ISM band
Encyclopedia
The industrial, scientific and medical (ISM) radio bands are radio bands (portions of the radio spectrum
) reserved internationally for the use of radio frequency
(RF) energy for industrial, scientific and medical purposes other than communications.
Examples of applications in these bands include radio-frequency process heating, microwave oven
s, and medical diathermy
machines. The powerful emissions of these devices can create electromagnetic interference
and disrupt radio communication using the same frequency
, so these devices were limited to certain bands of frequencies. In general, communications equipment operating in these bands must tolerate any interference generated by ISM equipment, and users have no regulatory protection from ISM device operation.
Despite the intent of the original allocation, in recent years the fastest-growing uses of these bands have been for short-range, low power communications systems. Cordless phones, Bluetooth
devices, NFC
devices, and wireless computer networks
all use the ISM bands.
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, unlicensed operations are typically permitted to use these bands, since unlicensed operation typically needs to be tolerant of interference from other devices anyway. The ISM bands do have licensed operations; however, due to the high likelihood of harmful interference, licensed use of the bands is typically low. In the United States of America, uses of the ISM bands are governed by Part 18 of the FCC rules, while Part 15
contains the rules for unlicensed communication devices, even those that use the ISM frequencies.
The ISM bands defined by the ITU-R are:
Regulatory authorities may allocate other parts of the radio spectrum for unlicensed communication systems, but these are not ISM bands.
In the US, the FCC
first made unlicensed spread spectrum available in the ISM bands in rules adopted on May 9, 1985.
Many other countries later adapted these FCC regulations, enabling use of this technology in all major countries. The FCC action was proposed by Michael Marcus of the FCC staff in 1980 and the subsequent regulatory action took 5 more years. It was part of a broader proposal to allow civil use of spread spectrum technology and was opposed at the time by mainstream equipment manufacturers and many radio system operators.
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 Sensor Networks
in the 868 MHz, 915 MHz and 2.450 GHz bands, as well as wireless LAN
s and cordless phone
s 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; ISM equipment does not usually include a radio receiver in the ISM band. In the United States, 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 passport
s and contactless smart card
s.
Wireless LAN
devices use wavebands as follows:
IEEE 802.15.4
, ZigBee
and other personal area networks may use the and 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.
Also note that several brands of radio control equipment use the 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 radio spectrum.
Radio spectrum
Radio spectrum refers to the part of the electromagnetic spectrum corresponding to radio frequencies – that is, frequencies lower than around 300 GHz ....
) reserved internationally for the use of radio frequency
Radio frequency
Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...
(RF) energy for industrial, scientific and medical purposes other than communications.
Examples of applications in these bands include radio-frequency process heating, microwave oven
Microwave oven
A microwave oven is a kitchen appliance that heats food by dielectric heating, using microwave radiation to heat polarized molecules within the food...
s, and medical diathermy
Diathermy
In the natural sciences, the term diathermy means "electrically induced heat" and is commonly used for muscle relaxation. It is also a method of heating tissue electromagnetically or ultrasonically for therapeutic purposes in medicine.-Surgical uses:...
machines. The powerful emissions of these devices can create electromagnetic interference
Electromagnetic interference
Electromagnetic interference is disturbance that affects an electrical circuit due to either electromagnetic induction or electromagnetic radiation emitted from an external source. The disturbance may interrupt, obstruct, or otherwise degrade or limit the effective performance of the circuit...
and disrupt radio communication using the same frequency
Frequency
Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency.The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency...
, so these devices were limited to certain bands of frequencies. In general, communications equipment operating in these bands must tolerate any interference generated by ISM equipment, and users have no regulatory protection from ISM device operation.
Despite the intent of the original allocation, in recent years the fastest-growing uses of these bands have been for short-range, low power communications systems. Cordless phones, Bluetooth
Bluetooth
Bluetooth is a proprietary open wireless technology standard for exchanging data over short distances from fixed and mobile devices, creating personal area networks with high levels of security...
devices, NFC
Near Field Communication
Near field communication, or NFC, allows for simplified transactions, data exchange, and wireless connections between two devices in proximity to each other, usually by no more than a few centimeters. It is expected to become a widely used system for making payments by smartphone in the United States...
devices, and wireless computer networks
Wireless network
Wireless network refers to any type of computer network that is not connected by cables of any kind. It is a method by which homes, telecommunications networks and enterprise installations avoid the costly process of introducing cables into a building, or as a connection between various equipment...
all use the ISM bands.
ISM bands
The ISM bands are defined by the ITU-RITU-R
The ITU Radiocommunication Sector is one of the three sectors of the International Telecommunication Union and is responsible for radio communication....
in 5.138, 5.150, and 5.280 of the Radio Regulations
Radio Regulations
The Radio Regulations is an intergovernmental treaty text of the International Telecommunication Union , the Geneva-based specialised agency of the United Nations which coordinates and standardises the operation of telecommunication networks and services and advances the development of...
. 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, unlicensed operations are typically permitted to use these bands, since unlicensed operation typically needs to be tolerant of interference from other devices anyway. The ISM bands do have licensed operations; however, due to the high likelihood of harmful interference, licensed use of the bands is typically low. In the United States of America, uses of the ISM bands are governed by Part 18 of the FCC rules, while Part 15
Part 15 (FCC rules)
Code of Federal Regulations, Title 47, Part 15 is an oft-quoted part of Federal Communications Commission rules and regulations regarding unlicensed transmissions. It is a part of Title 47 of the Code of Federal Regulations , and regulates everything from spurious emissions to unlicensed...
contains the rules for unlicensed communication devices, even those that use the ISM frequencies.
The ISM bands defined by the ITU-R are:
| | Frequency range | Center frequency | Availability | ||
|---|---|---|---|---|
| 6.765 MHz | 6.795 MHz | 6.780 MHz | Subject to local acceptance | |
| 13.553 MHz | 13.567 MHz | 13.560 MHz | ||
| 26.957 MHz | 27.283 MHz | 27.120 MHz | ||
| 40.660 MHz | 40.700 MHz | 40.680 MHz | ||
| 433.050 MHz | 434.790 MHz | 433.920 MHz | Region 1 ITU region The International Telecommunication Union , in its International Radio Regulations, divides the world into three ITU regions for the purposes of managing the global radio spectrum... only and subject to local acceptance |
|
| 902.000 MHz | 928.000 MHz | 915.000 MHz | Region 2 ITU region The International Telecommunication Union , in its International Radio Regulations, divides the world into three ITU regions for the purposes of managing the global radio spectrum... only |
|
| 2.400 GHz GHZ GHZ or GHz may refer to:# Gigahertz .# Greenberger-Horne-Zeilinger state — a quantum entanglement of three particles.# Galactic Habitable Zone — the region of a galaxy that is favorable to the formation of life.... |
2.500 GHz | 2.450 GHz | ||
| 5.725 GHz | 5.875 GHz | 5.800 GHz | ||
| 24.000 GHz | 24.250 GHz | 24.125 GHz | ||
| 61.000 GHz | 61.500 GHz | 61.250 GHz | Subject to local acceptance | |
| 122.000 GHz | 123.000 GHz | 122.500 GHz | Subject to local acceptance | |
| 244.000 GHz | 246.000 GHz | 245.000 GHz | Subject to local acceptance | |
Regulatory authorities may allocate other parts of the radio spectrum for unlicensed communication systems, but these are not ISM bands.
History
Radio frequencies in the ISM bands have been used for communication purposes, although such devices may experience interference from non-communication sources. In the United States, as early as 1958 Class D Citizen's Band was allocated adjacent to an ISM frequency.In the US, the FCC
Federal Communications Commission
The Federal Communications Commission is an independent agency of the United States government, created, Congressional statute , and with the majority of its commissioners appointed by the current President. The FCC works towards six goals in the areas of broadband, competition, the spectrum, the...
first made unlicensed spread spectrum available in the ISM bands in rules adopted on May 9, 1985.
Many other countries later adapted these FCC regulations, enabling use of this technology in all major countries. The FCC action was proposed by Michael Marcus of the FCC staff in 1980 and the subsequent regulatory action took 5 more years. It was part of a broader proposal to allow civil use of spread spectrum technology and was opposed at the time by mainstream equipment manufacturers and many radio system operators.
Uses
For many people, the most commonly encountered ISM device is the home microwave ovenMicrowave oven
A microwave oven is a kitchen appliance that heats food by dielectric heating, using microwave radiation to heat polarized molecules within the food...
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 Sensor Networks
Wireless sensor network
A wireless sensor network consists of spatially distributed autonomous sensors to monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or pollutants and to cooperatively pass their data through the network to a main location. The more modern...
in the 868 MHz, 915 MHz and 2.450 GHz bands, as well as wireless LAN
Wireless LAN
A wireless local area network links two or more devices using some wireless distribution method , and usually providing a connection through an access point to the wider internet. This gives users the mobility to move around within a local coverage area and still be connected to the network...
s and cordless phone
Cordless telephone
A cordless telephone or portable telephone is a telephone with a wireless handset that communicates via radio waves with a base station connected to a fixed telephone line, usually within a limited range of its base station...
s 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; ISM equipment does not usually include a radio receiver in the ISM band. In the United States, 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 passport
Biometric passport
A biometric passport, also known as an e-passport or ePassport, is a combined paper and electronic passport that contains biometric information that can be used to authenticate the identity of travelers...
s and contactless smart card
Contactless smart card
A contactless smart card is any pocket-sized card with embedded integrated circuits that can process and store data, and communicate with a terminal via radio waves. There are two broad categories of contactless smart cards. Memory cards contain non-volatile memory storage components, and perhaps...
s.
Wireless LAN
Wireless LAN
A wireless local area network links two or more devices using some wireless distribution method , and usually providing a connection through an access point to the wider internet. This gives users the mobility to move around within a local coverage area and still be connected to the network...
devices use wavebands as follows:
- BluetoothBluetoothBluetooth is a proprietary open wireless technology standard for exchanging data over short distances from fixed and mobile devices, creating personal area networks with high levels of security...
2450 MHz band - HIPERLANHIPERLANHiperLAN is a Wireless LAN standard. It is a European alternative for the IEEE 802.11 standards . It is defined by the European Telecommunications Standards Institute . In ETSI the standards are defined by the BRAN project...
5800 MHz band - IEEE 802.11IEEE 802.11IEEE 802.11 is a set of standards for implementing wireless local area network computer communication in the 2.4, 3.6 and 5 GHz frequency bands. They are created and maintained by the IEEE LAN/MAN Standards Committee . The base version of the standard IEEE 802.11-2007 has had subsequent...
/WiFiWIFIWIFI is a radio station broadcasting a brokered format. Licensed to Florence, New Jersey, USA, the station is currently operated by Florence Broadcasting Partners, LLC.This station was previously owned by Real Life Broadcasting...
2450 MHz and 5800 MHz bands
IEEE 802.15.4
IEEE 802.15.4
IEEE 802.15.4 is a standard which specifies the physical layer and media access control for low-rate wireless personal area networks . It is maintained by the IEEE 802.15 working group....
, ZigBee
ZigBee
ZigBee is a specification for a suite of high level communication protocols using small, low-power digital radios based on an IEEE 802 standard for personal area networks. Applications include wireless light switches, electrical meters with in-home-displays, and other consumer and industrial...
and other personal area networks may use the and 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
Digital Enhanced Cordless Telecommunications
Digital Enhanced Cordless Telecommunications , usually known by the acronym DECT, is a digital communication standard, which is primarily used for creating cordless phone systems...
phones use allocated spectrum outside the ISM bands that differs in Europe and North America. Ultra-wideband
Ultra-wideband
Ultra-wideband is a radio technology that can be used at very low energy levels for short-range high-bandwidth communications by using a large portion of the radio spectrum. UWB has traditional applications in non-cooperative radar imaging...
LANs require more spectrum than the ISM bands can provide, so the relevant standards such as IEEE 802.15.4a
IEEE 802.15.4a
IEEE 802.15.4a is an amendment to IEEE 802.15.4 specifying that additional physical layers be added to the original standard.-Overview:...
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.
Also note that several brands of radio control equipment use the 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 radio spectrum.
See also
- Frequency allocationFrequency allocationUse of radio frequency bands of the electromagnetic spectrum is regulated by governments in most countries, in a Spectrum management process known as frequency allocation or spectrum allocation. Radio propagation does not stop at national boundaries...
- Fixed wirelessFixed wirelessFixed wireless is the operation of wireless devices or systems used to connect two fixed locations with a radio or other wireless link, such as laser bridge. Usually, fixed wireless is part of a wireless LAN infrastructure. The purpose of a fixed wireless link is to enable data communications...
- Electromagnetic interference at 2.4 GHzElectromagnetic interference at 2.4 GHzElectromagnetic interference at 2.4 GHz can affect various devices.This article details the different users of the 2.4 GHz band, how they cause interference to other users and how they are prone to interference from other users.-Phone:...
External links
- 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 regulations for wireless LAN devices operating in the ISM bands.