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Family Radio Service
The Family Radio Service (FRS) is an improved walkie talkie system authorized in the United States since 1996. This personal radio service uses channelized frequencies in the ultra high frequency (UHF) band, and so 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 monitors. FRS uses frequency modulation (FM) instead of amplitude modulation (AM), and has a greater reliable range than license-free radios operating in the CB or 49 MHz bands.
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.
Additional recommended knowledge
FRS radios are limited to 500 milliwatts in the U.S., according to FCC regulations. 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 only if the power output is over FRS limits, up to GMRS 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. Though 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 channels; the GMRS stations may use up to 5 watts of power while the FRS stations are restricted to 0.5 watt.
The use of duplex radio repeaters and interconnects to the telephone network are prohibited under FRS rules, unlike in GMRS, where repeaters but not telephone interconnect are permitted, and the Amateur Radio Service. FRS radios must use only permanently-attached antennas. This limitation intentionally restricts the range of communications, and promotes sharing of the available channels.
FRS manufacturers generally claim an effective range of 3 km (2 miles) or more, but actual performance is limited by the physics of propagation. The presence of large buildings can reduce range. Under exceptional conditions, like hill-top to hill-top, communication is possible over 50 km (30 miles) or more. Under normal conditions with line-of-sight blocked by a few buildings or trees, FRS generally has an effective range of 0.5 to 1.5 km (1/3 to 1 mile).
FRS/GMRS Dual Service Radios
Recently, 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) under FRS rules. http://wireless.fcc.gov/services/index.htm?job=service_home&id=family
The FCC rules and statements regarding the use of hybrid radios on channels 1-7 stipulate the need for GMRS licensing only when operating under the RULES that apply to the GMRS. Many hybrid radios have an ERP that is lower than 1/2 watt 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 1/2 watt AND the unit is certified for FRS operation on these frequencies.
Channels 8-14 are reserved exclusively for the FRS, and GMRS operation is not allowed on these channels.
Channels 15-22 are reserved exclusively for GMRS, and FRS operation is not allowed on these channels.
List of FRS channels
Similar services in other countries
Services similar to the American FRS exist in other countries, although since technical standards and frequency bands may differ, usually FCC-approved FRS equipment may not be used in other jurisdictions.
American-standard FRS radios have been approved for use in Canada 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 GMRS/FRS radios have also been approved for use in Canada, giving additional channels.
Since tourists 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 Federal Telecommunications Commission has authorized use of the FRS frequencies and equipment similar to that in the US. However, dual-mode GMRS/FRS equipment is not approved in Mexico, so caution should be exercised in operating FRS devices purchased elsewhere.
In Europe, a personal radio service with the same sort of licensing restriction is PMR446 having eight channels in the 446MHz 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, so in principle a licensed amateur operator could use non-FCC-type-accepted PMR446 radios in the U.S. in compliance with the rules for amateur radio operation. 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.
Dual-mode GMRS/FRS equipment is also approved in Brazil and most South American 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 service similar to the American-style FRS in Hong Kong, Macau and China is also approved by respective organizations for legal license-free operation. 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, U.S. and Canada residents are advised not to use FRS or PMR446 radios for communication when traveling to the mentioned areas.
In Japan, a similar service uses low-power in the 420, 421, 422 MHZ bands.It is called "Tokutei Shoudenryoku Musen"(Specific low power radio). In Australia and New Zealand, the UHF CB citizen's band near 477 MHZ is used for a similar purpose.
|This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Family_Radio_Service". A list of authors is available in Wikipedia.|