William C.Y. Lee Looks Ahead to 4G Wireless
By Bruce Christian
Posted: 03/2001
Intellectual Capital
Calling it a patched-up system that could be inefficient, William C.Y. Lee, one of the world's leading authorities on mobile communications, says it may be best if the industry were to leapfrog over third-generation wireless and prepare for the fourth-generation.
"I don't like 3G," says Lee, chairman and chairman of the board for LinkAir Communications Inc. (www.linkair.com). "It is not a very good system. I feel it is wasting our time, and the performance won't be as we expected."
On the other hand, "4G technology can evolve quickly, so we can skip 3G and go directly to 4G," Lee says.
For 35 years, Lee has worked on the technology side of wireless communications. But he also recognizes the business side and the need for resellers and agents to offer wireless communications. Vital Stats:
Name: William C. Y. Lee
Title: Chairman
Hobbies: Writing
Professional Philosophy: Use mathematics to solve problems. Use physics to interpret results. Use experiments and counterexamples to check outcomes. Use pictures to emphasize important points.
Memberships: IEEE Fellow, RCA (Radion Communications Association), ITU (International Telecommunicatiohnology, U.S. Council on Compitiveness, Chairman of Transnational Committee of the IEEE Vehicular Technology Society, FCC Technical Advisory Council.
Honors: IEEE VTn Union , International Electrotechnical Commission, California Council on Science and TecS Avant Garde Award, CTIA Award, CDMA Industry Achievement Award, SATEC Award, Bell Lab Service Award, IEEE Third Millennium Medal Award.
Company Snapshot:
Name: LinkAir Communications, Inc.
Headquarters: Santa Clara, Calif.
Founded: 1999 by Ting Zheng, Daoben Li and Zuye Zou.
Mission: To develop and deliver leading edge 3G and 4G wireless telecommunications technologies that will enable wireless networks to deliver high-capacity and high-speed voice and data services.
Employees:150 people in the United States and China.
"They have to get into wireless to survive," Lee says. "In the future, portability and mobility will be vital to business and to personal communications. If the distribution channels don't get into wireless, I think they are missing the boat."
Lee began exploring wireless communications after receiving his doctorate at Ohio State University--writing his dissertation on satellite communications. He was hired in 1964 at Bell Labs to further his satellite research with AT&T Corp. (www.att.com). But before he arrived, Congress cut funding to the AT&T project, because lawmakers feared the major telecommunications company only would enhance its then monopolistic position. If Lee wanted to work on satellite communications, he would have to go somewhere else.
"I chose not to go," he recalls. He was then told of Bell Labs' new research department called AMPS, which would develop mobile communications. He accepted the challenge, because he had never heard of mobile communications.
"Sometimes you don't choose your future," Lee says. "But this turned out to be a very rich field for me."
Indeed it has. Lee has written three books on wireless and more than 200 papers. He has taught at the university level and lectured throughout the world. Lee's latest book, Lee's Essentials of Wireless Communications, was released in mid-January. It is part of the McGraw-Hill (www.mcgraw-hill.com) Telecommunications Series.
"Dr. Lee is among the elite telecom luminaries and has been a key player in the evolution of wireless technologies from its first generation through its current third generation," says Steve Chapman, executive editor at McGraw-Hill.
After 15 years at Bell Labs, Lee went to work for the ITT Defense Communications Division. Following his work there, Vodafone Airtouch plc (www.vodafone.com)--the world's largest mobile telecommunications company--hired him. His attention turned to personal communications network (PCN) technology and, in 1989, the United Kingdom granted Vodafone its PCN license.
Lee's 1990 work developing a new microcell system increased radio capacity by 2.5 times over the conventional microcell system.
In all, Lee's work has led to 25 U.S. patents, with 11 more pending. He also was instrumental in conducting key research for Pacific Telesis Group's (PacTel, now part of SBC Communications Inc., www.sbc.com) PCS experimental CDMA, which was perfected and launched in 1995 as a viable commercial mobile technology.
When Lee speaks of 4G, his emotions are betrayed. He becomes excited. He says the technology is a step beyond the immediate tomorrow.
He explains that the first three generations of wireless communications have required using a pair of frequencies. One frequency is used to send out a signal, a second one is used to receive.
"That is called the FDD [frequency division duplex]," Lee explains, as if he has returned to City University of New York, where he taught the first wireless classes offered there. "The first three generations use FDD because they have no way to isolate the interference in the sending out and receiving back in the cellular system.
"New scholars have come up with special smart codes that can isolate the interference in the host cellular system, so you don't need the FDD. Instead, we can use TDD (time division duplex)."
According to Lee, this innovation allows a signal to be sent on one time slot and return in another time slot on the same frequency.
"It's really about spectrum efficiency," he says. "With this system, you don't need complicated technology."
Lee says much of the research done to make wireless better has been focused on isolating interference.
"Interference is the killer. But now we have these special codes. We don't need any of the expensive technologies, like smart antennas," Lee says. "This is simple, high-tech efficiency in using the spectrum, which is very expensive."
Lee knows something about the cost of wireless. He remembers when the first mobile system was available commercially in the United States. It was rolled out just about the same time as the 1984 Los Angeles Olympics. The cost per unit was $3,800.
"All the Wall Street analysts were saying it was too expensive. They didn't think there would be many people who would want it."
The Wall Street analysts were wrong.
"People like mobility," Lee said. "People like to travel. California [residents] came to mobile quickly, because California likes to try new stuff."
Of course, Lee agrees with the industry analysts who say that the future for mobile communications is in data. It is another reason he is such a big proponent of 4G.
"Since the Internet has come up and data transmission has started, we need more bandwidth, and more capacity and now more frequency," Lee explains.
That is why using the available frequency more efficiently makes more sense, he adds.
"Sometimes you may be downloading very heavy traffic, but you may only be sending back an acknowledgement or a request, so we don't need the FDD. You should be able to use the single frequency."
Bruce Christian is editor of PHONE+ magazine
http://www.phoneplusmag.com/articles/131feat3.html
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