What exactly do you want the Arduino to do? Does it have to replace the box in the image (which I believe to be some sort of wireless transceiver)? Do you have details of the interface protocols?
The specifications for the original Mammut W-link service unit is as follows.
**************************************************************************************************************'
Mammut W-link Adapter:
Handy adapter for wireless and parallel communication with any number of PULSE Barryvox® devices.
Ideal for organizations and dealers for an unique and efficient fleet management.
Features:
Change configuration settings simply and clearly
Update PULSE Barryvox® devices with the latest software
Load personalized start image and text for identification
Check and call up service data and device status
Automatic device configuration via database interface
Do you know what is inside one of those boxes, other than the radio? Does it show up as a virtual com port when it is plugged in to a PC? If they charge a lot of money for one of the boxes, I doubt they will make it too easy to replicate. If you can get hold of a real one, you could try some USB sniffing software and intercept the traffic.
I´m afraid that I don´t have access to the real hardware so no sniffing can be done :0(
However I found this information about the software.
The service software is based on the .NET framework and runs on all windows versions later than windows 2000.
Arendi designed and implemented the whole software including protocol-, business- and GUI layer.