A New-Generation Radio

Swedish Defence, In a laboratory in Enköping there are seven green boxes which could have a major effect on the way in which the Armed Forces communicate. There they are developing a radio system which has no vulnerable central nodes and a minimum of hardware. 
 
“Software defined radio in combination with an IP-based ad hoc network represents a real generation shift,” says FMV’s project manager Thorbjörn Ericson. 
 
FMV has purchased some 70 American sets. Of the initial delivery of 20 sets, ten have gone to the SLB project (a battalion level command and control system) and ten are being used for testing and trials purposes. Bench testing is in progress and the first field trials will be conducted later this year. 
 
“It is not the equipment itself which is interesting, but the possibility of testing the waveform,” says Thorbjörn Ericson, the project manager for the GTRS-demo (software-defined radio) project. 
 
It is the waveform that controls which functions the radio can perform. And what can be changed without altering the actual hardware itself. Work on software defined radio is going on all over the world. But while much of this work is being concentrated on the hardware itself and communication between two units, FMV has chosen another way. 
 
“We have purchased the hardware and are now focusing our work on the network. That is where the real possibilities lie,” says Thorbjörn. 
 
Major advantages are just round the corner for a radio which can be given new properties simply by altering the software. Among other things, Torbjörn mentions step-by-step development and flexibility. Different functions can be added as the requirement changes and technology moves on. Another advantage is that the space taken up by radio equipment, for example in a patrol vehicle, can be minimised since one set can be used for a variety of functions by altering the software. The flexibility this gives will be put to good use when Sweden takes part in international missions. 
 
“This development is really exciting. I foresee great possibilities for radio in IP-based tactical ad hoc networks. If one unit is knocked out, the network is reconfigured and communication traffic can continue because there are no vulnerable central nodes.” 
 
There is still a lot of development work to be done before that stage is reached. In Thorbjörn Ericson’s view, industry has its own ideas and it is easy to fall into the trap of doing something just because there is the technology to do it. To make sure that development is going in the right direction, trouble has been taken to ask the users exactly what their needs are. User friendliness is important. 
 
“The aim is to produce a development model based on building blocks, allowing functions to be added or removed to match changing requirements, but we are not there yet,” he adds. 
 
Flexibility usually entails high costs. At this, Thorbjörn protests and points to today’s radio systems which are not especially flexible and where efforts are still made to put together systems in order to provide particular capabilities, which is also a costly process. The software defined radio may involve substantial initial costs but these can be recouped later, for example by reducing the amount of hardware that needs to be bought. 
 
So far there are relatively few suppliers of either the hardware or the software involved. For example, FMV received only two replies to its invitation to tender for the software radio. But Torbjörn predicts that this will change. 
 
In the laboratory in Enköping, the equipment for the software radio sits mounted in racks where capacity, delay and other characteristics can be measured. But the small number of sets is a limitation when it comes to testing performance in a network. That is why the project will also be making use of the Opnet model of the waveform which has also been purchased. 
 
With the aid of Opnet, which is a tool for network simulation, networks with a large number of nodes can be tested. It also gives us a way of testing new ideas and seeing whether the ideas are robust, so providing a firm basis on which to base our choice of the way ahead. And then it is up to the manufacturers to take this work and convert it into actual functioning radios.