ISM band

From Wikipedia, the free encyclopedia

The industrial, scientific and medical (ISM) radio bands were originally reserved internationally for non-commercial use of RF electromagnetic fields for industrial, scientific and medical purposes.

The ISM bands are defined by the ITU-R in 5.138 and 5.150 of the Radio Regulations. Individual countries' use of the bands designated in these sections may differ due to variations in national radio regulations. In the United States of America ISM is governed by Part 18 of the FCC rules and should not be confused with Part 15 rules. Communication is not permitted under Part 18 (ISM) rules.

In recent years they have also been shared with license-free error-tolerant communications applications such as wireless LANs and Bluetooth:

• 900 MHz band (33.3 centimeter wavelength)
• 1.8 GHz Band (16.7 cm wavelength)
• 2.4 GHz band (12.5 cm wavelength)
• 5.8 GHz band (5.2 cm wavelength)

(using an approximation to the speed of light of 3×10⁸ m/s)

IEEE 802.11b/g wireless Ethernet also operates on the 2.4 GHz band, and most microwave ovens use 2.45 GHz. Although these devices share the (Part 18) ISM band, they are not ISM devices in the United States, and fall under the regulation of Part 15.

[edit] See also

• Local area network
• IEEE 802.11
• Wireless network
• Fixed Wireless Data

[edit] External links

• 900 MHz vs. 2.4 GHz
• Cordless phone frequencies
• ITU page on definitions of ISM bands
• ITU page on Radio Regulations
• European Radiocommunications Office frequency information system
• In the US, CFR Title 47 Part 18 describes the regulation of the ISM bands. Part 15 Subpart 247 contains regulation related for communication devices operating in the ISM bands.