XGS-PON-Standard Compliant DBA Algorithm for Option 7.x Functional Split-Based 5G C-RAN

A 10-Gigabit Capable Symmetrical Passive Optical Network (XGS-PON) is considered as a cost-efficient fronthaul network solution for the Fifth Generation (5G) Centralized Radio Access Network (C-RAN). However, meeting the stringent latency requirements of C-RAN fronthaul with XGS-PON is challenging, as its upstream capacity is shared in the time-domain, and Dynamic Bandwidth Allocation (DBA) mechanism is employed to manage upstream traffic. The major issue with conventional DBA algorithms is that data arriving in the Optical Network Unit (ONU) buffer must wait for at least one DBA cycle before being scheduled, leading to poor delay performance. To address this, we propose a novel DBA algorithm named Traffic Prediction-based Enhanced Residual Bandwidth Utilization (TP-ERBU) that integrates a traffic prediction mechanism with enhanced residual bandwidth utilization to optimize delay performance in Option 7.x functional split-based C-RAN fronthaul over XGS-PON. The algorithm predicts future traffic to reduce delays in ONUs and reallocates residual bandwidth from lightly loaded ONUs to heavily loaded ones. Additionally, we develop an XGS-PON-based C-RAN simulation module named xCRAN-SimModule, using the OMNeT++ network simulator. Simulation results demonstrate that TP-ERBU improves packet delay by 20.59%, upstream channel utilization by 38.33%, packet loss by 25.00%, jitter by 5.71%, and throughput by 15.56% compared to existing algorithms.