Gigabit-class passive optical networks have been standardized and are now being deployed. This article presents possible migration scenarios toward the next-generation PON and proposes a technology roadmap of evolutionary growth (termed NG-PON1) vs. revolutionary change (termed NG-PON2). This article then details the general requirements for NG-PON1 to support various popular applications many service providers expressed interests on as well as to enable smooth migration from Gigabit PON.

Next-generation PON-part I: Technology roadmap and general requirements

Passive optical networks (PONs) are currently evolving into next-generation PONs (NG-PONs) which aim at achieving higher data rates, wavelength channel counts, number of optical network units (ONUs), and extended coverage compared to their conventional counterparts. Due to the increased number of stages and ONUs, NG-PONs face significant challenges to provide the same level of survivability like conventional PONs without exceeding the budget constraints of cost-sensitive access networks. Toward this end, partial optical protection, in combination with interconnecting a subset of ONUs through a wireless mesh network (WMN) front-end, are promising solutions to render NG-PONs survivable in a cost-effective manner. In this paper, we present a probabilistic analysis of the survivability of NG-PONs and hybrid fiber-wireless (FiWi) access networks, taking both optical and wireless protection into account. In addition, we propose different selection schemes to wirelessly upgrade a subset of ONUs, and investigate their performance for a wide range of fiber link failure scenarios and different NG-PON topologies.

Survivability Analysis of Next-Generation Passive Optical Networks and Fiber-Wireless Access Networks

Hybrid fiber-wireless (FiWi) access networks aim at combining the huge amount of available bandwidth of optical networks and the ubiquity and mobility of wireless access networks with the objective to reduce their cost and complexity. This article highlights key enabling optical as well as wireless technologies and explains their role in emerging FiWi networks. After briefly reviewing previous art, important challenges and imperatives for the design of future FiWi network architectures, protocols, and algorithms are identified and discussed in detail.

Fiber-wireless (FiWi) access networks: Challenges and opportunities

The evolution toward grid and cloud computing as observed for over a decennium illustrates the crucial role played by (optical) networks in supporting today's applications. In this paper, we start from an overview of the challenging applications in both academic (further referred to as scientific), enterprise (business) and nonprofessional user (consumer) domains. They pose novel challenges, calling for efficient interworking of IT resources, for both processing and storage, as well as the network that interconnects them and provides access to their users. We outline those novel applications' requirements, including sheer performance attributes (which will determine the quality as perceived by end users of the cloud applications), as well as the ability to adapt to changing demands (usually referred to as elasticity) and possible failures (i.e., resilience). In outlining the foundational concepts that provide the building blocks for grid/cloud solutions that meet the stringent application requirements we highlight, a prominent role is played by optical networking. The pieces of the solution studied in this respect span the optical transport layer as well as mechanisms located in higher layers (e.g., anycast routing, virtualization) and their interworking (e.g., through appropriate control plane extensions and middleware). Based on this study, we conclude by identifying challenges and research opportunities that can enable future-proof optical cloud systems (e.g., pushing the virtualization paradigms to optical networks).

Optical Networks for Grid and Cloud Computing Applications

Fiber has been envisioned for delivering broadband services to the residential customer for over 30 years, yet it has only recently entered the mainstream. Currently, fiber-to-the-home (FTTH) is being installed in many countries at remarkable rates (even though it still constitutes only a fraction of all broadband lines in most countries). Other lightwave transmission technologies have progressed far faster. What has held FTTH up for so long? What improvements along the way have occurred? What recent changes have made it successful? This article follows the progress in moving fiber toward the home and major architectural changes that have reduced costs while increasing capabilities to meet today's needs.

Fiber-to-the-Home: 1977–2007

Passive optical networks are the most important class of fiber access systems in the world today. This article first reviews the reasons why the PON as a general architecture is so important. We then outline in some depth the technologies used to implement this architecture, including the G-PON and E-PON systems being deployed today, and the advanced PON systems that provide the evolution path to ever higher bandwidths

D. Clearly

Papers

An introduction to PON technologies [Topics in Optical Communications]