Networks Types

 Clearly, different types of channels-cable or air-allow different kinds of networks to be formed. Telephone lines, for instance, may connect communications equipment within the same building or within a home. Networks also may be citywide and even international, using both cable and air connections. Local area, metropolitan area, and wide area networks are distinguished by the geographical area they serve.

LOCAL AREA NETWORKS

Networks with nodes that are in close physical proximity-within the same building, for instance-are called local area networks (LANS). Typically, LANS span distances less than a mile and are owned and operated by individual organizations. LANs are widely used by colleges, universities, and other types of organizations to link microcomputers and to share printers and other resources. The LAN represented typical arrangement and provides two benefits: economy and flexibility. People can share costly equipment. For instance, the four microcomputers share the laser printer and the file server, which are expensive pieces of hardware. Other equipment or nodes also may be added to the LAN-for instance, more microcomputers, a mainframe computer, or optical-disc storage devices. Additionally, the network gateway is a device that allows one LAN to be linked to other LANs or to larger networks. For example, the LAN of one office group may be connected to the LAN of another office group. There are a variety of different standards or ways in which nodes can be connected to one another and ways in which their communications are controlled in a LAN. The most common standard is known as Ethernet. LANS using this standard are sometimes referred to as Ethernet LANS.

HOME NETWORKS

While LANs have been widely used within organizations for years, they are now being commonly used by individuals in their homes and apartments. These LANS, called home networks, allow different computers to share resources, including a common Internet connection. Computers can be connected in a variety of ways, including electrical wiring, telephone wiring, and special cables. One of the simplest ways, however, is without cables, or wireless.

WIRELESS LAN

A wireless local area network is typically referred to as a wireless LAN (WLAN). It uses radio frequencies to connect computers and other devices. All communications pass through the network's centrally located wireless access autor point or base station. This access point interprets incoming radio frequencies and routes communications to the appropriate devices. 

PERSONAL AREA NETWORK

A personal area network (PAN) is a new type of wireless network that works within a very small area your immediate surroundings. PANS connect cell phones to headsets, PDAs to other PDAs, keyboards to cell phones, and so on. These tiny. self-configuring networks make it possible for all of our gadgets to interact wirelessly with each other.

METROPOLITAN AREA NETWORKS

The next step up from the LAN is the MAN-the metropolitan area network. MANs span distances up to 100 miles. These networks are frequently used as links between office buildings that are located throughout a city. Unlike a LAN, a MAN is typically not owned by a single organization. Rather, it is either owned by a group of organizations who jointly own and operate the network or by a single network service provider who provides network services for a fee.

WIDE AREA NETWORKS

Wide area networks (WANS) are countrywide and worldwide networks. These networks provide access to regional service (MAN) providers and typically span distances greater than 100 miles. They use microwave relays and satellites to reach users over long distances Of course, the widest of all WANS is the Internet, which spans the entire globe.

The primary difference between a LAN, MAN, and WAN is the geographical range. Each may have various combinations of hardware, such as microcomputers, mini computers, mainframes, and various peripheral devices.