Cost Comparison of Optical Circuit-Switched and Burst-Switched Networks

This paper examines the economic viability of two technologies - optical circuit-switched (OCS) networks and optical burst-switched (OBS) networks - in the core network. We analyze and dimension OCS network (OCSN) and OBS network (OBSN) architectures for a range of traffic demands given the constraints on the network element capacities. We investigate the effect of traffic grooming for both of these architectures. We evaluate these network architectures for a national core network in Australia in terms of their capital costs and packet-blocking probabilities. We observe that OBSNs with traffic grooming at the optical layer may become more cost effective than OCSNs with traffic grooming at both the IP and optical layers for the same quality of service in terms of blocking probability. The cost advantage of OBSNs over OCSNs grows as the capacity of the core network increases. Hence, among the all-optical networking options that do not involve buffering at the core, OBS appears to be an attractive option especially for high-capacity core networks.