Long Distance Fiber Optic Communication Systems example essay topic

Fiber optics technology is among fastest - growing communications technologies in the world. It is increasingly being used for communications signaling, and electrical control instead of older -technology hardwired system. Fiber optic cable uses light to transmit signals. The core of Fiber optic cable is composed of one or more thin strands of either very pure glass or plastic, millions of which can be bundled together in a sheathing.

In 1860, Alexander Graham Bell demonstrated that light reflected off of mirrors was modulated by waves of sound. Later, American researchers were able to demonstrate the transmission of an image through a bundle of glass fibers. Researchers began experimenting with cladding which greatly improved transmission characteristics by reducing the dispersion of light. Later, lasers were implemented as light sources because they could provide parallel light in a steady stream at only one wavelength. The first of the low-loss optical fibers was created in 1970. In 1980, the first major Fiber Optic communication link between Boston, Mass, and Richmond, VA, was created.

A year later, low-loss, single-mode fibers with high bandwidth and low loss capabilities to increase data transmission rates were created. Starting in the mid-eighties, the major communication companies began installing long-distance Fiber Optic communication systems using single-mode fibers. In 1988 the first transatlantic Fiber Optic cable was installed. Since then, Optical Fiber technology has been implemented in major communication networks that have realized its significance and importance.

Two basic optical fiber are commonly being installed: singlemode and multimode. Each type has a particular use in the communication industry, although there may be some overlap in usage. A singlemode optical cable may have a core diameter of 8 to 10 microns, while a multimode cable may have a core diameter of between 50 and 1,000 microns. A singlemode cable allows a higher bandwidth to be transmitted over a larger distance than a multimode cable. Singlemode cable The multimode optical cable, however, has a larger core, and will allow more modes of light to travel down it. The bandwidth of a digital system is the number of bits of signal per second that can be transmitted over the cable for a certain distance and specific amount of time.

Multimode optical cable Wavelength division multiplexing: Wavelength division multiplexing (WDM) is a type of multiplexing developed for both digital and analog transmission on fiber optic cables. Optical fiber transmits signals as pulses of light generated by a laser or LED. In WDM, each signal is assigned to a particular wavelength on an optical fiber communications line. WDM allows massive data transmission on a single cable.

A research report on WDM, published by IBM, concludes that eventually fiber optics cables will run to every residence, with about 10 percent of the homes being connected by 2005. With continued growth in fiber optic network, demands for data transmission across the internet infrastructure will increase dramatically. Fiber-optic cable eventually will experience fiber exhaust, which means that the amount of traffic on the network will exceed the available bandwidth. To handle the increased traffic that fiber optic cable to homes will cause on nationwide and worldwide networks, another form of WDM, called Dense Wavelength division Multiplexing (DWDM), has been developed. Using this technology, which puts data together from different sources, more than 80 separate signals could be placed on an individual fiber optic cable signal could carry separate Wavelength or channel.

Dense Wavelength Division Multiplexing (DWDM) Use of DWDM allows providers to offer services such as e-mail, video, and multimedia carried as Internet protocol (IP) data over asynchronous transfer mode (ATM) and voice carried over SONET / SDH. Despite the fact that these format-IP, ATM, and SONET / SDH-provide unique bandwidth management capabilities, all three can be transported over the optical layer using DWDM. This unifying capability allows the service provider the flexibility to respond to customer demands over one network. DWDM systems in the past were predominately deployed in long haul and submarine cable markets.

Long haul optics are essential due to cost-cutting advantages and increased efficiency. However, these systems have increased in use for the metropolitan markets. To date North America has led in the deployment of WDM systems. The fastest growth portion occurring in the metropolitan applications. On the other hand, in Europe, the span lengths are greatly reduced which may cause systems to be extensively deployed in the future. In 1998 the worldwide demand for DWDM systems was estimated be at $2.1 billion and was expected to grow to as much as $12.1 billion by 2005 (as forecasted by Electronica st).

The growth into the metropolitan areas is driven largely by the transparency of the network and the opportunity for revenue generating services. In conclusion, Optical fibers have a very high bandwidth and can transmit huge amount of data at very high speed and DWDM is a fiber optics transmission technique. When the different ways of using multiplexing are combined it improves the amount of bandwidth dramatically. These technologies are extremely important in today's society where we are seeing high demands for data traffic. By having an all-optical network, we are provided with the ability to integrate the many different technologies into one system.

The DWDM network enables the service providers to go long distances as well as provide for data lines and other growth in metropolitan area.