Hit the ground running with Brugg Cables; the requirements on mobile communications for the military can be both demanding and heavy. The Swiss company Brugg Cables has developed a fibre optic cable to overcome many of the obstacles inherent in land-based communication networks -- a cable that has begun to draw much attention. (What's Up?).

The cable was developed in 1998 out of a request tendered by Alcatel (now Thales) for a fibre optic cable to meet a Swiss Army requirement. The contract stated that the cable was to be laid in outdoor battlefield environments, and both cable and connectors had to be resistant to rodent attacks, vandalism and the elements. After a study of the stock available on the market, Alcatel met with engineers from Brugg Cables (then Brugg Telecom) who submitted a proposal for a hermetically sealed cable boasting a high tensile strength and complete resistance to both natural and chemical attacks.

This new backpack- and vehicle-deployed fibre optic cable was designed specifically to provide mobile field units with a tough and durable landline for battlefield voice and high-bandwidth data communications.

Enter the Mille

The name of this cable is the Mille, and it shines in the light of its extraordinary characteristics, in contrast to other one to four-fibre cables. The lightweight cable adds only 18 kg per kilometre onto a soldier's shoulders (25 with pack), providing for a less stressful and tiring manual deployment. Another interesting feature is the Mille's crush strength, 2500 kg per 10 cm of cable, up until which, as Brugg states, no attenuation is experienced throughout the line.

On close inspection of the Mille cable one finds a stainless steel tube out of which protrudes one, two or four colour-coded fibre optic strands. The tube, surrounded by a stabilising gel, is laser welded, hermetically sealed and protected by an armour jacket wound from a dozen wires. Lastly, into that recipe is thrown a hard, chemical-resistant plastic covering that defies all but the most fervent rodent attacks.

During testing, the Mille cable continued to function both during and after being exposed to a direct flame measured at 800 [degrees] C for three hours (parameters to IEC 60331) with no measurable loss of performance.

It was this sort of performance that won the eye of the Swiss Army, which (through Thales) signed a CHF 12 to 13 million contract with Brugg Cables. Deliveries under this agreement will be completed sometime in 2003.

The easy-to-handle Mille cable is a slim (3.4 mm) flexible cable that operates with a bandwidth of >10 GHz/km with normal signal loss. of about 0.4 dB.

The useful length per section of the Mille is 1000 metres, with a maximum distance of 8000 metres, and security is (almost) completely ensured with the Mille cable, since any compromise in the optical fibres usually creates a complete loss of circuit continuity, which results in a halt of communications and (one would expect) immediate investigation.

Mille cable comes fitted with special `soldier-proof' Tyco optical lens connectors that are attached in a US Federal Standard 209e classification 1000 particle/cubic foot certified clean room environment. As compared to connectors assembled before the clean room was installed, an average of 25 per cent improvement in attenuation has been achieved (or 0.3 dB). The finished connectors are then tested with many extreme measures that have included freezing in blocks of ice and immersion in mud puddles -- actions that compromise neither the cable's nor connector's performance, but have culminated in the design of a dedicated connector cleaning kit -- another soldier-proofing investment.

Brugg Cables is currently working on a field repair solution for the Mille (at present, all damaged cables must be returned to the company for repair) and also has plans for acquiring Nato certification sometime in 2002, although the cable already either meets or exceeds all current Nato requirements.

To date, the Mille cable has garnered much interest, and the company maintains a positive outlook for its future. Wolfgang Samero, Mille family Product Manager says, "We are on the road to becoming the standard-setter in technical fibre optic cable providers for military applications requiring between one and four fibres."

The company has recently delivered 18 kilometres of cable to a northern European country for testing, is currently in undisclosed partnership negotiations with STN Atlas and has solicited interest from a host of other parties in Europe and the US.