Metropolitan Area Network (MAN)

     MAN network is little larger than a LAN as it normally covers the area of a city. A television distribution like Cable Television (CATV) all follows this type of networking structure. MAN’s interest here is in the digital although some of them may use broadband coaxial cable as the transmission medium. This technology is new and it operates at high speeds (usually hundreds of megabit per second through several gigabits per second) over distances sufficient for a metropolitan area. So these are best adopted by governmental agencies and organization for their administrative works to carry out easily and rapidly around the metropolitian corners.

Wide Area Network (WAN):

WAN covers the wide area of geography around the world. In such type of networking, geographically isolated computers are linked by communication facilities like telecommunications or microwave relays. More typically, such technology involves two or more than two LANs situated far apart and are linked by telephone lines, dedicated telephone lines, or radio waves. The Internet is the largest Wide Area Network (WAN) in existence. Comparing to the freedom of LAN this type of networking have the direct or indirect involvement of public telecommunications authority.WAN is usually limited to use by large organization and government agencies due to high costs involved in building and maintaining them.Satellilte is the main transmission medium for WAN. An example of WAN is Intranet and Internet.

Wide Area Network

Local Area Networks (LAN):

Fig.1:LAN Structure

     

     Figure that shown above is the basic of LAN configuration.This type of network is best suited in small well-defined area such as office building, college or a room. A LAN can be made up of only microcomputers or any combination of microcomputer and large system. Usually, cables connect the LAN by linking the network cards that reside within each computer or printer on the network.

Characteristics of LAN:

1. LAN consists of two or more than two computers.
2. It can extends over the diameter more than a few kilometers.
3. Peripherals such as MODEM,HDD,etc are needed.
4. Co-axial or fiber optic cables are usually used to connect the computers and other s devices
5. A plug in board to handle the data transmissions.

Features of LAN:

1. LAN has a total data rate of at least several Mbps.
2. Complete ownership by a single organization.
3. The connections between the workstations are usually distances of a few hundred feet, up to several thousand feet.
4. The LAN transmits data between user stations and computers (LANS are also capable of transmitting voice and video images as well.
5. The LAN transmission capacity is usually greater than that of a WAN (Wide Area Network), Traditional LAN speeds are 10Mbps to 100Mbps. Modern LAN cables are capable of much higher data transfer per second.
6. LAN is typically privately owned by the organization using the facility.

Capabilities of LAN:

• Perform file-management tasks.

1. Transfer of files
2. Sharing of applications
3. Share files

• Share peripheral devices

1. Printers
2. CD-ROMS
3. Fax-Modems
4. Tape-Drivers
5. Scanners

• Interact with other user on the network

1. Schedule group-meetings
2. Send and receive mails
3. Hold electronic meetings
4. Play network games

LAN topologies:

Topology refers to the structure of connecting the computers and peripherals inside the network.There are several popular network topology on LAN that are listed with figures below:

• Bus topology
• Ring topology
• Star topology
• Mesh topology
• Tree topology

Fig.2:LAN topologies

next:MAN

Computer Network