Chances are slim to none that U.S. mobile phone operators will agree on one standard for the next generation of mobile phone services.
Already fragmented with three different digital standards-cdmaOne, TDMA (Time Division Multiple Access) and GSM (Global System for Mobile communications)-the United States is in a unique position compared with other countries around the world. Though the Federal Communication Commission is seeking comment on the possibility of auctioning additional spectrum for third-generation services, it’s unclear whether this will happen. U.S. mobile phone carriers likely will migrate their current systems to a third-generation (3G) standard and don’t want to scrap the investment they already have made in current-generation systems.
The U.S. standards-setting body, the Telecommunications Industry Association, and the T1P1 committee submitted four separate proposals to the International Telecommunication Union in June. The ITU is looking to create a family of compatible standards that will allow features such as global roaming and high-speed data rates.
The CDMA dilemma
The focus in the United States and around the world is on converging two variations of CDMA (Code Division Multiple Access) proposals that have been submitted to the ITU. One proposal-wideband CDMA (W-CDMA) technology-based on the GSM platform, is backed by GSM operators in the United States as well as standards bodies in Europe, Japan and South Korea. The other proposal-cdma2000-is based on the Interim Standard 95 protocol, the CDMA standard used today in the United States and in other countries.
The division between the two camps is deep, with both sides accusing the other of political posturing. The CDMA Development Group (CDG), an interest group representing CDMA carriers and manufacturers, wants a worldwide converged CDMA standard to allow for economies of scale and inclusion of IS-41 signaling networks used for roaming in the United States. GSM operators say convergence would benefit only certain narrowband wireless operators and cause a significant reduction in capacity. GSM operators say they strongly believe in having the freedom to choose their own technology.
“We are for convergence,” said Keith Paglusch, treasurer of the CDG and vice president of engineering and operations with Sprint PCS, the country’s largest CDMA operator. “One standard would be nice, but we are not for convergence at any cost. We just got done investing billions in our current infrastructure, and whatever policy or recommendation develops, we are on the side that says it has to be backward compatible … There is not any technical boundary that cannot be overcome. It’s an economic issue. And some parties are not willing to move off of their investments.”
“We don’t see upsides to convergence,” said Don Warkentin, chief executive officer of GSM personal communications services operator Aerial Communications Inc. and chairman of the GSM North American Alliance, a consortium of U.S. and Canadian PCS operators. “W-CDMA has been endorsed by the vast majority of the world’s operators. We think economies of scale will be with W-CDMA.”
One key sticking point in the entire 3G debate is San Diego, California-based Qualcomm Inc. and the intellectual property rights it claims to own to the W-CDMA standard. The cdmaOne innovator said it will not grant IPRs unless a single CDMA standard emerges that accommodates equally the two dominant signaling standards used in the world today-IS-41 and GSM-MAP. The European Telecommunications Standards Institute, which chose W-CDMA technology for 3G choice in January, has acknowledged that Qualcomm owns key CDMA IPRs.
It is unclear what ETSI will do now, and the ITU must come up with standards that are free from any IPR hurdles. Patent lawsuits could stop the deployment of any W-CDMA system in the United States and worldwide.
Both U.S. GSM and CDMA operators say they would accept technical modifications to their standards only if those modifications resulted in improvements in their technology. But changes in either direction result in one side being unhappy.
“It’s like in electricity-DC vs. AC,” said Sprint PCS’s Paglusch. “If you have certain characteristics that make up AC power, and if you remove certain characteristics, you don’t have what you had in the first place. IS-95 is a fantastic technology. If you take the fundamental framework and change enough of it, you don’t have what you started with.”
One key area of contention is the chip rate of the technology. W-CDMA’s proposed chip rate (4.096 Megachips per second) is higher than the cdma2000 proposal (3.686 Mcps). The higher chip rate makes W-CDMA technology incompatible with current cdmaOne systems, even if the rate is lowered to 3.84 Mcps-which has been a compromise put forward by the GSM camp. The GSM camp says the higher chip rate will allow for more capacity.
Cdma2000 advocates argue keeping the chip rate at 3.68 will not degrade the W-CDMA standard. They point to an independent study in Japan that indicates no difference exists between the two.
Gary Jones, director of standards policy with Omnipoint Communications Inc., a GSM PCS operator in New York, said the Japanese study found no significant impact in using the lower chip rate, but said the study concluded that changing the chip rate results in a 10-percent degradation of capacity.
More recently, the GSM camp offered a compromise chip rate that would allow manufacturers to build a digital signal processing chip with both chip rates on it, said Jones. “It would seem to get everything that Qualcomm is asking for, but they said no,” he said.
“You still really have two standards,” said Paglusch. “What that means to the North American carrier or customer is that customers will not be able to appropriately roam. Using multiple chip rates doesn’t really bring economies of scale.”
TDMA stance
So where do IS-136 Time Division Multiple Access operators fit in the entire 3G debate when it seems the rest of the world is pushing for W-CDMA?
The Universal Wireless Communications Consortium, a group made up of TDMA technology supporters, including AT&T Wireless Services Inc., early this year announced a migratable solution to 3G technology called UWC-136. UWCC says the solution provides an evolutionary path to the next generation from IS-136 to IS-136+ to IS-136HS-the high-speed component of UWC-136. GSM and CDMA technology also have their own migration paths.
Most importantly, the 3G TDMA technology represents a convergence with GSM technology. Consortium members have agreed TDMA data channels will be aggregated to look similar to GSM data channels. Eventually, TDMA voice channels could be compatible with GSM voice channels if carriers used packetized voice in the future. Though operators aren’t openly supporting W-CDMA technology, this solution paves the way for an eventual migration to W-CDMA, say analysts.
“There were eight distinct CDMA-based proposals submitted to the ITU as candidates for third generation. Among the eight candidates, there are various intellectual property rights issues,” said Chris Pearson, director of marketing with the UWCC. “Conversely, the TDMA camp has united under UWC-136 as the evolutionary course of TDMA IS-136 to provide third-generation service. Agreements between UWCC, TIA and ETSI have resulted in a common TDMA access channel that can be utilized by both TDMA IS-136 and GSM-based systems to provide third-generation services. This evolution, called 136 HS in UWCC/TIA and EDGE [GSM] in ETSI, is a common RF access channel providing the bridge from the two most successful existing digital cellular systems into the next generation.”
It’s clear TDMA operators support a family of systems concept within the ITU. TDMA cellular operator BellSouth Cellular Corp. said it wants the option of choosing the technology it feels is best for its customers.<
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“We’re trying to keep all of our options open,” said Joaquin Carbonell, vice president
and general counsel with BellSouth Cellular in Atlanta. “We’ll deploy whatever the market demands … Our position [in the 3G debate] is that we want a plurality of standards in the marketplace. Operators should have the opportunity to pick the best technical standard.”
Time lines
Sprint PCS is the only U.S. CDMA operator to announce any significant movement toward 3G technology. The company, in conjunction with major vendors, plans to trial 3G technology no later than 2000, with commercial deployment to follow.
The GSM Alliance announced in June plans to set up a testing and evaluation facility for W-CDMA technology. Microcell Connexions Inc., a wholly owned subsidiary of GSM Alliance member Microcell Telecommunications Inc. of Canada plans to set up and operate the facility. Tests will commence this fall.
“We’ve done the preliminary work toward a business case,” said BellSouth’s Carbonell. “We’re taking the next two or three years for that effort to get underway. It’s hard to develop a business case when you really have no cost information … There is another piece: Do customers really want it? We believe that more and more people will want data services in the wireless environment.”
Most U.S. carriers say they will deploy 3G service when they believe a business case exists for it. Data services are not in high demand today in the United States, and the various migration paths from current digital standards will address capacity problems.
