Protection Mechanism in PON Zhicheng Zhang 2010.12.14

1. Protection Mechanism in PONZhicheng Zhang2010.12.14

2. Outline Background Protection network architectures in the ITU-T recommendation Some novel protection architectures Architectures in tree-type WDM/TDM PON Architectures in ring-type WDM/TDM PON Conclusion and thinking

3. Background • As the bandwidth and services are evolved drastically in the access networks, preventive periodic test and protection from a failure without service disruptions become more and more important.

4. Protection network architectures in the ITU-T Recommendation

5. Four Architectures This approach offers an economical yet limited protection Only the feeder fiber is protected Cost and power budget is high Costly and high restore time

6. Some novel protection architectures

7. TDM PON Protection Novel 1:1 dedicated link protection architecture Two geographically disjoint fibers exist to protect against FF cuts. Every two adjacent ONUs form a pair to realize dedicated protection. More cost efficient

8. WDM PON Protection M=8 Four wavelengths in each wavebands A,C are for upstream and B and D are for downstream

9. Remotely Reconfigurable Protection Recovery within 90ms

10. Protection with ACS Monitor ACS: Access Control System CPD: automatic switching that will be controlled by ACS Activate section in ACS: responsible for sending generation of activation of signal

11. Mechanisms of Protections Green: normal Purple: a breakdown at working line Yellow: breakdown at working line and protection line Blue: breakdown at both working line and protection and also breakdown at working line neighbor

12. Protection in Ring-Type PON • Long-reach, ring type WDM/TDM hybrid PON • 2.Over 1 Tbps data flows through a ring fiber

13. Achitecture 1--A simple passive protection structure • Use fiber 1 with no fault • When fiber 1 has a fault, this makes LOS(loss of signals) of all OLT receivers high. Then detect these and go to "Use fiber 2 with fiber 1 fault". • 'clear signal' --fault clear, the status goes to "Use fiber with no fault". • 'LOS signal'--the status goes to "No Use fiber with all faults" • 4.wait a 'clear' high

14. OLT and RN Structure and Simulation results This method takes about 10.5 ms for the protection in the real situation.

15. Architecture 2--Using an electrical switch • 1+1 protection can be made of a coupler in a Tx and a switch in a Rx. • 1:1 protection can be made of a swtich in a Tx and a 1:1 coupler in a Rx. • The downstream uses 1:1 protection and the upstream uses 1+1 protection to make the passive protection.

16. 1. Less 1 ms recovery time 2. Require some amplifiers because the link loss is over 30 dB

17. Architecture 3 At OLT, the optical splitter combines the upstream traffic(US) and divides the optical power of downstream traffic(DS) to both lines.

18. Survivability for Double Failure When double failure happens, the capacity of the network use both line 1 and 2 at the same time provides survivability to the network.

19. Conclusion and Thinking • Most papers focus on restore time. • In PON, especially in WDM/TDM hybrid Pon, ONUs have different reliability requirements. Protection mechanism based on differentiated reliability requirement.

20. References [1]A Novel Protection Mechanism in TDM PON, M.M. Carvalho and E.A. De Souza, ICTON 2009 [2] Seamless maintenance and protection scheme for next generation access network, Jong Hoon Lee, [3] A simple passive protection structure in a ring type hybrid WDM TDM PON, Dong-Min Seol, ICACT 2009 [4] Pon protection in a long-reach WDM/TDM PON, Dong-Min Seol, COIN 2009 [5] protection scheme of fiber to the home passive optical network using access control system, Aswir Premadi, Kasmiran Jumari, [6] Next-Generation FTTH PON, Josep Segarra, 2008 [7] Protection Access Network: an Architecture Approach to Remote Monitor and Control, Aswir Premadi, Kasmiran Jumari, ICCTD 2009

21. Thanks!