NTIA TESTS SHOW MIXED RESULTS FOR UWB DEVICES IN NON-GPS BANDS

NTIA’s measurement and analysis report in non-GPS bands was submitted Thurs. to FCC, turning attention of industry and govt. to next steps in regulatory process. NTIA plans to release closely watched test results of impact of UWB signals on GPS receivers in early to mid-Feb., Rohde said. Results of both sets of tests were due in Oct. but were pushed back after NTIA cited engineering challenges that would require delay (CD Nov 1 p1). While delay centered on logistical challenges, such as ability to obtain necessary test equipment, analysis has drawn widespread interest, particularly in aviation community, which has raised concerns about effect on GPS systems used for air traffic navigation. Rulemaking process also has been watched closely by industry officials concerning respective policy roles of FCC and NTIA, which have purview over commercial systems and govt. operations, respectively. “We are one step closer to coming up with a final rule,” Rohde said.

For non-GPS tests, NTIA received 25 UWB devices and selected 5 from different manufacturers, whose names agency didn’t disclose. Tests focused on federal systems between 400 MHz and 6 GHz, which is where UWB operations are planned. UWB signals on protection criteria for 12 federal govt. systems were evaluated, including varying distances between systems and maximum UWB power outputs, Rohde said. Systems evaluated below 3 GHz included govt. operations in 960-1610 MHz range. Actual testing was done on air traffic control radio beacon systems and air route surveillance radar, with models created to conduct analyses on other systems in that band, officials said. Also evaluated were non-GPS federal govt. systems in 1610-3100 MHz. Airport surveillance radar in that band was tested and models were used to evaluate next- generation weather radar and maritime radionavigation radar. Systems above 3 GHz included fixed satellite service earth stations, radar altimeters, microwave landing systems and terminal doppler weather radar. Officials said tests also assessed aggregate effect of variety of UWB devices in particular area.

Potential interference concerns varied in testing depending on distance between UWB and other systems in certain bands. Rohde gave as example airport surveillance radar, in 2700-2900 MHz. When UWB device is operating 1,100 m away from FAA radar “there’s little fear there’s going to be a violation of the protection criteria” when device is operating at existing Part 15 levels of - 41.3 dBm/MHz, he said. Concern over violating that protection criterion emerges when UWB device draws within 200 m of FAA radar, he said. To avoid violation of protection criteria in such cases, UWB device would have to operate at lower power level, he said. Another mitigating factor when such interference issues arise is intervening physical structure such as wall, meaning one way to lessen interference could be to require devices to operate indoors in some cases, Rohde said.

Noting extent to which systems in 3100-5650 MHz were found to have potential to operate with federal govt. systems, Rohde said, “we are hopeful that this is going to provide a big enough window for the companies” that are developing UWB devices. NTIA tests relied on existing protection criteria used under ITU and other standards bodies, he said. Still, he acknowledged, questions are likely to arise on threshold points on federal systems used to determine interference: “Obviously this is going to be an area that will be subject to a lot of debate.”

While some interference issues were raised in report, one industry source said results “leave room for the FCC and NTIA to be able to be talking to each other.” In bands such as 1600-3100 MHz, UWB operators may have to take measures such as limiting operations of devices around waterways so that maritime radars wouldn’t be affected, source said.

“The NTIA test results showed that ultra-wideband technologies can operate in a broad range of frequencies used by the federal government without causing harmful interference,” Fantasma Networks Chief Technical Officer Robert Aiello said. Jeff Ross, vp-corporate development & strategy for Time Domain, said that “while we have questions regarding some of the conclusions made by NTIA, we are pleased that the test results confirm that compatible operation of UWB devices with government services is possible.” He added that “we have full confidence that the FCC will impose appropriate regulations and power limits, and look forward to the FCC’s timely completion of its rulemaking.”

Last year, FCC approved proposal to consider allowing operation of UWB technology on unlicensed basis, move that was viewed as balancing act that allowed technology development to move forward while remaining mindful of interference concerns of GPS operators. UWB operates similarly to very low-power spread spectrum communications over very wide band of spectrum, potentially making possible services such as high-speed data and radar-like functions.

Separately, Rohde also provided road map of what NTIA has accomplished in his year at agency, but shed no light on his plans following transition to Bush Administration. NTIA annual report for 2000 described agency’s efforts to close “digital divide,” promote e-commerce, including consumer protection and privacy, and bolster new technologies such as 3rd-generation wireless. Among “challenges ahead” he outlined at news conference was need to focus on high-cost reform, saying Telecom Act was built on “pillars” of competition and universal service. “We have not seen meaningful high-cost reform,” he said. Rohde also cited challenges posed by ITU assembly in Montreal in Oct. that approved recommendation that administrations involved in international Internet connections negotiate bilateral commercial arrangements for cost-sharing. That decision, made despite strong U.S. objections, signaled agreement by other ITU members that international agency now had role in Internet regulation, Rohde said. “We have put ourselves in a difficult position,” he said. “We have to find ways of listening to the developing world.” U.S. position was predicated on concerns such as fact that Internet charging arrangements were commercial and ITU opened door for conditions to be imposed on such pacts. While U.S. position was correct, “we have to rethink our strategy,” Rohde said. In particular, he pointed to need to focus on fostering Internet connectivity throughout developing world as “more proactive approach.” Without strategy that focuses more on measures such as outreach, U.S. could find itself in alienated position compared with rest of world, he said.