The World’s License-Free Radio Systems

LPD433 (Low Power Device 433 MHz) is one of Europe’s lesser-known license-free voice communication systems. It emerged in the 1990s as part of the broader 433 MHz ISM (Industrial, Scientific and Medical) band utilization, primarily in Germany and a few neighboring countries.

Unlike PMR446, which was harmonized at a European level, LPD433 developed in a more fragmented regulatory environment. It became particularly popular in Germany, where it offered a simple, ultra-low-power communication option for short-range use without licensing requirements.

Over time, PMR446 largely replaced LPD433 in consumer markets, but LPD devices are still found in hobbyist and niche applications.

Frequency range and channel allocation

LPD433 operates within the 433 MHz ISM band:

• 433.075 MHz – 434.775 MHz

It typically provides:

• 69 narrowband channels

• 25 kHz or 12.5 kHz spacing (device-dependent)

Because the 433 MHz band is primarily designated for low-power devices, LPD433 shares spectrum with numerous non-voice applications such as remote controls, sensors, alarms, and telemetry systems.

Technical characteristics

Key parameters include:

• Maximum output power: 10 mW ERP

• Analog FM modulation

• Narrowband operation

• No repeaters permitted

• Portable devices only

The extremely low 10 mW power limit is the defining characteristic of LPD433. Compared to PMR446 (0.5 W) or Freenet (1 W), LPD operates at a fraction of the output power.

This restriction was designed to allow dense device coexistence within the ISM band while minimizing interference risk.

Propagation characteristics

Operating at 433 MHz places LPD433 in the UHF spectrum. Its short wavelength (~69 cm) results in:

• Limited range

• Moderate penetration through light structures

• Highly localized communication

Typical real-world range:

• Indoors: a few hundred meters

• Urban environment: 300–800 meters

• Open terrain: up to 1–2 km under ideal conditions

Because of the very low power level, range is strongly dependent on antenna efficiency and environmental conditions.

Unlike CB radio, LPD433 does not support long-distance ionospheric propagation.

Spectrum sharing and interference

A major technical consideration with LPD433 is spectrum congestion.

The 433 MHz ISM band is widely used for:

• Wireless weather stations

• Garage door openers

• Car key fobs

• Alarm systems

• Industrial telemetry

As a result, LPD433 voice communication can experience interference from non-voice digital bursts and other low-power devices.

This shared-spectrum environment limits reliability compared to dedicated voice allocations like PMR446.

Equipment characteristics

LPD433 devices are typically:

• Compact handheld radios

• Equipped with short fixed antennas

• Low-cost consumer-grade equipment

Because of the 10 mW limit, external amplifiers and repeaters are not allowed. The system is designed strictly for short-range personal communication.

Many early consumer “walkie-talkies” in Germany supported both LPD433 and PMR446 in dual-mode configurations.

Geographic scope

LPD433 has historically been most relevant in:

• Germany

• Parts of Central Europe

However, regulatory treatment of 433 MHz voice communication varies across countries. In some regions, voice use on 433 MHz may be restricted or discouraged due to ISM band congestion.

Users must verify national regulations before operating LPD-capable radios outside their original market.

Position within license-free radio systems

LPD433 occupies the ultra-low-power end of the license-free radio spectrum. Compared to other systems:

• Much lower power than PMR446

• Shorter range than Freenet

• No external antenna flexibility like CB

• Shares spectrum with numerous non-voice devices

Its advantages:

• Extremely low interference footprint

• Simple operation

• Very low equipment cost

• No licensing requirement

Its limitations:

• Limited range

• Shared spectrum congestion

• Not harmonized at a pan-European level like PMR446

Today, LPD433 is largely overshadowed by PMR446 for voice communication. However, it remains an important example of how ISM-band spectrum can be adapted for short-range, license-exempt voice services under strict technical constraints.

RHA68 – Finland’s 68 MHz License-Free Radio System

RHA68 is a Finland-specific license-free radio service operating in the low VHF band around 68 MHz. It represents a distinctive Nordic approach to spectrum allocation, providing a short-range communication option without requiring an individual radio license.

Unlike pan-European systems such as PMR446, RHA68 is a national allocation. It developed to serve domestic needs, particularly in rural and sparsely populated regions where reliable short-range communication is valuable.

Because of its unique frequency range and limited geographic scope, RHA68 is relatively unknown outside Finland.

Frequency range and channel allocation

RHA68 operates in the low VHF band at:

• Approximately 68.000 – 68.200 MHz

• Typically 25 kHz channel spacing

• Multiple designated voice channels within this segment

Exact channel assignments and usage conditions are defined by the Finnish communications authority.

The low-band VHF placement is unusual compared to most modern license-free systems, which typically use UHF (e.g., 446 MHz).

Technical characteristics

Key parameters generally include:

• Maximum output power: typically around 5 W (national regulation dependent)

• Analog FM modulation

• Portable and mobile use permitted

• No repeaters allowed

Compared to PMR446 (0.5 W) or LPD433 (10 mW), RHA68 allows significantly higher power levels, which directly influences coverage.

Because it operates in a lower frequency band, antenna length is longer than for UHF systems, and handheld radios typically feature visibly longer antennas.

Propagation characteristics

At around 68 MHz, RHA68 operates in the lower VHF spectrum. This results in:

• Longer wavelength (~4.4 meters)

• Strong ground-wave propagation

• Better diffraction over terrain obstacles

• Improved rural coverage compared to UHF systems

Typical real-world range:

• Urban areas: 2–5 km

• Open terrain: 5–15 km

• Elevated line-of-sight conditions: potentially more

Unlike 27 MHz CB, RHA68 does not typically experience significant ionospheric skip under normal conditions, making coverage more stable and predictable.

The lower frequency also performs better in forested or uneven terrain—an important factor in Finland’s geography.

Equipment characteristics

RHA68 radios are generally:

• Handheld or mobile transceivers

• Equipped with longer VHF antennas

• Designed specifically for the Finnish market

Because the allocation is national, equipment is rarely marketed internationally.

External power amplification beyond legal limits is not permitted, and repeater operation is typically excluded from the license-free framework.

Geographic limitation

A critical consideration:

RHA68 is valid only within Finland.

The 68 MHz band is not harmonized across Europe as a license-free allocation. In other countries, these frequencies may be assigned to:

• Government services

• Military communication

• Professional land mobile radio

• Other regulated applications

Operating RHA68 equipment outside Finland may therefore be illegal and could interfere with licensed services.

Use cases and positioning

RHA68 is particularly suitable for:

• Rural property coordination

• Forestry and agricultural activities

• Outdoor recreational groups

• Remote-area communication

Its positioning within license-free systems can be summarized as:

• Greater range than PMR446

• Higher power than most European short-range services

• More stable coverage than 27 MHz CB

• Strictly national in scope

Role within global license-free systems

RHA68 demonstrates how individual countries may create tailored license-free allocations based on national geography and communication needs.

While not internationally harmonized, it represents a technically robust low-VHF alternative to the more common UHF-based consumer radio services.

Within the broader landscape of license-free radio systems, RHA68 stands out as a rare example of a low-band VHF allocation optimized for rural coverage under a national regulatory framework.

43 MHz CB – Italy’s 43 MHz VHF CB System

Italy is one of the few countries that introduced a VHF-based “CB-style” license-free radio service in addition to the traditional 27 MHz Citizens Band. Commonly referred to as 43 MHz VHF CB (sometimes simply “43 MHz CB”), this system was created as a national allocation to provide improved local communication quality compared to 27 MHz HF CB.

While the 27 MHz CB band remained internationally dominant, Italy developed the 43 MHz alternative to offer:

• More stable local coverage

• Reduced long-distance skip interference

• Better short-range clarity

As a result, 43 MHz CB became a uniquely Italian solution within the broader landscape of license-exempt radio services.

Frequency range and channel allocation

The Italian 43 MHz CB service operates approximately in the:

• 43.300 – 43.400 MHz range

• Typically 24 or 25 channels (national plan dependent)

• 10 kHz or 12.5 kHz channel spacing

Exact channelization and technical conditions are defined by Italian national regulation.

Unlike 27 MHz CB, which follows a globally recognized 40-channel structure, the 43 MHz allocation is not internationally harmonized.

Technical characteristics

Key parameters typically include:

• Output power: around 4 W (national regulation dependent)

• Analog FM modulation

• Portable and mobile operation allowed

• No repeaters permitted

Unlike modern PMR-style systems, external antennas are generally allowed, similar to 27 MHz CB, which enables improved performance with properly installed base or mobile antennas.

The system was designed for straightforward voice communication without advanced digital features.

Propagation characteristics

Operating at 43 MHz places this system in the lower VHF band, between traditional HF CB (27 MHz) and higher VHF allocations.

Wavelength at 43 MHz is approximately 7 meters.

Propagation properties include:

• Strong ground-wave coverage

• More stable local communication compared to 27 MHz

• Reduced ionospheric skip compared to 27 MHz

• Better predictability for regional use

Typical real-world range:

• Urban areas: 2–5 km

• Open terrain: 5–15 km

• Elevated line-of-sight conditions: potentially more

Unlike 27 MHz CB, 43 MHz CB is less affected by sporadic E and long-distance skip, making it more suitable for reliable local coordination.

Comparison with 27 MHz CB

Key differences:

27 MHz CB:

• Global recognition

• Possible long-distance DX via ionospheric reflection

• More prone to skip interference

43 MHz CB (Italy):

• National-only allocation

• More stable local communication

• Less long-distance propagation

• Reduced international interoperability

For users seeking predictable regional coverage rather than DX hobby activity, 43 MHz offered practical advantages.

Equipment and antenna considerations

43 MHz equipment typically includes:

• Mobile radios for vehicle installation

• Base stations

• Handheld transceivers (less common)

Because of the lower VHF frequency, antennas are longer than UHF systems but shorter than 27 MHz CB antennas.

External antennas are permitted within legal limits, allowing improved performance compared to fixed-antenna systems like PMR446.

Geographic limitation

A critical regulatory point:

43 MHz VHF CB is valid only within Italy.

The 43 MHz band is not harmonized across Europe as a license-free allocation. In neighboring countries, these frequencies may be assigned to:

• Military services

• Government communication

• Professional land mobile systems

• Other licensed users

Using 43 MHz CB equipment outside Italy may therefore be illegal and cause interference.

Role within global license-free systems

Italy’s 43 MHz CB represents an unusual but technically logical attempt to bridge the gap between:

• Long-distance capable 27 MHz HF CB

• Short-range UHF systems like PMR446

It demonstrates how national regulators can create alternative license-exempt services tailored to domestic communication needs.

Within the global overview of license-free radio systems, 43 MHz CB stands as a rare example of a VHF-based Citizens Band service that remained largely confined to a single country.

Jakt 31 MHz – Sweden’s 31 MHz Hunting Radio Band

Sweden has a long tradition of dedicated hunting radio systems, reflecting the country’s strong outdoor and hunting culture. One of the historically important allocations is the so-called “31 MHz hunting band” (Jakt 31 MHz), a low-VHF allocation designed specifically for communication during organized hunts.

Unlike consumer-oriented systems such as PMR446, the Swedish hunting bands were created to serve structured field coordination in forested and rural terrain. The 31 MHz band became widely used because of its favorable propagation in wooded environments and rolling landscapes typical of Scandinavia.

Although regulatory conditions have evolved over time, 31 MHz remains an important part of Sweden’s hunting communication heritage.

Frequency range and channel allocation

The 31 MHz hunting allocation operates approximately in the:

• 30–32 MHz low VHF range

• Nationally defined channel set

• Typically 10 kHz or 12.5 kHz channel spacing

Exact frequencies and channel numbers are determined by Swedish national regulation.

Unlike internationally harmonized services, the 31 MHz band is strictly national and purpose-specific.

Technical characteristics

Typical parameters include:

• Analog FM modulation

• Portable and mobile operation

• Output power defined by national rules (commonly several watts)

• External antennas permitted within legal limits

• No open public repeaters in the license-free framework

In some periods, certain Swedish hunting bands required a simplified authorization rather than a completely license-exempt model. Regulatory details have changed over time, so current compliance always requires checking Swedish communications authority guidance.

Compared to PMR446, the system allows higher power and greater flexibility.

Propagation characteristics

Operating around 31 MHz places this system in the low-VHF / upper-HF transition zone.

Wavelength at 31 MHz is approximately 9.7 meters.

Propagation properties include:

• Strong ground-wave coverage

• Excellent performance in forested terrain

• Better diffraction over hills compared to UHF

• Limited but possible sporadic long-distance propagation under certain conditions

Typical real-world range:

• Dense forest: several kilometers

• Open terrain: 5–15 km

• Elevated positions: potentially more

Compared to 27 MHz CB, 31 MHz offers:

• More stable local communication

• Less skip-related interference

• Reduced long-distance unpredictability

These characteristics made it particularly well suited for coordinated hunting activities, where reliable local coverage is more important than long-distance DX.

Equipment characteristics

31 MHz hunting radios typically feature:

• Robust handheld units

• Relatively long whip antennas (due to low frequency)

• High audio output for outdoor use

• Durable construction for harsh weather conditions

Because of the low frequency, antennas are significantly longer than those used for PMR446 or other UHF systems.

Mobile vehicle-mounted installations have also been common in rural use.

Geographic limitation

A critical regulatory point:

The 31 MHz hunting band is a national Swedish allocation.

The 30–32 MHz spectrum is not harmonized across Europe as a license-free band. In other countries, this range may be assigned to:

• Military services

• Government communication

• Land mobile radio

• Specialized licensed services

Operating Swedish 31 MHz equipment outside Sweden may therefore be illegal.

Position within global license-free systems

The Swedish 31 MHz hunting band represents a distinctive regulatory model:

• Purpose-specific

• Terrain-optimized

• Low-frequency for rural reliability

• Nationally controlled

Compared to global systems like 27 MHz CB or PMR446, it demonstrates how spectrum allocations can be tailored to specific cultural and geographic needs.

Within the broader landscape of license-free radio systems, Sweden’s 31 MHz hunting band stands out as a specialized, low-VHF solution designed for reliable field coordination rather than general consumer communication.

69 MHz CB – Sweden’s 69 MHz CB System

In addition to the internationally known 27 MHz Citizens Band, Sweden also introduced a national VHF-based CB-style service in the 69 MHz range. Often referred to as “69 MHz CB,” this allocation was designed to provide more stable and predictable short- to medium-range communication compared to HF-based 27 MHz CB.

The rationale behind the 69 MHz allocation was similar to other Nordic spectrum solutions: improve local coverage in forested and uneven terrain while avoiding the long-distance skip effects that often complicate 27 MHz communication.

Although not internationally harmonized, 69 MHz CB became a recognizable domestic alternative within Sweden.

Frequency range and channel allocation

The Swedish 69 MHz CB service operates approximately in the:

• 69.800 – 69.990 MHz range

• Nationally defined multi-channel allocation

• Typically 10 kHz or 12.5 kHz channel spacing

Exact channel count and regulatory parameters are defined by Swedish communications authorities.

Unlike 27 MHz CB, which follows a widely standardized 40-channel international structure, the 69 MHz band is a national allocation.

Technical characteristics

Typical parameters include:

• Analog FM modulation

• Output power defined by national regulation (commonly several watts)

• Portable, mobile, and base operation permitted

• External antennas allowed within legal limits

• No general public repeaters in the license-free framework

Compared to PMR446 (0.5 W, fixed antenna), the 69 MHz system offers greater flexibility and typically higher output power, resulting in extended coverage.

It also avoids the strict antenna limitations seen in many modern UHF license-free systems.

Propagation characteristics

Operating at approximately 69 MHz places this system in the lower VHF band.

Wavelength at 69 MHz is around 4.3 meters.

Propagation features include:

• Strong ground-wave performance

• Good diffraction over terrain

• Improved forest penetration compared to UHF

• Minimal ionospheric skip compared to 27 MHz

Typical real-world range:

• Urban areas: 2–5 km

• Rural/open terrain: 5–15 km

• Elevated line-of-sight: potentially more

Unlike 27 MHz CB, 69 MHz is far less affected by sporadic E and long-distance propagation events. This results in more stable local communication, which is often preferred for coordination purposes.

Comparison with 27 MHz CB

27 MHz CB:

• Global recognition

• Potential long-distance DX via ionospheric reflection

• More prone to skip interference

69 MHz CB (Sweden):

• National allocation

• More stable regional coverage

• Reduced long-distance unpredictability

• Better suitability for structured local communication

For users prioritizing predictable range over DX hobby activity, 69 MHz offered technical advantages.

Equipment characteristics

69 MHz radios typically include:

• Handheld field radios

• Mobile vehicle-mounted units

• Base station installations

Because of the lower VHF frequency, antennas are longer than those used for PMR446 but shorter than 27 MHz CB antennas.

Equipment was primarily marketed within Sweden and tailored to national regulations.

Geographic limitation

A critical regulatory consideration:

69 MHz CB is a Swedish national allocation.

The 69 MHz spectrum is not harmonized across Europe as a license-free band. In other countries, this range may be assigned to:

• Military services

• Government systems

• Professional land mobile radio

• Other licensed applications

Operating Swedish 69 MHz equipment outside Sweden may therefore be illegal and could interfere with licensed services.

Role within global license-free systems

Sweden’s 69 MHz CB represents a technically balanced middle ground between:

• 27 MHz HF Citizens Band

• Higher-frequency UHF consumer systems

It demonstrates how national regulators can create alternative license-exempt services optimized for geographic conditions and user needs.

Within the global context of license-free radio systems, the Swedish 69 MHz CB band stands as a distinctive VHF-based national solution prioritizing stable regional communication over international interoperability.

BMIS – The Czech Republic’s BMIS License-Free Radio System

BMIS is a Czech national license-free radio service operating in the lower VHF band around 80 MHz. It was introduced as a domestic short-range communication solution, positioned between traditional 27 MHz CB and the pan-European PMR446 system.

Unlike harmonized European allocations, BMIS is a country-specific service defined by the Czech telecommunications authority. It reflects a regulatory approach tailored to national spectrum availability and communication needs.

Although largely unknown outside the Czech Republic, BMIS has been used for local coordination, recreational communication, and small-scale organizational activities.

Frequency range and channel allocation

BMIS operates approximately in the:

• 80 MHz VHF band

• Nationally assigned channel set

• Typically 12.5 kHz channel spacing

Exact frequency assignments and channel numbers are defined by Czech regulation.

This allocation is not harmonized across Europe. In other countries, the same frequency range may be assigned to licensed services.

Technical characteristics

Typical BMIS parameters include:

• Analog FM modulation

• Output power defined by national rules (commonly several watts ERP)

• Portable and mobile operation permitted

• External antennas allowed within regulatory limits

• No general public repeaters

Compared to PMR446:

• Higher output power

• Greater antenna flexibility

• Longer potential communication range

Compared to 27 MHz CB:

• More stable local coverage

• No significant ionospheric skip

• Shorter antennas

BMIS therefore occupies a technical middle ground between HF CB and UHF short-range systems.

Propagation characteristics

Operating around 80 MHz places BMIS in the lower VHF spectrum.

Wavelength at 80 MHz is approximately 3.75 meters.

Propagation features:

• Strong ground-wave coverage

• Good diffraction over terrain

• Improved performance in rural and semi-urban areas

• Minimal ionospheric skip interference

Typical real-world range:

• Urban areas: 2–5 km

• Open terrain: 5–15 km

• Elevated line-of-sight: potentially more

Compared to UHF systems such as PMR446, VHF low-band systems like BMIS generally offer better coverage over uneven terrain and vegetation.

Equipment characteristics

BMIS radios typically include:

• Handheld VHF radios

• Mobile vehicle-mounted units

• Longer antennas than UHF systems

Because of the lower frequency, antennas are visibly longer than PMR446 radios but significantly shorter than 27 MHz CB antennas.

Equipment is primarily marketed within the Czech Republic due to the national scope of the allocation.

Geographic limitation

A critical regulatory point:

BMIS is valid only within the Czech Republic.

The 80 MHz band is not harmonized as a pan-European license-free allocation. In neighboring countries, these frequencies may be used for:

• Professional land mobile services

• Government communication

• Specialized licensed systems

Operating BMIS equipment outside the Czech Republic may therefore be illegal and could cause interference.

Position within global license-free systems

BMIS illustrates how national regulators can create license-exempt services adapted to domestic needs and available spectrum.

Within the broader landscape of license-free radio systems, BMIS stands as a VHF-based national alternative that provides:

• Greater range than UHF handheld systems

• More stable coverage than HF CB

• Strict geographic limitation

It represents a technically balanced regional solution rather than an internationally harmonized consumer standard.

78 MHz CB – Thailand’s 78 MHz VHF CB System

Thailand is one of the few countries that developed a VHF-based Citizens Band system outside the traditional 27 MHz allocation. The Thai 78 MHz VHF CB service was introduced to provide a more stable, locally focused communication platform with improved audio quality and predictable coverage compared to HF CB.

While 27 MHz CB remains globally dominant, Thailand’s regulator opted to create a domestic VHF CB allocation better suited to national communication needs, particularly in urban and semi-rural environments.

The result is a nationally defined VHF Citizens Band system that operates independently of international CB harmonization frameworks.

Frequency range and channel allocation

The Thai 78 MHz CB service operates approximately in the:

• 78 MHz VHF band

• Nationally defined multi-channel plan

• Narrowband FM channel spacing

Exact frequency assignments and channel numbers are defined by Thailand’s national telecommunications authority.

Unlike the globally recognized 26.965–27.405 MHz 40-channel CB plan, the 78 MHz allocation is country-specific.

Technical characteristics

Typical regulatory characteristics include:

• Analog FM modulation

• Output power defined by Thai regulation (commonly several watts)

• Portable and mobile operation permitted

• External antennas allowed within legal limits

• No general public repeaters in the license-free framework

Compared to UHF short-range systems, the 78 MHz allocation typically allows higher power and greater antenna flexibility.

Unlike PMR-style systems, fixed-antenna restrictions do not generally apply.

Propagation characteristics

Operating at approximately 78 MHz places this system in the lower VHF spectrum.

Wavelength at 78 MHz is about 3.85 meters.

Propagation properties include:

• Strong ground-wave coverage

• Good terrain diffraction

• Improved stability compared to 27 MHz

• Minimal ionospheric skip under normal conditions

Typical real-world range:

• Urban environments: 2–5 km

• Open terrain: 5–15 km

• Elevated line-of-sight: potentially more

Compared to 27 MHz CB:

• Less long-distance skip interference

• More predictable regional communication

• Reduced atmospheric noise

Compared to UHF systems like PMR446:

• Better coverage over uneven terrain

• Longer range at similar power levels

Equipment characteristics

Thai 78 MHz CB radios typically include:

• Handheld VHF transceivers

• Mobile vehicle-installed radios

• Base station configurations

Because of the lower VHF frequency, antennas are longer than UHF handheld radios but shorter than 27 MHz CB antennas.

Equipment is primarily marketed for domestic use within Thailand.

Geographic limitation

A critical regulatory consideration:

The 78 MHz CB allocation is valid only within Thailand.

The 78 MHz band is not internationally harmonized as a license-free Citizens Band allocation. In other countries, these frequencies may be assigned to:

• Government services

• Professional land mobile systems

• Military communication

• Other licensed applications

Operating Thai 78 MHz CB equipment outside Thailand may therefore be illegal.

Position within global license-free systems

Thailand’s 78 MHz VHF CB system represents a national adaptation of the Citizens Band concept.

It sits technically between:

• 27 MHz HF CB (with long-distance skip potential)

• UHF short-range license-free systems

Its design prioritizes:

• Stable local communication

• Reduced interference

• Improved audio clarity

• Predictable coverage

Within the global ecosystem of license-free radio services, the Thai 78 MHz CB band stands as a distinctive example of how regulators can redefine the Citizens Band model using VHF spectrum to better match national communication requirements.

China 409 MHz Public Radio – China’s 409 MHz License-Free System

China operates a nationally defined license-free personal radio service in the 409 MHz UHF band. Unlike internationally harmonized systems such as PMR446 (Europe) or FRS (United States), the Chinese 409 MHz allocation is domestic and regulated exclusively under Chinese telecommunications law.

The system was introduced to provide the general public and small businesses with short-range communication devices without requiring individual radio licensing, while maintaining tight regulatory control over equipment certification and spectrum use.

Because China does not adopt European or North American consumer radio standards, its 409 MHz system developed independently.

Frequency range and channel allocation

The Chinese public radio allocation operates approximately around:

• 409 MHz UHF band

• Nationally defined multi-channel plan

• Narrowband FM channel spacing (typically 12.5 kHz)

Exact channel numbers and operating parameters are determined by Chinese regulatory authorities.

This allocation is not harmonized internationally. Radios designed for China’s 409 MHz band are not compatible with PMR446, FRS, or other foreign license-free systems.

Technical characteristics

Typical parameters include:

• Analog FM modulation

• Low output power (generally around 0.5 W class devices)

• Handheld portable operation

• No open public repeaters

• Mandatory national equipment certification

Compared to PMR446:

• Similar short-range UHF design philosophy

• Different frequency allocation

• Strict domestic regulatory compliance

Chinese-market radios are usually locked to approved channels and technical limits.

Propagation characteristics

Operating at 409 MHz results in:

• Typical UHF short-range behavior

• Moderate building penetration

• Line-of-sight dominant propagation

• Limited rural range

Typical real-world range:

• Dense urban areas: 1–3 km

• Open terrain: several kilometers under ideal conditions

The system is optimized for local coordination rather than long-distance communication.

Regulatory considerations

The 409 MHz band is not recognized as a license-free allocation outside China. Foreign radios (PMR446, FRS, GMRS, etc.) are not automatically legal in China. China therefore represents a nationalized, closed regulatory model for consumer UHF communication.

Specific Low Power Radio – Japan’s Specific Low Power Radio System

Japan operates one of the most tightly regulated spectrum environments in the world. Rather than adopting a single broad license-free Citizens Band concept, Japan established several narrowly defined low-power communication categories.

The most common fully license-exempt category is known as “Specific Low Power Radio” (SLPR). This system was designed for extremely short-range communication in densely populated urban environments, minimizing interference risk.

Japan’s regulatory philosophy emphasizes low output power, strict equipment standards, and dense coexistence.

Frequency range and channel allocation

Japan’s Specific Low Power Radio system operates approximately in:

• 420–422 MHz UHF band

• Nationally defined channel plan

• Very narrow technical tolerances

Exact channelization is defined by Japan’s Ministry of Internal Affairs and Communications (MIC).

This allocation is domestic and not harmonized with PMR446 or other international consumer standards.

Technical characteristics

Typical SLPR parameters:

• Maximum output power: approximately 10 mW

• Fixed antenna devices

• Analog FM or digital (device-dependent)

• No repeaters

• Short-range operation

The 10 mW power limit is significantly lower than PMR446 (0.5 W) or FRS (up to 2 W), resulting in intentionally limited coverage.

Propagation characteristics

At 420 MHz:

• Very short-range coverage

• Strong attenuation in dense urban structures

• Reliable coexistence in crowded spectrum

Typical real-world range:

• Indoors: several hundred meters

• Urban outdoor: up to 1 km

Because of the extremely low power, SLPR is suitable for localized coordination rather than area-wide communication.

Higher-power alternatives in Japan

Japan also offers UHF digital radio services (for example around 351 MHz) under a simplified registration system. These are not fully license-free but:

• Do not require a technical exam

• Require registration

• Allow higher output power

• Support digital voice features

This hybrid model differs from Western-style license-exempt frameworks.

Regulatory considerations

European PMR446 and American FRS radios are not automatically legal in Japan.

Japan’s system prioritizes:

• Strict spectrum control

• National equipment certification

• Limited interoperability with foreign devices

UHF CB – Australia’s 477 MHz UHF Citizens Band