Fiber Optic Network
Design And Management
Lesson Plan No. 8: Case Studies
Note:
When
you finish this lesson, you may take the online exam for
your Fiber U Certificate of Completion.
Objectives:
From this self-study lesson you should learn:
- How
to Apply your knowledge from lessons 1-7 on a number
of different case studies
- How
to choose components and calculate loss budgets
- How
to calculate a loss budget
- How
to specify tests of a completed network.
Now it is time to apply what you have learned. The case
studies are descriptions of networks that are typical for
fiber optic installations that will require you to choose
the proper components, calculate loss budgets and make
other decisions as to how the cable plants should be
designed.
These are a series of case studies created for use as
laboratory and homework exercises as part of classes
preparing for the FOA CFOS/D Fiber Optic Network Design
Certification. Each case study presents a scenario that is
relevant to the actual work of designing a fiber optic
network.
For each case study, a schematic of the network or system
is given, along with some basic information on the
proposed communications equipment and a series of
questions on the scenario presented. Each system is
described generally, assuming that the student is familiar
with various types of fiber optic communications systems,
including what type of equipment is required and the
specifics of most communications equipment transceivers.
Students should use the information provided to create a
basic system design, choose components, do a loss budget
analysis, create a test plan and look at some alternative
scenarios. All the questions should be answered.
A reference table of typical specifications for fiber
optic components and communications systems is given below
for use in the exercises but most case studies will give
specifications appropriate for the case study itself.
References
References needed are available online as well as in the
FOA textbooks.
Student Assignment:
Complete the case study exercises below. You may not want
to complete all of them, but should complete the ones most
relevant to your work.
Case
Study No. 1: Fiber To The Home
Case
Study No. 2: Metropolitan Telecom Network
Case
Study No. 3: Long Distance Telecom Network
Case
Study No. 4: Corporate LAN Backbone
Case
Study No. 5: Campus LAN Backbone
Case
Study No. 6: Industrial Link
Case
Study No. 7: Data Center
Case
Study No. 8: CCTV Surveillance Link
Case
Study No. 9: Metropolitan Government Network
Case
Study No. 10: Optical LAN (OLAN)
Typical Specifications
Representative component specifications for typical
products on the market are included in the table below,
but do not necessarily have to be used.
Component Specifications
|
|
|
Fiber Loss
|
|
Multimode GI @ 850 nm
|
3 dB/km (TIA 568: 3.5 dB/km)
|
Multimode GI @ 1300 nm
|
1 dB/km (TIA 568: 1.5 dB/km)
|
Singlemode at 1310 nm
|
0.4 dB/km (TIA 568: 1 dB/km)
|
Singlemode at 1550 nm
|
0.25 dB/km
|
|
|
Splice Loss
|
(TIA 568: 0.3 dB, all types)
|
Multimode, fusion
|
0.1 dB
|
Multimode, mechanical
|
0.3 dB
|
Singlemode, fusion
|
0.05 dB
|
Singlemode, mechanical
|
0.3 dB
|
|
|
Connector Loss
|
(TIA 568: 0.75 dB, all types)
|
Multimode, adhesive/polish
|
0.3 dB
|
Multimode, prepolished/splice
|
0.75 dB
|
Singlemode, adhesive/polish
|
0.3 dB
|
Singlemode, prepolished/splice
|
0.75 dB
|
|
|
Coupler (PON)
|
Coupler Loss (includes typical excess loss)
|
1X2
|
4 dB
|
1X4
|
7
|
1X8
|
11
|
1X16
|
15
|
1X32
|
19
|
Active Device and System Specifications
|
|
|
Digital Transceiver Specs
|
Power (dBm), T=transmit, R=receive
|
850 nm LED (up to 10 Mb/s)
|
T: -15 / -25 (into 62.5 / 50 fibers)
|
|
R: -20 > -30
|
1300 LED (100-200 Mb/s)
|
T: -15 / -20 (into 62.5 / 50 fibers)
|
|
R: -20 > -30
|
850 VCSEL (>1 Gb/s)
|
T: -3 > -10
|
|
R: 0 > -10
|
1310 laser (>1 Gb/s)
|
T: 0
|
|
R: -10 > -20
|
1550 laser (>1 Gb/s)
|
T: 0
|
|
R: -10 > -20
|
1550 laser with fiber amplifier
|
T: +10 > +20
|
|
R: -10 > -20
|
Video Link Specs
|
|
850 nm LED
|
T: -15 / -20 (into 62.5 / 50 fibers)
|
|
R: -25
|
1310 laser
|
T: 0
|
|
R: -10 > 0
|
1550 laser
|
T: 0
|
|
R: -10 > 0
|
1550 laser with fiber amplifier
|
T: +15 > 20
|
|
R: -10 > 0
|
Notes
LED, Laser and receiver specifications are typical numbers
for use in course case studies but do not reflect any
actual product specifications.
LEDs couple about 5 dB less power into 50/125 fiber than
62.5/125 fiber, while it makes no difference for lasers.
Higher receiver power should be considered the point at
which receivers are over-driven and require attenuators.
Link margin specifications for most standardized fiber
optic networks are on the FOA Tech Topics Site
(http://www.thefoa.org/tech/Linkspec.htm). It should be
used as a reference for designers and for the courses.
Remember supportable distances for some links at > 1
Gb/s are bandwidth limited.
Get
a "Certificate of Completion" When You Complete
The Course
After you complete the Fiber U Basic Fiber Optics
online self-study course, you can now take an online
exam and, when you pass the exam, get a "Certificate
of Completion" for this course. You should complete
all lessons including taking the quiz ("Test Your
Comprehension") at the end of every lesson. When you
think you are prepared, you can take an online exam
for a nominal fee ($20) which will give you a
"Certificate of Completion" for this course.
If
you are working on FOA certification, print out
(PDF) your completed case studies from Lesson 8
and save along with your Fiber U Certificate of
Completion for your application for
certification.
Read
more about the Fiber U Certificate of
Completion program.
For
more information on the FOA and its
certification programs, go to the FOA
page on certification.
For information on the FOA "Work to Cert"
direct certification program for those
with industry experience, go
here.
When
you finish all lessons, go here to take the
Fiber U Design Certificate of Completion Exam
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