Fault Localization of PON
description
Transcript of Fault Localization of PON
Fault Localization of PON
Yeung Chue Hei (1008620051)Lam Yi Kwan (1008627154)
Network Structure
FTTX (fiber to the X)Passive (PON)Multiplexing (→P2MP)
TDMWDM
Goals
Maintain service quality 1/3 of service disruptions are due to fiber cable Fault can be a disaster
Assisting reparation Reduce lost Efficiency
Not affecting the other service
Challenges
High resolution VS high DR capabilitiesMeasurement timePoint-to-multipoint problem
Solutions for TDM-PONs
P2P Active By-pass Passive By-pass Integrated OTDR functionality
P2MP Tunable OTDR and wavelength selective reflectors Conventional OTDR and controlled reference reflections Brillouin OTDR
Solutions for WDM-PONs
Tunable OTDR/multi-wavelength source and optical reflectorRe-using existing light sourcesCommercial multi-wavelength OTDR
Other solutions
Optical Code-division MultiplexingOptical Frequency Domain Reflectometry
Measuring the Individual Attenuation Distribution of Passive
Branched Optical NetworksKuniaki Tanaka, Mitsuhiro Tateda, Senior Member, IEEE,
and Yasuyuki Inoue, Member, IEEEIEEE PHOTONICS TECHNOLOGY LETTERS, VOL 8,
NO 7, JULY 1996
Reference Reflector
Reference Reflector
Conventional OTDRSpecially designed branched networks Transmission line lengths differ with each other
Cannot test branched fiber losses individuallyGo to the subscriber terminals after branching and measure the transmission loss directly
Passive By-pass
“New” method
Arrayed Waveguide Grating (AWG)
Optical Splitter/Router Module
Optical Splitter/Router Module
Optical Splitter/Router Module
OTDR Configuration
OTDR Traces
Fiber Fault Identification for Branched Access Networks Using a Wavelength-
Sweeping Monitoring SourceChun-Kit Chan, Frank Tong,
Lian-Kuan Chen, Keang-Po Ho, Dennis Lam
Introduction
Conventional OTDR cannot differentiate Rayleigh backscattered light from different branchesMultiwavelength OTDR is expensive
Fiber Identification Scheme
To avoid pulse collision(2nL/c) < 1/(Nf)Eg. N=8, f=1kHz, n=1.5, max L=12.5km
Experiment
1 x 4 branched optical networkData channels: 1548nm, 1551nm1Gb/s 210-1 PRBS NRZL1=8.8km, L2=L3=6.6km, L4 is unmonitoredFBG: 1556.4nm, 1558nm, 1559.7nm3dB passband: 0.4nm, 0.8nm, 0.9nmSawtoothed signal: 2kHz
Summary
Makes use of FBGsNo additional monitoring sourceBoth time and frequency domainWith OTDR techniques, can locate exact fiber cut position
Q&A
Thank you for your attention!