19-01-2012, 02:28 PM
Fundamentals of Passive Optical Network – Components & its Variants
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Passive Optical Network
•Passive optical elements (splitter, coupler, …) based optical distribution network
•Special form of FTTC or FTTH
•Physical star, but logical bus
•Cost effective technology for distribution services
•No powering of remote electronics
•Eliminates need for conditioned enclosures
•Transparent to signal formats
•Simplifies future upgrades
Passive Optical Network
•Optical Distribution Network (ODN)
–Comprised of single-mode optical fibers and the passive optical components (optical splitters)
–Offers one or more optical paths between one OLT and one or more ONUs
–Attenuation (path loss): difference in path loss between two homes limited to 15dB
GPON
•Main requirements
–Full service support including voice (TDM, both SONET and SDH), Ethernet (10/200 BaseT), ATM, leased lines and more
–Physical reach of at least 20km with a logical reach support within the
protocol of 60 km
–Support for various bitrate options using the same protocol, including symmetrical 622 Mbps, symmetrical 1.25 Gbps, 2.5 Gbps DS and 1.25 Gbps US and more
–Strong OAM&P capabilities offering end to end services management
–Security at the protocol level for DS traffic due to the multicast nature of PON
