Wednesday, March 9, 2005

FCC Issues Waiver for UWB Emission Testing

The FCC issued a waiver permitting radiated emissions from ultra-wideband (UWB) transmitters to be measured while the transmitter is in its normal operating mode. This waiver responds to the petition filed by the Multi-band OFDM Alliance Special Interest Group. The waiver provides greater flexibility and innovation in designing UWB devices.

The FCC previously established regulations permitting the marketing and operation of products incorporating UWB technology. Because UWB devices operate on the same frequency bands used by licensed stations, the Commission established a conservative procedure to measure the levels of radio frequency emissions generated by these devices. UWB transmitters that employ frequency hopping techniques must be measured with the hop stopped and the transmitter operating in a continuous mode; UWB transmitters that gate the emissions on and off must be measured with the emissions gated on. These procedures can result in measured emission levels that are greater than the UWB signal levels under actual operation.

  • In December 2004, The FCC adopted new rules to permit unlicensed wideband devices in the 6 GHz, 17 GHz and 24 GHz bands. Specifically, the FCC amended its rules for general Part 15 unlicensed operations that use wide bandwidths but are not classified as UWB devices under its rules. It increased the peak power limits and reduced the unwanted emission levels for 3 frequency bands that were already available for unlicensed operation: 5925-7250 MHz, 16.2-17.2 GHz, and 23.12-29 GHz, and indicated that higher peak power limits in these bands would facilitate wideband operations such as short range communications, collision avoidance, inventory control and tracking systems. The Commission also amended its measurement procedures to permit frequency hopped, swept frequency, and gated systems operating within these bands to be measured in their normal operating mode.

  • In February 2002, the FCC decided to permit the use of ultra-wideband (“UWB�?) technology in certain types of new products, such as short-range, high-speed wireless data transmissions or ground penetrating radar. UWB operates by employing very narrow or short duration pulses that result in very large or wideband transmission bandwidths.

  • Ultra-wideband operates without using an RF Carrier for its signal. Instead, data is transmitted using time and amplitude modulated pulses of less than one nanosecond in duration. The U.S. military has long used the technology for highly secure communications and other applications.

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