Routing and switching in a wavelength convertible optical network

Wavelength-convertible switch architecture and routing algorithm for circuit-switched wavelength-division multiplexing optical networks is studied in this paper. Wavelength converters are used to resolve wavelength conflicts and to reuse wavelengths. These converters are not dedicated to individual channels, but are shared by the channels of a node or those of an outbound link in the share-per-node or the share-per-link wavelength-convertible switch, respectively. A routing algorithm is developed to conserve wavelength converters while maintaining performance close to that of a network with abundant converters. We find that converters can improve the network performance such as the blocking probability and fairness considerably.link_to_subscribed_fulltex

Routing for all-optical networks using wavelengths outside erbium-doped fiber amplifier bandwidth

In wavelength-division multiplexed wide-area optical networks, erbium-doped fiber amplifiers (EDFAs) are usually employed to boost lightwave power. However, EDFAs can only cover 35 nm of the 200 nm fiber bandwidth at 1.55 μm, and therefore messages transmitted on the remaining fiber bandwidth cannot be amplified. We propose to use wavelengths outside the EDFA bandwidth for sending messages over short distances in which amplification is not necessary. Routing determines which wavelength and links a message is routed on, and hence whether or not a message needs amplification. We design static and dynamic routing algorithms in circuit-switched networks and analyze the performance using simulation. The results show that use of wavelengths outside the EDFA bandwidth can decrease blocking and increase the network capacity.link_to_subscribed_fulltex

Circuit rerouting algorithm for all-optical wide-area networks

Rerouting for a circuit-switched wavelength-division-multiplexed all-optical network is considered in this paper. Due to the wavelength continuity constraint, a new connection may be blocked even if bandwidth is available between the origin and the destination. Rerouting can make the available bandwidth wavelength-continuous by changing the routes of certain existing connections to accommodate the new connection. To avoid disruptions of existing connections, Move-To-Vacant Wavelength-Retuning (MTV_WR) is proposed as the basic operation of circuit migration, in which a circuit is moved to a vacant wavelength on the same path, and the Parallel MTV_WR rerouting scheme is considered to reroute multiple circuits on disjoint sets of links. We design the optimal algorithm which minimizes the weighted number of rerouted circuits with the Parallel MTV_WR rerouting scheme. Numerical results using simulation show that rerouting can effectively reduce the blocking probability due to the wavelength continuity constraint while minimizing the incurred disruptions.link_to_subscribed_fulltex

Wavelength-convertible optical network

Wavelength-division multiplexing is emerging as the dominate technology in future all-optical networks. To efficiently use the wavelengths, wavelength converters are employed for a circuit-switched optical network in which a circuit can change its wavelength to resolve wavelength conflicts and to reuse the wavelengths. To improve the efficiency, a few converters are provided and shared by the incoming circuits in the share-per-node or the share-per-link wavelength-convertible switch. A heuristic algorithm for dynamic routing is used to reduce the number of converters. Performance gain in call blocking probability and fairness and in the reduction of the number of converters are shown.link_to_subscribed_fulltex

Survey of research and standards in high-speed networks

This paper surveys research and standards in high-speed networks. It first classifies high-speed networks according to the area of coverage. Secondly, it discusses the switches. Then, it examines network management protocols: media access control, routeing, flow control and error control. Finally, it investigates current hig-speed network standards: DQDB, FDDI, ATM, and SONET.link_to_subscribed_fulltex