Path: utzoo!utgpu!watmath!clyde!att!osu-cis!killer!vector!nobody From: unido!iaoobel!woerz@uunet.UU.NET (Dieter Woerz) Newsgroups: comp.dcom.telecom Subject: Re: Cellular Phone Question Message-ID: Date: 18 Nov 88 01:04:36 GMT Sender: chip@vector.UUCP Lines: 41 Approved: telecom-request@vector.uucp X-Submissions-To: telecom@bu-cs.bu.edu X-Administrivia-To: telecom-request@vector.uucp X-TELECOM-Digest: volume 8, issue 183, message 3 In article weinstoc@SEI.CMU.EDU (Chuck Weinstock) writes: >X-Administrivia-To: telecom-request@vector.uucp (USENET Telecom Moderator) > >If I call a number associated with a cellular phone, how does the >cellular phone operator know which phone to ring and where it is. I >can think of two possible answers: > >1. Periodically each cellular phone emits a "here I am" which is > received by the nearest cells and recorded in a database. Here in Germany, the cellular phones emit a "here I am" on administartive frequency, which is associated with the Cell-sender, they hear the best. Then the Cell-sender returns a short message on that channel together with some data on how good the reception of the phone is at the sender. On this channel the connect requests and the frequency changes during a call, while talking with in one cell or while changing cells are negociated. I think, this takes only a short packet of binary data to be transmitted. >2. When a call for a particular phone comes through all cells in the system > broadcast a "where are you" and the cellular phone responds. > >If anyone knows the details of the protocol used I'd appreciate >hearing from them. > >Chuck Weinstock Hope this helps ------------------------------------------------------------------------------ Dieter Woerz Fraunhofer Institut fuer Arbeitswirtschaft und Organisation Abt. 453 Holzgartenstrasse 17 D-7000 Stuttgart 1 W-Germany BITNET: iaoobel.uucp!woerz@unido.bitnet UUCP: ...{uunet!unido, pyramid}!iaoobel!woerz