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PMR446 (Private Mobile Radio, 446  MHz) is a licence exempt service in the
UHF Ultra high frequency (UHF) is the ITU designation for radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one tenth of a meter (on ...
radio frequency Radio frequency (RF) is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around to around . This is roughly between the up ...
band and is available for business and personal use in most countries throughout the
European Union The European Union (EU) is a supranational union, supranational political union, political and economic union of Member state of the European Union, member states that are located primarily in Europe, Europe. The union has a total area of ...
. PMR446 is typically used for small-site, same-building and line of sight outdoor activities. Equipment used ranges from consumer-grade to professional quality walkie-talkies (similar to those used for FRS/ GMRS in the United States and Canada). Depending on surrounding terrain range can vary from a few hundred metres (in a city) to a few kilometres (flat countryside) to many kilometres from high ground. Historically, analogue FM is used but a digital voice mode has been available in radios conforming to
digital private mobile radio dPMR or digital private mobile radio, is a common air interface for digital mobile communications. dPMR is an open, non-proprietary standard that was developed by the European Telecommunications Standards Institute (ETSI) and published under the ...
(dPMR446) and digital mobile radio (DMR Tier 1) standards designed by
ETSI The European Telecommunications Standards Institute (ETSI) is an independent, not-for-profit, standardization organization in the field of information and communications. ETSI supports the development and testing of global technical standard ...
. Originally 8 channels were available in analogue mode but this has now been increased to 16 channels. Typically PMR446 is used for both recreational and business use, additionally it has been utilized by amateur-radio operators and radio enthusiasts as a license-free experimental band.


History

The first steps towards creating licence-free short range radio communications were taken in April 1997 when the European Radio Communications Committee decided on a 446 MHz frequency band to be used for the new radios. In November 1998, ERC Decision (98)25 allocated frequency band 446.0–446.1 MHz for analogue PMR446; another two decisions established licence exemption for PMR446 equipment and free circulation of the PMR446 equipment. The first country which introduced these frequencies for licence-free use was Ireland on 1 April 1998. The United Kingdom introduced PMR446 service in April 1999; since 2003, it has replaced the former short-range business radio (SRBR) service. In October 2005, ECC Decision (05)02 added unlicensed band 446.1–446.2 MHz for use by digital DMR/dPMR equipment. In July 2015, ECC Decision (15)05 doubled the number of analog channels to 16 by extending analog operation onto the 446.1–446.2 MHz band previously used by digital DMR/dPMR equipment, effective January 2016; from January 2018, the number of digital channels was doubled by extending onto the 446.0–446.1 MHz band used by analog FM.


Range

Until recently, PMR446 radios were handheld
transceiver In radio communication, a transceiver is an electronic device which is a combination of a radio ''trans''mitter and a re''ceiver'', hence the name. It can both transmit and receive radio waves using an antenna, for communication purposes. Thes ...
s with fixed antennas (see Technical information). In November 2015,
Midland Radio Midland Radio Corporation, also known as Midland Radio, or just Midland, is a manufacturing company, headquartered in Kansas City, Missouri, US. Midland Radio develops radio communications products. History and structure Midland Radio Corpor ...
announced the release of the GB1 mobile PMR446 radio for vehicular use.World First Midland GB1 PMR 446 Mobile Attached Antenna
/ref>Midland GB1 First Look Midland GB1 Mobile PMR446 - Manual Download Includes Specs
/ref>Midland GB1 First Look *Updated With English Manual*
/ref> The range of PMR446, just like any VHF or UHF radio, is dependent on many factors like environment (in-city range is far less than in an open field), height above surrounding obstructions, and, to a lesser extent, weather conditions. The antenna type and location, transmit power and receive sensitivity also affect range. However, with PMR446 most of these variables are fixed at manufacturing to comply with the PMR446 specifications. Most of the time the maximum range that a user in a city can expect is a few hundred metres or less. Range may be many kilometres, for example between hilltops, or only a few hundred metres, if for example a hill or large metal object is in the transmission path between radios. The best known long-distance record is 333 mi (535.8 km) from Blyth in the United Kingdom to
Almere Almere () is a planned city and municipality in the province of Flevoland, Netherlands, located about 20 km to the east of Amsterdam (as the crow flies) across the IJmeer. Bordering Lelystad and Zeewolde, the municipality of Almere compr ...
, Netherlands. This was the result of enhanced propagation conditions, not a line-of-sight signal.


Use worldwide

PMR446 radios use frequencies that in Australia, the U.S., and Canada are allocated to
amateur radio Amateur radio, also known as ham radio, is the use of the radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency commu ...
operators, and military
radar Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, Marine radar, ships, spacecraft, guided missiles, motor v ...
systems. Instead, the U.S., Canada and Mexico use the
Family Radio Service 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 around 462 and 467 MHz in the ultra high frequency (UHF) band. I ...
(FRS) system, which provides a similar service on different frequencies, around 462 and 467 MHz. These frequencies are allocated to the emergency services in Europe, notably the fire brigade in the UK, police in Russia and commercial users in Australia. Interference with licensed radio services may result in prosecution. Australia, New Zealand, Vanuatu and Malaysia use the UHF Citizen's Band system in the 476–477 MHz range and a maximum power output of 5 W giving a vastly improved range over the lower power PMR system. PMR446-compliant equipment may be used anywhere throughout Europe. Type approved PMR446 radios with power up to 500 mW can be used without any licence in India and Vietnam. The devices may not be base stations or repeaters, and must use integrated antennas only.


Technical information

PMR446 covers band 446.0–446.2 MHz. The general ECC decision however still requires integral antennas and the actual implementation varies between different countries.


Analogue FM and digital TDMA

Analogue PMR446 uses 16 FM channels separated by 12.5 kHz from each other. Maximum power is 500 mW ERP and equipment must be used on a mobile basis.
CTCSS In telecommunications, Continuous Tone-Coded Squelch System or CTCSS is one type of in-band signaling that is used to reduce the annoyance of listening to other users on a shared two-way radio communication channel. (See squelch.) It is sometimes ...
is usually used, with more upmarket models also featuring DCS and/or fixed-carrier voice inversion. Before January 2016, only the lower 8 channels were allowed for analog FM operation. Digital PMR446
DMR Tier I DMR is an initialism that may refer to: Biology * Differentially methylated regions, a genomic region that is methylated differentially on each parental allele * Dwarf mistletoe rating system, a scale for rating the severity of a dwarf mistletoe ...
(TDMA) uses 16 digital voice channels separated by 12.5 kHz from each other with 4-level FSK modulation at 3.6 kbit/s. Before January 2018, only the higher 8 channels were allowed for digital TDMA operation. Some Digital PMR446 radios (Hytera BD305LF, Retevis RT40, ...) support Dual Capacity Direct Mode (DCDM), which allows for the use of two timeslots during simplex (radio-to-radio) communication. This effectively doubles the channel capacity by allowing two simultaneous transmissions on one channel. Color Code (0 to 16) is the equivalent of CTCSS for digital. It's used to isolate a population of users (a company, an association, a family, ...). By convention CC1 is used for public contact. TalkGroups are used to separate groups of users (ex: TG1 for direction and TG2 for room service in a hotel using channel 12 CC7). By contacting a specific TG, each user subscribing to this TG will hear you (Group Call). A user can subscribe to many TGs (RX Group List). It is also possible to contact all users in your color code (All Call). Radio ID One for each user, to be contacted directly (Private Call).


Analog (NFM) and digital TDMA (DMR)


Digital

FDMA Frequency-division multiple access (FDMA) is a channel access method used in some multiple-access protocols. FDMA allows multiple users to send data through a single communication channel, such as a coaxial cable or microwave beam, by dividing ...

Digital PMR446 dPMR (FDMA) uses 32 digital voice channels separated by 6.25 kHz from each other with 4-level FSK modulation at 3.6 kbit/s. Before January 2018, only the upper 16 channels were allowed for digital FDMA operation.


PMR446 gateways

Recently some users have implemented the simplex repeater system, a cheap and easy way to extend the radio range by using extra radios connected to a small repeater controller. This is also known as "Parrot", "ATX-2000" or just "Echo Repeater" after how it sounds repeating every transmission it receives. PMR446 gateways extend the range of PMR446. These gateways are connected through internet using a client/server
VoIP Voice over Internet Protocol (VoIP), also called IP telephony, is a method and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet. The terms Internet t ...
system such as
eQSO Radio over Internet Protocol, or RoIP, is similar to Voice over IP (VoIP), but augments two-way radio communications rather than telephone calls. From the system point of view, it is essentially VoIP with PTT (Push To Talk). To the user it can be i ...
or the Free Radio Network
FRN
.


Law


Decision ERC (98) 25Decision ERC (98) 26Decision ERC (98) 27Decision ECC (05) 12Decision ECC (15) 05


See also

*
70-centimeter band The 70-centimeter or 440 MHz band is a portion of the UHF radio spectrum internationally allocated to amateur radio and amateur satellite use. The ITU amateur radio allocation is from 430 to 440 MHz; however, some countries, such as the Unit ...
* KDR 444 *
LPD433 LPD433 (low power device 433 MHz) is a UHF band in which license free communication devices are allowed to operate in some regions. The frequencies correspond with the ITU region 1 ISM band of 433.050  MHz to 434.790 MHz, and operati ...
* Personal radio service * Public Radio Service * Business band


References


External links


PMR Radio (eQSO for PMR)Bandplan 433MHz (LPD and PMR Frequencies)General PMR446 Website (and UK forum)
{{Two-way radio Bandplans Radio hobbies Radio technology Radio regulations