Family Radio Service
Encyclopedia
The Family Radio Service (FRS) is an improved walkie talkie radio system authorized in the United States
since 1996. This personal radio service uses channelized frequencies in the ultra high frequency
(UHF) band. It does not suffer the interference effects found on citizens' band
(CB) at 27 MHz, or the 49 MHz band also used by cordless phones, toys, and baby monitor
s. FRS uses frequency modulation
(FM) instead of amplitude modulation
(AM). Since the UHF band has different radio propagation
characteristics, short-range use of FRS may be more predictable than license-free radios operating in the HF
CB band.
Initially proposed by Radio Shack
in 1994 for use by families, FRS has also seen significant adoption by business
interests, as an unlicensed, low-cost alternative to the business band
.
Worldwide a number of similar personal radio services exist; these share the characteristics of low power, operation in the UHF (or upper VHF) band using FM, and simplified or no end-user licenses. Exact frequency allocations differ, so equipment legal to operate in one country may cause unacceptable interference in another.
according to FCC
regulation
s. Channels
1 to 7 are shared with low-power interstitial channels of GMRS, the General Mobile Radio Service
. A license
is required for those channels if the power output is over FRS limits.
Unlike Citizens' Band (CB) radios, FRS radios frequently have provisions for using sub-audible tone squelch
(CTCSS
and DCS) codes, filtering out unwanted chatter from other users on the same frequency. Although these codes are sometimes called "privacy codes" or "private line codes" (PL codes), they offer no protection from eavesdropping and are only intended to help share busy channels. Tone codes also do nothing to prevent desired transmissions from being swamped by stronger signals having a different code.
FRS stations on channels 1 through 7 may communicate with GMRS stations on those shared channels; the GMRS stations may use up to 5 watts of power, while the FRS stations are restricted to 0.5 watts.
FRS radios must use only permanently-attached antennas
, such as walkie-talkies; there are also table-top FRS "base station" radios that have whip antennas. This limitation intentionally restricts the range of communications, allowing greatest use of the available channels.
The use of duplex radio repeater
s and interconnects to the telephone network
are prohibited under FRS rules, unlike GMRS and the Amateur Radio Service
.
FRS manufacturers generally claim exaggerated range. The presence of large buildings, trees, etc., will reduce range. Under exceptional conditions, (such as hill-top to hill-top) communication is possible over 60 km (37.3 mi) or more, but that is rare. Normal conditions, with line-of-sight blocked by a few buildings or trees, mean FRS has an actual range of 0.5 to 1.5 km (1/3 to 1 mile).
Hybrid FRS/GMRS
consumer radios have been introduced that have 22 channels. Many of these radios have been certified for unlicensed operation (on the 14 FRS frequencies, channels 1-14) under FRS rules.
The FCC rules and statements regarding the use of hybrid radios on channels 1-7 stipulate the need for a GMRS license when operating under the rules that apply to the GMRS. Many hybrid radios have an ERP
that is lower than 0.5 watts on channels 1-7, or can be set by the user to operate at low power on these channels. This allows hybrid radios to be used under the license-free FRS rules if the ERP is less than 0.5 watts and the unit is certified for FRS operation on these frequencies.
In the United States of America operation on channels 15-22 require an FCC GMRS license. Interference to licensed services may be investigated by the FCC
.
Channels 8-14 are exclusively for FRS. Accordingly, GMRS operation is not allowed on these channels. Channels 15-22 are reserved exclusively for GMRS. As noted, FRS operation is not allowed on these channels.
Some clubs have recommended FRS Channel 1 as a national emergency/calling channel, such as REACT International, Inc. and the National SOS Radio Network.
Channel 2 is typically used by geocaching
groups when trying to connect with other geocachers.
since April 2000. The revised technical standard RSS 210 has essentially the same technical requirements as in the United States. Since September 2004,low-power GMRS radios and dual-standard FRS/GMRS radios have also been approved for use in Canada, giving additional channels. In Canada, no license is required and no restrictions are imposed on the GMRS channels.
often bring their FRS radios with them, and since trade between the U.S., Canada, and Mexico
is of great value to all three countries, the Mexican Secretary of Communication and Transportation has authorized use of the FRS frequencies and equipment similar to that in the US. However, dual-mode FRS/GMRS equipment is not approved in Mexico, so caution should be exercised in operating hybrid FRS/GMRS devices purchased elsewhere.
and most other South America
n countries. Portable radios are heavily used in private communications, mainly by security staff in nightclubs and malls, but also in private parking, maintenance, and delivery services.
, a personal radio service with the same sort of licensing restriction is PMR446
having eight channels in the 446 MHz range. One cannot legally use the FRS radio in Europe or PMR446 in the U.S. The 446 MHz band is allocated to amateur radio
in the United States. In Great Britain
, FRS frequencies are used for fire brigade communications and this sometimes causes problems when FRS equipment is imported from the U.S. and used without awareness of the consequences by members of the public. Sweden and Norway have a Short distance radio service with six UHF FM channels between 444.600 and 444.975 MHz; some dual-mode KDR/PMR radios are sold but are only useable in Sweden and Norway. European countries also have Low-power communication device
s operating in the 433 MHz band, and short-range devices (SRD) operating on frequencies between 868 and 870 MHz. These devices are restricted to 10 mW output power and are intended to provide an alternative to PMR 446 over short distances.
, Macau
, and China
is also approved by respective organizations for legal "license free" operation, with the name of "Public Radio Service". However, different UHF
frequencies with 20 allocated channels near 409 MHz are used. 462 MHz and 446 MHz band are not opened to FRS service, so European, American, and Canadian residents are advised not to use FRS or PMR446 radios for communication when traveling to the aforementioned areas.
List of China Public Radio Service Channels:
, a similar service is limited to 10 milliwatts in the 420, 421, and 422 MHz bands.
It is called "Tokutei Shoudenryoku Musen" ("SLPR:Specified Low Power Radio").
422.0500-422.1750MHz (Business use) 10mW 11ch 12.5kHz spacing.
422.200-422.300MHz (Leisure use) 10mW 9 channels 12kHz spacing.
License free radio systems (in Japanese)
s may be used, but these require individual station licences. The Australian Communications and Media Authority
(ACMA) also allocated a band near 434 MHz for low-powered devices with low potential for interference to other users of the band.
.
are not permitted, and units are limited to 2.5 watts.
This service has been allocated 40 channels at 325 MHz:
between 245.000 and 245.9875 MHz. Units are allowed up to 5 watts RF power. Besides personal use, the equipment is used by search and rescue and businesses. Operating rules are less restrictive than amateur radio service, with an initial license fee required. The hand-held units usually have a red case. There are an estimated one million users of the service, often in large cities.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
since 1996. This personal radio service uses channelized frequencies in the ultra high frequency
Ultra high frequency
Ultra-High Frequency designates the ITU Radio frequency range of electromagnetic waves between 300 MHz and 3 GHz , also known as the decimetre band or decimetre wave as the wavelengths range from one to ten decimetres...
(UHF) band. It does not suffer the interference effects found on citizens' band
Citizens' band radio
Citizens' Band radio is, in many countries, a system of short-distance radio communications between individuals on a selection of 40 channels within the 27-MHz band. Citizens' Band is distinct from the FRS, GMRS, MURS and amateur radio...
(CB) at 27 MHz, or the 49 MHz band also used by cordless phones, toys, and baby monitor
Baby monitor
A baby monitor, also known as a baby alarm, is a radio system used to remotely listen to sounds made by an infant. The transmitter unit, equipped with a microphone, is placed near to the child. It transmits the sounds the baby makes by radio waves to a receiver unit with a speaker carried by, or...
s. FRS uses frequency modulation
Frequency modulation
In telecommunications and signal processing, frequency modulation conveys information over a carrier wave by varying its instantaneous frequency. This contrasts with amplitude modulation, in which the amplitude of the carrier is varied while its frequency remains constant...
(FM) instead of amplitude modulation
Amplitude modulation
Amplitude modulation is a technique used in electronic communication, most commonly for transmitting information via a radio carrier wave. AM works by varying the strength of the transmitted signal in relation to the information being sent...
(AM). Since the UHF band has different radio propagation
Radio propagation
Radio propagation is the behavior of radio waves when they are transmitted, or propagated from one point on the Earth to another, or into various parts of the atmosphere...
characteristics, short-range use of FRS may be more predictable than license-free radios operating in the HF
High frequency
High frequency radio frequencies are between 3 and 30 MHz. Also known as the decameter band or decameter wave as the wavelengths range from one to ten decameters . Frequencies immediately below HF are denoted Medium-frequency , and the next higher frequencies are known as Very high frequency...
CB band.
Initially proposed by Radio Shack
Radio shack
Radio shack is a slang term for a room or structure for housing radio equipment.-History:In the early days of radio, equipment was experimental and home-built. The first radio transmitters used a noisy spark to generate radio waves and were often housed in a garage or shed. When radio was first...
in 1994 for use by families, FRS has also seen significant adoption by business
Business
A business is an organization engaged in the trade of goods, services, or both to consumers. Businesses are predominant in capitalist economies, where most of them are privately owned and administered to earn profit to increase the wealth of their owners. Businesses may also be not-for-profit...
interests, as an unlicensed, low-cost alternative to the business band
Business band
The business band is the name used by US radio users and scanner hobbyists who listen to Federal Communications Commission licensees using Industrial/Business pool frequencies...
.
Worldwide a number of similar personal radio services exist; these share the characteristics of low power, operation in the UHF (or upper VHF) band using FM, and simplified or no end-user licenses. Exact frequency allocations differ, so equipment legal to operate in one country may cause unacceptable interference in another.
Technical information
FRS radios are limited to 500 milliwattsWatt
The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...
according to 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...
regulation
Regulation
Regulation is administrative legislation that constitutes or constrains rights and allocates responsibilities. It can be distinguished from primary legislation on the one hand and judge-made law on the other...
s. Channels
Channel (communications)
In telecommunications and computer networking, a communication channel, or channel, refers either to a physical transmission medium such as a wire, or to a logical connection over a multiplexed medium such as a radio channel...
1 to 7 are shared with low-power interstitial channels of GMRS, the General Mobile Radio Service
General Mobile Radio Service
The General Mobile Radio Service is a licensed land-mobile FM UHF radio service in the United States available for short-distance two-way communication. It is intended for use by an adult individual who possesses a valid GMRS license, as well as his or her immediate family members...
. A license
License
The verb license or grant licence means to give permission. The noun license or licence refers to that permission as well as to the document recording that permission.A license may be granted by a party to another party as an element of an agreement...
is required for those channels if the power output is over FRS limits.
Unlike Citizens' Band (CB) radios, FRS radios frequently have provisions for using sub-audible tone squelch
Squelch
In telecommunications, squelch is a circuit function that acts to suppress the audio output of a receiver in the absence of a sufficiently strong desired input signal.-Carrier squelch:...
(CTCSS
CTCSS
In telecommunications, Continuous Tone-Coded Squelch System or CTCSS is a circuit that is used to reduce the annoyance of listening to other users on a shared two-way radio communications channel. It is sometimes called tone squelch...
and DCS) codes, filtering out unwanted chatter from other users on the same frequency. Although these codes are sometimes called "privacy codes" or "private line codes" (PL codes), they offer no protection from eavesdropping and are only intended to help share busy channels. Tone codes also do nothing to prevent desired transmissions from being swamped by stronger signals having a different code.
FRS stations on channels 1 through 7 may communicate with GMRS stations on those shared channels; the GMRS stations may use up to 5 watts of power, while the FRS stations are restricted to 0.5 watts.
FRS radios must use only permanently-attached antennas
Antenna (radio)
An antenna is an electrical device which converts electric currents into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver...
, such as walkie-talkies; there are also table-top FRS "base station" radios that have whip antennas. This limitation intentionally restricts the range of communications, allowing greatest use of the available channels.
The use of duplex radio repeater
Radio repeater
A radio repeater is a combination of a radio receiver and a radio transmitter that receives a weak or low-level signal and retransmits it at a higher level or higher power, so that the signal can cover longer distances without degradation. This article refers to professional, commercial, and...
s and interconnects to the telephone network
Public switched telephone network
The public switched telephone network is the network of the world's public circuit-switched telephone networks. It consists of telephone lines, fiber optic cables, microwave transmission links, cellular networks, communications satellites, and undersea telephone cables, all inter-connected by...
are prohibited under FRS rules, unlike GMRS and the Amateur Radio Service
Amateur radio
Amateur radio is the use of designated radio frequency spectrum for purposes of private recreation, non-commercial exchange of messages, wireless experimentation, self-training, and emergency communication...
.
FRS manufacturers generally claim exaggerated range. The presence of large buildings, trees, etc., will reduce range. Under exceptional conditions, (such as hill-top to hill-top) communication is possible over 60 km (37.3 mi) or more, but that is rare. Normal conditions, with line-of-sight blocked by a few buildings or trees, mean FRS has an actual range of 0.5 to 1.5 km (1/3 to 1 mile).
FRS/GMRS hybrid radios in the United States
General Mobile Radio Service
The General Mobile Radio Service is a licensed land-mobile FM UHF radio service in the United States available for short-distance two-way communication. It is intended for use by an adult individual who possesses a valid GMRS license, as well as his or her immediate family members...
consumer radios have been introduced that have 22 channels. Many of these radios have been certified for unlicensed operation (on the 14 FRS frequencies, channels 1-14) under FRS rules.
The FCC rules and statements regarding the use of hybrid radios on channels 1-7 stipulate the need for a GMRS license when operating under the rules that apply to the GMRS. Many hybrid radios have an ERP
Effective radiated power
In radio telecommunications, effective radiated power or equivalent radiated power is a standardized theoretical measurement of radio frequency energy using the SI unit watts, and is determined by subtracting system losses and adding system gains...
that is lower than 0.5 watts on channels 1-7, or can be set by the user to operate at low power on these channels. This allows hybrid radios to be used under the license-free FRS rules if the ERP is less than 0.5 watts and the unit is certified for FRS operation on these frequencies.
In the United States of America operation on channels 15-22 require an FCC GMRS license. Interference to licensed services may be investigated by 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...
.
Channels 8-14 are exclusively for FRS. Accordingly, GMRS operation is not allowed on these channels. Channels 15-22 are reserved exclusively for GMRS. As noted, FRS operation is not allowed on these channels.
List of FRS channels
| Channel | Frequency (MHz) | Notes |
|---|---|---|
| 1 | 462.5625 | Shared with GMRS. |
| 2 | 462.5875 | Shared with GMRS. |
| 3 | 462.6125 | Shared with GMRS. |
| 4 | 462.6375 | Shared with GMRS. |
| 5 | 462.6625 | Shared with GMRS. |
| 6 | 462.6875 | Shared with GMRS. |
| 7 | 462.7125 | Shared with GMRS. |
| 8 | 467.5625 | FRS use only |
| 9 | 467.5875 | FRS use only |
| 10 | 467.6125 | FRS use only |
| 11 | 467.6375 | FRS use only |
| 12 | 467.6625 | FRS use only |
| 13 | 467.6875 | FRS use only |
| 14 | 467.7125 | FRS use only |
Some clubs have recommended FRS Channel 1 as a national emergency/calling channel, such as REACT International, Inc. and the National SOS Radio Network.
Channel 2 is typically used by geocaching
Geocaching
Geocaching is an outdoor sporting activity in which the participants use a Global Positioning System receiver or mobile device and other navigational techniques to hide and seek containers, called "geocaches" or "caches", anywhere in the world....
groups when trying to connect with other geocachers.
Similar services in other regions
Personal UHF radio services similar to the American FRS exist in other countries, although since technical standards and frequency bands will differ, usually FCC-approved FRS equipment may not be used in other jurisdictions.Canada
American-standard FRS radios have been approved for use in CanadaCanada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
since April 2000. The revised technical standard RSS 210 has essentially the same technical requirements as in the United States. Since September 2004,low-power GMRS radios and dual-standard FRS/GMRS radios have also been approved for use in Canada, giving additional channels. In Canada, no license is required and no restrictions are imposed on the GMRS channels.
Mexico
Since touristsTourism
Tourism is travel for recreational, leisure or business purposes. The World Tourism Organization defines tourists as people "traveling to and staying in places outside their usual environment for not more than one consecutive year for leisure, business and other purposes".Tourism has become a...
often bring their FRS radios with them, and since trade between the U.S., Canada, and Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
is of great value to all three countries, the Mexican Secretary of Communication and Transportation has authorized use of the FRS frequencies and equipment similar to that in the US. However, dual-mode FRS/GMRS equipment is not approved in Mexico, so caution should be exercised in operating hybrid FRS/GMRS devices purchased elsewhere.
South America
Dual-mode GMRS/FRS equipment is also approved in BrazilBrazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
and most other South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
n countries. Portable radios are heavily used in private communications, mainly by security staff in nightclubs and malls, but also in private parking, maintenance, and delivery services.
Taiwan
Some manufacturers in Taiwan have radios that carry both FRS and GMRS frequencies, using channels 1 to 99. Channels 1 to 14 are well-known, while channels 15 to 99 are less popular.Europe
In EuropeEurope
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, a personal radio service with the same sort of licensing restriction is PMR446
PMR446
PMR446 is a part of the UHF radio frequency range that is open without licensing for personal usage in most countries of the European Union. It has roughly the same use as FRS or GMRS in the United States and Canada. Depending on surrounding terrain range can vary from a few hundred metres to a...
having eight channels in the 446 MHz range. One cannot legally use the FRS radio in Europe or PMR446 in the U.S. The 446 MHz band is allocated to amateur radio
Amateur radio
Amateur radio is the use of designated radio frequency spectrum for purposes of private recreation, non-commercial exchange of messages, wireless experimentation, self-training, and emergency communication...
in the United States. In Great Britain
Great Britain
Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...
, FRS frequencies are used for fire brigade communications and this sometimes causes problems when FRS equipment is imported from the U.S. and used without awareness of the consequences by members of the public. Sweden and Norway have a Short distance radio service with six UHF FM channels between 444.600 and 444.975 MHz; some dual-mode KDR/PMR radios are sold but are only useable in Sweden and Norway. European countries also have Low-power communication device
Low-power communication device
In telecommunication, a low-power communication device, also short-range device is a restricted radiation device, exclusive of those employing conducted or guided radio frequency techniques, used for the transmission of signs, signals , writing, images and sounds or intelligence of any nature by...
s operating in the 433 MHz band, and short-range devices (SRD) operating on frequencies between 868 and 870 MHz. These devices are restricted to 10 mW output power and are intended to provide an alternative to PMR 446 over short distances.
China
A service similar to the American-style FRS in Hong KongHong Kong
Hong Kong is one of two Special Administrative Regions of the People's Republic of China , the other being Macau. A city-state situated on China's south coast and enclosed by the Pearl River Delta and South China Sea, it is renowned for its expansive skyline and deep natural harbour...
, Macau
Macau
Macau , also spelled Macao , is, along with Hong Kong, one of the two special administrative regions of the People's Republic of China...
, and China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
is also approved by respective organizations for legal "license free" operation, with the name of "Public Radio Service". However, different UHF
Ultra high frequency
Ultra-High Frequency designates the ITU Radio frequency range of electromagnetic waves between 300 MHz and 3 GHz , also known as the decimetre band or decimetre wave as the wavelengths range from one to ten decimetres...
frequencies with 20 allocated channels near 409 MHz are used. 462 MHz and 446 MHz band are not opened to FRS service, so European, American, and Canadian residents are advised not to use FRS or PMR446 radios for communication when traveling to the aforementioned areas.
List of China Public Radio Service Channels:
| Channel | Frequency (MHz) |
|---|---|
| 1 | 409.7500 |
| 2 | 409.7625 |
| 3 | 409.7750 |
| 4 | 409.7875 |
| 5 | 409.8000 |
| 6 | 409.8125 |
| 7 | 409.8250 |
| 8 | 409.8375 |
| 9 | 409.8500 |
| 10 | 409.8625 |
| 11 | 409.8750 |
| 12 | 409.8875 |
| 13 | 409.9000 |
| 14 | 409.9125 |
| 15 | 409.9250 |
| 16 | 409.9375 |
| 17 | 409.9500 |
| 18 | 409.9625 |
| 19 | 409.9750 |
| 20 | 409.9875 |
Japan
In JapanJapan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, a similar service is limited to 10 milliwatts in the 420, 421, and 422 MHz bands.
It is called "Tokutei Shoudenryoku Musen" ("SLPR:Specified Low Power Radio").
422.0500-422.1750MHz (Business use) 10mW 11ch 12.5kHz spacing.
422.200-422.300MHz (Leisure use) 10mW 9 channels 12kHz spacing.
License free radio systems (in Japanese)
Australia and New Zealand
In Australia and New Zealand, the UHF CB citizen's band near 477 MHz is used for a similar purpose. In New Zealand hand-held transcievers are "class licensed" and require no individual registration. RepeaterRadio repeater
A radio repeater is a combination of a radio receiver and a radio transmitter that receives a weak or low-level signal and retransmits it at a higher level or higher power, so that the signal can cover longer distances without degradation. This article refers to professional, commercial, and...
s may be used, but these require individual station licences. The Australian Communications and Media Authority
Australian Communications and Media Authority
The Australian Communications and Media Authority is an Australian government statutory authority within the Department of Broadband, Communications and the Digital Economy portfolio...
(ACMA) also allocated a band near 434 MHz for low-powered devices with low potential for interference to other users of the band.
South Africa
South Africa is in the process of conforming to ITC region 1 recommendations. They do allow 8 channels between 446.0-446.1 MHz band currently, this is the same as the European PMR446PMR446
PMR446 is a part of the UHF radio frequency range that is open without licensing for personal usage in most countries of the European Union. It has roughly the same use as FRS or GMRS in the United States and Canada. Depending on surrounding terrain range can vary from a few hundred metres to a...
.
Philippines
The Philippines has a radio service for use of families and small businesses. This service is called SRRS or Short Range Radio Service. RepeatersRadio repeater
A radio repeater is a combination of a radio receiver and a radio transmitter that receives a weak or low-level signal and retransmits it at a higher level or higher power, so that the signal can cover longer distances without degradation. This article refers to professional, commercial, and...
are not permitted, and units are limited to 2.5 watts.
This service has been allocated 40 channels at 325 MHz:
| Channel | Frequency | Channel | Frequency | Channel | Frequency | Channel | Frequency |
|---|---|---|---|---|---|---|---|
| 1 | 325.0000 | 11 | 325.1250 | 21 | 325.2500 | 31 | 325.3750 |
| 2 | 325.0125 | 12 | 325.1375 | 22 | 325.2625 | 32 | 325.3875 |
| 3 | 325.0250 | 13 | 325.1500 | 23 | 325.2750 | 33 | 325.4000 |
| 4 | 325.0375 | 14 | 325.1625 | 24 | 325.2875 | 34 | 325.4125 |
| 5 | 325.0500 | 15 | 325.1750 | 25 | 325.3000 | 35 | 325.4250 |
| 6 | 325.0625 | 16 | 325.1875 | 26 | 325.3125 | 36 | 325.4375 |
| 7 | 325.0750 | 17 | 325.2000 | 27 | 325.3250 | 37 | 325.4500 |
| 8 | 325.0875 | 18 | 325.2125 | 28 | 325.3375 | 38 | 325.4625 |
| 9 | 325.1000 | 19 | 325.2250 | 29 | 325.3500 | 39 | 325.4750 |
| 10 | 325.1125 | 20 | 325.2375 | 30 | 325.3625 | 40 | 325.4875 |
Thailand
Thailand has an 80 channel CB-style service using FMFrequency modulation
In telecommunications and signal processing, frequency modulation conveys information over a carrier wave by varying its instantaneous frequency. This contrasts with amplitude modulation, in which the amplitude of the carrier is varied while its frequency remains constant...
between 245.000 and 245.9875 MHz. Units are allowed up to 5 watts RF power. Besides personal use, the equipment is used by search and rescue and businesses. Operating rules are less restrictive than amateur radio service, with an initial license fee required. The hand-held units usually have a red case. There are an estimated one million users of the service, often in large cities.
Singapore
Since 3 February 2004, the Infocomm Development Authority of Singapore (IDA) has allocated the 446.0-446.1 MHz frequency band for low-powered walkie-talkies on a non-interference, non-protected and shared-use basis. As these walkie-talkies are low-powered devices which do not potentially cause interference to other licensed radio services, it need not be licensed for use in Singapore. However, the device must be type approved by IDA for local sale.External links
- CTCSS Codes for some Radios
- FRS Radios in Mexico
- Industry Canada discussion on the approval of FRS in Canada
- Personal Radio Association
- FRS and GMRS radio information and forums
- F-R-S Communications Center
- The situation of License Free Radio System in Japan
- REACT International, Inc.
- National SOS Radio Network
- Join the International FRS DX Group