Performance evaluation of XG-PON based mobile front-haul transport in cloud-RAN architecture

Time division multiplexing passive optical network (TDM-PON) technologies are viewed as an attractive solution for flexible and cost-efficient mobile front-haul for cloud radio access network (C-RAN) architecture. However, it is a challenge for TDM-PONs to meet the strict latency requirement of mobile front-haul in C-RAN because they use a dynamic bandwidth allocation (DBA) mechanism to manage upstream traffic. The latency issue of TDM-PON based mobile front-haul has been extensively investigated in the literature with particular focus on IEEE TDM-PON (e.g., 10G-EPON). However, ITU TDM-PONs such as XG-PON and XGS-PON have not yet even been explored in the context of mobile front-haul. To cover this gap, we first evaluate the performance of two recently proposed XG-PON-standard-compliant DBAs, namely, group-assured GIANT (gGIANT) and round-robin DBA (RR-DBA), over simulated mobile front-haul traffic. We conclude based on our evaluation that neither RR-DBA nor gGIANT satisfies the delay required for mobile front-haul. Therefore, we propose an optimized DBA known as optimized round-robin (optimized-RR) that support front-hauling over XG-PONs. The performance evaluation of our optimized DBA against gGIANT and RR-DBA shows significant improvement in upstream delay and utilization as well as lower packet loss and jitter for front-haul uplink traffic transmitted via XG-PON in virtualized C-RAN architecture.