title page
ABSTRACT
Contents
List of Abbreviations 10
I. Introduction 12
II. Overview of WDM/Ethernet-PON Architecture 17
2.1. Architecture and Operational Principle of WE-PON 17
2.2. Critical Problems in Existing WE-PON: Constraints for Splitting Ratio 19
III. Proposed Time Division Duplex-based MAC protocol 24
3.1. TDD-based MAC Protocol with Improved Splitting Ratio 24
3.2. A Dynamic Bandwidth Sharing Mechanism 25
3.2.1. Frame Structure for Upstream and Downstream Traffic 26
3.2.2. Bidirectional Transmission Mechanisms 28
3.2.3. ONT Request-Based Threshold Decision Algorithm 31
3.2.4. ONT and OLT Request-Based Threshold Decision Algorithm 35
3.2.5. QoS Provisioning for High-Priority Downstream Traffic 37
IV. Performance Evaluation 39
4.1. Simulation Environment 39
4.2. Simulation Results 49
V. Conclusion 59
[국문요약] 61
References 63
Acknowledgement 67
Curriculum Vitae 68
Table 1.1. Comparison of Different Access Network Solutions 13
Table 1.2. Comparison Summary of WDM/TDM Hybrid PONs 15
Table 2.1. Specification of Optical Components (ETRI's internal document) 21
Table 4.1. Simulation Parameters 39
Figure 2.1. Overall WE-PON Architecture 18
Figure 2.2. RSOA output versus input power 19
Figure 2.3. Amplifier Gain versus Input Power 22
Figure 3.1. Fundamental Downstream Frame Structure 26
Figure 3.2. Upstream Frame Structure 27
Figure 3.3. Elastic Threshold Shift for ATA 28
Figure 3.4. Simplified Functional Block Diagram 30
Figure 3.5. DBA Algorithm for ATA. 31
Figure 3.6. SBA Algorithm for ATA. 33
Figure 3.7. Schematics of the OLT Scheduler 34
Figure 3.8. Fair Service-Based DBA Algorithm 36
Figure 3.9. OLT Scheduler for QoS Provisioning 37
Figure 4.1. Basic Topology Organizations 40
Figure 4.2. OLT Node Organizations 42
Figure 4.3. ONT Node Organizations 44
Figure 4.4. Splitter/Combiner Node Organization 46
Figure 4.5. Example of Traffic Load Allocation 48
Figure 4.6. Continuous time Diagram for Upstream and Downstream Link Throughput 50
Figure 4.9. Queue Size versus Offered Load 53
Figure 4.10. Traffic Scenario 54
Figure 4.11. Theoretical Link Throughput 54
Figure 4.12. Link Utilization via Simulation 55
Figure 4.13. Average Threshold Variation 55
Figure 4.14. Unused Downstream Bandwidth 56
Figure 4.15. Amount of Service Delayed 56
Figure 4.16. End-to-End Delay according to the classes 58