Adicom stakes claim to key 3G patents
By Patrick Mannion
EE Times
(01/15/01, 9:58 a.m. EST
MANHASSET, N.Y. — From out of the blue, Adicom Wireless (Pleasanton, Calif.) has filed an intellectual property rights statement with the International Telecommunications Union (ITU) in a move that plants the company squarely in the way of anyone on a migration path to third-generation (3G) networks.
According to the company, its patent on multi-rate, a key part of the ITU's recently released specification for wideband code-division multiple-access (W-CDMA), has enough overlap with the ITU specification to make Adicom a necessary licensing stop for anyone on the way to 3G.
The degree to which the Adicom patent claim sticks is to be determined. Meantime, in the overall scheme of things, it is but one claim in a minefield of patent rights that has formed a major barrier to 3G progression.
According to Brian Modoff, wireless technology analyst for Deutsche Banc Alex. Brown (San Francisco), "What's interesting about this whole 3G debate is that there's a lot of companies out there doing this, hence you have a lot of patents to overcome." Modoff pointed to Qualcomm's multiple blocking patents, as well as to applicable patents from Ericsson and Nokia. "Then there's a whole bunch of smaller companies with other patents, so it'll be interesting to see how it all pans out. It's a real can of worms," he said. "The degree to which the Adicom patent holds might determine how soon they're bought up by one of the larger companies out there."
But being bought isn't a focus right now. According to Adel Ghanem, chief executive and cofounder of Adicom, "We'd like to leverage our expertise, together with some of the leading companies developing 3G products right now, and come up with new technologies and new products for 3G." Though the company is laying claim to multi-rate patents, according to Ghanem, the goal now is to "expedite and accelerate the introduction of 3G [using W-CDMA] in the future."
In filing its intellectual property rights statement with the ITU, the company stated that it intended to license its multi-rate IP on "fair, reasonable and non-discriminatory terms."
Though W-CDMA is but one of five 3G standards, it is gaining increasing recognition as the scheme of choice in many regions, including Japan, Europe and now Korea, where W-CDMA has recently emerged as a clear favorite.
According to Christopher Flores, vice president of engineering at Adicom, multi-rate is a key part of the specification, as it allows for multiple, simultaneous, full-duplex communications channels (subscribers) to be supported at varying rates and with varying, negotiated levels of quality of service (QoS).
In a practical implementation, each user is assigned a variable bit rate, a variable processing gain, a variable transmit power and a unique fixed rate spreading code, resulting in a constant bandwidth signal received at a relative power level corresponding to the negotiated QoS.
The forward link between basestation and user terminal, and the reverse link between the user terminal and basestation, can correspond to either a frequency-division duplex (FDD) arrangement where the forward and reverse links occupy different carrier frequencies but overlap in time; or a time-division duplex (TDD) arrangement where the forward and reverse links occupy the same carrier frequency but are in non-overlapping time intervals.
According to Flores, the degree to which the channel can be scaled is limited by physics. "It depends on how refined your coding schemes are, how low you can go with the spreading code, the efficiencies of the amplifiers and other such issues. It's basically the limitations imposed by a particular implementation."
Alternative routes to achieve the same goal include Qualcomm's use of concatenated channels to increase the bearer channels. "We, and the ITU, believe that our way is much more efficient," said Ghanem. In addition, he said, the overall flexibility of MR, by changing the size of the channel — versus concatenating channels — is much higher. "As far as the application is concerned, it's seeing one channel with a particular size, whereas, with concatenation, you have to go through segmentation and reassembly, which uses a lot of overhead and therefore reduces the efficiency of the network.
MR technology can be applied to both mobile cellular and wireless local loop (WLL), which is where Adicom cut its teeth. The company has implemented MR technology in its ACE chip set, which powers the company's line of Aditus, narrowband-CDMA fixed wireless networks.
"We've been thinking about this approach for many years, and in 1996 we came up with the idea and applied then for a patent," said Ghanem. The patent (U.S. Patent No. 5,745,480) was granted on Apr. 28, 1998.
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