Optimized Line Amplifier Placement for Energy Saving: a Case Study of ethio telecom Optical Backbone Network

In recent years, traffic volume is increasing tremendously. In line with this increment, telecom operators expand their network infrastructure. This increases power consumption of the network. Especially in a backbone network, where power consumption is dependent on traffic volume, the increase in power consumption is becoming critical. Researchers are made efforts dedicated to reduce unnecessary energy waste in backbone networks using physical topology optimization for highly connected networks, but this optimization is not feasible for low connected networks like ethio telecom. In addition, line amplifiers are placed at regular interval of 80km without considering physical and economic restrictions. In practice, amplifier placement is commonly implemented by operators to guarantee a signal quality considering placement location with availability supply power, shelter, and physical security with the expense of high power consumption. Current ethio telecom line amplifiers are placed at span length ranging from 25 to 120km considering these physical and economic restrictions; due to this, ethio telecom is subjected to high power consumption in line amplifiers. In this thesis, optimized line amplifier placement, which takes power consumption and physical and economic restrictions in to account is investigated. Mixed Integer Linear Programming (MILP) formulation which takes span length and input power level constraint is proposed. The proposed power-saving approach is evaluated considering ethio-telecom North circle optical backbone network topology. MATLAB is used to assign optimum placement location. The result is compared with theoretical standard (80km spacing) and the practical (ethio telecom current deployment scenario) using number of amplification sites and power saving performance. The comparison results show that amplifier site placement using the new approach can minimize the number of amplification sites by 9 from the theoretical approach and by 5 from the existing configuration and a 2% power saving can be achieved in the case study network portion.