SIA, Cingular Ask FCC To Reconsider Its UWB Order

SIA said in adopting the waiver order the FCC “improperly disregarded evidence in the record.” Attacking the order as arbitrary and capricious, Cingular said it violates Administrative Procedure Act requirements for public notice and comment. Both said the order moved away from a “conservative” and “cautious” approach to potential interference announced in the UWB rulemaking.

The FCC last month permitted radiated emissions from UWB transmitters to be measured while transmitters are in normal operating mode. It eliminated the requirement that multi-band orthogonal frequency division multiplexing (MB- OFDM) UWB devices and direct sequence UWB devices be tested with frequency hopping, frequency sweeping, step function and gating features turned off. The Commission granted the waiver in response to a petition by the MB- OFDM Alliance Special Interest Group (MBOA-SIG).

Cingular said the order grants “an open-ended blanket waiver of the Commission’s standards for measuring the power of a wide variety” of UWB devices, substituting a new standard for those set by agency rules. That ignores the Administrative Procedure Act’s notice-and-comment provisions, it said. The order said “codifying” the rule change would require rulemaking, but, Cingular said, “the Commission cannot avoid that requirement by cloaking the rule in the guise of an open-ended prospective ‘waiver’ of general applicability.”

Cingular warned that the order would mean a significant rise in harmful interference from UWB devices “beyond that contemplated in the UWB rulemaking.” The change in power measurement would let UWB devices transmit at EIPR levels 6dB higher than previously allowed, the firm said. “It may be possible to increase the transmit EIRP even more if the duty cycle is altered from what is currently envisioned for MB-OFDM devices,” Cingular said: “By approving the waiver, the Commission has opened the door to further additional increases in transmit EIRP without any testing or actual measurements.”

SIA criticized the FCC for using data from MBOA-SIG as the basis for deciding that even with a 4-fold increase in the potential for UWB devices to interfere with C-band earth station receivers, interference potential would be within an acceptable range. “The test results purported to show that, even if MB-OFDM and direct sequence UWB devices were tested with their frequency hopping, frequency sweeping, step function and gating features turned on, they would have no greater interference potential than the impulse-generated UWB devices that the Commission states in the order it used as a benchmark when it developed its UWB emissions limits,” SIA said.

SIA said in granting the waiver, the FCC “made faulty assumptions and improperly disregarded evidence in the record.” It said the Commission should re-examine the order, setting “more stringent” UWB emission limits to protect fixed satellite service earth station receivers operating on C-band downlink frequencies (3650-3700 MHz and 3700-4200 MHz). For example, it said with respect to the interference-to-noise ratio, the Commission was “off the mark by 20dB.” The Commission should give a “satisfactory explanation” for choosing MBOA-SIG’s findings over Freescale’s as the basis for its decision, SIA said.

SIA complained that the waiver was “overbroad,” applying to all MB-OFDM UWB devices, since the MBOA-SIG technical analysis on which the decision was based was limited to the “MB-OFDM F1F2F3” format. It urged the FCC to re-examine the interference assessment, weighing the potential for aggregate interference from interleaved UWB devices. SIA said if the waiver isn’t rescinded, it should “at a minimum be revised to exclude the 3650-4200 MHz band pending the outcome of NTIA’s measurement program.”