We analyze the occurrence of FWM noise in bursty metro network transmission of Ethernet packets directly on the WDM layer. We obtain more than 5 dB reduction in FWM noise for traffic loads less than 0.7 both for uniform and self-similar traffic. Gigabit Ethernet is increasingly gaining in importance as a protocol for the future WDM metropolitan networks due to its low cost and relatively straightforward implementation - indeed efforts are under way to implement 10 Gb/s Ethernet interfaces. The question of efficient framing mechanism for Gigabit Ethernet, however, remains still open with the same underlying expectation that it should be straightforward and inexpensive, In this manuscript we analyze the performance of a framing protocol which does not use idle patterns to fill up gaps between packets - it rather only envelops the packets. As such, it results in power fluctuations on the line which are statistical in nature and are determined by the nature of the traffic model. The consequence of this is that non-linear effects which are power dependent also become statistical in nature. We analyze the performance with regards to one particular effect, the four-wave mixing FWM noise. Because of the statistical nature of the transmission, not all the channels are present all the time, meaning that there will be reduction in the generated FWM noise. We derive an analytical reduction factor, compare it to the reduction obtained through simulations and note an excellent agreement. We further note that the reduction is not dependent on the burstiness of the traffic.
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