Performance evaluation of an ultra-fast pipeline scheduler for next-generation networks

The Internet Protocol (IP) plays a dominant role in current networking technologies and the Wavelength Division Multiplexing (WDM) technology provides tremendous bandwidth. The IP-over-WDM is becoming the right choice for Next-Generation Internet networks where Optical Burst Switches (OBS) is a promising technique to bridge the gap between IP and WDM. However, traditional OBS scheduling algorithms either have low computational complexity with high burst dropping probability or high computational complexity with low burst dropping probability. A critical design issue in OBS is how to reduce burst dropping probability as a result of resource contention using a high performance scheduling algorithm. In this paper, we present an ultra-fast scheduler which integrates the merits of both low computational complexity and low burst dropping probability. The key idea is to maintain all scheduled data bursts and void intervals in a binary representation. Then, fast hardware logic operations are performed to schedule incoming data bursts without the need to traverse and search all scheduled bursts in all channels. The new approach provides an effective optical burst switching for variable-length bursts with low computational complexity compared to existing scheduling algorithms.