Efficient routing for hybrid optical-CDMA and WDM all-optical networks
Shadaram,Mehdi
University of Texas at San Antonio
Musa,Ahmed
University of Texas at El Paso
Medrano,John
University of Texas at El paso
Gonzalez,Virgilio
University of Texas at El paso
Cotae,Paul
University of Texas at San Antonio
In this article, we propose an optimal dynamic routing algorithm based on flooding mechanism [15] in conjunction with Viterbi algorithm using wavelength and optical code division multiplexing (O-CDM and WDM). The proposed algorithm addresses the problem of routing optical signals across an all-optical circuit-switched backbone network while maintaining the best possible quality of the optical signal. This constraint problem is addressed by incorporating the photonic-specific attributes that degrade the routed signal in the routing metrics (or costs). Furthermore, the proposed algorithm is able to select the optimal route in a network in which each channel that is labeled by a wavelength in conjuncture with a code has a different quality metric and the switch affects differently each input/output combination.
A fundamental understanding of the basic routing techniques and the factors that influence their behavior is critical in designing and selecting appropriate routing strategies for a network. The proposed algorithm provides a better signal quality connection than others (e.g., FWMDP algorithm). In addition, better utilization of the network resources can be achieved when the impairments in the network are taken into consideration in the routing algorithm. Thus, a significant reduction in the connection-blocking probability can be observed at a heavy network traffic load.
Because of the utilization of flooding mechanism in the devised algorithm, a heavy traffic load is generated during the path establishment period. This gigantic load will lead to computational complexity. However, to alleviate this complexity, different optimization methodologies are proposed. Furthermore, a rule of thumb can be used to establish a path based on a predefined number of packets. For instance, at 180 Erlangs network traffic load, one can establish a path based on the first and the sixth received packet with a probability of success equal to 71% and 100% respectively.
Dr. Mehdi Shadaram, Briscoe Distinguished Professor and Chair of the Department of Electrical and Computer Engineering has extensive experience in obtaining and successfully directing engineering grants. He has been either PI or Co-PI for numerous grants and contracts, totaling more than $6 million, in the past 10 years. NASA, Jet Propulsion Laboratory, National Science Foundation, Office of Naval Research, Department of Defense, Texas Instruments and Lucent Technologies have funded his research projects. His main area of research activity is in broadband analog and digital fiber optic communication systems. He has published more than seventy articles in refereed journals and conference proceedings. He has extensive experience with mentoring minority and underrepresented groups. Under his supervision, seven PhD candidates and thirty-five Master’s students have finished their degree program in the past 20 years. He is a senior member of IEEE and member of OSA, SPIE, ASEE, and HKN. He received his Ph.D. in electrical engineering in 1984.