Flexible Wavelength and Dynamic Bandwidth Allocation for NGEPONs

Flexible Wavelength and Dynamic Bandwidth Allocation for NG-EPONs Hussain et al. IEEE/OSA Journal of Optical Communications and Networking, Vol. 10 No. 6 June 2018 1

Outline • Background • Related works • Algorithm • Results 2

Background 3

Background • 4

Optical Distribution Network Optical Line Terminal (OLT) Optical Network Unit (ONU) 5

NG-EPON network diagram 7

GRANT of an OLT ONU #20 GRANT transmission windows OLT某一次的GRANT Send Data Frame REPORT buffer state 8

Related Works 9

Grant allocation comparison • 例子 1：總共 16個ONU，平均每個ONU可用頻寬是 6. 25 Gb/s。假設某一ONU要求120 KB，而四 個波長分別已經分配了5, 15, 20, 22 KB。 (a) Transmission time = 38. 4 us (b) Transmission time = 12. 96 us (a)會有延遲問題 11

Algorithm 13

Flexible wavelength and Dynamic Bandwidth Allocation • 14

Flexible wavelength and Dynamic Bandwidth Allocation(cont’d) • 15

Flexible wavelength and Dynamic Bandwidth Allocation(cont’d) 16

Comparison of FW-DBA and WF-DBA ONU 1的分配 Alpha這邊設為 1，代表有效使用率要大於 50% 17

Comparison of FW-DBA and WF-DBA(cont’d) ONU 2的分配 4 3 2 1 Guard time總共需要15. 625 KB 18

Comparison of FW-DBA and WF-DBA(cont’d) Guard time總共需要25 KB 19

Results 20

Performance evaluation • 比較modified-IPACT、WF-DBA、FW-DBA(α=1, 3) • ONU數量： 32, 64, 128 • 4個不同波長的通道，各25 Gb/s • 一個ONU中有90%民用，10%商用(設為民用的10倍) • 整體網路正規化後的負載分布在 0. 1~0. 9之間，例如在 0. 1時128個 ONU的平均負載是 78. 12 Mb/s • 所有訊框分布在 64到 1518 bytes之間 • Bursty traffic使用Markov Modulated Poisson Process(MMPP)產生 21

Average delay 22

Standard deviation of delay 23

Average number of wavelength used per grant 由左至右：WF-DBA, IPACT, FW-DBA alpha=1, FW-DBA alpha=2, FF-DBA 24

Reason for different delay performance • 25

Grant utilization 26

Frame resequencing delay 27

Relation between alpha and total numbers of ONU 實驗模擬 8, 16, 32, 64, 128, 256個ONU Alpha值 0到 100，每次增加 0. 5 28

THANKS FOR LISTENING 30