Some notes on OTAP over Wi-Fi.

In EMEA, all -e series MOTOTRBO radios support Wi-Fi*. This allows the radio to operate on a Wi-Fi network and either Receive OTAP data from Radio Management or Connect into the WAVE PTX service using the built-in client.

OTAP (Over The Air Programming) can be done either via the Radio Network (RF) or Wi-Fi. Repeaters can be programmed via Ethernet.

OTAP data is sent to the radios via the Device Programmer service that runs either on the Radio Management server or another PC. 

In order to do OTAP over Wi-Fi, the IP network must allow IGMP which is needed by Device Programmer to join multicast groups that devices will announce their presence on.

The network must allow multicast DNS (mDNS) packets to pass to the Device Programmer. mDNS uses UDP port 5353 to send packets to a standardised IP address of 224.0.0.251. 

By default, routers do not forward messages sent to 224.0.0.251 outside the subnet from which they originated. If the Device Programmer is in another LAN, some configuration of the Router (or Switch) is needed to allow this to be routed between subnets correctly. If anyone has successfully implemented this, please let me know?

If the above is not possible, a low power PC or NUC can be deployed on the subnet where a radio will need to get OTAPed. The PC would run the Device Programmer and this would connect back to the Radio Management Server or Job Processor host PC.

The Device Programmer listens on 224.0.0.251 for the presence of radios in the network. When a radio connects to Wi-Fi (and the IP network) it announces its presence using the above IP address. Radio Management sees this message and determines if there are any jobs ready for the serial number the radio sent in the mDNS message.

A number of applications use mDNS and this can interfere with the speed and operation of OTAP over Wi-Fi. It, therefore, makes sense to not load all kinds of unnecessary things onto the Device programmer host PC - examples include Apple iTunes and Google Chrome together with Apps/Plugins.

If you doing some fault finding and have WireShark, these two filters will be very useful:

ip.dst == 224.0.0.251 shows all packets sent to the group. Note that other devices might also use this address.

dns.srv.name contains "MOTOTRBO" this shows mDNS packets from MOTOTRBO radios.

* In EMEA radios shipped after 18.11.2019 will have Wi-Fi enabled by default. -e series radios shipped before this date may require a software licence to enable this.