To: Ruffian who wrote (4583 ) 12/27/1999 8:00:00 PM From: Webster Read Replies (1) | Respond to of 13582
Regarding 3G or Not 3G - here is a copy of an earlier post which was referenced on the yahoo club on UMTS 3G standard. I thought it would be an appropriate follow up for anyone who reads the H&Q report on 3G. Per usual H&Q makes no reference to HDR and how it might impact high speed data market. Thanks Web Here it is..... Re: UMTS 3G standard operating_prophet > From what I can tell, it seems to be inferior to HDR concerning peak data rate (UMTS: 2Mbits HDR 2.4 MBits). HDR is superior in other ways, some of them profoundly significant: One is capacity. By transmitting Internet data on a separate channel from voice data, HDR can take advantage of the looser latency requirements to maximize throughput. The IEEE white paper available at QUALCOMM's web site explains this intersting latency-throughput tradeoff, and indicates forward link (downlink) capacity increases of three to four times over IS-95C (aka cdma2000 1X, which is the most spectrally efficient of the IMT-2000 standards). Note that maximum downlink capacity is critical for mobile Internet applications (web and e-mail clients in particular). A second advantage stems from HDR's use of a 1.25MHz bandwidth instead of a 4 or 5MHz bandwidth: carriers can partition their spectrum into different modes more efficiently. For example, a carrier could have some block of spectum dedicated to AMPS circuits, some for IS-95A, some for IS-95C (aka cdma2000 1X) and some for HDR. Any future improvements on CDMA might also benefit from this flexibility. As subscriber equipment is upgraded and customer demands change over time, the carrier could easily rebalance its spectrum utilization. With larger chunks of frequency (4 or 5MHz), it would be very hard for a carrier with a total of 25 or 30MHz of spectrum to phase in high-speed data service. Third: a fascinating possibility that QUALCOMM describes is a stand-alone (i.e. independent of any voice network) network deployment. Such a deployment would use off-the-shelf pure-IP networking equipment, providing for a far cheaper and more robust (with redundancy and fail-over) solution than the old telecom dinosuars could ever build. One can easily imagine a solution which would employ voice-over-IP and a separate 1X airlink channel for voice, to deploy a voice and data network for much less than the cost of a conventional network build-out. As far as I can tell, there are no good candidates for operators to undertake this type of greenfield deployment (what with NextWave all tied up in a legal morass), but the possibility is exciting nonetheless. Another possible advantage of HDR is that it getting by with cheaper components than a higher-chip-rate solution. (I'm a little out of my depth here, so can anyone with more specific info please respond... but I think that cheaper VCOs and less silicon devoted to correlators are two examples.) And finally (this is a guess of mine) a big advantage of HDR is IPR issues. While QUALCOMM's IPR covers all these standards (HDR, cdma2000, and W-CDMA), it looks like W-CDMA is turning into a rats nest of IPR claims, a la the original GSM. In summary, the potential of HDR is awesome. It remains to be seen how and when that potential can be realized. The whole HDR vs. 3G debate is shaping up to be no less dramatic than the old TDMA vs. CDMA holy wars. Only this time, QUALCOMM wins either way! That's not to say they would have no preference -- I would wager the advantages to the carrier and the consumer of HDR would make for much wider deployment of services in time and wider acceptance of wireless Internet devices, and that's where QUALCOMM wins big. See (http://www.qualcomm.com/hdr/tech_1.html) for more technical specs, or other parts of the HDR section (http://www.qualcomm.com/hdr) for more general information. [OP]