UWB COMPETITORS EYE UPCOMING NTIA LAB TESTS WARILY

Final details of the statement of work still are being worked out under the Cooperative R&D Agreement (CRADA) with NTIA’s Institute for Telecom Sciences (ITS), an industry source said. Motorola expects the research to take about 9 months to complete.

Questions on the technology’s regulatory compliance backed by the Multiband-OFDM (Orthogonal Frequency Domain Modulation) Alliance (MBOA) arose as part of an continuing IEEE standards debate. An IEEE working group has been drafting a UWB standard for wireless personal area networks. One draft proposal for the 802.15.3a standard has been backed by the MBOA, whose 60 companies include Alereon, Intel, Nokia, Panasonic, Samsung, Texas Instruments and others. It would rely on a frequency-hopping (FH) technology over multiple bands, which backers say is allowed under the FCC’s Feb. 2002 order on UWB. A rival Direct Sequence CDMA-based proposal by Motorola and XtremeSpectrum, which Motorola bought in Nov., uses a pulsed UWB system that needs a broad area of spectrum. One question in the standards dispute has been whether the kind of FH system backed by MBOA would have to be tested for compliance with the hopping function turned off. Motorola has argued that, depending on whether its or MBOA’s interpretation of testing requirements is correct, FH devices may emit energy far above FCC limits, despite passing a compliance test, or they might have to operate at lower power levels than non-FH systems to comply. MBOA members disagree.

Details of the test plans were outlined in a meeting last week at NTIA with industry representatives, acting NTIA Dir. Michael Gallagher and FCC Office of Engineering & Technology (OET) Chief Edmond Thomas. “All our focus at this point is on determining whether the MOFDM approach is more, less or no different in terms of interference potential compared to what we contemplated in our rulemaking,” said Julius Knapp, deputy chief of OET. He said there were both govt. and non-govt. services in that spectrum: “We are working closely with NTIA to make sure that the interference analysis is done for the federal and nonfederal systems.”

The tests will focus on potential interference to C-band receivers operating at 3.7 GHz, sources said. The FCC’s UWB rules allow UWB-based communications devices to operate at 3.1-10.6 GHz, subject to certain power limits. C-band receivers were selected for the testing because that spectrum “is the heart of where UWB devices will be operating,” the source said. Another source said the spectrum was chosen because previous NTIA tests either looked at bands below 3.1 GHz or focused on systems whose bandwidth was so narrow that a receiver couldn’t see a 500 MHz wide signal.

XtremeSpectrum and Motorola had asked the FCC last summer to provide guidance on how to interpret parts of its UWB rules that covered compliance testing of certain FH modulations. The agency said in Sept. it had no immediate plans to respond to the request for a declaratory ruling on the appropriate measurement methods for particular signals because the matter was under active IEEE discussion (CD Sept 15 p6). The FCC urged the IEEE to perform technical analyses to ensure that any UWB standards didn’t cause interference beyond that already anticipated by the agency’s UWB rules. Separately, the FCC has said it intends to revisit its UWB rules to examine whether parts of them need to be tightened or made more flexible.

The point of the testing is to focus on potential interference rather than measurement techniques, Knapp said. The FCC is watching the test results as part of its “due diligence” on understanding them, he said. “We want to make sure that NTIA and the Commission are working together on this hand in hand and that we do the scientific work first to determine if there are any concerns,” he said. “There is an interest in moving it quickly.”

Industry sources said MBOA members agreed to participate in the testing at last week’s meeting, although plans still were being finalized. An industry source who supports the testing said the ITS lab was seen as a “neutral forum.” XtremeSpectrum has argued that testing has indicated that when FH systems are turned on, the signal wave form is more interfering than the FCC allows. The source said the OET last year had expressed interest in the IEEE’s pursuing technical analyses of interference potential. “The IEEE has not been aggressive at following the FCC’s request,” the source said.

But an official with an MBOA member company said “extensive testing” had been done that showed that Multi-Band OFDM systems caused less interference than pulsed-based UWB systems. The source said that was important because the FCC rules focused on pulse-based systems such as Motorola’s direct sequence technology. “It’s clear to everybody that pulse-based systems are allowed under the rules,” the source said. The MBOA testing examined white noise, MBOA systems and pulsed-based systems, the source said. The white noise caused the least interference, MBOA caused the 2nd highest level and the pulsed based caused the most, the source said.

One early point of contention on the test plans appears to be the time they will take to complete. “The MBOA is not going to find a 9-month time frame acceptable,” a source said. One concern is the impact that such a time frame would have on the time it took to bring new products to market, the source said.