WiFi stands for a trademarked phrase which means IEEE 802.11x, and is a short-range wireless transmission technology. WiFi is a technology using wireless means to interconnect personal computers, hand-held devices (such as PDA, smart phone etc.) and other terminals. It is a brand of wireless network communication technology which is held by the WiFi Alliance. The purpose is to improve the interoperability between wireless network products based on the IEEE802.11 standards. Generally, to set up a wireless network, an access point (AP) and wireless network adapters are the basic necessity. This way it can use the wireless medium and coordinate with the structure of the existing wired network to share network resources. As a result the cost of the set up and the complexity are far below the traditional wired network.
Banerji and Chowdhury’s study (2013), shows that the coverage area of normal AP is around 20 meters indoors and 100 meters outdoors. It is more suitable for being used in office and home environments. WiFi was the first widely used and deployed high-speed wireless technology, and it has a wide range of applications in networks at home, office, and in growing number of cafes, hotels and airports.