Network refers to the set of devices (nodes) connected by communication links. A node can be a computer, printer, or any other device capable of sending and/or receiving data generated by other devices on the network.
A network is categories into three types such as Local Area Network (LAN), Metropolitan Area Network (MAN) and Wide Area Networks (WAN). And in this article, we will cover all about Local Area Network (LAN).
Local Area Network (LAN)
Local area network is the computer network that connects computers within the limited area such as schools, colleges or universities.
Local area networks, generally called LANs, are privately-owned networks. They provide a useful way of sharing resources between end users. The resources such as printers, file servers, scanners, and internet are easily sharable among other connected computers in a network.
LANs are distinguished from other kinds of networks by three characteristics:
- Their transmission technology
- Their size
- Their topology
Transmission Technology used in LANs
local area networks use either Wi-Fi or Ethernet to connect computer and devices in a network.
A typical Wi-Fi LAN operates one or more wireless access points that devices within coverage area connect to. These access points, manage network traffic which is flowing to and from the connected devices. In our home, school, office’s LAN, wireless broadband routers perform the functions of an access point.
A typical Ethernet LAN consisting of an ethernet cable to which all the machines are attached, like in our school labs, number of computers connected to each other through the common ethernet cable.
Though Ethernet and Wi-Fi are usually used in most home and office-based Local area networks, because of both the low cost and speed requirements, you can also set up a LAN with fiber optics which is more costly and provide better communication speed compared to Ethernet LAN or Wi-fi LAN.
Traditional LANs run at speeds of 10 to 100 Mbps (but now much higher speeds can be achieved) but newer LANs operate at up to 10 Gbps speed.
Size of LANs
LANs are restricted in size, a local network can contain anywhere from one or two devices up to a thousand devices. Some devices like printers, scanners, and other servers stay permanently with the LAN while mobile devices like computers, laptops, and phones may connect and disconnect from the network at various times.
LAN size depends on the transmission technology used in a network. For example, The size of Wi-fi LAN can be the actual coverage area of the wireless broadband routers whereas the size of an Ethernet LAN can be up to the size of the cable.
In both cases, though, Local Area Networks can be extended to cover much larger distances if required, by connecting together multiple access points or cables through a switch or hub.
The size of Local area networks is smaller than the Metropolitan Area Network (MAN) and Wide Area Networks (WAN).
Topologies used in LANs
Various topologies are possible to form a LANs but three core forms can be identified easily as follows:
Bus topology: All devices are connected to a backbone cable, called the bus. The Bus networks are relatively less costly and very easy to install for small networks. Ethernet systems use a bus topology.
For more detail: WHAT IS BUS TOPOLOGY? ADVANTAGES AND DISADVANTAGES OF BUS TOPOLOGY
Ring topology: All devices are connected to one another in the shape of a closed loop, so that each device is connected directly to the neighboring device, one on either side of it. Ring topologies are relatively expensive and difficult to install, but they offer high bandwidth and can cover large distances.
For more detail: WHAT IS RING TOPOLOGY? ADVANTAGES AND DISADVANTAGES OF RING TOPOLOGY
Star topology: All devices are connected to a central hub device. Star networks are relatively easy to install and manage, but bottlenecks can occur because all data must pass through the hub.
For more detail: WHAT IS STAR TOPOLOGY? ADVANTAGES AND DISADVANTAGES OF STAR TOPOLOGY
These topologies can also be mixed to perform better. For example, a bus-star network consists of a high-bandwidth bus, which connects a collection of slower-bandwidth star segments.
Characteristics of Local Area Network
- LANs are private owned-network, can be extended up to a few kilometers.
- LANs operate at relatively high speed as compared to the typical WAN
- It connects computers within a single office, building, block or campus, i.e. they work in a relatively small geographical area.
Advantages of LAN
- Resource Sharing: LAN provides resource sharing such as computer resources like printers, scanners, modems, DVD-ROM drives, and hard disks can be shared within the connected devices. This reduces cost and hardware purchases.
- Software Applications Sharing: In a Local Area Network, it is easy to use the same software in a number of computers connected to a network instead of purchasing the separately licensed software for each client a network.
- Easy and Cheap Communication: Data and messages can easily be shared with the other computer connected to the network.
- Centralized Data: The data of all network users can be stored on a hard disk of the central/server computer. This help users to use any computer in a network to access the required data.
- Data Security: Since data is stored on the server computer, it will be easy to manage data at only one place and the data will be more secure too.
- Internet Sharing: Local Area Network provides the facility to share a single internet connection among all the LAN users. In school labs and internet Cafes, single internet connection is used to provide internet to all connected computers.
Disadvantages of LAN
- High Setup Cost: The initial setup costs of installing Local Area Networks is high because there is special software required to make a server. Also, communication devices like an ethernet cable, switches, hubs, routers, cables are costly.
- Privacy Violations: The LAN administrator can see and check personal data files of each and every LAN user. Moreover, he can view the computer and internet history of the LAN user.
- Data Security Threat: Unauthorised users can access important data of an office or campus if a server hard disk is not properly secured by the LAN administrator.
- LAN Maintenance Job: Local Area Network requires a LAN Administrator because there are problems such as software installations, program faults or hardware failures or cable disturbances in Local Area Network. A LAN Administrator is required to maintain these issues.
- Covers Limited Area: LANs are restricted in size they cover a small area like a single office, single building or a group of nearby buildings.