Updated: Some notes on OTAP over Wi-Fi.

Several MOTOTRBO radio models 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. The data is sent to the radios via the Device Programmer service that runs either on the Radio Management server or another PC.

All new MOTOTRBO radios which support Wi-Fi come with preconfigured credentials. This allows a  radio to automatically connect to a staging access point without ever needing to be connected via a programming cable first

The default profile settings are:

• SSID: MOTOTRBO
• Security Type: WPA/WPA2 Personal (AES)
• Passphrase: Radio Management

It is recommended to remove this default profile once initial provisioning is complete.

In order to do OTAP using a staging access point , the IP network must allow IGMP which is needed by Device Programmer to join multicast groups that the radios will use to announce their presence. This 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.

A reader reported that they were able to achieve the above. Essentially it needs a dedicated VLAN, GRE VPN Tunnel and DHCP subnet available across all points of the network. The readers network has a distributed virtual switch and second NIC on the virtual RM server all based as a single entity “tricking” the radios and server into thinking they are on the same network even though it's over a virtual MPLS in the cloud. Getting around the mDNS “hello” to pass without enabling broadcasting on various network kit was the hardest bit.

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.

⚠Having a Wi-Fi network with known credentials is a huge security risk therefore I strongly recommend isolating the staging access point from your company network. Additionally, I would recommend locking down the network so that the radios can only access specific servers and the device programmer host. Similarly, the device programmer host must be firewalled and patched to prevent any funny business from within the staging Wi-Fi network.

Try this: search for your company address on wigle.net

When used on the above staging access point, the RM Device Programmer listens on 224.0.0.251 for the presence of radios in the network. When a new radio connects to Wi-Fi 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.

If you doing some fault finding on the staging network with 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.

One of the recommended settings for the initial configuration, is to set the Device Discovers Server Name. This way, instead of using 224.0.0.251, the radio will connect to the device programmer host using it’s IP address (e.g. 192.168.0.209) or domain name (dp1.mynetwork.lan). The latter requires a DNS server. Both however, can transverse subnets so the Device Programmer host and radio do not have to be on the same subnet.

Wi-Fi supports more operations due to its higher bandwidth. Standard OTAP via RF cannot perform software upgrades, language pack updates, or voice announcement updates. However, Wi-Fi allows for all of these plus the Activation of Premium Features.

To program radios via Wi-Fi, the Communication Method in RM Device Programmer must be set to Wireless (LAN) or USB + Wireless (LAN). 

When the administrator creates the scheduled job in the RM Configuration Client, the selected Connection Method must match the Device Programmer's setting (e.g., USB + Wireless (LAN))

For an unprogrammed radio to be updated automatically out of the box over a staging Wi-Fi network, the system administrator must have already added the radio to the RM database (using the serial number from the invoice or packing list) and scheduled the write job in advance. There is also an Automatically Add Radios setting in the server that will add a serial number as soon as it's seen for the first time.

It is also possible to OTAP over Wi-Fi in offline mode. In this case, the Device Programmer PC, a Wi-Fi Access Point (optional) and a ZIP file containing the write jobs travel to site. The Device Programmer processes the ZIP file and as soon as the radios are seen on the Wi-Fi network, the write job will start.

It is also possible to do this using an existing W-Fi network to which the radios are already connected (or can connect to on demand). In this case, the Device Programmer only needs to be on the network, either permanently or when needed.

The point here is that there is no IP connectivity between this Device programmer and the RM Server. The write jobs are stored in a ZIP file that is copied to the Device programmer PC.

This post originally appeared on 29 September 2020. It was updated on 10 April 2026 to include new features that became available after the original date.