Network:

A network is group of two or more systems linked together.

Home Network Applications

  • Access to remote information
  • Online Library, Newspaper
  • Person-to-person communication
  • Instant messaging, news group, torrent
  • Interactive entertainment
  • Live Channels, videos, Audios
  • Electronic commerce
  • Home shopping, access to financial institutions

Types of Networks

1-Basis on Medium

There are two types of medium

a) Wired Network

  •          Using Twisted Pair Cable
  •          Using Coaxial Cable
  •          Using fiber optics

Advantages & Disadvantages:

Wired networks use Ethernet cables and network adapters.

It can difficult to run cables under the floor or through walls, especially when computers are in different rooms.

A wired doesn’t cost much because Ethernet cables, hubs and switches are inexpensive.

b) Wireless Network

  1. 1.Wifi (Wireless fidelity) 802.11 a/b/g/n
  2. 2.WiMax (Worldwide Interoperability for Microwave Access) 802.16e

Advantages & Disadvantages:

Wireless signals are subject to interference from other home appliances

Wi-Fi performance is distance sensitive

wireless communication signals travel through the air and can easily be intercepted.

2-Basis on Network Architecture

Computer networks may be classified according to the functional relationships which exist among the elements of the network

Client/Server Architecture

Advantages

  1. 1.Centralized resources
  2. 2.Improved security
  3. 3.Server Level Administration
  4. 4.Scalable Network

Disadvantages

  1. 1.Increased Cost
  2. 2.A Weak Link
Peer-to-Peer Architecture

Advantages

  1. 1.No need for a network administrator
  2. 2.Network is fast/inexpensive to setup & maintain
  3. 3.Each PC can make backup copies of its data to other PCs for security.
  4. Easiest type of network to build, peer-to-peer is perfect for home.

Disadvantages

  1. This network is not centralized, making administration difficult
  2. Lack of security
  3. No link in the network is reliable
  4. Useful for a small number of computers (generally about 10)

3-Basis of Scale/Area

http://www.electricalengineering4u.com/computer-hardware/computer-network-and-devices-used-in-networking/

4-Basis of Topologies:

Bus Topology

All of the nodes of the network are connected to a common transmission medium which has exactly two end points

Ring Topology

Each of the nodes of the network is connected to two other nodes in the network and with the first and last nodes being connected to each other, forming a ring

Star Topology

Each of the nodes of the network is connected to a central node with a point-to-point link

Mesh Topology

Each of the nodes of the network is connected to each of the other nodes in the network with a point-to-point link

5-Basis of Logical Topologies

Token Ring:

Token Ring network uses a token passing technology. A computer with a message to deliver waits until it receives free token. The computer then changes the free token into a busy token, attaches its message to it, and retransmits it on the circuit to the next computer.

Standards Terminologies used for Token Ring

Token Ring-4: 4Mbps over twisted wire

Token Ring-16: 16Mbps over twisted wire

Ethernet:

This is a system where each computer listens to the cable before sending anything through the network. If the network is clear, the computer will transmit. If some other node is already transmitting on the cable, the computer will wait and try again when the line is clear. Sometimes, two computers attempt to transmit at the same instant. When this happens a collision occurs. Each computer then backs off and waits a random amount of time before attempting to retransmit.

Standards Terminologies used for Ethernet

10Base5: 10Mbps baseband signal with 500 meter range

100Base2: 100Mbps baseband signal with 200 meter range

100BaseT: 100Mbps baseband signal with Twisted pair wire

100Broad36: 100Mbps broadband signal with 3600 meter range