Introduction to wireless networks and standards

Wireless networks have become very popular in the last decade, and it is now one of the most essential connectivities we need for our gadgets to stay connected. At a high level, a wireless network can be of the following types:

• Wireless Personal Area Networks (WPAN): Wireless devices stay within 5-10 meters of each other and can be built ad-hoc-based
• Wireless Local Area Network (WLAN): Wireless devices stay within 100 meters of each other
• Wireless Metropolitan Area Network (WMAN): Wireless devices stay less than 100 meters away from each other and within ~5 kilometers (3.1 miles), and usually provide coverage for a suburb or town

Figure 9.1: Types of Wireless Networks

Let's have a quick look at various WLAN standards. The IEEE 802.11 committee has been developing wireless LAN standards since the mid-1990s and has published several, from 802.11b to 802.11ac, as given here:

Standard	802.11b	802.11a	802.11g	802.11n	802.11ac
Year	1999	1999	2003	2009	2013
Frequency...