rings the circuit and it could care less if one or more phones answer at the same time. It is electrically equivalent.
Office phone systems can do this too because the logic is managed by the local network box – the PBX. It has to deal with the same issues I mentioned earlier, but since the phones don’t move, it is slightly easier. VOIP PBX’s can handle both forking and mobility, but they went through some pain to do it. However, this feature is very important for an office setting – it is a big enough requirement to require the pain.
This shouldn’t be a problem for very much longer as phones become merely VOIP terminals and have no voice connection, only a Data connection. Cell phones are finally getting out of the proprietary slump that follows the beginning of any emergent technology and are finally achieving the status where the hardware is disposable and not linked to various data accounts in any meaningful way.
I do not understand the point of the rotary cell phone. How does she fit it in her purse?
No, seriously, I don’t understand the point of the rotary cell phone. It seems to defeat the whole purpose of a cell phone. If you want a rotary phone, you can get a refurbished one to plug into your home phone system. If it’s the cordlessness you’re after, well, it still has a cord connecting to the base. What am I missing here?
I almost bought a Uniden home cordless phone system at Costco that will also accept your cell phone calls if you are at home, similar to this. This may be along the same line as the docking phone setup referred to in a previous post, but it’s done via bluetooth so you don’t have to plug in your cell phone to it; it’s done automatically. It seems like a simpler way to accomplish what you’re after.
I’m not the OP, but I guess it is just a cordless rotary phone. Sure, the handset has a cord, but the unit as a whole does not. The unit can be taken around the house, from room to room, or even outside.
I’m not sure why it is GSM instead of just a cordless phone, but it may be targeted for either a) European markets or b) for people that do not have a landline.
Moved to General Questions from Great Debates.
It’s a wonderful gift for the luddite in your family 
Who bothers with a land line any more??? :eek:
I do. And if someone calls me from a cell, I ask if they can call instead from a landline so we can communicate properly. The quality of cellphone connections in my area is abominable, one-way instead of two-way, the fidelity is terrible, the effective squelch too aggressive, cutting off the start and end of phrases and making some conversations unintelligible. It’s very hard to carry on a conversation with a cell phone on one or both ends.
Remember when Sprint used to advertise the sound quality? No longer exists, except thru landlines. I’d be happy if all cellphones were abolished, but I have to put up with them myself for portability reasons.
I can get a second SIM-card for my GSM cell phone subscription here in Norway. Both phones will ring if I get an incoming call. Is this impossible to implement in the CDMA system, or just not offered? And is it an available service in the US from any provider?
Actually there is a very very legit reason for this service.
I am working on starting up a new business and would LOVE to avoid getting a land line number if at all possible. it would simplify things immensely if I could get 3 cell phones all cued to ring off of a single number, one for me, one for my partner and one for the main office.
the goal here is simple. land line phones are archaic, you cant text/receive texts on them, and you are attached to the damn things with pen and paper in order to clear voice mails.
with a cell you can set the business up to receive customer texts from the start and you can check voice mails over the net with headphones leaving your hands free to do this crazy thing called typing. also you can click to listen to a message again instead of navigating some stupid ass phone menu AND you can simply store a message permanently on your hard drive for later if its important/crazy/has legal ramifications.
I really really want this to happen.
As I understand it, your needs as slightly different than the OP. The OP would like two mobile phones to be associated with a single account because both phones are for the same person. They don’t really want to pay for two different mobile phone services.
In your case you have three different people with three different mobile phones, but you want a single phone number for customer calls and voicemails. This is possible by routing the customer number to the three mobile phones. Look at using a Google Voice account associated with your three mobile phones (as someone mentioned up-thread). I think it will do exactly what you want and it is free.