Next Generation Home Network and Home Gateway Associated with Optical Access

As optical broadband access networks have been popularized, triple play services using IP technologies, such as Internet access, IP telephony, and IP video distributing services, have been also popularized. However, consumers expect new services for a more comfortable life. Especially, when QoS guarantee and high reliable services are provided in NGN (Next Generation Network) era, various home network services over NGN are deployed. For this purpose, the home gateway has been installed in consumer houses for the connection between access and home networks, and providing various services to consumers. Even though, the broadband router currently plays a role similar to the home gateway, this home gateway should comprehend functionalities of the broadband router, and should have additional features. The functional requirements of such home gateway have been discussed in standard bodies. That is, the next generation home gateway in NGN era generally should have four features as follows; High performance for IP processing, Compliance with the interface of carrier grade infrastructure including NGN, Flexible platform for various services, and Easy management and maintenance. This chapter describes the standardization of the home gateway and, proposes its evolution scenario the present to the future. Then, it also proposes these four requirements, and technologies to comply with features described above.

Modeling and Techno-Economic Evaluations of WDM-PONs

In the near future, broadband access networks will be required with data rates of over 1Gbit/s per customer. Currently, time-division multiple access passive optical networks (TDMA-PONs) are deployed. However, TDMA-PONs cannot keep up with the requirements for the broadcasting of a great number of HDTV channels and the unicasting of several triple-play services (voice, data and video). In contrast, wavelength-division-multiplexed PONs (WDM PONs) will be able to provide these required high data rates per user causing higher costs than with TDM-PONs. The introduced paradigm shift, at least one wavelength per service and user, leads to the introduction of new aspects in the design of future WDM PON access networks. In techno-economic evaluations, new network architectures with the highest potential concerning economic considerations have been identified. Access to these newly identified network architectures will prompt market introduction as well as market penetration helping Fiber-tothe- Home (FTTH) to become reality.

The New Generation Access Network

This chapter offers a qualitative approach towards the development of the new generation access network, based on FTTx implementations. After a brief description of the current state of traditional access networks and an estimation of the expected data rate per household in terms of services, the chapter examines all the available Network Technologies (FTTx), Access Technologies (xDSL, Ethernet and PON) for both P2P and P2MP development schemes and their relevant implementations. The prospects of NGA are also strategically examined in view of the complicated multi-player environment, involving Telco (ILEC and CLEC), regulators and pressure interest groups, all striving to serve their individual, often conflicting interests. The chapter concludes with an outline of the different deployment strategies for both ILEC and CLEC Telco.

The Vertical-Cavity Surface-Emitting Laser

The proposal chapter aims at highlighting the tremendous emergence of the Vertical-Cavity Surface- Emitting Laser (VCSEL) in the FTTX systems. The VCSEL is probably one of the most important and promising components of the “last-leg” Optical Access Networks. To satisfy the bandwidth rise as well as the inexpensive design constraints, the VCSEL has found its place between the Light-Emitting-Diode (LED) and the Edge-Emitting-Laser (EEL) such as the DFB (Distributed-Feedback) laser. Hence, the authors dedicate a chapter to the promising VCSEL technology that aims to give an overview of the advances, the physical behavior, and the various structures regarding VCSELs. They discuss the VCSEL features and performance to weigh up the specific advantages and the weaknesses of the existing technology. Finally, diverse potentials of Optical Access Network architectures are discussed.

An Introduction to Optical Access Networks

With the current continuously growing bandwidth demand, it is apparent that conventional broadband access solutions will quickly become bottlenecks in terms of bandwidth provision. In this chapter, the authors analyze the present global challenge for extended bandwidth provision in the scope of the fast developing electronic communications sector, creating a fully converged environment. In particular, first the authors examine several potential options imposed by distinct technologies, as they are currently applied in the marketplace. Then they present a comprehensive review of the emerging optical access solutions, focusing mainly on passive optical network (PON) technologies that promise to efficiently meet the anticipated growth in bandwidth demand and at the same time be economically viable and future-proof from an operator’s perspective, and evaluate their capabilities to the conventional copperbased broadband solutions. They also survey the current deployment efforts and relevant policies in the European Community area, as well as discuss why Europe is lagging with regard to deployment pace when compared to Asia and the USA. Specific and detailed analysis is given for recent developments performed in the European Union, where the authors identify current trends, potential hurdles and/or difficulties, as well as perspectives for further growth and development.

Broadband Optical Access using Centralized Carrier Distribution

Passive optical network (PON) is considered as an attractive fiber-to-the-home (FTTH) technology. Wavelength division multiplexed (WDM) PON improves the utilization of fiber bandwidth through the use of wavelength domain. A cost-effective solution in WDM PON would use the same components in each optical networking unit (ONU), which should thus be independent of the wavelength assigned by the network. Optical carriers are distributed from the head-end office to different ONUs to produce the upstream signals. Various solutions of colorless ONUs will be discussed. Although the carrier distributed WDM PONs have many attractive features, a key issue that needs to be addressed is how best to control the impairments that arise from optical beat noise induced by Rayleigh backscattering (RB). Different RB components will be analyzed and RB mitigation schemes will be presented. Finally, some novel PONs including signal remodulation PONs, long reach PONs and wireless/wired PONs will be highlighted.

Optical Access Comes of Age in a Packet-Delivery World

The access network is the last loop, or last mile, in the provider network between the central office (CO) or point of presence (PoP) and the customer premises. Competitive pressure to provide high-bandwidth services (such as video) to consumers, and Ethernet transport to enterprises, is forcing service providers to rebuild their access networks. More optical fibers are being added in the last mile to meet these new bandwidth demands since legacy access networks have not been sufficient to support bandwidth-intensive applications. This chapter reviews the multiple definitions of “optical access” and the migration from direct copper loops to a variety of optical architectures, including Synchronous Optical Networking (SONET), Synchronous Digital Hierarchy (SDH), Fiber to the x (FTTx), Ethernet and wavelength delivery. Key business drivers such as carrier competition, bandwidth needs, and the reliability and service level agreement issues of optical technology are covered. The chapter concludes by considering the near future of optical access product trends and key optical deployment options in applications such as cellular backhaul. The data presented in this chapter is mainly based on our recent deployment experience in the North American optical access market segment.

Wavelength Division Multiplexed Passive Optical Networks

Wavelength division multiplexed passive optical network has emerged as a promising solution to support a robust and large-scale next generation optical access network. It offers high-capacity data delivery and flexible bandwidth provisioning to all subscribers, so as to meet the ever-increasing bandwidth requirements as well as the quality of service requirements of the next generation broadband access networks. The maturity and reduced cost of the WDM components available in the market are also among the major driving forces to enhance the feasibility and practicality of commercial deployment. In this chapter, the author will provide a comprehensive discussion on the basic principles and network architectures for WDM-PONs, as well as their various enabling technologies. Different feasible approaches to support the two-way transmission will be discussed. It is believed that WDM-PON is an attractive solution to realize fiber-to-the-home (FTTH) applications.

Bandwidth Allocation Methods in Passive Optical Access Networks (PONs)

Passive Optical Networks (PONs) are very suitable architectures to face today’s access challenges. This technology shows a very cost saving architecture, it provides a huge amount of bandwidth and efficiently supports Quality of Service (QoS). In PON networks, as all subscribers share the same uplink channel, a medium access control protocol is required to provide a contention method to access the channel. As the performance of Time Division Multiplexing Access (TDMA) protocol is not good enough because traffic nature is heterogeneous, Dynamic Bandwidth Allocation (DBA) algorithms are proposed to overcome the problem. These algorithms are very efficient as they adapt the bandwidth assignment depending on the updated requirements and traffic conditions. Moreover, they should offer QoS by means of both class of service and subscriber differentiation. Long-Reach PONs, which combine the access and the metro network into only one by using 100 km of fibre, is an emergent technology able to reach a large number of far subscribers and to decrease the associated costs.

Active Optical Access Networks

In this chapter, active optical access networks (AONs) are examined. AONs are a special type of optical access networks in which the sharing of optical fibers among users is implemented by means of active equipment (as opposed to passive optical networks –PONs– where sharing is achieved by using multiplepassive splitters). In active optical access networks, user-side units, known as Optical Network Units (ONUs), are usually grouped in access Synchronous Digital Hierarchy (SDH) rings and fiber-interconnected to a local exchange unit, known as Optical Line Termination (OLT). In AONs (as well as in PONs) the optical fiber (originally used in the trunk network) is introduced in the access domain, namely between the customer and the local exchange. Practically, this means that the huge bandwidth provided by the optical fiber becomes directly available to the normal user. Despite the obvious financial and technoeconomical issues related to the massive deployment of optical access networks, the possibilities and challenges created are enormous. This chapter examines the various units and modules composing an active optical access network and presents the basic procedures for implementing such a network.