Page 137 - Optical Switching And Networking Handbook

06_200023_CH05/Batesx 1/17/01 8:19 AM Page 122

122 Chapter 5

Installing More Fiber Just Does
Not Do It!

In the past, the carriers have installed more fiber in their backbone
networks, as well as more transmission equipment. With every new
fiber installed, the carrier adds between 2.4 and 9.9 Gbps of capac-
ity. Unfortunately, this is extremely costly, and in many cases, the
installations are difficult and costly to maintain. Rights-of-way along
major highways throughout the country are continually being dug
up. Local communities are beginning to rebel at the continual digs
that occur. Besides disrupting traffic patterns, frustrating drivers,
and generally being unpleasant to view, the constant digging adds to
the number of cable cuts, which disrupt existing network capacities.
The cost of adding additional fiber cables can be estimated from
$70,000 to $100,000 per mile depending on the dig. Moreover, as
shown in Figure 5-8, this is escalating. To this we must add the sup-
port systems and electronics costs. As the cost of digging, establish-
ing rights-of-way, and labor all escalate, overall costs continue to
spiral upward.
The old joke about the “backhoe fade” problem is a reality. In fact,
many of the carriers use the same construction crews. These crews
should know where the lines have been installed from their last dig.
However, record keeping is one of the least functional areas in this
industry. Too often the construction crew must make in-field
changes to overcome obstacles. This means that they dig in different
places from where the drawings state. By using a WDM or DWDM
arrangement, the carriers can get away from the constant digging
and merely turn on new lights when necessary to satisfy the
demands. This assumes that earlier installations included the cor-
rect equipment upfront.