round the 2.4GHz ISM Band Radio Communication Basics Table 4-2: Radio Frequency Bands in Use for Wireless Networking RF band Wireless networking specification 915/868 MHz ISM ZigBee 2.4 GHz ISM IEEE 802.11b, g, Bluetooth, ZigBee 5.8 GHz IEEE 802.11a 5.8 GHz (Table 4-2). As well as these narrow band applications, new networking standards such as ZigBee (Section "ZigBee (IEEE 802.15.4), p. 273)" will make use of the FCC spectrum allocation for ultra wideband radio (UWB - see Section "Ultra Wideband Radio p. 119") that permits very low power transmission across a broad spectrum from 3.1 to 10.6 GHz. Radio Frequency Spectrum Regulation The use of the radio frequency spectrum, in terms of the frequency bands that can be used for different licensed and unlicensed services, and the allowable transmission power levels for different signal formats, are controlled by regulatory authorities in individual countries or regions (Table 4-3). Although there is an increasing trend towards harmonisation of spectrum regulation across countries and regions, driven by the International Telecommunications Union's World Radio Communication Conference, there are significant differences in spectrum allocation and other conditions such as allowable transmitter power levels which have an impact on wireless networking hardware design and interoperability. As an example, in the 5.8 GHz ISM band used for IEEE 802.11a networks, the FCC in the USA allows a maximum transmitted power of Table 4-3: Radio Frequency Spectrum Regulatory Bodies Country/Region Regulatory body Federal Communications Commission Canada Industry Canada Europe European Telecommunications Standards Institute Japan Association of Radio Industries and Businesses Chapter Four Table 4-4: 2.4 GHz ISM Band Regulatory Differences by Region Regulator 2.4 GHz ISM specifications FCC (USA) 1 W maximum transmitted power 2.402-2.472 GHz, 11 X 22 MHz channels ETSI (Europe) 100 mW maximum EIRP 2.402-2.483 GHz, 13 X 22 MHz channels ARIB (Japan) 100 mW maximum EIRP 2.402-2.497 GHz, 14 X 22 M