Telecommunications Management
Homework Assignment #3

K. Friebel
13 February 1995
Hello, Sumit! Just click on each question to view my answers.


LAN Cabling


Question A

In researching the cost differences among twisted-pair, coaxial cable, and optical fiber, I found that it was not easy to get one, straight-forward answer to this question because most companies are selling integrated LAN services.

General information was abundant.


Twisted-Pair

When looking at information concerning twisted-pair, I came across this ranking from Electronic Industries Assoiation/Telecommunication Industries Association (EIA/TIA - 568) that lists five different categories for evaluating twisted-pair cabling.


Coaxial Cable

Coaxial cable is available in different varieties and thicknesses and can support both broadband and baseband LANs. It can also run unboosted longer than twisted-pair cabling.

General characteristics include:

Costs range between $6 for 8', $7 for 15' and $9 for 25' according to Cables To Go.


Optical Fiber

Fiber optical cabling is used for high-speed transfers that won't be affected by electrical noise and runs over longer distances than the other two options. In general fiber optical is good for backbones and offers better security. The downsides include, expense of cable and installation due to the skill required.

In order to determine costs per foot, more information is required. There are currently three standard connectors: FDDI, SMA, ST which determine the price. The salesperson from Cables to Go was rather vague only saying that the prices are a couple dollars per foot, although without other specifications, it was hard to say exactly how much.


Final analysis.

The Heinz LAN supports the work of graduate students, faculty and staff. I believe that would include over 250 users. Applications range from wordprocessing, filesharing, Internet connectivity, connectivity to Andrew, database applications, programming environments, CASE tools and the like. Fast Ethernet, which permits data rates up to 100 Mbps, offers the opportunity for the Heinz School to use relatively inexpensive over twised-pair cables that would be able to support the applications needed here.

How it is measured in industry?

The cabling itself is measured in cost per feet although many other costing issues are involved in wiring a LAN. Most of the literature I came across in my research, however, did not separate the costs for the specific cables. They are selling integrated solutions, some of which are offered through a VAN.

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Question B

There are many other variables that are relevant to making the decision about which transmission medium to use when building a LAN. Cable and cabling equipment must meet both current and future transmissions requirements, electircal characteristics of the given LAN, and its topology. One book strongly recommended that a telecommunications manager adopt a structured approach to cabling that includes a plan to manage and support future growth.

Future challenges include:

Other issues that seem to dominate the industry include:

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References


Trade Journals and Magazines


Book


WWW sites


Companies

In addition to the manufacturers on the WWW, I ran across ads for these companies of interest.

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