DWDM

Question 1

DWDM

MANs

Answer 1

• Combines multiple inputs Into diff. Color single output wavelength channel.

• Fiber Trans
• Optical Networks
• Uses Colors for light Trans
• Speed problem (Chromatic Dispersion)

Question 2

Access Layer Network

Answer 2

DSL, SONETS, Fiber Ch., Cable modems, Ethernet

Question 3

Long Haul Topologies

Answer 3

Mesh, Ring, Pt. To Pt.
• Conn to MANs
• More bandwidth

Question 4

TDM

More than 1 call can be on single line

Answer 4

• Increases voice traffic on single line

Question 5

SONET

North America

Answer 5

Used in North America

• Comes in 4 inputs(OC-48), Goes out 1 output (OC-192)

Question 6

SDH

Synchronous Data Heirarchy

Answer 6

Used Elsewhere

Question 7

WDM

Increase carrying capa of fiber

Answer 7

• Each ch. TX @ diff Freq. / diff color

* several ch. make rainbow

Question 8

Diff between WDM/DWDM

1 degree of space

Answer 8

DWDM has 1 degree of space between wavelengths for more capacity.

Question 9

Optical AMP

Amplifies Signal / Re-Amplifies Signal

Answer 9

Does not re-generate / re-shape signal.

Question 10

Regenerator

Answer 10

Re-shapes, re-times, re-TX Signal.

Question 11

DWDM

Saves Money

Answer 11

Increases network capacity w/o expensive upgrades.

Question 12

Optical Add Drop Mux

OADM

Answer 12

Passive - Still works w/o power. High mean time between failure (MTBF) DWDM protection

Question 13

1Adv of SONET - (DCC) Data Comm. Ch.

Answer 13

For operations, alarms, signals info.

Question 14

Fiber

Answer 14

Carries signal much further than copper, lower error rate, immunity to noise.

Question 15

Wide Band WDM

1980’s

Answer 15

• 1 Fiber pair TX

* 1 Fiber pair RX

Question 16

Narrow Band WDM

Answer 16

2 to 8 ch. of fiber used.

Question 17

Dense WDM

Mid 90’s

Answer 17

16 to 64 Fiber Ch.

Question 18

Dense WDM

Late 90’s

Answer 18

64 to 160 Fiber Ch.

More ch. by decreasing spacing between wavelengths

Question 19

Wavelengths

nm

Answer 19

Represented in nm

Question 20

Main job of optical fiber

Guide light/Min Loss

Answer 20

Guide light with min loss of signal.

Question 21

100% of light that strikes surface

Answer 21

Is Reflected (bounces back)
 or Refracted (Angle is Altered)

Question 22

TX Challenges of Fiber

Answer 22

• Attenuation

* Chromatic Dispersion