This article summarizes the main challenges that arise, and that need to be addressed in the core optical networks of the next generation, focusing on energy efficiency and awareness, heterogeneity of the traffic and the ever-growing need for transmission capacity. In all-optical mixed line rate (MLR) network, feasibility of a lightpath is determined by the physical layer impairment (PLI) accum...

Advance reservation of lightpaths in Grid environments is necessary to guarantee QoS and reliability. In this paper, we have evaluated and compared several algorithms for dynamic scheduling of lightpaths using a flexible advance reservation model. The main aim is to find the best scheduling policy for a Grid network resource manager that improves network utilization and minimizes blocking. The ...

All-optical wavelength division multiplexing networks are the most promising candidate for the next generation wideband backbone networks. To improve the utilization of wavelength, time division multiplexing technology is introduced. The routing, wavelength and time-slots assignment problem was studied in such time-space switched networks. Two new dynamic algorithms were proposed which distribu...

Recent developments in optical devices and communication protocols have made possible real-time provisioning in DWDM optical networks without human intervention. In order to provide an end-to-end optical path for an IP client, the widely known Routing and Wavelength Assignment (RWA) problem must be solved. In this paper we introduce a new RWA procedure meant to support different classes of serv...

We consider the problem of routing uniform communication instances in switched optical rings that use the wavelength-division multiplexing (or WDM) approach. A communication instance is called uniform if it consists exactly of all pairs of nodes in the graph whose distance is equal to one from a specified set S = fd1;d2; : : : ;dkg. When k = 1 or 2, we prove necessary and sufficient conditions ...

According to a quick growth of the bandwidth capacity of WDM network, traffic damage due to a failure of network components is becoming unacceptable. To overawe this problem, a protection method that prepares backup light paths for each working path is now considered to improve reliability of networks. In this paper, it proposes an energy efficient routing in WDM passive optical networks. Routi...

Routing and wavelength assignment (RWA) is an important problem that arises in wavelength division multiplexed (WDM) optical networks. Previous studies have solved many variations of this problem under the assumption of perfect conditions regarding the power of a signal. In this paper, we investigate this problem while allowing for degradation of routed signals by components such as taps, multi...

In this paper, we propose methods for solving broadly applicable integer multicommodity flow problems. We focus in particular on the problem of routing and wavelength assignment (RWA), which is critically important for increasing the efficiency of wavelength-routed all-optical networks. Our methodology can be applied as a special case to the problem of routing in a circuit-switched network. We ...

The traffic grooming technique provides a two-layer traffic engineering capability by aggregating and routing up-layer low-bandwidth traffic flows over low-layer re-configurable routed high-bandwidth connections. In this paper, we optimize traffic grooming for static traffic in mesh Wavelength Division Multiplexing (WDM) networks with wavelength converters. The optimization objective is to maxi...