Is This Possible? 2 Lines Squeezed Into One Line Phone??

I have the need to squeeze 2 lines into one line on my phone.

[Note - getting a 2 line phone is not a solution as I already have a 2 line and 2nd line is taken by VOIP.]

One of the lines is standard tel co line -- other is essentially my gate bell. In my fantasy -- I imagine talking on the phone and when someone rings the gate, the call waiting feature alerts me and I can jump back and forth. Is this possible or am I deluding myself?

[TELECOM Digest Editor's Note: You are _not_ deluding yourself. It is quite possible, and is done frequently. I had this on my _two line_ phone (a little button near the top of the phone, twist it one way for line one, twist it the other way for line two, raise the plunger of the switchhook to put either line on hold). Let's talk about what you refer to as your 'gate bell'. Are you the only user of this 'gate' or is it a common entrance way into the building for many people?

There was a device made by telco years ago which was a sort of hybrid centrex. In addition to your phone, and a phone at the gate, there was equipment in the telco central office. All the pairs coming to your building from the central office were 'dedicated'; that is, always kept for just that purpose, serving your building. This system was called 'Enterphone'. The front gate phone ran on a pair back to the central office and the device where it was distributed out to the individual apartments, by _temporarily_ camping onto the associated pair. Now in more recent years, since telco went out of business, the same device has been mounted at the customer premises instead and it goes by the name _I_nterphone. Other than Enterphone versus Interphone and the box with the electronics inside it being located on customer premises versus at the central office, the rest of it works the same way.

Assuming there are several users of the 'gate' then you need a larger control box. If you are the only user, then a smaller version is quite enough. Person at the gate wants to enter; lifts phone, gets dial tone and dials your _code number_, NOT your telephone number. The little electronic box hears what was dialed, and 'translates' it into the number associated with your wire pair. Cheaper versions of this simply translate it into your _phone number_ (and thus send it back to the central office for handling) but there are problems with this version which I will explain in a minute. Better quality units translate what was dialed into your pair number locally, then look for that pair in your own house wiring. Finding that pair, it 'tests for busy' and if the line is not in use, it temporarily seizes the pair, inserts a short, distinctive ring tone on it, repeating as needed three or four times. If when it tests for busy, it finds that your line is indeed in use, it inserts a 'distinctive call waiting tone' (different so you can tell if the call waiting is another outside call arriving or it is the gate calling) and presents that tone instead.

Above I said 'better' and (a bit more expesnsive) to translate the code number dialed into your 'house pair' number rather than trans- lating it into your telephone number and handing it back to the central office because if you do not have call-waiting on your line otherwise, the gate-visitor could get a busy signal when you did not want it (now gate knows you are on the phone with someone) or if you are not on the phone (and get a normal ring from the c.o.) you have no way of knowing it is the gate calling, which could make a difference. The really cheap Interphone systems just tell gate to dial your number (?!) which is the worst of all; at the very least you want a code number dialed (which is changeable at will) and a translation done.

So now you have received a gate call, how do you deal with it? The gizmo detirmines your line is free (or was busy, but presented a call waiting signal and allowed you to tap the hook and click in) and it puts the central office line on hold (assuming you were on a call) and allows you to dial '4' to accept the gate visitor or something else to deny the gate visitor and return to the call you left on hold. If you decide to accept the gate visitor and dial '4', the gizmo in turn throws a current load at a solonoid which unlatches the gate for some preset length of time (typically 4-5 seconds) allowing the person at the gate to open it and walk in, then the solonoid clicks shut and the gate is locked once again.

So you were partly right and partly wrong: you used the phrase 'squeeze two lines onto one' and that it does not do. A pair is only good for one call at a time; something has to 'hold' the other call or busy it out. But this gizmo Interphone/Enterphone sits there midst all the house pairs, with central office pairs coming in and going out the other side, and upon signal, examines the appropriate pair, seizes it for a couple seconds and does its thing. With most Interphone/Enterphone devices, they are set to time out after 'conversations' which can last ten or twenty seconds tops. After all, how long does it take to answer the front gate and tell the person to come in, or go away, or whatever. I do not know who sells these devices currently, you might ask Mike Sandman

formatting link
for advice, or possibly Google for 'Enterphone' and also for 'Interphone'. PAT]

Reply to
chris2029
Loading thread data ...

Cabling-Design.com Forums website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.