WIRELESS LOCAL AREA NETWORKS AND WI-FI

As you have read in Chapter 4, wireless local area networks have been making their way to the wireless forefront. A wireless LAN (WLAN) is like a wired LAN without the cables. WLANs transmit and receive data over the airwaves from a short distance in what is known as Wi-Fi (Wireless Fidelity). Wi-Fi is described in Table 7.1 and in Chapter 4.
The Wi-Fi Revolution. In a typical configuration, a transmitter with an antenna, called a wireless access point (WAP) connects to a wired LAN from a fixed location or to satellite dishes that provide and Internet connection. A WAP provides service to a number of users within a couple hundred feet, known as a “hotspot zone,” or hotspot. Several WAPs are needed to support larger numbers of users across a larger geographical area. End users can access a WLAN with their laptops, desktops, or PDAs by adding a wireless network card. Figure 7.2 shows how Wi-Fi works. Mitchell (2008) provides a step-by-step guide for building Wi-Fi at home or in small-business settings.
WLANs provide fast and easy Internet or intranet broadband access from public hotspots such as airports, hotels, Internet cafes, and conference centers. WLANs are also being used in universities, offices, and homes in place of the traditional wired LANs (see weca.net).





The major benefits of Wi-Fi are its lower cost and its ability to provide simple Internet access. As a matter of fact, Wi-Fi is the greatest facilitator of the wireless Internet.
Illustrative Applications of Wi-Fi. The years 2004 through 2008 were a breakthrough era for wireless networking in offices, airports, hotels, and campuses around the world. Since then, each month brings new examples of businesses that have added Wi-Fi, REID, or other wireless services for their employees, business partners, or customers. Several examples are presented in Table 7.2. Many more examples of Wi-Fi are included in this chapter and throughout the book.
Despite all of the development, progress is still slow, as shown next.
Barriers to Commercial Wi-Fi Growth. Two factors are standing in the way of Wi-Fi market growth: cost and security. First, some analysts question why anyone would pay $30 a month, $7.95 a day, or any other fee for Wi-Fi access when it is readily available in many locations for free (e.g.,in certain cities, airports, and shopping malls such as in Manila, Philippines). Because it’s relatively inexpensive to set up a wireless access point that is connected to the Internet, a number of businesses offer their customers Wi-Fi access without charging them for the service. In fact, there is an organization, freenetworks.org, aimed at supporting the creation of free community wireless network projects around the globe. In areas such as San Francisco, where there is a solid core of high-tech professionals, many “gear heads” have set up their own wireless hotspots that give passersby free Internet connections. This is a part of a new culture known as war chalking and war driving (see en.wilipedia.org/wiki/Warchalking).
In Sections 7.2 through 7.6 of this chapter, we will study m-commerce applications in a number of diverse categories. A summary of the applications is provided at en.wikipedia,org/wiki/Mobile_Commerce.