Understanding SONET: Network Standards and Operations
Indicate whether the following statement is true or false:
SONET was not the first effort to standardize the digital hierarchy in the world.
FALSE TRUE
Mark with X or correct:
SDH is a standard coaxial cable network with…
XXX
With twisted pair…
…
With microwave radio…
XXX
With optical fiber cable…
XXX
None of the above…
…
Problem Solving:
If the propagation of the transmitted beam is along the boundary of two media and the angle of incidence is 66.10°, determine the refractive index N1.
n1 sen x = n2 sen y; n1 = (n2 sen y) / (sen x) = (3.2 * 1) / (sen 66.1) = 3.5
Mark with X:
The input data rate is the influent C-12
1.5 Mbps… …
2 Mbps… …
6 Mbps… XXX
8 Mbps… …
34 Mbps… …
45 Mbps… …
140 Mbps… …
Mark with an X or correct answers:
The light rays travel in straight lines unless there is a change in:
The speed of light… …
The acceleration of photons… …
The refractive index… XXX
None of the above… …
Network Design:
Draw a single SONET network using the following devices. Label all lines, multiplexers, five road sections, and STS (3 inputs and 2 outputs), 3 multiplexers insertion/extraction, 7 generations level.
[Diagram would be inserted here]
SONET Operations:
SONET carries out the construction of frames, mixing, and handling errors.
Photonics Section Line Road:
Calculate each of the following capabilities:
CAU-4 = 8 x (9 + 261 x 9) x 8 x 103 Mbps = 150,912 Mbps
CVC-4 = 8 x (261 x 9) x 8 x 103 Mbps = 150,336 Mbps
CC-4 = 8 x (260 x 9) x 8 x 103 Mbps = 149,760 Mbps
Show that the actual capacity of an STM-1 is:
150,336 Mbps
C_(c-4) = 8 x (9 x 261) x 8 x 10-3 = 150,336 Mbps
Questions and Answers:
What is the relationship between SONET and Synchronous Digital Hierarchy?
It is natural that the specification of SONET and layout of the frames includes mechanisms to carry signals incompatible tax systems (particularly asynchronous services such as DS-0 and DS-1).
Why is the SONET network called synchronous?
By using a single clock to manage the timing of transmissions and computers across the entire network. Since this synchronization adds a certain predictability to the system, this together with a strong frame design allows individual channels to be multiplexed, thereby improving the speed and reducing cost.
What is the relationship between STS and STM?
Each level STS (synchronous transport signal), supports a certain data rate, specified in Mbps and STM should be compatible with existing hierarchies and STS levels. This is the relationship that the lowest level of STM, STM-1, is set to 155.520 Mbps, which is exactly equal to the rate of STS-3.
- STS Speed (Mbps)
- STS-1 51.840
- STS-3 155.520 STM-1
- STS-9 466.560
- STS-12 622.080 STM-4
- STS-18 933.120
- STS-24 1,244,160 STM-8
- STS-36 1,866,230
- STS-48 2,488,320 STM-16
- STS-96 4,976,640
- STS-192 9,953,280 STM-64
What is the function of a SONET regenerator?
We say that an STS is a regenerative repeater, the only thing that is receiving an optical signal and regenerates it, that would be its main function, besides the SONET regenerator overhead replaces any existing information (header information) with new information. These devices operate at the data link level.
What are the four levels of SONET?
1. Photon level. 2. The section level. 3. Line level. 4. Level of road.
Describe the functions of each level SONET.
1. Photon level – It is with the physical layer of the OSI model, including the physical specifications for fiber channel, receiver sensitivity, the functions of multiplexing, etc. SONET uses NRZ coding. 2. Level – This is the section that handles the transfer of a signal through the physical section also deals with the construction of frames, mixing and control of errors, the section level overhead is added to the plot at this level. 3. Line level – It is responsible for the transfer of a signal through the physical line, in addition to the overhead line level is added to the plot of this level. STS multiplexers and multiplexers insertion/extraction offer line-level functions. 4. Level of road – Responsible for transferring a signal from its source to its destination optical optics. In the optical source, the signal is changed from one form to a form optical electronics, is multiplexed with other signals and are encapsulated in a frame. Optical destination, the received frame is demux and individual optical signals are converted to their corresponding electronic forms. The level of path overhead is added at this level. STS multiplexers provide path-level functions.
What kind of coding is used in SONET?
NRZ encoding is used.
How do you organize an STS-1 frame?
The basic format of an STS-1 frame in the photonic level shown in Fig. Each frame contains 6480 bits (810 bytes). STS-1, also transmit at a speed of 51.840 Mbps.
Multiple Choice:
17. SONET is a standard for networks… … … …:
a) twisted pair cable.
b) coaxial cable.
c) Ethernet.
d) fiber optic cable. (Correct)
18. SONET is an acronym for Network… … … .:
A) Optical synchronous. (Correct)
b) standard optics.
c) Open symmetrical.
d) Open standard.
19. In a SONET system, … … … .. eliminate the noise of a signal and can also add or remove headers:
a) A multiplexer STS.
b) A regenerator. (Correct)
c) A multiplexer insertion/extraction.
d) A repeater.
20. In a SONET multiplexer, …. Can eliminate signs of a path:
a) A multiplexer STS. b) A regenerative c) A multiplexer insertion / extraction. d) A repeater. 21. The optical link between two SONET devices called either … … …: a) A section. b) A line. c) A road. d) None of the above. 25. The level … … .. SONET carries out the construction of frames, mixing and handling errors: a) Road. b) Line. c) Section. d) photons. 26. The level … … … .. SONET transfers a signal through a physical line: a) Road. b) Line. c) Section. d) photons. 27. The level … … … …. SONET transfers data from its source to its destination optical optics: a) Road. b) Line. c) Section. d) photons. 32. In an STS-1 frame, the first three columns contain … … ….: A) line overload and section. b) User data. c) Overload the road line and section. d) Overloading of the road. 20. Indicate the main areas of application of optical fibers. R. Interconnection trunk connections between telephone exchanges local Seaway Networks Metropolitan Networks 22. Indicate the optical advantages most commonly used in telecommunications. R. Noise immunity: Low signal attenuation greater bandwidth