LANs: Local Area Networks
Local Area Networks also called LANs have been a major player in industrialization of computers. In the past 20 or so years the worlds industry has be invaded with new computer technology. It has made such an impact on the way we do business that it has become essential with an ever-growing need for improvement. LANs give an employer the ability to share information between computers with a simple relatively inexpensive system of network cards and software. It also lets the user or users share hardware such as Printers and scanners. The speed of access between the computers is lighting fast because the data has a short distance to cover. In most cases a LAN only occupies one or a group of buildings located next to each other. For larger area need there are several other types of networks such as the Internet.
LANs systems can be defined and connected in many different ways. This is the reason for the standardization for every one can have a common ground to start from. The LANs described Herein are distinguished from other types of data networks in that they are optimized for a moderate size geographic area such as a single office building, warehouse, or a campus. The IEEE 802 LAN is a shared medium peer-to-peer communications network that broadcasts information for all stations to receive. As a consequence, it does not inherently provide privacy. The LAN enables stations to communicate directly using a common physical medium on a point-to-point basis without any intermediate switching node being required. There is always need for an access sublayer in order to arbitrate to access to the shared medium. The network is generally owned, used, and operated by a single organization. This is in contrast to Wide Area Networks (WANs) that interconnect communication facilities in different parts of a country or are used as a public utility. These LANs are also different from networks, such as backplane buses, that are optimized for the interconnection of devices on a desk top or components within a single piece of equipment. (IEEE 802 Standard 1990) That is the standard definition for LANs by Institute of Electrical and Electronics Engineer committee 802. They are the committee used to set the standard in workmanship and operations for technicians that set-up and perform maintenance on LANs systems. And through all the technical words what they are trying to say is a LAN is a small area network that distributes information among computer in a small work environment unlike WANs that distribute information across global areas. It is usually the case that LAN is owned by the same organization that owns the attached devices. For WANs, this is less often the case, or at least a significant fraction of the network assets are not owned. This has two implications. First, care must be taken in the choice of LAN, since there may be substantial capital investment (compared to dial-up or leased charges for wide-area networks) for both purchase and maintenance. Second, the network management responsibility for a local network falls solely on the user . (Local and metropolitan area networks 1997).
The question now is you have a standard and you have a connection now how do you manage the system to run flawlessly? Networks use protocols, or rules, to exchange information though a single shared connection. These protocols prevent collisions of data caused by simultaneous transmission between two or more computers. Computers on most LANs use protocols known as Ethernet or Token Ring. An Ethernet-linked computer checks if a shared connection is used. If not, the computer transmits data. Since computer can sense an idle connection and send data at the same time, transmitting computers continue to monitor their shared connection and stop transmitting if a collision occurs. Token Ring protocols pass a special message called a token through the network. A computer that receives the token is given permission to send a packet of information or, if the computer has no packet to send, it passed the token to the next computer. (Local Area Network Microsoft 2000) I know that it is complicated to understand, but for the actual user the software takes care of most all of the management for you.
There are seven things that a LANs can do that you cannot with ease do with non-networked stand-alone systems. First sharing files A LAN enables many user to share a single copy of a file stored on a central file server computer. (Introduction to Networking 1992) Transferring files A LAN enables you to copy files from machine to machine without having to exchange floppy disks. (Understanding Data Communications 1993) Access information and files A LAN enables anyone to run the accounting software, for example, or other application software from any of the workstations (Introduction to Networking 1992) Share applications A LAN enables two people to use the same copy of the Microsoft Word word processing program simultaneously (Introduction to Networking 1992) Simultaneously key data into an application. Printer sharing and electronic mail with in the system.
In conclusion the LAN has become essential in the modern work environment. The ever-growing need for advancement has become a very profitable industry in its self and it will continue to grow for a long time to come. For now we are barely skimming the possibilities and uses for this new networking technology.