OTDM light trail networks

Due to the limitation of the electrical port speed, current Ethernet switches can only run at most 10 Gb/s. In order to realize 100 Gb/s Ethernet switching, the OTDM technology can be exploited. OTDM lightpath network has the ability for 100 Gb/s Ethernet switching, however, more modulators need to be equipped in the transmitters, and only connections from the source node to its downstream nodes in a super lightpath can be realized. In this paper, the concept of OTDM light trail networks is proposed. Based on the light trail principle, which allows intermediate nodes to access the light trail, by using OTDM technology, the 100 Gb/s line speed can be realized without increasing the port speed or the number of modulators in the transmitters. One node structure for the OTDM light trail network is proposed and four methods for time slots assignment are classified. It is proved by numerical simulation that OTDM light trail networks can successfully increase the capacity of normal light trail networks. Compared with OTDM lightpath networks, cost can be saved and better performance can be obtained in OTDM light trail networks.