The MPT 1327 Trunking Protocol
(As used on Victorian SMR)

MPT 1327 is a industry standard for trunked radio communications networks. It was developed in 1988 by the British Department of Trade and Industry (DTI), and is primarily used in the UK, Europe, South Africa, and Australia. All British radio specifications are usually specified as MPT x. MPT1320=British 27MHz FM CB Service and MPT1321 is the British 934MHz UHF and MPT1327 is a trunking radio specification. So MPT usually means a UK radio protocol. I am not sure what other bands have MPT 1327 use in Victoria, or what MPT 1327 networks exist in other states.

Systems based on MPT 1327 generally consist of several radio channels. At least one of these channels is defined as the CC (control channel) and all other channels are TCs (traffic channels). Data messages between mobiles and the network are exchanged on the control channel at 1200 bit/s. Each subscriber in an MPT-1327 trunked radio network has a unique call number. It consists of a prefix (3 digits), the fleet number (4 digits) and the subscriber’s call number within the fleet (2 or 3 digits). After it has been entered the call number will be converted in the mobile to a 20 bit address.

For the duration of his call a subscriber is exclusively allocated a traffic channel from the available trunk.

The different types of communications on an MPT-1327 network and their definitions:

Traffic types:

  • Mobile-mobile in a cell
  • Mobile-mobile in different cells
  • Mobile-line access unit via landline or radio
  • Mobile-dispatcher station via landline or radio
  • Mobile-PABX, Mobile-PSTN

Data Communication:

  • Status messages on the CC (5 bit data length)
  • Short data messages on the CC (186 bit data length)
  • Transparent data transmission on the TC (data communication).

Calls:

  • Point to point connections
  • Group calls with talk entitlement
  • Group calls without talk entitlement

MPT-1327 Decoding and Tracking

For MPT-1327/1343 Systems, there is an excellent decoding and monitoring kit available using the FTrunk application (for scan ner users) and Ptrunk for the more dedicated MPT1327 listener. - see the following link for more details: (These programs etc are written by Micheal Evans, many of you will remember him as regular scanner writer for CB Action, R&C and ESR!.

The WinRadio suite of digital decoding applications also supports the MPT-1327 protocol. Check out the following link for more information on the WinRadio digital decoding suite of products.

 

 

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  Australian Scanning Encyclopedia & Radio Communications Centre 
 
This site and the Australian Radio Communications (Yahoo) Group Created By Ashley Geelan and
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Australian Scanning Encylopedia Site Last Modified on: Saturday July 17, 2004 16:46hrs