Packet delay variation (PDV) can be avoided by controlling the departure of IEEE 1588 Precision Time Protocol (PTP) packets such that they experience close to constant delays over the fronthaul. This paper analyzes controlled PTP departure over fronthaul tree topologies and considering that radio (fronthaul) traffic itself behaves as background traffic relative to PTP. Since the method involves buffering of radio traffic prior to controlled PTP transmissions, its impact on buffer sizes at the baseband and radio units, and the corresponding increase in fronthaul latency are also analyzed. In the end, results collected through a self-developed FPGA-based testbed are presented.
Leave a Reply