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Until recently, the problem of how to design survivable optical networks under single link failure has been studied quite extensively. However, the study on the design of optical networks for single node failure has been rarely discussed. This paper proposes 3 methods to reconfigure multicast traffic in WDM network for single node failure based on Integer Linear Programming (ILP) technique by reconfiguration of entire network, reconfiguration of traffic traversing through failure node and reconfiguration of traffic adjacent to failure node.The last two methods, we used node-disjoint share protection path between primary path and backup path to reconfigure multicast traffic. We used multicast routing and wavelength assignment (MC-RWA) namely, Light-Tree(LT) and Virtual Light-tree(VLT) to design multicast traffic in WDM network for a single node failure. The objective of this paper is to design WDM network which supports multicast traffic for a single node failure in order to minimize fiber for survival network, given a static multicast traffic set, the number of wavelength per fiber can support and the network design approach (LT and VLT).

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Traffic congestion on not only highways but also complex urban road networks has attracted the attention of many researchers. Traffic congestion growing in urban road networks is an inevitably important problem especially for populated cities during rush hours. A traffic blockage can be realized as the source of traffic congestion, which can propagate to form queues and sometimes a gridlock. Traffic blockages are triggered by complicated factors ranging from temporal and spatial situations. Recurrent congestion is a traffic congestion that occurs during morning and evening rush hours e.g. from school buses and parent vehicles to drive their children to-and-from schools. In addition, unforeseen, unexpected events that can cause as non-recurrent traffic congestion e.g. car breakdowns, accidents, road maintenance, and severe weather conditions, which can disorder normal traffic flows and reduce road capacity. Traffic blockage may spread its negative impacts to neighbouring upstream and downstream links. And that can lead to the formation of congestion gridlock, which further reduce traffic flow efficiency in a complex urban road network. These problems are vital but often tough to resolve in urban road networks. In this paper, the Chula-Sathorn SUMO Simulator (Chula-SSS) dataset has been used with Simulation of Urban Mobility (SUMO) to simulate recurrent and non-recurrent congestion cases. The detection is based on the information from simulated lane area detectors. For non-recurrent case, lanes are closed to simulate the gridlock occurrences. With the morning case of calibrated Chula-SSS dataset, both recurrent and nonrecurrent congestion based gridlock have been studied with upstream and downstream nearby detectors and preliminary results are herein reported upon the gridlock status as detected by using different combinations of traffic jam length and mean speed conditions at both the upstream and downstream detectors of every intersection within the critical looped road segments.

VANET are now becoming an interesting area of wireless network research. In road network where road infor mation is exchanged among cars, all traffic information must be accurately measured, processed and disseminated to the vehicles in a timely manner. This paper proposes the data dissemination protocol for VANET which is deployed in a roadside unit to help cars exchange their traffic information efficiently. In order to verify the performance of the proposed protocol, this paper uses the network simulator (NS2) software to model and test road network scenarios. Simulation results shows that using the proposed protocol with the roadside unit can decrease traffic load, total dissemination time and can increase the data received ratio and throughput.