ACCORDANCE: A novel OFDMA-PON paradigm for ultra-high capacity converged wireline-wireless access networks

This paper presents ACCORDANCE, a novel ultra-high capacity extended reach optical access network architecture based on OFDMA technology/protocols, implemented through the proper mix of state-of-the-art photonics and electronics. Such architecture is not only intended to offer improved performance compared to evolving TDMA-PON solutions but also provide the opportunity for convergence between optical, radio and copper-based access. Although OFDM has been used in radio and copper-based communications, it is only recently that is making its way into optics and is expected to increase the system reach and transmission rates without increasing the required cost/complexity of optoelectronic components. ACCORDANCE hence aims to realize the concept of introducing OFDMA-based technology and protocols (Physical and MAC layer) to provide a variety of desirable characteristics, such as increased aggregate bandwidth and scalability, enhanced resource allocation flexibility, longer reach, lower equipment cost/complexity and lower power consumption, while also supporting multi-wavelength operation. In addition, it enables the convergence of the optical infrastructure with standard wireless solutions, thus offering a way to integrate dominant wired and wireless technologies in a hybrid access network supporting seamless ubiquitous broadband services.

1. INTRODUCTION

Passive optical networks (PONs) based primarily on time division multiple access (TDMA), have evolved as an access solution that provides simplicity and low operational cost with tens of Mbps offered to each user. Nevertheless, the increasing demands of modern applications such as HDTV, 3DTV and ultra-high speed browsing, as well as emerging applications such as multimedia conferencing and multiplayer online gaming have lately lead the research towards increased-capacity optical access solutions. For example, wavelength division multiplexed PONs (WDM-PONs) which enable service providers to offer dedicated wavelengths straight to homes and businesses over the existing optical backbone have been increasingly considered. However, WDM-PONs are currently considerably costly to implement, precisely operate and maintain while not offering satisfactory flexibility in terms of bandwidth granularity. Moreover, next generation access networks should ensure that customers receive acceptable QoS whenever or wherever required, whether at a fixed point, such as the home or an office or on-the-go.