2000-11-08 Packet - Laserfiche WebLink

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Leased communications links facilities tend to be the least reliable and the least stable, but often are the least expensive unless the County already has glass fiber installed and cost justified on another basis. Currently, Anoka County relies on telephone lines leased from Qwest Communications, Inc.. Those telephone lines, especially because they are DC continuous lines, have proven to be less reliable than they should be to meet the need of public safety land mobile radio communications. Unless the County has glass fiber available or can cost justify installing glass fiber on another basis, glass fiber tends to be the most expensive alternative available unless there are a very large number of circuits required. The number of circuits required for public safety land mobile radio systems in Anoka County are relatively small in number and, therefore, glass fiber will be far more expensive than microwave. In addition, construction of a glass fiber link requires that the County have the required right -of -way. Glass fiber links can be constructed either overhead on poles or underground. Overhead construction requires making arrangements with the power company, the telephone company, railroads, and other right -of -way owners including the State of Minnesota. Estimating the cost for the various alternative communications links is difficult as costs vary depending on factors that are applicable to any particular communications link. For example, the availability of an adequate structure to support microwave antennas may dictate the need for additional strengthening of the support structure. Telephone line lease costs are dependent on whether or not the line is entirely within the service area of a single telephone company and upon many other factors. The following table provides representative costs as a way of comparing typical leased telephone line costs to typical hot- standby point -to -point microwave links. The table also shows payback periods in years for various numbers of lines required on each of the links. The payback period is calculated by multiplying the annual telephone line cost times the number of lines and dividing that number into the link initial cost amount. By comparison, typical cost for construction of a glass fiber link, assuming that the right -of -way is available, are $12,000 per mile for overhead construction and $18,000 per mile for underground construction with an additional cost of $30,000 per end for the fiber multiplex equipment. MAX MW LINK ANNUAL 5 LINE 10 LINE 20 LINE FREQ DISTANCE INITIAL TELEPHONE PAYBACK PAYBACK - PAYBACK BAND MILES COST LINE COST PERIOD YRS PERIOD YRS PERIOD YRS 6 gHz 15.0 $100,000 $1,320.00 15.2 7.6 3.8 10 gHz 9.0 $ 90,000 $1,080.00 16.7 8.3 4.2 18 gHz 4.0 $ 70,000 $ 840.00 16.7 8.3 4.2 23 gHz 2.5 $ 40,000 $ 600.00 13.3 6.7 3.3 Ronald Vegemasi Engineering, Inc. - Report: Anoka County