PMR446: Difference between revisions

Content deleted Content added

Inline

Revision as of 14:45, 17 March 2020

Motorola TA288 PMR446 licence-free radio

PMR446 (Private Mobile Radio, 446 MHz) is a licence exempt service in the UHF radio frequency band and is available for business and personal use in most countries throughout the European Union.^[1]

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 (dPMR446) and digital mobile radio (DMR Tier 1) standards designed by ETSI.

Originally 8 channels were available in analogue mode but this has now been increased to 16 channels.

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 will also be doubled by extending onto the 446.0–446.1 MHz band used by analog FM.

Range

Until recently, PMR446 radios were handheld transceivers with fixed antennas (see Technical information). In November 2015, Midland Radio announced the release of the GB1 mobile PMR446 radio for vehicular use.^[2]^[3]^[4]

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, Netherlands.^[5] This was the result of enhanced propagation conditions, not a line-of-sight signal.

Usage worldwide

PMR446 radios use frequencies that in Australia, the U.S., and Canada are allocated to amateur radio operators, and military radar systems.^[6]

Instead, the U.S. and Canada uses the 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.^[7] 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 5W giving a vastly improved range over the lower power PMR system.

PMR446-compliant equipment may be used anywhere throughout Europe.^[8]

Type approved PMR446 radios with power up to 500mW can be used without any licence in India. The devices may not be base stations or repeaters, and must use integrated antennas only.^[9]

Technical information

PMR446 covers band 446.0–446.2 MHz. Radios may now have removable antennas in some countries as long as the ERP does not exceed 500 mW, for example in the UK.^[10] The general ECC decision^[11] 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 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.^{[citation needed]}

Digital PMR446 DMR Tier I (TDMA) uses 16 digital voice channels separated by 12.5 kHz from each other with 4-level FSK modulation at 3.6 kbit/s.^[12] Before January 2018, only the higher 8 channels were allowed for digital TDMA operation.

Some models (Hytera BD305LF, Retevis RT40, ...) have DCDM function (Dual Capacity Direct Mode); DCDM function enhanced the frequency utility ratio, It’s a feature which allows two slots operation on simplex => 16 channels x 2 slots = 32 ways, equivalent of the 32 FDMA channels.^{[citation needed]}

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)^[13]
Channel	Frequency (MHz)	Bandwidth (kHz)	Comments (Channel / CTCSS)
1	446.00625	12.5	FM => Emergency communication (1/12) FM => Trucker (1/9)
2	446.01875	12.5	FM => Geocaching FM => Camping
3	446.03125	12.5	FM => Prepper Canal, in disasters
4	446.04375	12.5	FM => Drone-Pilot Intercom (4/14) FM => 4WD (4/4) FM => Boat (4/16)
5	446.05625	12.5	FM => Scouts (5/5)
6	446.06875	12.5	FM => Hunters (6/12)
7	446.08125	12.5	FM => Moutain (7/7)
8	446.09375	12.5	FM => DX & Calling Channel (8/8) FM => Distress (8/18) FM => Moutain Italy (8/16)
9	446.10625	12.5	DMR => Digital Calling Channel (CC1 TG99) DMR => Distress (CC1 TG9112)* *EmCOMM other channel with same TG
10	446.11875	12.5
11	446.13125	12.5
12	446.14375	12.5
13	446.15625	12.5
14	446.16875	12.5
15	446.18125	12.5
16	446.19375	12.5

Digital FDMA

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.^[14] Before January 2018, only the upper 16 channels were allowed for digital FDMA operation.

Digital FDMA (dPMR446)^[13]
Channel	Frequency (MHz)	Bandwidth (kHz)	Comments
1	446.003125	6.25
2	446.009375	6.25
3	446.015625	6.25
4	446.021875	6.25
5	446.028125	6.25
6	446.034375	6.25
7	446.040625	6.25
8	446.046875	6.25
9	446.053125	6.25
10	446.059375	6.25
11	446.065625	6.25
12	446.071875	6.25
13	446.078125	6.25
14	446.084375	6.25
15	446.090625	6.25
16	446.096875	6.25
17	446.103125	6.25
18	446.109375	6.25
19	446.115625	6.25	dPMR => Calling Channel (CC1 TG99) dPMR => Mutual assistance (CC1 TG9112)
20	446.121875	6.25
21	446.128125	6.25
22	446.134375	6.25
23	446.140625	6.25
24	446.146875	6.25
25	446.153125	6.25
26	446.159375	6.25
27	446.165625	6.25
28	446.171875	6.25
29	446.178125	6.25 kHz
30	446.184375	6.25
31	446.190625	6.25
32	446.196875	6.25

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.^[15]

PMR446 gateways extend the range of PMR446. These gateways are connected through internet using a client/server VoIP system such as eQSO or the Free Radio Network (FRN).

Law

References

^ "Analogue and Digital PMR446 Information Sheet" (PDF). Ofcom. Retrieved 2013-01-05.
^ World First Midland GB1 PMR 446 Mobile Attached Antenna
^ Midland GB1 First Look Midland GB1 Mobile PMR446 - Manual Download Includes Specs
^ Midland GB1 First Look *Updated With English Manual*
^ "Delboy's DX Contact UK to Amsterdam". Delboy Enterprises. 5 August 2003. Archived from the original on 2008-02-09.
^ "420-450 MHz" (PDF). National Telecommunications and Information Administration. March 1, 2014. Retrieved July 23, 2019. The band 420-450 MHz is used extensively by the military agencies for land-based, shipborne, and airborne radar systems to perform important national security functions.
^ "Can I bring my FRS / GMRS Radio to Europe - Austria, Germany, Switzerland : British Expat Discussion Forum". Britishexpats.com. 2005-05-10. Retrieved 2010-11-18.
^ dPMR446 - Welcome to the dPMR Association
^ "Wireless Planning and Coordination Wing Notification G.S.R. 1047(E)" (PDF). The Gazette of India. 2018-10-18. Retrieved 2020-01-03.
^ "Analogue and Digital PMR446 Information Sheet" (PDF). Ofcom. Retrieved 2013-01-05.
^ ECC Decision (15)05 (PDF) (Technical report). 3 July 2015.
^ "PMR446 Frequencies - Analogue and Digital". Homepage.ntlworld.com. Archived from the original on 2008-05-28. Retrieved 2010-11-18.{{cite web}}: CS1 maint: bot: original URL status unknown (link)
^ ^a ^b "A guide to the new PMR446 license-free radio frequencies following ECC Decision (15)05 and what it means to you" (PDF). Kenwood Communications. August 2016. Retrieved 2019-09-21.{{cite web}}: CS1 maint: url-status (link)
^ "dPMR: A low cost digital successor to PMR446 is on the Horizon". Cmlmicro.com. Retrieved 2010-11-18.
^ Sowden, Dave (2012-10-07). "RADIO PIXIE: PMR446 Parrot Repeater". RADIO PIXIE. Retrieved 2019-10-20.

External links

[1] "Analogue and Digital PMR446 Information Sheet" (PDF). Ofcom. Retrieved 2013-01-05.

[stw-2] World First Midland GB1 PMR 446 Mobile Attached Antenna

[rt1-3] Midland GB1 First Look Midland GB1 Mobile PMR446 - Manual Download Includes Specs

[sw2-4] Midland GB1 First Look *Updated With English Manual*

[5] "Delboy's DX Contact UK to Amsterdam". Delboy Enterprises. 5 August 2003. Archived from the original on 2008-02-09.

[6] "420-450 MHz" (PDF). National Telecommunications and Information Administration. March 1, 2014. Retrieved July 23, 2019. The band 420-450 MHz is used extensively by the military agencies for land-based, shipborne, and airborne radar systems to perform important national security functions.

[7] "Can I bring my FRS / GMRS Radio to Europe - Austria, Germany, Switzerland : British Expat Discussion Forum". Britishexpats.com. 2005-05-10. Retrieved 2010-11-18.

[8] PMR446 - Welcome to the dPMR Association

[9] "Wireless Planning and Coordination Wing Notification G.S.R. 1047(E)" (PDF). The Gazette of India. 2018-10-18. Retrieved 2020-01-03.

[10] "Analogue and Digital PMR446 Information Sheet" (PDF). Ofcom. Retrieved 2013-01-05.

[11] ECC Decision (15)05 (PDF) (Technical report). 3 July 2015.

[12] "PMR446 Frequencies - Analogue and Digital". Homepage.ntlworld.com. Archived from the original on 2008-05-28. Retrieved 2010-11-18.{{cite web}}: CS1 maint: bot: original URL status unknown (link)

[:0-13] "A guide to the new PMR446 license-free radio frequencies following ECC Decision (15)05 and what it means to you" (PDF). Kenwood Communications. August 2016. Retrieved 2019-09-21.{{cite web}}: CS1 maint: url-status (link)

[14] "dPMR: A low cost digital successor to PMR446 is on the Horizon". Cmlmicro.com. Retrieved 2010-11-18.

[15] Sowden, Dave (2012-10-07). "RADIO PIXIE: PMR446 Parrot Repeater". RADIO PIXIE. Retrieved 2019-10-20.

[1]

[2]

[3]

[4]

[5]

[6]

[7]

[8]

[9]

[10]

[11]

[12]

[13]

[14]

[15]

v t e Two-way radio
Amateur and hobbyist	Amateur radio Amateur radio repeater Citizens band radio Family Radio Service Public Radio Service General Mobile Radio Service KDR 444 LPD433 Mobile rig Multi-Use Radio Service PMR446 UHF CB (Australia)
Aviation (aeronautical mobile)	Air traffic control Aircraft emergency frequency Airband Common traffic advisory frequency Mandatory frequency airport MULTICOM Single Frequency Approach UNICOM
Land-based commercial and government mobile	Base station Business band Mobile radio Professional mobile radio Radio repeater Specialized Mobile Radio Trunked radio system Walkie-talkie
Marine (shipboard)	2182 kHz 500 kHz Coast radio station Marine VHF radio Maritime mobile amateur radio
Signaling / Selective calling	CTCSS D-STAR Dual-tone multi-frequency MDC-1200 Push-to-talk Quik-Call I Quik-Call II Selcall SELCAL
System elements and principles	Antenna APRS Automatic vehicle location Call sign CAD DC remote Dispatch Dynamic range compression Fade margin Link budget Rayleigh fading Tone remote Radiotelephony procedure Voting (diversity combining)