A Hierarchical Weighted Round Robin EPON DBA Scheme and Its Comparison with Cyclic Water-Filling Algorithm

A H-WRR (hierarchical weighted round-robin) EPON (Ethernet passive optical network) DBA (dynamic bandwidth allocation) algorithm is devised and investigated. WRR table entries having reports are scanned to generate the gate which is limited to the token size of the entry. LLEDs (logical link IDs) are grouped into classes and maximum delay control is provided per class and minimum idle state polling rate is configurable for each ONT (optical network terminal). The scheme´s bandwidth allocation behavior and delay performance are shown through VHDL simulation with highly random self- similar traffic and comparison is made with previous CWF (cyclic water-filling) DBA (Kim et al., 2005). We conclude that in general, WRR DBA outperforms cyclic DBA and the H-WRR DBA scheme provides very low delay and high throughput.