Telecommunications provide internet services, mobile and stationary phone services, television services, security services and automation and control of traffic and utility infrastructure. The existing copper based telecom infrastructure has limitations in the bandwidth that it can carry; new applications have evolved that require fibre optic cable, such as wireless services.

According to TeraSpan the evolution of the internet has pushed networks to their limits and now the world is faced with the need for a global telecom infrastructure upgrade. “In reality the upgrade that needed to happen in order to meet bandwidth demands was to bring an optical fibre to every building where people live and work.” TeraSpan questioned how this could be done with traditional methods.

TeraSpan said that “The impact to the community and the cost would be staggering. Of course there are lots of existing conduits where fibre can be economically pulled and plenty of aerial routes where optical cables can be economically strung, but there are not nearly enough and they rarely lead exactly where the network needs to go. There are always major road blocks in building fibre networks with traditional methodology and thinking.”

Micro trenching - a new approach

TeraSpan said that the development of the VIF was motivated by a desire for route flexibility and to protect city infrastructure; as this is the most costly element when building a new underground network. TeraSpan recognised that the networks must be installed on public property as there is no other path that leads to all buildings.

“The new approach must surgically install the fibre cable into the ground. The surgery must work on all elements that one can encounter along the public property of a city,” said the company. TeraSpan also wanted the system to work for all terrains, as it is costly to change methodologies too often along the route.

TeraSpan said that this thought process led to pushing everything to the smallest size that it could possibly be. “The backhoe would be traded for a diamond saw blade that could cut a very narrow surgical slot where a small conduit could be placed. The saw cut must be small enough to fit between two footpath panels without being noticed; otherwise the city would require that the sidewalk be replaced.” TeraSpan did not want the system to be installed too deep as this would have risked other utilities. Also, by being close to the surface, it was easy to pull the cable up to form branches and to get the system out of the way if civil work needed to be done.

The evolution of the VIF

In the beginning the company simply put a small 4 mm cable into the saw cut, but soon realised that this was too difficult for city workers to work around and was often damaged. In response TeraSpan created a very tough conduit system that could take a major hit from a rock or a shovel without damage. The company also focused on making the conduit a removable two part system, applied over the fibre optic cable. This allowed for greater ease of maintenance as networks could now be lengthened or shortened without cutting the cable inside. Also with the two part system there was no cable pulling required and no limit to the length of cable that could be installed. Every step of the installation could now be done as the team moved along. The conduits are deployed into 13 mm wide cuts in roads, footpaths and other hard surfaces. In soil, gravel or other soft infrastructure, the conduits are deployed into narrow 200-300 mm deep trenches.

According to TeraSpan, the VIF system is a cost-effective fibre optic solution, designed to be installed without damaging city infrastructure, thus eliminating costly restoration. Over the past decade the product has been used in all sorts of climates and conditions. Municipalities that have approved the VIF include San Diego, New York, Boston, Toronto, Calgary, Vancouver, Stockholm and Riyadh. Telecom providers throughout the world such as NextG, Shaw Cable Systems, Rogers, Alcatel and Saudi Telecom have also used the VIF to good effect.

Micro trenching may offer another tool in the ongoing project to reduce disruptions, modernise assets and find cost effective solutions; the key aims of Trenchless Technology.