Page 124 - Optical Switching And Networking Handbook

06_200023_CH05/Batesx 1/17/01 8:19 AM Page 109

Wave-Division and Dense-Wave-Division Multiplexing 109

bits per second (kbps) to 2.048 megabits per second (Mbps). However,
as the popularity grew, faster services were needed. Frame Relay
was bumped up a notch to run at speeds of up to 50 Mbps. At the
same time, Asynchronous Transfer Mode (ATM) was introduced to
operate at speeds of 50, 155, and 622 Mbps. The future will offer
speeds of 2.488 Gbps. Add to these network services the growth of
the Internet, the exponential growth of wireless connectivity (cellu-
lar and PCS), and the increased speeds of silicon chipsets and one
can see where the bandwidth is being demanded more in the appli-
cations but also in the networks to sustain the throughput.

Wave-Division Multiplexing

Ten years ago, implementation of the OC-48 SONET specification
had the industry believing that limitless bandwidth was available.
One can just imagine that a mere decade ago the 2.5-Gbps capac-
ity of the optical fiber networks was innovative and exceeded our
wildest imaginations about how we would ever fill these communi-

Decline in prices and increases in investments and revenues
Figure 5-2
Chart of value 80
80% Decreases
over time
70

60 60% Increases
50 Price decreases per minute for long distance

40 Investment Increases in Outside Plant 40% Increases
30 Revenue Increases
20
10

Time