Radio communications have become such an integral part of Grand Prix racing that it's easy to forget that there was a time when everything was done by pit signals. If a team wanted to get a message to a driver, he had to physically read it off the pit board, and he only had one chance every lap to do so, by which time it might be too late. Of course, if it said something like, "Move over and let your team mate by", he might just choose not to see it at all…

Pit boards are still in use, of course – especially to communicate gaps to other drivers, laps to go, and so on – but the important stuff is done by radio.

This month's Hungarian GP provided a perfect illustration of how valuable good communications can be. In a wet race, a team has to make quick calls on strategy and tyre choice, and it's essential that the drivers hear everything properly the first time. If they miss a call to the pits, or the team doesn't understand a request to come in, valuable time can be lost.

It's an incredibly complex operation. The race engineers talk to the drivers, the drivers talk back, and crew members talk to each other. However, despite the ludicrous scenes depicted in the Sylvester Stallone Champ Car movie Driven, drivers cannot discuss tactics directly with their team mates in the middle of a race. And while girlfriends and wives might be loaned headphones with which to listen in, unlike in Driven, they are not allowed to actually make conversation with their other halves when the cars are running.

The man who looks after MF1 Racing's radio communications is Spaniard Jose Santos, who joined the team last year. He was trained by his veteran predecessor, Gilles Flaire, who was with MF1 until after this season's San Marino GP. The Frenchman has now retired from racing – to open a restaurant in Valencia, of all things!

Jose and the team still use the systems that Gilles put in place, and indeed he remains in touch with the team, even turning up at a recent test in Jerez to check things out.

Acknowledged as an expert in this very specialised field, Flaire has a military background and worked in many interesting areas before getting involved in motorsport.

"I am a specialist in radio communications, both satellite and normal communications systems," he explains. "That includes things like encryption systems to protect fax data for big companies and official people, plus bugging, debugging and eavesdropping."

Flaire came into the sport by chance. A friend of countryman Olivier Panis, he went to the 1996 Japanese GP as a guest, and ended up getting the job of sorting out the Ligier team's radios. Later, he had spells with Sauber and McLaren before joining Jordan.

It goes without saying that a racing car moving at 300+ km/h is not an ideal environment for producing a good radio signal, and that's where Gilles's expertise has paid off over the years.

"The most complicated thing is the radio link between the car and the pit. We have special equipment in the car, and because all the electronics must be light, it weighs around 200 grams. The driver wears earplugs, and inside the helmet we install a microphone. The microphones are very, very small – something like 5mm diameter and 2mm thickness – and extremely light.

"Speaking when the engines are on is a little bit difficult, so we use noise-cancelling technology that requires a double-face microphone. You have an opposite face, which is looking for the noise, and a face into which you talk. So you have two signals: noise and voice. The electronics inside are able to compare them and kill the noise. In the laboratory, we can have 80% suppression, although in the field it's another question!

"In the car it's extremely complicated, because the pressure of the noise is extremely heavy," agrees Jose. "So the big enemy in the car is the noise. Also in the car, we have electrical problems, because the generator and the voltage regulator keep getting smaller and smaller, and therefore, from an electrical point of view, more and more noisy.

"So you have to cut first the audio noise from the microphones of the drivers, and after that, to cut the electrical noise that interferes with the radio. And when that is finished, I have mechanical noise due to the vibration. So it is not easy to have good communication with the driver for all these reasons."

At every race, the teams and other travelling F1 personnel are allocated specific frequencies by the local authorities, a complex but well organised process. Very often, you will see a couple of guys from a government agency wandering around the paddock, waving a machine that looks something like a giant mobile phone. They're looking for unauthorised signals

Legal or not, the number of radios in use around a race circuit creates a headache.