ISM Bands Around the World

 

Introduction

The International Telecommunication Union (ITU) has designated several radio frequency bands for industrial, scientific, and medical (ISM) applications. These ISM bands are license-exempt, meaning that users do not need to obtain a license or pay any fees to operate wireless devices within these frequencies. This global allocation of ISM bands has facilitated the development and widespread adoption of various wireless technologies, including Wi-Fi, Bluetooth, and radio-frequency identification (RFID) systems.

The purpose of this article is to provide a comprehensive overview of the ISM bands utilized around the world, their respective frequencies, and their applications. By understanding the ISM band allocations in different regions, manufacturers and users can ensure compliance with local regulations and optimize the performance of their wireless devices.

ISM Band Allocations

The ISM band allocations vary across different regions and countries due to variations in regulatory bodies and spectrum management policies. However, there are some commonly used ISM bands that are recognized worldwide.

Global ISM Bands

The following table presents the globally recognized ISM bands, their respective frequencies, and common applications:

Band	Frequency Range	Applications
LF	125-134 kHz	RFID, wireless charging
HF	13.56 MHz	RFID, Near Field Communication (NFC)
VHF	27.12 MHz	Remote control systems, wireless security systems
UHF	433.92 MHz	Remote control systems, wireless security systems, RFID
	915 MHz	RFID, wireless sensors, wireless communication systems
SHF	2.4 GHz	Wi-Fi (IEEE 802.11b/g/n/ax), Bluetooth, ZigBee, RFID, wireless communication systems
	5.8 GHz	Wi-Fi (IEEE 802.11a/n/ac/ax), wireless communication systems
	24.125 GHz	Vehicular radar systems, radar sensors
	61-61.5 GHz	Wireless communication systems, wireless backhaul links
	122-123 GHz	Wireless communication systems, radar sensors
	244-246 GHz	Wireless communication systems, radar sensors

It's important to note that while these bands are globally recognized, their specific usage and regulations may vary across different countries or regions.

Regional ISM Band Variations

In addition to the globally recognized ISM bands, some regions have their own specific allocations or variations. Here are a few examples:

Europe

In Europe, the European Telecommunications Standards Institute (ETSI) and the Electronic Communications Committee (ECC) regulate the use of ISM bands. The following are some notable European ISM band allocations:

• 868-868.6 MHz: Used for short-range devices, RFID, and wireless sensor networks.
• 865-868 MHz: Used for RFID and wireless sensor networks in some European countries.

North America

In North America, the Federal Communications Commission (FCC) in the United States and Innovation, Science and Economic Development Canada (ISED) in Canada regulate the use of ISM bands. The following are some notable North American ISM band allocations:

• 902-928 MHz: Used for RFID, wireless communication systems, and wireless sensor networks.

Japan

In Japan, the Ministry of Internal Affairs and Communications (MIC) regulates the use of ISM bands. The following are some notable Japanese ISM band allocations:

• 920-928 MHz: Used for RFID, wireless communication systems, and wireless sensor networks.

Applications of ISM Bands

The ISM bands are extensively used in various wireless technologies and applications, including:

Wi-Fi

Wi-Fi, based on the IEEE 802.11 standards, operates primarily in the 2.4 GHz and 5 GHz ISM bands. These bands are widely used for wireless local area networks (WLANs) in homes, offices, and public spaces, providing internet access and enabling communication between devices.

Bluetooth

Bluetooth is a widely adopted wireless technology for short-range communication between devices. It operates in the 2.4 GHz ISM band, enabling low-power connections for applications such as wireless headsets, speakers, and peripheral devices.

ZigBee

ZigBee is a low-power, low-data-rate wireless communication protocol designed for applications such as home automation, industrial control, and wireless sensor networks. It operates in the 2.4 GHz ISM band and supports mesh networking capabilities.

Radio-Frequency Identification (RFID)

RFID systems utilize various ISM bands, including low-frequency (LF), high-frequency (HF), and ultra-high frequency (UHF) bands. RFID technology is widely used for tracking and identification purposes in supply chain management, inventory control, access control, and asset tracking applications.

Remote Control Systems

Many remote control systems, such as those used for garage door openers, keyless entry systems, and wireless security systems, operate in the ISM bands, particularly in the UHF range (e.g., 433.92 MHz).

Wireless Sensor Networks

Wireless sensor networks, which are used for monitoring and data collection in various industries (e.g., environmental monitoring, industrial automation, and healthcare), often leverage ISM bands like 2.4 GHz and sub-GHz bands for low-power, long-range communication.

Radar Systems

Some ISM bands, such as the 24.125 GHz and 61-61.5 GHz bands, are utilized for vehicular radar systems and radar sensors in applications like automotive collision avoidance systems and industrial level measurement systems.

Regulatory Considerations

While the ISM bands are license-exempt, there are still regulatory considerations and requirements that manufacturers and users must adhere to. These regulations aim to ensure efficient spectrum utilization, prevent harmful interference, and maintain compatibility between different wireless devices and systems.

Some key regulatory considerations include:

• Transmit power limits: Regulations typically impose maximum transmit power limits for devices operating in ISM bands to minimize interference.
• Duty cycle restrictions: Certain ISM bands may have restrictions on the duty cycle (the ratio of transmission time to idle time) to promote fair spectrum sharing.
• Channel spacing and bandwidth requirements: Regulations may specify channel spacing and bandwidth requirements to ensure efficient use of the spectrum.
• Labeling and certification requirements: Devices operating in ISM bands may need to be labeled and certified to demonstrate compliance with relevant standards and regulations.

It's essential for manufacturers and users to consult the specific regulations and requirements applicable to their region or country when designing, deploying, or operating wireless devices in ISM bands.

Frequently Asked Questions (FAQs)

1. What is the difference between licensed and license-exempt bands?

Licensed bands require users to obtain a license and pay fees to operate wireless devices in those frequencies. License-exempt bands, such as the ISM bands, allow users to operate wireless devices without obtaining a license, but they must still comply with certain regulations.

2. Can I use any wireless device in the ISM bands without restrictions?

No, while the ISM bands are license-exempt, there are still regulations and requirements that must be followed. These include transmit power limits, duty cycle restrictions, channel spacing, and bandwidth requirements, among others.

3. Are the ISM bands the same across all countries?

While there are some globally recognized ISM bands, there can be variations and additional allocations in different regions or countries. It's important to consult the specific regulations for the region where the wireless device will be used.

4. Can I use the same wireless device operating in an ISM band in any country?

Not necessarily. Even though the ISM bands may be similar, regulations and requirements can vary between countries. It's essential to ensure that the wireless device complies with the regulations of the country where it will be used.

5. What are some common applications that use the ISM bands?

Some common applications that use the ISM bands include Wi-Fi (2.4 GHz and 5 GHz), Bluetooth (2.4 GHz), ZigBee (2.4 GHz), RFID systems (various bands), remote control systems (e.g., 433.92 MHz), wireless sensor networks (2.4 GHz and sub-GHz bands), and radar systems (e.g., 24.125 GHz, 61-61.5 GHz).