To: Seeker of Truth who wrote (50745 ) 3/16/2002 11:02:30 AM From: Eric L Read Replies (1) | Respond to of 54805 Malcolm, << The results, if we can trust this magazine, look devastating to QCOM in my eyes. Surely the superiority of CDMA has been the most discussed topic on this board. Did we somehow fail to get at the truth? >> The article talked primarily about digital voice quality and had a small blurb about WAP data. CDMA has always hyped "superior voice quality" - but then again so has GSM and IS-136 TDMA. Digital "voice quality' has always been superior to analog - well almost always, as the original CDMA vocoders were pretty darned bad. If you go back to the launches of digital services in the US - GSM & IS-136 TDMA in 1995 and CDMA in late 1996, all were hyping "voice quality" (compared to analog AMPS) and justifiably so. There wasn't much more to hype as cdmaOne and IS-136 TDMA offered virtually no data services. Digital voice quality is a byproduct of coverage, capacity, and the type and quality of the vocoder in the phone, and it is evaluated rather subjectively. I used AMPS (fixed car phone) 92 to 97, and have used CDMA/AMPS since. I also have used GSM for travel abroad since 1994 and my current GSM dates to back to late 97, while I have had 3 CDMA/AMPS models since 2000. Despite that I prefer GSM voice quality to CDMA. It is (to me) a more natural sound and lacks the pumpy, breathy, characteristic of CDMA, and is not susceptible to channel pollution when yet one more caller is added to a CDMA channel. All this is primarily attributable to the vocoder, and it's a matter of personal preference, but coverage and capacity definitely play a role. I do think that China Unicom is going to have a tough time convincing many of their current subscribers that CDMA voice quality is better than the GSM voice quality they are used to. perhaps the "power of suggestion" will work its magic on a portion of the subscriber base, but it will be a hard sell. I also think that China Unicom will have a tough time selling CDMA on the issue of reduced radiation. SAR simply varies all over the place and many GSM mobiles have lower SAR than their CDMA counterparts As for the comments on Verizon WAP (I'm a Verizon user who stopped attempting to use WAP shortly after I started to use it), the article comments were that it was faster in NYC than Chicago. That could be. Verizon first brought up WAP on their Eastern network (BAM) using an Openwave platform. Chicago & LA were brought up later and possibly they don't have the gateways under control as well as the eastern region does, or they simply could have networks configured differently. Bottom line is that the principle advantage of CDMA is that it provides greater spectral efficiency than GSM or IS-136 TDMA. While that capacity difference may not be as great as Dr. Jacobs claims, it is certainly significant. The question relative to 2G has been to what degree does that spectral efficiency translate into reduced cost in building out a network. Not too long ago it was more expensive to build out a CDMA network than a GSM network, but supposedly economies of scale have altered that. << Or is the superiority only in the 2.5G or 3 G of the future? >> As for 2.5G, if you consider 1xRTT to be a 2.5G technology then certainly it has both capacity advantages (about to be reduced when GSM introduces AMR codecs and other capacity increasing enhancements), and rate of transmission advantages over GPRS. If you consider 1xRTT to be a 3G technology then it really remains to be seen whether it has any advantages over 3GSM other than the fact that it has matured earlier. 3GSM (WCDMA - FDD & TDD) is more complex, more versatile, more open, more focused on underlying services, and more flexible, but its complexity means that it will mature considerably slower. When fully matured - and that is NOT near term - capacity is likely to be about the same. Bottom line is that carriers are in the best position to evaluate which technology platform is better suited to their needs - "superior" for their purposes, if you will - over the long haul. << Did we somehow fail to get at the truth? >> To get to the truth about cdmaOne/cdma2000 (or competing technologies for that matter) there is a LOT of hype to wade through on these boards. In the end, technology adoption and the rate of same are what's important. - Eric -