Path: utzoo!telecom-request Date: 21 Jun 91 17:51:18 GMT From: Wilson Mohr Newsgroups: comp.dcom.telecom Subject: Re: Dumb (Neophyte) Cellular Question Message-ID: Organization: Motorola Inc., Cellular Infrastructure Div., Arlington Hgts, IL Sender: Telecom@eecs.nwu.edu Approved: Telecom@eecs.nwu.edu X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@eecs.nwu.edu X-Telecom-Digest: Volume 11, Issue 477, Message 10 of 11 Lines: 47 In article , lairdb@crash.cts.com (Laird P. Broadfield) writes: > Can you have two cellphones (I guess you can't call them "desk sets", > can you?) on the same number? I'm sure you could get ring-no-answer Each Cellular telephone made has a unique ESN. This ESN is programmed into the switch of the "home" operating system as a unique idenifier to the MID assigned to that phone. (MID = Mobile ID). Via one of several methods, this information is verified periodically by the service providing carrier.(not necessarily the "home" switch.) If a MID responds that does not have a matching ESN, then the ESN is denied (usually nation wide) regardless of MID. This is known as a Bandit mobile. > What happens if they're in the same cell? Nothing until they are called or try to make a call. If called, it becomes a race condition between the phones. If the correct phone answers first the call is completed, otherwise, the call is killed. Only the correct phone can make a call. The Bandit will be denied. (first and all subsequent.) ***discalimer**** This is true of the most simple cellular service offerings. Larger networks have a more agressive manner in which to validate subscribers. I truncated my description because of the complexity. For simplicity I have generalized the validation process description. > What happens if they both originate a call? > What happens if they both *answer* a call at the same time? Same holds true. Some service providers have services whereby you can have more than one phone to a number, but this is your usual hunt group scenario with each phone having a unique indentifier and the switch controlling the routing. (as it should be 8^) !) There are ways to beat this (as in all electronic validation schemes.) But this is costly and a BIG TIME federal offense. The most recent case involves a fraud scheme uncovered by the FBI and Secret Service. (Had us all running!) Wilson Mohr - Motorola CIG 1501 W. Shure Drive, IL27-2315 ..!uunet!motcid!mohr Arlington Heights, IL 60004-1497