Optimized XG-PON DBA mechanism for front-haul upstream traffic in virtualized small cell cloud-RAN architecture

Time division multiplexing passive optical networks (TDM-PONs) technologies are viewed as an attractive solution for flexible and cost-effective mobile front-haul for dense deployment of small cells in cloud radio access network (C-RAN) architecture. Due to the high latency of upstream transmission in TDM-PON because of using a dynamic bandwidth allocation (DBA) mechanism to share the upstream bandwidth, it is a challenge for TDM-PON to meet the strict latency requirement of C-RAN mobile front-haul. Several DBA mechanisms have been proposed in the literature to address this issue for IEEE Ethernet passive optical network (i.e. 10G-EPON) based mobile front-haul. However, ITU TDM-PON such as XG-PON have not yet even been explored in the context of mobile front-haul. In this paper, we present an optimized XG-PON-compliant DBA mechanism called Optimized-Round Robin (Optimized-RR) to support front-haul traffic transport over XG-PON in virtualized small-cell C-RAN architecture. We evaluate its performance in terms of delay, jitter and packet loss over a dynamic data rate mobile front-haul traffic by comparing it with two other recently proposed XG-PON- compliant DBAs namely, Group Assured GIANT (g GIANT) and simple Round-Robin (RR-DBA) DBAs. The performance evaluation results not only show its significant improvement in terms of upstream delay and utilization, but also show a lower packet loss and jitter for aggregated small cells front-haul traffic when comparing it to gGIANT and RR-DBA.