MPT 1327

MPT 1327

Frequencies	176.5 MHz,184.5 MHz,201.5 MHz,162.5 MHz,207.5 MHz,420 MHz,800 MHz,461 MHz
Frequency Range	162.5 MHz - 800 MHz
Mode	NFM
Modulation	FM,FFSK
ACF	106.66 ms
Emission Designator	—
Bandwidth	10 kHz,25 kHz,20 kHz,12.5 kHz
Location	Worldwide
Short Description	MPT1327 (Ministry of Posts and Telegraph 1327) is a signaling protocol standard for analog trunked radio
I/Q Raw Recording	Download file
Audio Sample

MPT 1327 (Ministry of Posts and Telegraph 1327) is a signaling protocol standard for analog trunked radio. It was developed in 1988 by the British Department of Trade and Industry (DTI).

This mode is primarily used in the United Kingdom, Europe, South Africa, Australia, and New Zealand.

The trunking control channel is used to communicate between the mobile radios and the network at 1200 bits per second with fast Frequency Shift Keying (FFSKFast Frequency-Shift Keying) subcarrier modulation. Since this is an analog mode, voice traffic is sent with analog FMFrequency Modulation, so it can easily be monitored with a simple FMFrequency Modulation receiver.

Samples

Mobile Packets

MPT1327 Establish Link
MPT1327 Mark end of individual transmission
MPT1327 Terminate Link

Recordings of MPT1327 Voice Comms

You can hear the above 3 MPT 1327 mobile packets in these recordings of MPT1327 voice traffic. At the beginning of each radio-to-radio link there is a Mobile call packet to establish a link. Then, during this link, as each person talks, each time they key off their radio the MPT1327 Mark packet marks the end of the individual transmission (not the end of the entire link; the FMFrequency Modulation carrier is still there). When the link is done, a long Terminate Link packet will be heard, after which the FMFrequency Modulation carrier will stop and the link considered terminated.

Recorded from Riga, Latvia on May 1st, 2010 at 423.6 MHzMegaHertz (MHz) 10^6 Hz.

Additional Samples

Mobile, calling
Mobile, closing

Frequencies

In the UK, seen in sub bands 176.5-184.5 MHzMegaHertz (MHz) 10^6 Hz, and 201.5-207.5 MHzMegaHertz (MHz) 10^6 Hz. Also sometimes seen around 162.5 MHzMegaHertz (MHz) 10^6 Hz. Commonly seen at 420-440 MHzMegaHertz (MHz) 10^6 Hz, and in the 800 MHzMegaHertz (MHz) 10^6 Hz band.

Decoding Software

Hobby Level Software

• Trunkview
• Unitrunker
• sdrtrunk

Professional Software

• go2DECODE
• go2MONITOR
• Rohde&Schwarz CA100

Decoding Tutorials

• Following trunked radio with the RTL-SDR

Video Examples

• RTL-SDR Trunkview Decoder MPT 1327
• 165.2 MHz - Signal Identification (MPT 1327)
• MPT1327 Trunking Control Channel

Additional Links

• MPT 1327: A Signaling Standard for Trunked Private Land Mobile Radio Systems, DTI 1988
• Radioreference.com MPT 1327 Info
• Radio-Electornics MPT-1327 Info
• Wikipedia MPT 1327
• WAVECOM Database: MPT 1327
• about2wayradio.com MPT 1327
• ukmidlandscanner.co.uk
• signalharbor MPT 1327 info

Additional Images

MPT 1327 Control Channel MPT 1327 Control Channel MPT 1327 Control Channel MPT 1327 Spectrum (RadioScanner.RU) Spectrogram of MPT1327, showing the FFSKFast Frequency-Shift Keying waveform in the sidebands of this signal. MPT1327 seen at Plymouth, UK at 164.719 MHzMegaHertz (MHz) 10^6 Hz. MPT1327 seen in Sydney, Australia.