1. Study Project: Radio-over-Fiber
Abstract: Wi-Fi over fiber systems face challenges due to fiber transmission and other non-
linear effects in fiber. Radio-over-fiber (RoF) technology is wireless with optical backhaul. The
encoded data from Optical Line Terminal (OLT) is sent through the fiber to the Optical Network
Unit (ONU). The data is accessed at ONUs to the access points. The QAM encoded data is
passed through OFDM modulator and sent to the ONU. The ONU is fixed to operate at certain
wavelength. An ad-hoc network of ONU’s communicating with each other is suggested to share
ONU-to-OLT resources. OFDM scheme is used since it is resistant to multipath fading. QAM
data is sent to the OFDM modulator where cyclic prefix is added and transmitted over the fiber.
The data accessed at ONU’s will be a ISM band centered around 5 GHz. This band can
accommodate more channels than 2.4 GHz band. As per allocation standards for Wi-Fi, a
spacing of 20MHz can accommodate up to 32 channels. Fiber length will be optimized based on
the distances in the network. The test bed is designed on OptiSystem 11 platform. The QAM
constellation at output is analyzed after transmission impairment compensation and realizable Bit
Error Rate (BER) will be obtained.
Figure: Architecture of system and ring topology of Wi-Fi routers.
Time duration required:One semester (4 months, 20 days).
Optical
Line
Terminal
OLT
ONU1
ONU2
ONU3
ONU4
ONU5

2. References:
1. Abhishek Dixit,Bart Lannoo,Didier Colle,Mario Pickavet,etal,”Energy Efficient Dynamic
Bandwidth Allocation for Ethernet Passive Optical Networks,” 2012 IEEE International
Conference on Advanced Networks and Telecommunication systems(ANTS).
2. Hee-Jung Byun, Ji-Myung Nho and Jong-Tae Lim, “Dynamic bandwidth allocation
algorithm in ethernet passive optical networks”, Electronics letters,26th June 2003,Vol
39,No.13.
3. Leonid Kazovsky , Kadir Melih Albeyoglu, Anujit Shastri ,“Hybrid Optical Wireless
Access Networks”,Proceedings of IEEE,Vol 100,No.5,May 2012.
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PON’s with Adaptive Dynamic Bandwidth Allocation and Colorless ONUs”,IEEE
proceedings ,Future network and mobile summit,2012 ,pages 1-8, july 4-6, 2012.
5. R.P.Khare,” Fiber Optics and Optoelectronics”,Oxford University Press.
6. Hans-Jorg Thiele, Marcus Nebeling, “Coarse Wavelength Divison Multiplexing
technologies and applications”.
7. G.P Agarwal,”Fiber Optic Communications”,New York.
8. Biswanath Mukherjee,”Optical WDM networks”, Springer, New York.
9. Rajiv Ramaswami, Kumar N.Sivaranjan, “Optical networks,a practical perspective,2nd
edition.