antennas. Routers with more antennas support higher capacity and speeds. To achieve the highest speeds and capacity, user devices as well as access points must have an equal number of antennas. The increasing capabilities of Wi-Fi networks have resulted in greater dependence on wireless networks. This is particularly true in mobile environments such as hospi- tals, factories, and educational institutions. In addition, staff members in organizations now assume that they can take advantage of wireless access for tablets and smart- phones during meetings, at lunch, and wherever they are within their building or within their organization's campus. WLAN Architecture in Enterprises All WLANs have base stations (access points) and user radios (which are also referred to as the user interface). The air interfaces used in the base station must be compatible with that in the user device. In addition, networks with multiple base stations often have controllers that direct traffic to particular access points. Central monitoring soft- ware can be used to remotely change access point configurations and monitor traffic on the wireless network. User Devices Wi-Fi chips are embedded within a growing number of computers, handsets, and remote monitoring devices, such as the following: Wi-Fi Standards, Architecture, and Use in Cellular Networks Laptops Cellular USB modems Cellular smartphones, and other handsets Tablet computers Set-top boxes connected to HDTVs for streaming TV and movies from the Internet; for example, Roku and Apple TV Printers Low-power medical devices used to monitor conditions remotely; for example, blood pressure and glucose monitors Remote monitoring devices connect wirelessly to the broadband service within a home or building. Within enterprises, remote monitoring devices connect to the LAN backbone. The broadband circuit transmits information to a central location. Access Points An access point has an antenna and chips with 802.11a, 802.11b, 802.11g, and 802.11n radios. Access points also translate between 