Indonesian Journal of Electrical Engineering and Computer Science Vol. 31, No. 1, July 2023, pp. 305~312 ISSN: 2502-4752, DOI: 10.11591/ijeecs.v31.i1.pp305-312  305 Journal homepage: http://ijeecs.iaescore.com Fragmentation aware heuristic algorithm for routing and wavelength assignment in optical networks Hamsaveni Mogannaiah 1 , Savita Choudhary 2 , Paramesha Kenchappa 1 1 Department of Computer Science and Engineering, Vidyavardhaka College of Engineering, Mysuru, India 2 Department of Computer Science and Engineering, Sir M Visvesvaraya Institute of Technology, Bengaluru, India Article Info ABSTRACT Article history: Received Sep 12, 2022 Revised Feb 6, 2023 Accepted Feb 12, 2023 Wavelength division multiplexing (WDM) is one of the dominating technologies with high-capacity back bone networks. The cost associated with the high-capacity networks given more importance. The major issue is allocating and managing the available resources. To achieve this most efficient algorithms has to be used. We are considering the routing of lightpath and wavelength assignment problem, called as the routing and wavelength assignment (RWA) problem. The optimization of wavelength fragmentation in the WDM network is very much important in resource utilization. Wavelength fragmentation is one of the most important challenges in the area of the WDM network. Where it leads to some serious issues for the operators, such as the rejection of new requests. We are using integer linear program (ILP), here the problem is based on the node link formation. It is based on the multilayer concept and the original WDM network consists of several layers. We propose an efficient heuristic approach to solve this problem of finding the shortest path and assigning a wavelength without wavelength conversion. The model achieves better performance with fragmentation aware wavelength allocation strategy that minimizes fragmentation. Keywords: Fragmentation Multilayer Optimization Routing and wavelength assignment Wavelength division multiplexing This is an open access article under the CC BY-SA license. Corresponding Author: Hamsaveni Mogannaiah Department of Computer Science and Engineering, Vidyavardhaka College of Engineering Mysuru, India Email: hamsaveni.m@vvce.ac.in 1. INTRODUCTION In todays scenario the popularity of data intensive applications and real time applications are increasing tremendously over the entire globe. We can see that for each and every work what we do with the electronic gadgets requires an internet connection with high speed data transmission. The technology what we are using demands a high speed internet for processing the data, for using live applications, live streaming, smart home, and smart city. Due to which there is a huge demand for high speed internet for communication. As the global data demand is growing the bandwidth requirement is also increasing. Approximately 5.3 billion internet users, that is 66% of the population in the entire globe access internet for the year 2023 [1]. We can see that smart devices, electronic gadgets, smart city, and smart house. Which needs internet connection for there functioning has been increasing day by day which demands a high network speed. To fulfil the increasing bandwidth demand, optical networks are one of the best solution for these issues. In optical wavelength division multiplexing (WDM) wavelength and division multiplexing the data is transmitted using light beams. Optical networks with WDM technology are more essential because of their seamless characteristics, huge bandwidth capability, low signal attenuation, signal distortion, low cost and low power requirement. The range of bandwidth in WDM network range high which enables the various frequencies to carry data on the same medium. This reduces the loss of data compared to the wired transmission.