Investigation of FTTH Architectures Based on Passive Optical Networks

Abstract

Fiber based access networks can deliver performance that can support the increasing demands for high speed connections. One of the new technologies that have emerged in recent years is Passive Optical Networks. Fiber-to-the-home (FTTH) is experiencing great public acceptance throughout the world. To satisfy future bandwidth demands, existing fiberto- the-home (FTTH) access networks must be upgraded. Since the lifetime of a passive optical network (PON) is expected to be greater than 25 years, replacing the existing PON infrastructure is not desirable when upgrading the network throughput. In this thesis, we propose inexpensive solutions for next generation PONs using the existing passive splitterbased infrastructure. This master's thesis aims to explain the design and planning of a PON. The main idea of this project is to build a fictitious environment that will allow us to study in depth about FTTH networks and decide which is the most optimal option for this environment. First of all, a network architecture based on FTTH systems with GEPON (Gigabit Ethernet Passive Optical Networks) access is presented. This architecture is targeted to deliver a very high speed, end to end optical communication between the edge notes connecting the end users. This transmission allows the simultaneous delivery of triple play service (data, voice and video). The comparative investigation and suitability of various data rates is presented. It has been observed that the proposed system is most suitable at data rate of 2 Gbps. It is demonstrated that as we increase the data rate, number of users to be accommodated decreases due to increase in bit error rate. Also it is demonstrated that as we increase the distance of transmission the value of bit error rate increases which is undesirable. In second case, another network architecture based on FTTH system access with 10 Gbps data rate is presented. This architecture is responsible for end to end simultaneous transmission of voice and data for 56 ONUs. The comparative investigation and suitability of various optical modulation formats for internet and voice over IP transmission is also presented. It has been observed that the most suitable modulator is Optical sin2 modulation. Also the use of semiconductor optical amplifier helps in increasing the transmission distance up to a larger extent ii In last section, we present a bidirectional PON based FTTH architecture. This architecture provides uplink and downlink transmission at different data rates according to various PON standards. The system utilizes a Travelling wave Semiconductor Optical Amplifier (TSOA). It is observed from the BER results that the performance of our scheme is good for 10 Gbps system for downstream transmission as it accommodates 64 ONUs. So this scheme is a practical solution to meet the data rate of the optical links simultaneously in tomorrow’s PON access networks.