Benefits of optical bypass in WDM networks with hybrid optical-and-electronic switching node architecture

• Authors: Pratkasem Vesarach;Poompat Saengudomlert
• Venue: AINTEC '09 Asian Internet Engineering Conference
• Year: 2009

In a traditional WDM network, all traffic needs to be terminated at switching nodes and is switched electronically, e.g., by DXC, IP router, ATM switch, and SONET/SDH switch. With the emergence of the all-optical switching technology, traffic switching in the optical domain is becoming more practical and cost effective. With all-optical switching, traffic can potentially bypass electronic switching; this mechanism is referred to as optical bypass. When optical bypass is applied in the network, the total amount of electronic switches and thus their costs can be reduced. Due to this benefit, this paper investigates a hybrid switching node architecture in which a node consists of both types of switches (i.e., electronic and all-optical). We provide the MILP formulation for the optimization of network resource provisioning based on the hybrid switching node architecture. Unlike previous works, our MILP formulation includes the wavelength continuity constraint which must be satisfied for practical all-optical switches without wavelength conversion. The results demonstrate that, when the optical bypass technique is applied, the amount of electronic switching in a WDM network can decrease dramatically without reducing the amount of traffic supported by the network.