From owner-freebsd-chat Mon Jan 22 16:16:37 2001 Delivered-To: freebsd-chat@freebsd.org Received: from wantadilla.lemis.com (wantadilla.lemis.com [192.109.197.80]) by hub.freebsd.org (Postfix) with ESMTP id 3B09437B69F; Mon, 22 Jan 2001 16:16:18 -0800 (PST) Received: by wantadilla.lemis.com (Postfix, from userid 1004) id 2F0DA6A93A; Tue, 23 Jan 2001 10:46:15 +1030 (CST) Date: Tue, 23 Jan 2001 10:46:15 +1030 From: Greg Lehey To: "Michael C . Wu" , Brad Knowles , Kris Kennaway , freebsd-chat@FreeBSD.ORG Subject: Re: GSM vs. CDMA (was: VCD (was Re: cvs commit: src/sys/dev/ata atapi-cd.c)) Message-ID: <20010123104615.B16006@wantadilla.lemis.com> References: <200101211447.f0LElEk04073@mobile.wemm.org> <20010121145018.A73989@citusc17.usc.edu> <20010121165422.A44505@peorth.iteration.net> <20010122103136.L93049@wantadilla.lemis.com> <20010121182033.C44819@peorth.iteration.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <20010121182033.C44819@peorth.iteration.net>; from keichii@iteration.net on Sun, Jan 21, 2001 at 06:20:33PM -0600 Organization: LEMIS, PO Box 460, Echunga SA 5153, Australia Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-418-838-708 WWW-Home-Page: http://www.lemis.com/~grog X-PGP-Fingerprint: 6B 7B C3 8C 61 CD 54 AF 13 24 52 F8 6D A4 95 EF Sender: owner-freebsd-chat@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Sunday, 21 January 2001 at 18:20:33 -0600, Michael C . Wu wrote: > On Mon, Jan 22, 2001 at 10:31:36AM +1030, Greg Lehey scribbled: >> On Monday, 22 January 2001 at 0:46:38 +0100, Brad Knowles wrote: >>> At 4:54 PM -0600 2001/1/21, Michael C . Wu wrote: >>> However, Europe made the "leap" to TDMA technology in GSM, before >>> CDMA existed -- standard AMPS/NAMPS style analog cell phone >>> technology had been stretched beyond its limits, and they had no >>> choice but to go digital. >> >> It's true that GSM is a TDMA technology, but it's definitely not what >> is called TDMA in the USA. > > GSM is a set of protocol for mobile phones, and so is PCS. As I've mentioned before, PCS is a term meaning "digital wireless telephony", and thus covers GSM. > I tend to think of them as being comparable to TCP vs. UDP. > Believe it or not, the OSI 7-layer useless model applies > to mobile phones and telecomm too. We have counterparts > to TCP/IP OSI model in the mobile comm OSI model. > > Why do I think that OSI model is useless? To paraphrase/quote > wpaul: "Nobody in the real world uses the OSI model, it was created > just so that professors and other people can make paper tests that > have no importance other than making students memorize useless > things." I think this is a one-sided viewpoint. Yes, the OSI model is deeply flawed: when they designed it, they didn't have a good understanding of what layers would really make sense. But the concept, rather than the implementation, is still very useful. >>> The same will happen in the US, as 3G takes over from existing >>> TDMA, CDMA, AMPS/NAMPS networks, but at least many of those >>> companies will have relatively less money thrown down the TDMA hole >>> which they then have to completely write off. >> >> Don't forget that they have recently started introducing GSM into the >> USA. I've found that it works better than the CDMA service. This has >> nothing to do with the relative merits of the technology, but with the >> fact that the service providers learnt that their cell placement was >> too sparse for the old analogue/*DMA network, and they placed them >> closer for GSM. > > Yes, I recently switched from AT&T PCS to Voicestream GSM in America. What kind of PCS were you using before? And how's the GSM coverage in Austin? Greg -- Finger grog@lemis.com for PGP public key See complete headers for address and phone numbers To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-chat" in the body of the message