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.
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🌍 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
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)
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.
Mobitex
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