International Journal of Electrical Engineering. ISSN 0974-2158 Volume 7, Number 1 (2014), pp. 43-51 © International Research Publication House http://www.irphouse.com Performance Analysis of 2. 5 Gbps downlink GPON Prof. S. Sugumaran 1 , Prof. P. Arulmozhivarman 2 , M. S. R. Praneeth 3 , P. Saikumar 4 , Prof. A. Jabeena 5 1, 2, 5 Faculty (SENSE), VIT University, Vellore, 3, 4 B. Tech (ECE), Abstract In this paper we discuss the performance of a Giga byte Passive Optical Network (GPON) for different wavelengths and power in a system having multiple users. The main characteristics is the use of passive splitters in the fibre distribution network, enabling one single feeding fibre from the provider's central office to serve multiple homes and small businesses. GPON architecture offers converged data and voice services at speeds upto 2. 5 Gbps. The quality of performance of a digital communication system is specified by its BER or Q factor. Index Terms – BER, DBA, Eye diagram, GPON, Q-factor. I. INTRODUCTION A passive optical network (PON) technology was available since the mid 90s. It is a network architecture that brings fibre cabling and signals to the home using a point- to-multipoint scheme that enables a single optical fibre to serve multiple premises. Passive Optical Network (PON) has no active components between Central Office and customer. Passive equipment has no electrical power needs, it guides the traffic signals contained within specific optical wavelengths. Voice, video and data traffic flows (triple play) can be easily implemented using different wavelengths. GPON has a downstream capacity of 2. 488 gbps and upstream capacity of 1. 244 Gb/s that is shared among user. The passive optical network technology is based on passive star fibre network and offers a cost effective optical access solution. Although there are other technologies that could provide fibre to the home, passive optical networks (PONs) like GPON are generally considered the strongest candidate for widespread deployments. The main components of PON architecture includes optical line terminal (OLT), optical network unit (ONU) and passive optical splitters, in which splitters are the main characteristics in the fibre distribution network it also has a maximum split ratio of 1:128. A typical deployed split factor is 1:32, a result of trade-off between the