International Journal of u and e-Service, Science and Technology Vol. 9, No. 3, (2016), pp. 403-414 http://dx.doi.org/10.14257/ijunesst.2016.9.3.38 * Corresponding Author ISSN: 2005-4246 IJUNESST Copyright ⓒ 2016 SERSC Efficient Spectrum Allocation with Survivability Technique in Elastic Optical Networks Pushpanathan Krishnamoorthy 1* , Sivasubramanian Arunagiri 2 , Jawahar Arumugam 3 , Jesuwanth Sugesh R.G 4 , MenaghaPriya.B.R 5 1,4,5 Electronics and Communication Engineering, Anand Institute of Higher Technology (Affiliated to Anna University), Chennai, Tamil Nadu, India. 2 Electronics and Communication Engineering, Vellore Institute of Technology (Chennai Campus), Chennai, Tamil Nadu, India. 3 Electronics and Communication Engineering, S.S.N College of Engineering (Affiliated to Anna University), Chennai, Tamil Nadu, India. * Corresponding author: Pushpanathan Krishnamoorthy, pushpanathan999@gmail.com. Abstract In recent years, traffic requirement with variable bit rates and Quality of Service due to online High Definition video streaming, downloading movies and transferring of files are being satisfied with Elastic Optical Network (EON). Most efficient spectrum utilization is required to satisfy the demand with minimum blocking probability. The network is unstable and a small failure can lead to tremendous loss of data, hence survivability is mandatory. Slot Capacity based Spectrum Allocation with Survivability (SCSAS) algorithm is proposed which aims at the efficient spectrum utilization and configuration of protection paths. Duty Cycle Division Multiplexing (DCDM) and hop based modulation technique are also introduced to manage the spectrum which further reduces the spectrum wastage. The formation of spectrum fragments on the termination of existing requests increases the blocking probability. In order to improve the spectrum utilization, a spectrum defragmentation technique is introduced in the proposed work. Dynamic configuration of backup paths provides survivability. Results show an increase in free spectrum for dynamic requests, lesser spectrum wastage, and reduced blocking probability than the traditional algorithms such as fixed, flexible and random spectrum allocation. Keywords: Elastic Optical Network, Spectrum Allocation, Modulation, Duty Cycle Division Multiplexing, Spectrum Defragmentation, Survivability. 1. Introduction The growth in network usage demands large volumes of data transfer due to increase in network users. Spectrum is being a limited and an expensive resource and efficient spectrum allocation has to be done over the network for each request. This paper [1] provides a Path Computation Element (PCE) architecture for EON to maximize the spectral efficiency. An adaptive spectrum control defragmentation technique was proposed in [2] to reduce the blocking probability created by the spectral fragments when requests terminate. Spectrum Expansion/Contraction (SEC) policy for modifying the spectrum allocated to each connection enables the dynamic sharing of