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Lorraine Galkowski September 3, 2011 Local Area Networks (LANs) NURSP 2275


Objectives After this presentation you should understand:  What are LANs?  What is the history of its creation?  What are physical components of LANs?  What service do they provide?  What are some limitations of a LAN?


What is a LAN (local area network)? • Local area networks (LANs) are computer networks ranging in size from a few computers in a single office to hundreds or even thousands of devices spread across several buildings. They function to link computers together and provide shared access to printers, file servers, and other services. • LANs allowed for the transmission of data between workers. In turn, they enabled this shared data to be directed to a common printer, serving a larger group of users.


History of LANs • Originally involved an “ethernet” - a system for connecting computers within a building using hardware running from machine to machine. • Robert Metcalfe, a researcher at • Zerox, is known as the creator of • the LAN. • In 1976, He and his assistant, David Boggs published a paper titled, "Ethernet: Distributed Packet-Switching For Local Computer Networks.“ • Now an international computer industry standard, “ethernet” is the most widely installed LAN protocol.


Physical Components of LANS • First there are Network access units (or interfaces) that connect the personal computer to the network. • These units are actually interface cards installed on computer motherboards.

• They provide a connection, monitor availability of access to the LAN, set or buffer the data transmission speed, ensure against transmission errors and collisions, and assemble data from the LAN into usable form for the computer.


Physical Components of LANS • Early LANS used Coaxial Cables as the communication medium • 1980’s -Twisted Pair wires (i.e.Cat-5)became standard Pros - Inexpensive/ higher bandwidth (capacity) Con - Susceptible to electrical interferences

• Fiber-optic cable offers highest bandwidth and lowest susceptibility to electrical interferences. Its lightweight and easy to install. • Twisted Pair wires and Fiber-optics are used together also. • Now wireless and radio wives are also used with LANs


Physical Components • The components of a LAN also include physical media, protocols, and software. • Networks also include repeaters, bridges, and routers (which can connect to WANs – wide area networks). • The cost of a local area network will vary based on your network's size and security requirements. Still, LANs help you save time, money, and resources by sharing hardware. • Software licenses tend to cost less for computer networks.


Who is using LANs? • A local area network (LAN) is a computer network that connects computers and devices in a limited geographical area such as home, school, computer laboratory or office building They’re everywhere! We have one in our home connecting computers to our printer.


The role of LANs in Health Care • As a connectivity device it speeds internal processes of delivery of care. • It integrates records • Dr. offices or clinics have them internally and through LANs are connected to Labs and Pharmacies. Referrals can be sent to other departments. • Hospital systems make use of LANs and also due to size bridge to form WANs.


Conclusion • This is not an all-inclusive explanation of LANs but rather introductory. • The various components and mechanisms that make LAN work are complex and detailed. • In the history of computer hardware evolution, LANS are pivotal. Growth in this area continues with the demand for faster and more inclusive technology • Thank you.


Evolution of Computer- LANs