Abstract—Wavelength converters help to reduce the blocking probability of the network and enhance the fibre utilization. Since wavelength converter is an expensive component with respect to other components in optical network researches are constrained in minimizing this cost keeping the blocking performance as optimum as we can. The impact of the proposed algorithms on blocking probability is investigated. These algorithms are compared on the basis of blocking probability; number of channels and number of links are kept constant whereas the response of the algorithms is calculated by varying the load per link (in Erlangs). The blocking probability is also calculated for the network with wavelength conversion and without wavelength conversion. Keywords— Wave division multiplexing, Wavelength Converters, Blocking performance. I. INTRODUCTION A. Traffic grooming RAFFIC grooming is the process of grouping many small telecommunications flows into larger units, which can be processed as single entities. For example, in a network using both time-division multiplexing (TDM) and wavelength- division multiplexing (WDM), two flows which are destined for a common node can be placed on the same wavelength, allowing them to be dropped by a single optical add-drop multiplexer. Often the objective of grooming is minimizing the cost of the network. The cost of line terminating equipment (LTE) (also called add/drop multiplexers or ADMs) is the most dominant component in an optical WDM network's cost. Thus grooming typically involves minimizing the usage of ADMs. [1] The transmission capacity of a link in today’s optical networks has increased significantly due to wavelength division multiplexing (WDM) technology. The network performance is now mainly limited by the processing capability of the network elements, which are mainly electronic. By efficiently grooming low-speed traffic streams onto high-capacity optical channels, it is possible to minimize this electronic processing and eventually increase the network performance. Traffic grooming is an emerging topic that has been gaining more research and commercial attention. Most previous research on traffic grooming is mainly based Neeraj Mohan is working as HOD in Deptt. Of Computer Science & Engg. Rayat & Bahra Institute of Engineering & Bio-Technology, Sahauran, Distt. Mohali (Punjab)-140104 INDIA Amanjot Kaur is student in Computer Science & Engineering Department, Rayat & Bahra Institute of Engineering & Bio-Technology, Sahauran, Distt. Mohali (Punjab)-140104 INDIA. on the ring network topology. It is expected that there will be much more interest on the mesh topology suitable for longhaul, wide-area networks. This paper reviews most of the recent research work on traffic grooming in WDM ring and mesh networks. Data streams within a single optical fiber are carried over different wavelengths. Each wavelength can be further divided into more than one channel having a lower ratio of the entire wavelength bandwidth. A lightpath from a source to destination may be formed using such wavelength channels of finer granularities. Efficient planning for placing the grooming devices within a mesh network is a complex task. Placing the grooming devices all over the mesh network can be both cost significant and lead to a bad performance. [2] Traffic grooming in wavelength division multiplexing (WDM) optical networks routes and consolidates sub- wavelength connections onto lightpaths, to improve network utilization and reduce cost. It can be classified into static or dynamic, depending on whether the connections are given in advance or randomly arrive/depart.[3] The concepts of blocking probability, and end-to-end blocking probability, which are used interchangeably, are equivalent to the so-called burst/packet loss ratio defined as a ratio of the bursts/packets that are lost to the bursts/packets that are sent. The main cause of loss is lack of sufficient network resources as losses due to physical layer errors are negligible. Traffic grooming refers to the problem of efficiently packing low-speed connections onto high-capacity lightpaths to better utilize network resources.[4] II. LITERATURE SURVEY Hongyue Zhu et.al. [5] had proposed a new generic graph model for traffic grooming in heterogeneous WDM mesh networks. The novelty of this model was that, by only manipulating the edges of the auxiliary graph created by model and the weights of these edges, model can achieve various objectives using different grooming policies, while taking into account various constraints such as transceivers, wavelengths, wavelength- conversion capabilities, and grooming capabilities. Based on the auxiliary graph, we develop an integrated grooming algorithm, IGABAG, which jointly solves the four traffic-grooming subproblems for one traffic demand, and a grooming procedure, INGPROC, which can accommodate both static and dynamic traffic grooming using the IGABAG algorithm. Srivatsan Balasubramanian et.al. [6] provide an overview Dynamic Traffic Grooming in Optical Networks Amanjot Kaur, and Neeraj Mohan T 2nd International Conference on Emerging Trends in Computer and Electronics Engineering (ICETCEE'2013) Sept 17-18, 2013 Hong Kong 31