Fiber Optics And Communication

Abstract

Over the years advancement in technologies has improved transmission limitations, the number of wavelengths we can send down a piece of fiber performance, amplification techniques, and protection and redundancy of the network. When people have described and spoken at length about optical networks, they have typically limited the discussion of optical network technology to providing physical-layer connectivity. When actual network services are discussed, optical transport is augmented through the addition of several protocol layers, each sets of unique requirements, to make up a service-enabling network.

Fiber optics is the contained transmission of light through long fiber rods of either glass or plastics. The light travels by a process of internal reflection. The core medium of the rod or cable is more reflective than the material surrounding the core. That causes the light to keep being reallected back into the core where it can continue to travel down the fiber, fiber optic cables are used for transmitting voice, images and other data at close to the speed of light.

Recent technical innovations in optical networking have altered the economics for access and melro networks and enabled new service offerings to a number of different markets. While these innovations may herald a more aggressive transformation of the network infrastructure, there remain business and technical challenges that must be addressed before wider scale deployments will occur. The challenges facing large carriers are borne mainly out of the characteristics of their existing infrastructure and the business processes that have developed over the years to support that infrastructure and the services that run over it.

Communication traffic has grown owing to the rapid growth of the Internet and broadband services. transmission systems have supported the evolution of information and communication technology.

Introduction

The telecommunications network consists of two layers: the service layer that delivers the network services, and the transport layer that provides connectivity between the service layer network elements. Explosive growth in the service layer has put inordinate demands on the transport layer resulting in a complex, multi sublayerstructure, with each sublayer managing bandwidth at a different, fixed granularity.

(DWDM) technology will address the rapid growth currently being experienced, while simultaneous enabling the transition of the service layer to data-optimized technologies, such as ATM and IP. This paper also describes how the migration of all services to this new service laver. coupled with the expansion of the DW'DM-based transport infrastructure, will lead to a simplified network by reducing the number of layers. The result will be a simpler, more cost-effective, higher-capacity, data-optimized network consisting of a multi-service infrastructure interconnected over a DWDM-based Optical Transport Network (OTN).

Advances in telecommunications and data technology are creating new opportunities for countries, businesses and individuals--just as the Industrial Revolution changed fortunes around the globe. The new economy is defining how people do business, communicate, shop, have fun, learn, and live on a global basis--connecting everyone to everything. The evolution of Internet has come into existence & Internet service is expanding rapidly. The demands it has placed upon the public network, especially the access network, are great. However, technological advances promise big increases in access speeds, enabling public networks to play a major role in delivering new and improved telecommunications services and applications to consumers .The Internet and the network congestion that followed, has led people to focus both on the first and last mile as well as on creating a different network infrastructure to avoid the network congestion and access problems

A Brief History of Fiber-Optic Communications

This section discusses the history of fiber optics, from the optical semaphore telegraph to the invention of the first clad glass fiber invented by Abraham Van Heel. Today more than 80 percent of the world's long-distance voice and data traffic is carried over optical-fiber cables. networks have evolved during a century-long history of technological advances and social changes. The networks that once provided basic telephone service through a friendly local operator are now transmitting the equivalent of thousands of encyclopedias per second. Throughout this history, the digital network has evolved in three fundamental stages: asynchronous, synchronous, and optical.

Asynchronus :

The first digital networks were asynchronous networks. In asynchronous networks, each network element's internal clock source timed its transmitted signal. Because each clock had a certain amount of variation, signals arriving and transmitting could have a large variation in timing, which often resulted in bit errors.

More importantly, as optical fiber deployment increased, no standards existed to mandate how network elements should format the optical signal. A myriad of proprietary methods appeared, making it difficult for network providers to interconnect equipment from different vendors.

Synchronous (SONET) :

The need for optical standards led to the creation of the synchronous optical network (SONET). SONET standardized line rates, coding schemes, bit-rate hierarchies, and operations and maintenance functionality.SONET also defined the types of network elements required, network architectures that vendors could implement, and the functionality that each node must perform. Network providers could now use different vendor's optical equipment with the confidence of at least basic interoperability.

Optical Networks :

Optical Transport Network based on Dense Wavelength Division Multiplexing technology will enable the evolution to a data-optimized, multi-service network infrastructure, while relieving the stresses currently being experienced due to the growth of existing services, and the exploding demand for new high bandwidth data services. This transition is critical to the success of the metropolitan service provider; the new infrastructure will increase revenues by supporting a broad array of new high capacity data services, and reduce capital costs and operating costs through the elimination of service-specific network elements and the more efficient