How Wireless Fidelity Works Computer Science Essay

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The term wi-fi is short for wireless fidelity. The wi-fi alliance, the organization that owns wi-fi registered trademark term, specifically defines wi-fi as any wireless local area network (WLAN) products that are based on the institute of electrical and electronics engineers (IEEE) 802.11 standards. It is a wireless local area network, using radio waves or radio frequency, a frequency within the electromagnetic spectrum associated with radio wave propagation to provide a wireless high-speed internet and network connections, just in the same way as a wired (cabled) system.

There are several variants of 802.11.The most common one is 802.11b which provides speeds up to 11mbps. 802.11g and 802.11n are faster versions. Many 802.11g and 802.11n products are backward compatible with the original 802.11b. Wi-fi coverage is only provided in small, specific areas called "hot spots". Range of a typical wi-fi base station (access point) is typically around 100 feet to 300 feet indoors and up to 2000 feet outdoors.

Wi-fi networks can be set up and operated by anyone with different networks allowing different kinds of access, for example, a university may offer on premises free access for verified students. While most wi-fi connections are between a mobile device and an access point, it is also possible to create an "adhoc" network directly among two or more devices without an access point.


Wi-fi was developed from the availability of unlicensed spread spectrum together with competitors such as home RF, Bluetooth, and of late, cordless telephone. It was invented in the early 1990's by a company known as NCR Corporation /AT and T (Later Lucent and Agere Systems) in Newgrin, in the Netherlands. The investors of wi-fi initially targeted to use it for cashier systems. This was observable when they first released their wireless product on the market under the name wave LAN with speeds of 1mbits to 2mbits.

The name wi-fi was delayed from being used commercially until August 1999. The wi-fi alliance was formed to develop the wi-fi brand, to include any type of network or wireless local area network product, based on any of the 802.11 standards including 802.11b, 802.11g, 802.11n, in an attempt to stop confusion about LAN interoperability.

The 802.11b standard is the first, widely used wireless networking technology. The 802.11g was developed offering greater performance (speed and range) and remains today's most common wireless networking technology. While the 802.11n standard is currently under development and is scheduled to be completed in 2009. All of these standards use the same 2.4GHz radio frequency and as a result are designed to be compatible with each other.


There must be a group of wireless devices to an adjacent wired local area network that is connected by the wireless access point (WAP), which is almost the same as the network hub relaying the data between connected wireless devices in addition to a single connected wired device, at most times an Ethernet hub or switch that allows wireless devices to communicate with other wired devices. Wireless adapters allow devices to connect to a wired network. They connect to devices using different external or internal interconnects, for instance, PCI, mini PCI, USB, Card bus, PC card, etc. Many latest laptop computers have internal adapters.

Wireless routers integrate a wireless access point, Ethernet switch, internal router firmware application that provides IP routing, NAT, DNS forwarding through an integrated WAN interface. Wired and wireless Ethernet local area network devices connect to single WAN device, for instance, cable modem or DSL modem allowed by the wireless router. All three devices mainly the access point and router are allowed by the wireless router to be configured through one central utility, which is most usually an integrated web server which serves web pages to wired and wireless local area network clients and often optional to WAN clients. The utility may also be an application that is run on a desktop computer such as Apple's airport.

Wired network is connected to wireless network file by wireless network bridges, an access point connect wireless devices to a wireless network at the data link layer. Two wireless bridges can be used to connect two wired networks over a wireless link, which can be useful in situations where a wired connection may be unavailable. For instance, between two separate homes.

The range of an existing wireless network can be extended by wireless range extenders or wireless repeaters. The range extenders can be strategically placed to elongate a signal area or allow for the signal to reach around barriers such as those created in L-shaped corridors. Wireless devices connected through repeaters will highly suffer from an increased latency for each hop. Again, a wireless device connected to any of the repeaters in the chain will have a throughput that is limited by the weakest link between the two nodes in the chain from which the connection originates to where the connection ends.



Wi-fi technology is relatively new. Swaziland is no exception from this, wi-fi is not a popular term within the nation. Be that as it may, there is some good news on the holistic implementation of the concept. There are several companies with this technology but we will concentrate on the Royal Swazi Sun Hotel.

The Royal Swazi Sun Hotel

This is a hotel business situated along the valley of Ezulwini. It is under the Sun International group of hotels. The core business of the company is hospitality. They provide paid lodgings on a short term basis. Originally, this type of business was more concerned with providing accommodation for its customers. The competition in the hospitality business has become stiff such that other well known businesses have run out of business. The pressure has been mounted by the increasing diversity of customers, due to the high rate of information availability. Information is now easily accessible to anyone at much lower cost than in the past as a result of improved development in information and communication technology.

In a bid to maintain its position within the industry, Royal Swazi Sun has introduced wi-fi that allows customers to access the network or internet whilst they are staying in the hotel. These enable customers to connect to their families while enjoying their stay at the hotel, it also allow business people to stay in touch with their offices while staying at the hotel.

Wi-fi is used by the hotel to boost its customer service, it's a strategy used to maintain competitive advantage.


The wi-fi can never come without a price or drawbacks, it possess a number of drawbacks.

1. All of our research companies cry foul about the major network supplier, Swaziland Post and Telecommunications (SPTC).They complain that the network signal sometimes is very slow or sometimes they receive no network signal. This then hinders the wi-fi user to view any data at that time or at fast speed, when the network is slow.

2. Sending a large amount of data is an impossible mission with the wi-fi, as the speed of the devices become slower.

3. Wi-fi could be affected by thick wall; this means that one in another room can hardly access the internet.

4. The direction of the access points can also affect the system. In the case of the Royal Swazi Sun hotel, two access points are pitched facing opposite direction and the reason is to allow people from the different directions to have access. If it was not the case one party would have gone without the network.

5. Wi-fi technologies are power hungry and suck out a lot of electricity. This is more often experienced by users of laptops and other battery dependant devices. The technology also cause a heat concern, if wi-fi consumes so much electricity it will be a damper on the very concept of mobility because they will have to look for the nearest power point to charge batteries.

6. The most common wireless encryption standard wired equivalent privacy or WEP has been shown breakable even when correctly configured. Hackers can easily access information of the company or personal information by using airsnort or aircracking tools to recover web encryption keys. Airsnort can determine the encryption password once it has seen 5 to 10 million encrypted packets. Aircrack-plus can use Klein's attack to crack a WEP key with a 50% success rate using only 40 000 packets. The reason why it is easily traced is that WEPallowed the same station encryption key to be used over and over again.

7. Wi-fi access points typically default to an open mode. Novice users benefit from a zero configuration device that works out of the box but might not intend to provide open wireless access to their local area network.

8. Wi-fi networks have limited range. A typical wi-fi home router using 802.11b or 802.11g with a stock antenna might have a range of 45 metres (150 feet) indoors and 90 metres (300 feet) outdoors. Range also varies with frequency band, as wi-fi is no exception to the physics of radio wave propagation. Wi-fi in the 2.4 GHz frequency block has a better range than with wi-fi in the 5GHz block, and less range than the (oldest wi-fi and pre wi-fi) 900MHz block. Outdoor range with improved antennas can be several kilometres or more with line of sight.

9. Wi-fi pollution, meaning interference of a closed or encrypted access point with other access points in the area, especially on the same or neighbouring channel, can prevent access and interfere with the use of other open access points by others caused by overlapping channels in the 802.11g or 802.11b spectrum as well as with decreased signal noise ratio (SNR) between access points. This is wide problem in high density areas, such as large apartment complexes or office buildings with many wi-fi access points.

10. Wi-fi networks that are unencrypted can be monitored and used to read and copy data including personal information and financial information transmitted over the network. For example, a company can copy another company's data through unsecured network.

11. Interoperability issues between brands or deviations from the standard can disrupt connections or lower throughout speeds on other users devices within range. Wi-fi alliance programs test devices for interoperability and designate devices which pass testing as wi-fi certified. If devices have not undergone the test of wi-fi interoperability they will result in incompatibility.

12. Radio waves conflicts, if one is using his or her wi-fi near other radiation emitting devices such as micro wave ovens and cordless phones, the resulting conflicts between devices and networks tend to slow down the wi-fi device. In older versions of wi-fi the conflicts were so high such that if the user were to go near the microwave the data transfer would immediately stop.

13. Sometimes, there are breakdowns of the router requiring the purchase of a new one.

14 Spectrum assignments and operational limitations are not consistent world wide, most of Europe allows for an additional two channels beyond those permitted in the United States. Japan has more on top of that and some countries like Spain prohibit the use of the lower numbered channels. Furthermore some countries, such as Italy used to require a general authorization for any wi-fi used outside an operators own premises, or require something akin to an operator registration

15. Internal cards are not easy to install, if the device does not have a built in wireless adapter.


So far the pros and cons carry similar weight at this moment of the wi-fi technology, primarily, to ensure connectivity. As wi-fi attempt to further its own definition and to find its place in the broadband digital age, the ease of access is front and centre. With the increasing converting and installing hotspots domestically and internationally, it looks crystal clear that wi-fi might find legs to stand on. While it might seem like it is a great distance -global coverage -the distance one can deviate from an access point drastically hinders its capability, antennas like hawking model are assisting with the connectivity and strength of signal.

A number of companies have invested on wi-fi technologies because they have seen its potential especially in security measures, where the WPA has proved to be the standard for now. A wi-fi market also gaining considerable an amount of steam is the PDA

The 802.11g format increases transfer rates up to 54Mbps. Stanford University developed AGN100 wi-fi chipset that could increase speed up to 108Mbps. The 802.11g format is nearly five times the speed of the common used rate 802.11b. If the AGN100 wi-fi chipset becomes viable and enters the market, it doubles the speed of 802.11g and is about ten times faster than 802.11b.