Jaypee Institute of Information Technology (JIIT) 2008 B.E Test 3 : Optical Fibre Networks - Question Paper
JAYPEE UNIVERSITY OF INFORMATION TECHNOLOGY, WAKN.\GHAT TEST-UI (November-2008)
B.Tech (VII Semester) ECE/CS/ITvBI COURSE CODE: 07B71PH404 MAX.MARKS: 30
COURSE NAME: OPTICAL FIBER NETWORKS
COURSE CREDITS: 3 ( 3-0-0)_MAX.TIME' 1 HR 30 MIN.
.Vote: Attempt all questions. Marks are assigned against each question.
1. (a) A ray of light moving in a material of refractive index 1.2 is incident on the optical fiber opening ai an angle of 60 degree with respect to the normal. Determine whether this ray of light will propagate in fiber or not. (Refractive index of core is 1.5 and that of cladding is 1.4).
(b) What are Leakey modes of an optical fiber? How are these modes removed from the fiber
(c) Consider an 8/125 single mode fiber operating at 1300 nm with a loss of 0.8 dB/km. The line width of the source is 0.013 nm Calculate the threshold power levels of Brillouin and Raman scattering.
(2+2+2)
2. Consider a system operating at a 1300 nm wavelength at lOOMb s data me with the following components
(i) Transmitter: InGaAs LED producing 50 microwatt into fiber with spectral width of 40 nm.
(ii) Connectors: 0.5 dB Losses
(iii) Fiber. Losses 1.5dB'Tunt Intermodal bandwidth disiancc product-800MHz.km, q~ 0-6. Length- Any length available.
(iv) Receiver: InGeAs pin photodiode. Sensitivity required for BFR*10* is given by PR(dBnu il 1.5 /ogBa) * 60.5. (B# is data bit rate in Mb/s). Allowance for aging, etc : 6dB. Coding:NRZ
(a) Calculate the maximum link distance assuming (hat the link is attenuation limited.
(b) Calculate the maximum link distance assuming that the link is dispersion limited.
(3+3)
3. (a) Explain SONET overhead channels. Explain with suitable diagrams the layout of line and path overhead STS*l frame of SONET
(b) Consider a star network that operates with sources that produces *3dBm of output power in a fiber. Assume that the fiber loss is 0.6 dB\m and that the station to star distance is 2 km. The required receiver sensitivity is -30 dBm. Calculate the number of stations that can be on this network if the connector loss is I dB per connector. The total insertion loss of the star is 3dB (from any input any output) and the link margin is 0 dB.
(3+3)
4. (a) Explain the working of Wavelength-Routed transmission network. Explain the concept of wavelength reuse in this system w ith suitable diagrams
(b) What are switched networks and how are they formed using Wavelength-Routed transmission network.
(3+3)
5. Write Shod notes on (i) ATM (ii) Wavelength selective WDM (iii) optical Multiplexers.
(2+2+2)
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