Date: Tue, 23 Jan 2001 00:40:38 -0000 (GMT) From: Duncan Barclay <dmlb@dmlb.org> To: Brad Knowles <brad.knowles@skynet.be> Cc: freebsd-chat@FreeBSD.ORG, Kris Kennaway <kris@FreeBSD.ORG>, Michael C.Wu <keichii@peorth.iteration.net>, Greg Lehey <grog@lemis.com> Subject: Re: GSM vs. CDMA (was: VCD (was Re: cvs commit: src/sys/dev/ata Message-ID: <XFMail.010123004038.dmlb@computer.my.domain> In-Reply-To: <v04220808b6927dd3b3bc@[10.0.1.4]>
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On 23-Jan-01 Brad Knowles wrote: > At 10:42 AM +1030 2001/1/23, Greg Lehey wrote: > >> Nor would it make much difference, since the analogue networks in >> Europe are much less well developed than in the USA. > > Keep in mind that we're talking about one theoretical phone that > can supposedly get coverage anywhere in the world. The analog > portion would be intended for use primarily in the US, in those > places where you can't get GSM, TDMA, or CDMA coverage. Africa is buying up a lot of Europe's old Analog equipment. >> Are you sure that you can get combined GSM/CDMA phones? They'd be >> particularly useful in Australia, where we have only partially >> overlapping GSM service (in populated areas) and CDMA (in the >> Outback). There are no phones which will do both, and a salesdroid >> recently told me, full of conviction, that there would never be such a >> beast. > > To the best of my knowledge, there are not currently any combined > GSM/TDMA or GSM/CDMA phones. I do recall reading something about a > year ago about some new TI DSP chips that were coming out that should > make it possible to have a single phone handle every type of network > that exists in the world (including even satellite, if you had the > right transceiver electronics), but that it probably wouldn't start > showing up in actual phones for about another year. I don't recall > having read anything about it since. The problem for a mutlimode phone is not the DSP or even the protocol. That is "trivally" solved by just having more code in the handset. The phone would just swap mode when the user requested. The real problem lies in the circuits for the RF portion. There are no common features between CDMA and GSM phones, so that making a radio that does both well enough to be comptative on _manufacturing cost_ is really hard. Note that manufacturing costs are really important, these things might cost a lot but with 100's of millions of handsets made a year this is important. Up until now people have been thinking of so-called "velco" phones that are really two phones in one box. With 3G and the European operators plans to only use 3G in urban areas there will be real demand in three or five years for 3G-GSM handsets. The people that make the RF chips for mobile phones are now thinking about how to do a cost-effective multi-band/mutli-mode handset. These will cover GSM900-GSM1800 and 3G, and for small additional cost GSM-1900. It is unlikely that these will be used in IS-95 handsets (the Qualcomm CDMA) because of the licensing issues surrounding Qaulcomms design - the chips may well be capable of it. Mutli-mode phones will be around earlier than the three years but as velcro phones. Duncan --- ________________________________________________________________________ Duncan Barclay | God smiles upon the little children, dmlb@dmlb.org | the alcoholics, and the permanently stoned. dmlb@freebsd.org| Steven King To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-chat" in the body of the message
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