428 MHz Frequency, Uses, and Global Applications

The 428 MHz frequency resides in the UHF spectrum and supports a wide range of industrial, telemetry, and medical applications. Though not globally harmonized, this frequency is especially important in countries like Japan and South Korea, where it plays a crucial role in wireless metering and healthcare systems.

Table of Contents

🌍 Frequency Summary

Parameter	Details
Center Frequency	428 MHz
Common Range	426.5–429.5 MHz (depending on country)
ITU Regions	🌍 Region 1 (limited), 🌎 Region 2, 🌏 Region 3
License Type	Varies (license-exempt in Japan, licensed in US)
Primary Use	Medical telemetry, smart meters, industrial IoT
Global Harmonization	No (country-specific regulations)

🔌 What Is 428 MHz Used For?

The 428 MHz frequency is tailored for low-power, narrowband wireless applications where reliable performance and long-range connectivity are critical.

📋 Typical Applications

🏥 Medical Telemetry: Real-time patient monitoring in hospitals (Japan)
⚡ Smart Utility Meters: Gas, water, and electric meters using wireless data links
🏗️ Industrial Telemetry: Remote monitoring in factories or field equipment
🚨 Disaster Communication Systems: Emergency alerting networks in Asia
🌱 Environmental Sensing: Air quality, water level, and temperature monitoring

🌐 Regional Use Overview

Region	Typical Allocation
🌍 Region 1 (Europe, Africa)	Not harmonized; 433 MHz preferred
🌎 Region 2 (Americas)	Part of 420–450 MHz UHF band (Amateur, military use)
🌏 Region 3 (Asia-Pacific)	Actively used in Japan, Korea, Malaysia for telemetry

🇯🇵 Japan

426.5375–429.7375 MHz allocated for Low Power Radio Stations
Power limit: 10 mW ERP
Common in hospitals, utilities, and city-wide alert systems

🇺🇸 United States

Falls within 420–450 MHz UHF amateur band
Shared with federal radiolocation services (e.g., military radar)
Use restricted; no general license-free use for industrial/medical systems

🇰🇷 South Korea

Allocated for wireless data transmission and control systems
Subject to type approval and government licensing

📻 Technical Characteristics

Characteristic	Details
Modulation Types	GFSK, 4FSK, ASK, MSK
Typical Bandwidth	12.5 kHz to 200 kHz
Max Transmission Power	10 mW ERP (Japan), up to 50 W (licensed US use)
Range (Line of Sight)	500 m to 5 km (depending on environment)
Antenna Size	~16.5 cm quarter-wave monopole

🔐 License & Restrictions

Region	License Requirement	Restrictions
🇯🇵 Japan	License-exempt	Max 10 mW ERP, low interference duty cycle
🇺🇸 USA	Licensed (Amateur/Radar)	Military and amateur shared use only
🇰🇷 Korea	Licensed or approved	Subject to local telecom laws
🇪🇺 Europe	Not harmonized	Prefer 433 MHz SRD band

Devices may require type approval or certification (e.g., MIC in Japan, FCC in US)
In shared bands, coordination or dynamic channel access may be required

🔍 Adjacent Bands

Band	Frequency Range	Use Case
420–430 MHz	Government, amateur, radar (USA)
426–429 MHz	Low-power telemetry (Japan, Korea)
430–440 MHz	Amateur radio, SRD (Europe uses 433 MHz)
440–450 MHz	Land mobile, amateur, government use

🛠️ Related Technologies

📡 LoRa-like Narrowband Systems (in Japan and Korea)
🏥 Wireless Medical Telemetry Service (WMTS)
🧰 Proprietary SCADA/RTU Systems
🔧 Utility M2M Protocols (low-bitrate communication)
📦 Wireless Meter Bus (WMBus) alternatives in Asia

🧭 Regulatory Authorities

Country	Regulator
🇯🇵 Japan	MIC (Ministry of Internal Affairs and Communications)
🇺🇸 USA	FCC (Federal Communications Commission) + NTIA (Gov’t use)
🇰🇷 Korea	MSIT (Ministry of Science and ICT)
🇪🇺 Europe	ETSI / National regulators (e.g., Ofcom, ANFR)

📜 Historical Context

Japan pioneered use of 428 MHz for low-power wireless since early 2000s
Adopted in smart metering and hospital telemetry ahead of 920 MHz ISM release
In the US, 420–450 MHz remains reserved for government and amateur use, limiting commercial adoption
Influenced development of narrowband protocols suited to short packets and low duty cycles

🧾 Summary

Feature	Value
Center Frequency	428 MHz
Applications	Telemetry, metering, medical
Global Status	Region-specific use
Power Limits	10 mW ERP (Japan), licensed higher in US
Adjacent Bands	426–429 MHz (Asia), 430–440 MHz (Europe)
Licensing	Mostly restricted or approved use

428 MHz is a specialized, sub-GHz frequency ideal for long-range, low-data wireless communication. While it’s not a globally open band like 433 MHz or 915 MHz, it remains essential in Japan and South Korea, powering medical telemetry, disaster systems, and utility automation. Its low interference profile and solid propagation make it a hidden gem for mission-critical applications in select regions.