Note: comments posted are strictly the opinion of the poster and not necessarily those of Fiber Planners Inc. or any other posters.
Wednesday, February 25, 2004
Canada: "Fibre firm takes telecom out of the trenches"
"A Vancouver company thinks it has the solution to solving last mile headaches without tearing up the downtown core. TeraSpan Networks has developed a vertical inlaid fibre system of trenchless deployment. Instead of tearing up the street a saw cut is made down the asphalt or a crack cut in the sidewalk, and the cable is dropped in and then filled over."
This is a good article on TeraSpan's inlaid cable system for placing fiber cable in roadways and sidewalks with out costly and disruptive trenching or directional drilling.
Sprint Canada is using the system and likes it despite some critics' concerns that these installations are not as robust as fiber cable buried deeper in conduits. As the Sprint manager points out, the only real protection against interruptions is a truly redundant system laid out in a ring topology. (Note, the other cable has to follow a different route -- it can't just be a few ducts away in the same duct bank, a shortcut sometimes taken.)
A backhoe digging in the wrong place is usually going to take out a cable whether it's a few inches into the road surface or two feet below it. (A much safer exception to this would be fiber cable placed really deep below other utilities, but that's usually only done in conjunction with a sewer system deployment)
30 years ago, buried cable installations were more reliable than aerial installations, but this is no longer true, especially in big cities where there is so much utility construction. Buried cable installations are certainly more expensive. In extreme cases, they can cost hundreds of thousand of dollars per mile in places like Manhattan.
By substantially reducing costs, the TeraSpan system may actually facilitate better reliability by making it easier to cost-justify and deploy redundant fiber. The fiber cable itself only costs only a few thousand dollars per mile depending on fiber counts. posted by Al Bonnyman
Wednesday, February 25, 2004#