ISM band

The industrial, scientific and medical (ISM) radio bands were originally reserved internationally for the use of RF electromagnetic fields for industrial, scientific and medical purposes other than communications. In general, communications equipment must accept any interference generated by ISM equipment.
The ISM bands are defined by the ITU-R in 5.138, 5.150, and 5.280 of the Radio Regulations. Individual countries' use of the bands designated in these sections may differ due to variations in national radio regulations. Because communication devices using the ISM bands must tolerate any interference from ISM equipment, these bands are typically given over to uses intended for unlicensed operation, since unlicensed operation typically needs to be tolerant of interference from other devices anyway. In the United States of America, uses of the ISM bands are governed by Part 18 of the FCC rules, while Part 15 Subpart B contains the rules for unlicensed communication devices, even those that use the ISM frequencies. Part 18 ISM rules prohibit using ISM for communications.
The ISM bands defined by the ITU-R are:

Frequency range [Hz]	Center frequency [Hz]	Availability
6.765–6.795 MHz	6.780 MHz	Subject to local acceptance
13.553–13.567 MHz	13.560 MHz
26.957–27.283 MHz	27.120 MHz
40.66–40.70 MHz	40.68 MHz
433.05–434.79 MHz	433.92 MHz
902–928 MHz	915 MHz	Region 2 only
2.400–2.500 GHz	2.450 GHz
5.725–5.875 GHz	5.800 GHz
24–24.25 GHz	24.125 GHz
61–61.5 GHz	61.25 GHz	Subject to local acceptance
122–123 GHz	122.5 GHz	Subject to local acceptance
244–246 GHz	245 GHz	Subject to local acceptance

For many people, the most commonly encountered ISM device is the home microwave oven operating at 2.45 GHz. However, in recent years these bands have also been shared with license-free error-tolerant communications applications such as wireless LANs and cordless phones in the 915 MHz, 2.450 GHz, and 5.800 GHz bands. Because unlicensed devices already are required to be tolerant of ISM emissions in these bands, unlicensed low power uses are generally able to operate in these bands without causing problems for ISM users. According to 47 CFR Part 15.5, low power communication devices must accept interference from licensed users of that frequency band, and the Part 15 device must not cause interference to licensed users. Note that the 915 MHz band should not be used in countries outside Region 2, except those that specifically allow it, such as Australia and Israel, especially those that use the GSM-900 band for cellphones. The ISM bands are also widely used for Radio-frequency identification (RFID) applications with the most commonly used band being the 13.56 MHz band used by systems compliant with ISO/IEC 14443 including those used by biometric passports and contactless smart cards.

Commercial use

Wireless LAN devices use wavebands as follows:

• Bluetooth 2450 MHz band
• HIPERLAN 5800 MHz band
• IEEE 802.11/WiFi 2450 MHz and 5800 MHz bands

IEEE 802.15.4/ZigBee personal area networks may use the 915 MHz and 2450 MHz ISM bands.
Wireless LANs and cordless phones can also use frequency bands other than the bands shared with ISM, but such uses require approval on a country by country basis. DECT phones use allocated spectrum outside the ISM bands that differs in Europe and North America. Ultra-wideband LANs require more spectrum than the ISM bands can provide, so the relevant standards such as IEEE 802.15.4a are designed to make use of spectrum outside the ISM bands. Despite the fact that these additional bands are outside the official ITU-R ISM bands, because they are used for the same types of low power personal communications, these additional frequency bands are sometimes incorrectly referred to as ISM bands as well. In the United States ISM is governed by Part 18 of the FCC rules. Part 18 ISM rules prohibit using ISM for communications.
Also note that several brands of radio control equipment use the 2.4 GHz band range for low power remote control of toys, from gas powered cars to miniature aircraft.
Worldwide Digital Cordless Telecommunications or WDCT is an ISM band technology that uses the 2.4 GHz radio spectrum.