Page 59 - Optical Switching And Networking Handbook

03_200023_CH02/Batesx 1/17/01 8:17 AM Page 44

44 Chapter 2

using a “data pump” to get the flow really moving, increasing the
overall throughput and data rates. The result is faster throughput
and shorter distances equaling more data.

Benefits of Fiber over Other Forms

of Media

The benefits of fiber over other forms of media are shown in Table
2-4. However, it is important to note that fiber has been used
extensively in the long-distance telecommunications networks and
local telephone company networks. It is more recent that single-
mode fiber has worked its way into end-user networks (LANs and
CANs). With single-mode fiber, the speeds are constantly being
upped, and the error performances are being improved continually.
The table concentrates on bit error rates (BERs) and the speed of
such cabling systems.

Table 2-4 Lower errors BER approximates 10 –15, –16 for fiber, whereas copper
–8
will be in the 10 –3,–4 for UTP to 10 for coaxial cable
Summary of
Fiber’s Attractive cost Cost per foot for fiber is now approximately $0.20
per foot compared with $0.13 for copper (Category 5+)
Advantages
Compared with Performance Immune from RFI and EMI without extra cost of
Other Media shielding on copper

Ease of Ease of installation due to lower weight and thickness
installation
Distances Greater distance with fewer repeaters. Now can
achieve 30 to 200 miles without repeaters. Copper and
radio are limited to less than 30 miles. UTP digital
transmission systems require repeaters every mile.
Bandwidth Fiber is nearing 1.6 Tbps, copper achieves 100 Mbps,
improvements and coax can carry up to 1 Gbps

Capable of carrying Using TDM and WDM, the fiber is both digital and
analog and digital frequency multiplexed, increasing capacity