PMR446
Encyclopedia
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...
radio frequency
Radio frequency
Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...
range that is open without licensing for personal usage in most countries of the European Union
European Union
The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...
. It has roughly the same use as FRS
Family Radio Service
The Family Radio Service 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 band. It does not suffer the interference effects found on citizens' band at 27 MHz, or the...
or GMRS
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...
in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and Canada
Canada
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...
. Depending on surrounding terrain range can vary from a few hundred metres (in a city) to a few kilometres (flat countryside). PMR446 is primarily used in consumer-grade walkie-talkie
Walkie-talkie
A walkie-talkie is a hand-held, portable, two-way radio transceiver. Its development during the Second World War has been variously credited to Donald L. Hings, radio engineer Alfred J. Gross, and engineering teams at Motorola...
s similar to those used for FRS
Family Radio Service
The Family Radio Service 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 band. It does not suffer the interference effects found on citizens' band at 27 MHz, or the...
/GMRS
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...
in the United States and Canada. Historically analogue FM
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...
is used, but a digital voice mode is available, called digital private mobile radio (dPMR), which is not to be confused with digital mobile radio
Digital Mobile Radio
Digital mobile radio is an open digital radio standard for professional mobile radio users specified in the European Telecommunications Standards Institute Standards TS 102 361 parts 1 to 4 and used in products sold in all regions of the world. The applicable ETSI compliance standards are EN 300...
.
History
The first steps towards creating licence-free short range radio communications were taken in April 1997 when the European Radio Communications CommitteeEuropean Conference of Postal and Telecommunications Administrations
The European Conference of Postal and Telecommunications Administrations was established on June 26, 1959, as a coordinating body for European state telecommunications and postal organizations...
decided on a 446 MHz frequency band to be used for the new radios. In November 1998 another three decisions followed which designated the new frequency band for PMR446, established licence exemption for PMR446 equipment and established free circulation of the PMR446 equipment.
The first country which introduced these frequencies for licence-free use was Ireland and it did so on 1 April 1998. The United Kingdom introduced PMR446 service in April 1999; since 2003 PMR446 has replaced the former Short-Range Business Radio (SRBR) service. For an updated list of current status in different European countries see the page of European Radiocommunications Office.
In addition to PMR446, some countries in the EU have begun to introduce LPD433
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...
(Low Power Device 433 MHz) and SRD860
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...
(Short Range Device 860 MHz) licence-free short range transceiver radios. Both LPD433 and SRD860 are deployed as dedicated handsets and in combination with PMR446 handsets, as with the Alan 777. These radios give an additional 69 channels (LPD433) and 126 channels (SRD860) which can be used with CTCSS or DCS to improve co-operation on shared channels. These extra LPD and SRD channels have been introduced to reduce the burden on the 8 PMR446 channels over shorter distances (<1 km).
Range
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 times the maximum range that a user in a city can expect is a few hundred metres or less.Range may be many kilometres, e.g. from hilltop to hilltop, 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 535.8 km (333 mi) from Blyth
Blyth
- Places :Australia* Blyth, South Australia, a small townCanada* Blyth, Ontario, a villageUnited Kingdom* Blyth, Northumberland, a town* Blyth, Nottinghamshire, a village* Blyth, Suffolk, a village* River Blyth, Northumberland* River Blyth, Suffolk...
in the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
to Almere
Almere
Almere is a planned city and municipality in the province of Flevoland, the Netherlands, bordering Lelystad and Zeewolde. The municipality of Almere comprises the districts Almere Stad, Almere Haven, Almere Buiten, Almere Hout, Almere Poort and Almere Pampus .Almere is the youngest city in the...
, Netherlands
Netherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...
. However, this was the result of enhanced propagation conditions, not a line-of-sight
Line-of-sight propagation
Line-of-sight propagation refers to electro-magnetic radiation or acoustic wave propagation. Electromagnetic transmission includes light emissions traveling in a straight line...
signal, and so is not representative.
Usage worldwide
PMR446 radios use frequencies allocated to U.S. amateur radioAmateur 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...
operators. PMR446 radios can only be used in the United States under FCC amateur regulations by licensed amateur radio operators. The conflicting allocations have been something of a nuisance to U.S. amateur operators due to use of the equipment by European tourists in the U.S.
Instead, the U.S. and Canada uses the FRS
Family Radio Service
The Family Radio Service 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 band. It does not suffer the interference effects found on citizens' band at 27 MHz, or the...
system, which provides a similar service on slightly different frequencies. FRS frequencies are allocated to the emergency services in Europe, notably the fire brigade in the UK, police in Russia. Interference with licenced radio services may result in prosecution.
PMR446 compliant equipment may be used anywhere throughout Europe and Scandinavia except in Montenegro.
Technical information
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...
channels separated by 12.5 kHz from each other. Per regulation, maximum power, like FRS, is 500 mW ERP
ERP
- Economics :* Economic Report of the President, published annually by the United States President's Council of Economic Advisors on recent economic activity and future policies and predictions...
and equipment must be handheld with a fixed antenna
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...
. 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...
is usually used, with more upmarket models also featuring DCS.
| PMR Channel | Frequency (MHz) |
|---|---|
| 1 | 446.00625 |
| 2 | 446.01875 |
| 3 | 446.03125 |
| 4 | 446.04375 |
| 5 | 446.05625 |
| 6 | 446.06875 |
| 7 | 446.08125 |
| 8 | 446.09375 |
dPMR446 uses sixteen digital voice at 3.6 kbit/s and 4-Level FSK modulation channels separated by 6.25 kHz from each other. These overlap with DMR Tier I channels.
| dPMR446 Channel | Frequency (MHz) |
|---|---|
| 1 | 446.103125 |
| 2 | 446.109375 |
| 3 | 446.115625 |
| 4 | 446.121875 |
| 5 | 446.128125 |
| 6 | 446.134375 |
| 7 | 446.140625 |
| 8 | 446.146875 |
| 9 | 446.153125 |
| 10 | 446.159375 |
| 11 | 446.165625 |
| 12 | 446.171875 |
| 13 | 446.178125 |
| 14 | 446.184375 |
| 15 | 446.190625 |
| 16 | 446.196875 |
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" or "ATX-2000".PMR446 gateways extend the range of PMR446. These gateways are connected through internet using a client/server VoIP system such as eQSO
EQSO
eQSO is a client–server software program designed by amateur radio enthusiasts for linking amateur radio frequency gateways and repeaters via the internet by using a Voice over IP protocol...
or the Free Radio Network (FRN). Repeaters and gateways are prohibited in the UK.
Law
Similar services in other countries
See also Kort Distanse RadioKort Distanse Radio
Short distance radio or KDR also KDR 444, is a radio service in the UHF range that is open without licensing for personal usage in Sweden and Norway...
and Family Radio Service
Family Radio Service
The Family Radio Service 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 band. It does not suffer the interference effects found on citizens' band at 27 MHz, or the...
as examples of similar personal UHF radio services available in other areas.