Informatics Publishing Limited

S. Indira Gandhi ¹, V. Vaidehi ¹, Xavier Fernando ²

Affiliations
1 Madras Institute of Technology, Anna University, Chrompet–600044, IN
2 Department of Electrical Engineering, Ryerson University, Toronto, CA

Abstract

Effective Routing and Wavelength Assignment are the two important criteria used for improving the blocking performance in optical Wavelength Division Multiplexing (WDM) networks. Due to the increase in data traffic in the internet scenario, the existing algorithms for effective wavelength assignment and routing are not adequate to provide an optimal level of performance. Hence, the need arises to propose efficient routing and wavelength assignment algorithms to meet the requirements of different types of networks that are part of the internet. In this paper, Hop Routing Algorithm (HRA) has been proposed to improve the Overlay Routing Algorithm (ORA) for Automatically Switched Optical Networks (ASON). The existing ORA allocates long light path for each connection request. This is not an efficient method for utilizing the light path if the connection request requires only minimum bandwidth. The proposed HRA checks the bandwidth requirement of the connection request and compares it with link bandwidth. If the bandwidth of the connection request is lower than the available link bandwidth, then HRA allocates a light path for the next hop. Thus, longer light path for each small connection request is restricted by HRA and it uses minimum number of wavelengths. It is observed that the proposed HRA accepts more requests without exceeding the available bandwidth. From the simulation studies it is found that the packet loss has been reduced in the proposed HRA. Also, this paper presents a computational model for estimating the Blocking Probability in ASON network.

Keywords

Optical Networks, Routing, ASON, ORA, WDM.

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S. Indira Gandhi ¹, V. Vaidehi ¹, Xavier Fernando ²

Affiliations
1 Department of Electronics Engineering, Madras Institute of Technology, Tamil Nadu, IN
2 Department of Electrical and Computer Engineering, Ryerson University, CA

Abstract

Dynamic Online Routing Algorithm (DORA) has been already proposed for conventional networks to distribute load evenly across the network. However, the exponential growth of the internet has placed heavy burdens on network management and control application when the existing protocols are used. Adding more resources to the network may temporarily remove congestion conditions. However, it is not a cost-effective solution in solving resource contention problems in the long run. The network providers are facing problems in setting up on-demand network tunnels in backbone or transport networks. The MDORA proposed in this work is useful to decide the optimum number of regenerators to be placed on each node. Placement of regenerator in all the nodes is not cost effective and hence in this work, techniques have been proposed to place the regenerators only in selected nodes. Node selection for regenerator placement is performed using fuzzy logic.

Keywords

DORA, MDORA, Fuzzy Logic, Conventional Network.

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