Confirmed group data

DMR only supports unconfirmed delivery of data to a group. The problem with this is that the source application does not have a means to determine whether every radio has received the message or not.

The Confirmed Group Data feature, only available with MOTOTRBO, allows the application to send a message to a group of radios then receive confirmation from each. This improves the throughput of announcement messages significantly. Also, the message is delivered to all the radios simultaneously.

This would be useful for example in a manufacturing plant where the failure of a machine on the a production line needs to be communicated to several employees. Or, in a mining operation, where the location of hazards need to be sent to all the workers.

An application requests to transfer a data message to a set of radios by providing the data payload, a list of recipient radios, and a talkgroup to the MNIS data gateway. MNIS forms and transmits a confirmed packet. After transmitting the packet, the system polls all the recipient radios one by one for their acknowledgment.

Packets can only be transferred from a data application using MNIS. The source cannot be a radio or control station. 

The maximum size of the message is 636 bytes (including IP and UDP headers) and the maximum number of target radios is limited to 200. The target radios must all be MOTOTRBO radios and members of the same talkgroup.

This feature is available in all configurations of MOTOTRBO, except Connect Plus.