Performance analysis of optical packet switches enhanced with electronic buffering

Optical networks with Wavelength Division Multiplexing (WDM), especially Optical Packet Switching (OPS) networks, have attracted much attention in recent years. However, OPS is still not yet ready for deployment, which is mainly because of its high packet loss ratio at the switching nodes. Since it is very difficult to reduce the loss ratio to an acceptable level by only using all-optical methods, in this paper, we propose a new type of optical switching scheme for OPS which combines optical switching with electronic buffering. In the proposed scheme, the arrived packets that do not cause contentions are switched to the output fibers directly; other packets are switched to shared receivers and converted to electronic signals and will be stored in the buffer until being sent out by shared transmitters. We focus on performance analysis of the switch, and with both analytical models and simulations, we show that to dramatically improve the performance of the switch, for example, reducing the packet loss ratio from 10^-2 to close to 10^-6, very few receivers and transmitters are needed to be added to the switch. Therefore, we believe that the proposed switching scheme can greatly improve the practicability of OPS networks.