A Performance Study of CPRI over Ethernet with IEEE 802.1Qbu and 802.1Qbv Enhancements

There has been a debate on whether or not Ethernet, a highly cost effective technology, could meet the stringent latency and jitter requirements imposed by CPRI. To facilitate the discussion, we conducted simulations to understand how Ethernet performs when carrying CPRI traffic with the two Ethernet enhancements, currently being standardized by IEEE, namely frame preemption (802.1Qbu) and scheduled traffic (802.1Qbv). Our simulation results led to two conclusions: 1) Ethernet networks with or without frame preemption, regardless of being shared or dedicated to CPRI traffic, can not meet the CPRI jitter requirement of 8:138 ns, confirming a widely hold belief; 2) Ethernet with the enhancement of scheduled traffic in conjunction with a well defined scheduling algorithm could significantly lower or even completely remove jitter thus could meet CPRI jitter requirement. To the best of our knowledge, this paper is among the first to study the performance of Ethernet with IEEE 802.1Qbu and 802.1Qbv enhancements and to demonstrate by simulation that Ethernet with scheduled traffic could meet CPRI jitter requirement.