To: Maurice Winn who wrote (19142 ) 12/4/1998 4:28:00 PM From: Ruffian Respond to of 152472
CDG-W-CDMA Comments> From the Nov. 30, 1998 issue of Wireless Week CDG Spells Out W-CDMA Drawbacks By Peggy Albright Could it be that the next round in the already hard-to-follow third generation wireless standards debate could begin in a footnote? The CDMA Development Group officially distributed its 3G white paper at the CDG Americas Congress press summit in Los Angeles this month. A central argument in the paper is that wideband code division multiple access technology, the global system for mobile communications-based proposal for the global 3G standard, won't work in the United States. "We haven't been vocal on some issues," said Perry LaForge, executive director of the CDG. "There has been pressure to be quiet" on the effect of W-CDMA's chip rate on system performance, channel interference and FCC power emissions requirements, he said. In addition, manufacturers have been reluctant to get involved because they are "afraid of reprisals in European markets." W-CDMA, proposed to the International Telecommunication Union by GSM technology advocates, would use a 4.096 megabits per second chip rate. Cdma2000, proposed by CDMA advocates, uses a 3.6864 Mbps chip rate. The CDG said in the white paper that, "What proponents of the W-CDMA chip rate often overlook are the negative effects on spectrum use and power emissions by using the higher value chip rate. The CDMA air interface signal of IMT-2000 needs to fit into a 5 MHz spectrum to comply with different frequency plans around the world." To substantiate this argument, the white paper cites a similar finding in an Aug. 19 document published by the American National Standards Institute's T1P1's harmonization ad hoc committee. T1P1 is the U.S. standards organization that submitted the rival W-CDMA proposal to the ITU. According to the CDG's footnote, T1P1 showed that "even with a difficult-to-realize, complex filter, the 4.096 Mbps rate signal does not meet the FCC out-of-band emission requirement for a 5 MHz deployment." Techniques suggested for mitigating these effects would themselves offset some of the capacity advantages offered by the larger chip rate, the CDG said. For CDMA operators, incremental deployment of 3G services via cdma2000 upgrades would in fact yield greater overall capacity, it said. When asked if T1P1 would have proposed a standard that is problematic for deployment in the U.S., Asok Chatterjee, chairman of the T1P1 committee and vice president of technology for ADC Telecommunications, confirmed that the language did appear in the harmonization committee's Aug. 19 report, but said the language in question presented just one of multiple viewpoints. "It was a view that was expressed. However, there was definitely no consensus on this issue because there were opposing views," he said. One vendor siding with the CDG in the harmonization debate at the Americas Congress was Lucent Technologies Inc., which announced it is working with both Bell Atlantic Mobile Inc. and Sprint PCS to begin testing phase one of cdma2000 on those systems. David Poticny, vice president for global wireless strategy at Lucent, presented the economic and technical case for converging the two standards, saying, "Harmonization would be very advantageous to the industry" because it costs less and is less complex. The vendor also said that "wideband CDMA for data services is not a simple business case," for transitioning to 3G, according to a Lucent document on manufacturer 3G requirements. W-CDMA's drawbacks, this document said, are that it requires new radio equipment and new subscriber handsets; there is no "ready base" of applications or subscribers; and "standards issues that still to be resolved [are] pushing the deployment time frames out beyond 2000." | Home Page | Site Map | Search Archive | PowerSearch | | International | Wireless Web Sites | Hot Stories | Please send comments and suggestions on this Web site to jcollins@chilton.net Wireless Week, 600 S. Cherry St., #400, Denver, CO 80246 Voice: 303-393-7449, Fax: 303-399-2034 Published by Cahners Business Information © Copyright 1998. All rights reserved.