A Wireless Local Area Network - Term Paper Example

Introduction A wireless local area network (WLAN) is a data communication system where two or more computers are joined together using radio frequency (RF) transmissions. Thus there is no need of wires for networking as is found in normal LAN’s. Using wireless LAN’s users can access and share data, applications and access internet or other network resources in a manner similar to wired LAN’s. The main idea behind WLAN’s being mobility, flexibility, convenience and portability, they are used with mobile devices having wireless facility such as notebook computers and tablet PC’s. Using these devices users can access shared information conveniently without having to plug in and connect to other devices physically. Working The transmission of data between devices in the network takes place by the simple process of modulation with radio frequencies acting as carriers of the information being transmitted. The RF is modulated according to the information signal and carried to the receiving end. At the receiving end the exact information is extracted from the modulated signal by the process of demodulation. A number of signals can be transmitted through air at the same time provided that their frequencies have a considerable gap between them. In other words the frequency of operation should be different and they will not interfere. There are one or more devices known as ‘access points’ through which the wireless devices communicate. An access point (AP) is a simple transmitter/receiver or ‘Transceiver’. A wireless network interface card (NIC) is required to access a wireless network which is available in various forms. Nowadays devices are available with built in NIC’s. But they can also be installed separately latter. These NIC’s also require necessary software drivers to be installed for their functioning. Types Now let us discuss about various types of wireless networks. Depending on the technology used for designing a wireless LAN they are of following types. Narrowband wireless LAN’s Narrowband WLAN’s keep the bandwidth of the radio frequency signal as narrower as possible, in order to just pass the information. Although the distance between the devices is reasonable but the speeds achieved are not as good as required by the corporate users. A general problem that could arise in WLAN’s is the interference, which can be overcome by allotting different frequencies to different individuals. In this case since the bandwidth is narrow, interference can very well be avoided. Spread spectrum wireless LAN’s These WLAN’s use wideband RF. The use of wideband signal helps in attaining greater speeds. The most popular WLAN being used is 802.11b attaining a speed of about 11 Mbps. With the advancement of technology the speeds have been boosted even up to 50 Mbps and more. A disadvantage with spread spectrum WLAN’s is the reduction of reliability, integrity and security. Since wideband signal is used, therefore it is obviously easier to detect it by an unauthorised person, making it less secure. Infrared wireless LAN’s Infrared WLAN’s have not been used much commercially as the speeds achieved in this case are very less and also shorter ranges are available. The speeds in this case are in the range of 115 Kbps to 4Mbps. Very fast infrared (VFIR) wireless WLAN’s are coming up in the near future which will increase the speeds considerably. IR frequencies are very high frequencies and have a disadvantage, like light, of not being able to penetrate opaque objects. Devices using infrared technology should be in line of sight which makes their use limited. However there are some IR WLAN’s which do not require line of sight, but still their range is limited. Advantages and disadvantages Wireless LAN’s have many advantages over wired LAN’s as stated below. One can access the network from anywhere within the range of access point allowing the users to remain connected even when they are moving inside the range. It is relatively easy to install a WLAN as compared to wired LAN as minimum cabling is required. A wireless LAN can be installed at places where it is impossible to do wiring. Initially the investment required for WLAN can be higher than LAN but the overall installation and maintenance cost is lesser. A WLAN is advantageous in some cases where the installation is temporary. WLAN’s also have some disadvantages. The data transfer rate to each device decreases considerably as the no. of devices attached to the network increases. The security is weaker than wired LAN’s. The network can be accessed at a limited distance from the access point. Moreover the solid obstacles between user and access points result in weakening of the signal. So in order to increase the signal strength more access points are needed which in turn increase the installation cost. The data speed depends upon the distance of the user from the access point. The larger the distance, the lesser is the speed. Certain radio frequencies used for WLAN’s may interfere with each other as the no. of users increases. With the advancement of technology it becomes necessary to upgrade the devices to higher specifications requiring to change them sometimes. Current uses As a result of various advantages of wireless LAN’s they are being put to numerous uses. WLAN is used in hospitals by doctors for instantly accessing the information about patients using notebook computers. It is used by students to access libraries through internet while sitting in classrooms. It finds use in old and historical buildings where the laying of wires by drilling holes is difficult. It is used in trade shows where there is a need of temporary networking and use of wires is cumbersome and time consuming. Warehouse workers use WLAN’s for exchanging information with headquarters resulting in increased productivity. Executives use WLAN to make decisions quicker having instant information available on their notebook computers, while they are in a meeting. Security Security is one of the issues regarding wireless LAN’s which has been discussed for years. The main problem here is the attack threats and vulnerability of the network. The threats to data security have increased throughout the world in many forms. The need is to update the systems with new threats and continuously find solutions to emerging security problems. The presence of a wireless LAN can be detected by a compatible wireless device. Appropriate security measures should be taken in order that no one from outside has access to the network. Complex encryption techniques are used which make it almost impossible for unauthorised persons to get access to the network traffic. Costs The cost of a wireless LAN depends on various factors. The most costly device in a WLAN is an access point. Cost of an access point depends on quality of antennae, encryption used for access points, etc. The number of users that can access the network and the connectivity of internet through access points also has an effect on the cost of WLAN’s. Access points are available between 40 and 800 pounds. Similarly wireless cards are also priced around 10 pounds. Wireless networking in IT centres In order to implement a secure wireless network for places like universities and IT training centres the following steps must be taken. The security of devices being used should be checked and upgraded from time to time. Users should be educated about security and networking. The username and password of administrator should be changed regularly. Whenever WLAN is not in use the access points should be turned off. Directional antennas should be used to restrict the wireless signal only to the area where it is needed. A firewall should be used to allow only authorised persons accessing the network. Regular updates of virus detection softwares should be done in order to save the network from internet hackers. Use of virtual private network (VPN) should be considered allowing users to enter the network using username and password. Wireless LAN’s and academia There are a wide range of benefits of wireless LAN’s as far as facilitation of education is concerned. WLAN’s are equally beneficial to both students as well as faculty. WLAN’s offer mobility and convenience to its users. Inside the campus or in classroom users can access any information required at that time particularly related to the subject. Using search engines on the internet users can find on the spot solutions to their problems in academics. Today’s world is competitive and by introducing such facilities in universities and colleges, the institutions compete for better students and faculty. Moreover introducing these technologies makes the job of students and faculty full of fun. However there are certain challenges faced by the authorities in this regard. As the number of students and faculty gaining access to the network increases the performance starts to degrade. There is a limit to users accessing an access point. Due to this the densely populated areas such as libraries face a problem of connectivity. This requires placing of access points closer to each other which can cause channel overlapping. Conclusion Flexibility and mobility of wireless LAN’s are the factors making them a favourite choice of users around the world. They are hassle free and have almost all the functionality of wired LAN’s. Here we find the simplicity of installation and maintenance. Users find it extremely simple to operate their systems within a wireless network. The fact that users can access the network even when they are having a walk makes it extremely useful. The low cost of ownership and wider range are the added bonus for acquiring a wireless LAN. For all these reasons wireless LAN’s are finding extensive use in universities and colleges. They are even used in schools now. Students find learning interesting and innovative, thereby making the job easier. On the other hand teachers access any information regarding their academics easily and within the campus. Therefore it makes both teaching and learning very easy. The students have a role to play in setting up and functioning of this technology. They must learn about the security and use of WLAN’s. It is their duty to put WLAN’s to a constructive use. Students must use it for their academic benefits and not try to create nuisance by introducing viruses, etc. into the network. How the students handle the network will decide its functioning. The proper or improper functioning of the network will undoubtedly affect the students. To sum up the wireless LAN technology can benefit the users in numerous ways and it finds many uses. However there are some issues like high costs and low speeds which have to be worked upon. With the present rate of advancement in technology these disadvantages will be overcome in the near future. References British Educational Communications And Technology Agency, BECTA. (January 2005). Wireless Local Area Networks (WLAN). Retrieved February, 24, 2006, from http://www.becta.org.uk/leaders/leaders.cfm?section=3_2&id=396 Read More