Network and Telecommunications : The Evolution in Telecommunication: From Wire to Wireless

Telecommunication Network is a network of telecommunication links and nodes arranged so that messages may be passed from one part of the network to another part of network over multiple links and through various nodes.

There are few examples of telecommunications network:

• The computer network
• The Internet network
• The public switched telephone network
• The global Telex network
• The aeronautical ACARS network
  

Wired Technologies

Twisted-pair Wire

Twisted-pair wire is the most widely used medium for telecommunication. Twisted-pair wires are ordinary telephone wires which consist of two insulated copper wires twisted into pairs and are used for voice and data transmission. The use of two wires twisted together helps to reduce crosstalk and electromagnetic induction. The transmission speed ranges from 2 million bits per second to 100 million bits per second.

Coaxial Cable

Coaxial cable is widely used for cable television systems, office buildings, and other worksites for local area networks. The cables consist of copper or aluminum wire wrapped with insulating layer typically of a flexible material with a high dielectric constant, all of which are surrounded by a conductive layer. The layers of insulation help minimize interference and distortion. Transmission speed range from 200 million to more than 500 million bits per second.

Fiber Optic Cable

Fiber optic cable consists of one or more filaments of glass fiber wrapped in protective layers. It transmits light which can travel over extended distances without signal loss. Fiber-optic cables are not affected by electromagnetic radiation. Transmission speed may reach trillions of bits per second. The transmission speed of fiber optics is hundreds of times faster than for coaxial cables and thousands of times faster than for twisted-pair wire.

Wirelss Technologies

Wireless LANs

Wireless local area network use a high-frequency radio technology similar to digital cellular and a low-frequency radio technology. Wireless LANs use spread spectrum technology to enable communication between multiple devices in a limited area. An example of open-standards wireless radio-wave technology is IEEE 802.11b.

Communications Satellites

The satellites use microwave radio as their telecommunications medium which are not deflected by the Earth's atmosphere. The satellites are stationed in space, typically 22,000 miles above the equator. These Earth-orbiting systems are capable of receiving and relaying voice, data, and TV signals.

Bluetooth

Bluetooth is a short range wireless technology. Operate at approx. 1Mbps with range from 10 to 100 meters. Bluetooth is an open wireless protocol for data exchange over short distances.

Type of Network

Local Area Network

A local area network (LAN) is a network that connects computers and devices in a limited geographical area such as home, school, computer laboratory, office building, or closely positioned group of buildings. Each computer or device on the network is a node. Current wired LANs are most likely to be based on Ethernet technology, although new standards like ITU-T G.had also provided a way to create a wired LAN using existing home wires (coaxial cables, phone lines and power lines)

Wide area network

Wide area network (WAN) is a computer network that covers a large geographical area such as a city, country, or spans even intercontinental distances, using a communications channel that combines many types of media such as telephone lines, cables, and air waves. A WAN often uses transmission facilities provided by common carriers, such as telephone companies. WAN technologies generally function at the lower three layers of the OSI reference model: the physical layer, the data link layer, and the network layer.

Virtual Private Network

Virtual private network (VPN) is a computer network in which some of the links between nodes are carried by open connections or virtual circuits in some larger network (e.g., the Internet) instead of by physical wires. The data link layer protocols of the virtual network are said to be tunneled through the larger network when this is the case. One common application is secure communications through the public Internet, but a VPN need not have explicit security features, such as authentication or content encryption. VPNs, for example, can be used to separate the traffic of different user communities over an underlying network with strong security features.

Client-server
Client-server computing or networking is a distributed application architecture that partitions tasks or work loads between service providers and service requesters, called client. Often clients and servers operate over a computer network on separate hardware. A server machine is a high-performance host that is running one or more server programs which share its resources with clients. A client does not share any of its resources, but requests a server's content or service function. Clients therefore initiate communication sessions with servers which await incoming requests.

Peer to Peer

A peer-to-peer, commonly abbreviated to P2P, is any distributed network architecture composed of participants that make a portion of their resources such as processing power, disk storage or network bandwidth directly available to other network participants, without the need for central coordination instances such as servers or stable hosts. Peers are both suppliers and consumers of resources, in contrast to the traditional client-server model where only servers supply, and clients consume.