Dynamic Mixed Mode

Dynamic Mixed Mode (DMM) allows customers to easily migrate from analogue to digital with minimal disruption. It works by allowing analogue and digital radio users to use the same repeater. 

In DMM, the repeater dynamically switches between analog and digital modes based on the call it receives from radios. If an analogue radio transmits, the repeater switches to analogue mode to repeat that call. However, the repeater only repeats analog calls that are qualified by PL (DPL/TPL) - this is important as CSQ (Carrier Squelch) operation could result in the repeater staying in analogue mode and thus becoming inaccessible to digital radio users. 

If a digital radio transmits, then the repeater switches to digital mode to repeat the digital call if the call uses the right color code. While the repeater repeats one analogue call at a time, it can repeat twp digital calls at the same time, one on each logical channel. The repeater cannot however repeat an analogue and digital call at the same time.

Dynamic Mixed Mode is a repeater only configuration . For radios, one simply needs to configure a scan list containing an analogue channel and a digital channel. MOTOTRBO radios support both analogue and digital operation. 
The legacy analogue radios will not be able to do digital and the technology used in these radios cannot discern between an analogue and digital transmission.  It therefore makes sense to configure these radios with DPL/TPL so that they can block out the digital bursts on the channel during a digital call. It is also adviseable not to use TPL frequencies 67 and 103,5Hz as the DMR transmissions can mimic these two tones.

Dynamic Mixed Mode does not support the following configurations/features:
  • IP Site Connect configuration - This means that in Dynamic Mixed Mode, the repeater can only repeat the digital calls over-the-air and cannot send the voice/data packets over the IP network. The status of the repeater and the control of the repeater cannot be performed from a remote PC application like RDAC-IP.
  • Capacity Plus configuration - This means that in Dynamic Mixed Mode, trunking the logical channels of multiple MOTOTRBO repeaters as per Capacity Plus is not supported.
  • FCC Type-I and Type-II monitoring - Since FCC Type-I and Type-II monitoring are not supported in single site analog operation in any of the earlier MOTOTRBO releases, it is also not supported in Dynamic Mixed Mode single site operation.
  • Transmit Interrupt feature - The Voice Interrupt, Emergency Voice Interrupt, Remote Voice Dekey, and Data Over Voice Interrupt features are presently not supported in Dynamic Mixed Mode systems.
  • RDAC over IP feature - RDAC over local USB and connections via GPIO are supported. RDAC over the network is NOT supported.
  • Repeater Knockdown - In Dynamic Mixed Mode systems, this feature is not supported during an ongoing digital transmission.
  • PTT on a 4-wire interface - In Dynamic Mixed Mode systems, this feature is not supported during a digital repeat operation.


  1. This comment has been removed by the author.

  2. While DMM does not support IPSC, you can program in the repeater a DMM channel for local support and an IPSC channel for wide area MDR linking then switch remotely between the roles using RDAC as required.

    I think DMM is a bit disappointing given the EID cost but the remote switching option via RDAC is as useful workaround for some situations.

    John ZL4JY

    1. I didn't know that. In EMEA, DMM is free.

    2. I remember designing a simple cross-busy system that would do IPSC and analogue...just have to find it.


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