Optical fiber communication

Fiber-optic communication is a method of transmitting information from one place to another by sending pulses of light through an optical fiber. The light forms an electromagnetic carrier wave that is modulated to carry information. First developed in the 1970s, fiber-optic communication systems have revolutionized the telecommunications industry and have played a major role in the advent of the Information Age. Because of its advantages over electrical transmission, optical fibers have largely replaced copper wire communications in core networks in the developed world.

The process of communicating using fiber-optics involves the following basic steps: Creating the optical signal involving the use of a transmitter, relaying the signal along the fiber, ensuring that the signal does not become too distorted or weak, receiving the optical signal, and converting it into an electrical signal.

Optical fiber is used by many telecommunications companies to transmit telephone signals, Internet communication, and cable television signals. Due to much lower attenuation and interference, optical fiber has large advantages over existing copper wire in long-distance and high-demand applications. However, infrastructure development within cities was relatively difficult and time-consuming, and fiber-optic systems were complex and expensive to install and operate. Due to these difficulties, fiber-optic communication systems have primarily been installed in long-distance applications, where they can be used to their full transmission capacity, offsetting the increased cost. Since 2000, the prices for fiber-optic communications have dropped considerably. The price for rolling out fiber to the home has currently become more cost-effective than that of rolling out a copper based network. Prices have dropped to $850 per subscriber in the US and lower in countries like The Netherlands, where digging costs are low.

Since 1990, when optical-amplification systems became commercially available, the telecommunications industry has laid a vast network of intercity and transoceanic fiber communication lines. By 2002, an intercontinental network of 250,000 km of submarine communications cable with a capacity of 2.56 Tb/s was completed, and although specific network capacities are privileged information, telecommunications investment reports indicate that network capacity has increased dramatically since 2004.

Reference link

• Optical Fibre Communication SystemsHow Things Work

• The Origins of Fiber Optic Communications

• Transmission Characteristics of Optical Fiber

• Optical fiber communication — An overview

• Receiver design for optical fiber communication systems

• OPTICAL FIBER COMMUNICATION

• OPTICAL FIBER COMMUNICATIONS 1. Introduction: The general system

• Data Communication & Network

Mobile IP

The Mobile IP protocol allows transparent routing of IP datagrams on the Internet. Each mobile node is identified by its home address disregarding its current location in the Internet. While away from home, a mobile node is associated with a care-of address which gives information about its current location. Mobile IP specifies how a mobile node registers with its home agent and how the home agent routes datagrams to the mobile node through a tunnel. Mobile IP provides an efficient, scalable mechanism for roaming within the Internet. Using Mobile IP, nodes may change their point-of-attachment to the Internet without changing their IP address. This allows them to maintain transport and higher-layer connections while moving. Node mobility is realized without the need to propagate host-specific routes throughout the Internet routing fabric.

Reference materials:

• Mobile IP

• Security for Mobile IP in the 3G Networks

• Mobile IP Technology Overview

• Introduction to Mobile IP

• Mobile IPv6 & Cellular Telephony

• http://en.wikipedia.org/wiki/Mobile_IP

• www.mobilein.com/mobile_IP.htm