server and additional utility fees for air conditioning and electricity. This is often pos- sible because more of the functions are distributed to access points rather than con- tained in central controllers. Some Wi-Fi manufacturers provide an option called Software as a Service. This is a cloud offering in which the Wi-Fi manufacturer manages the controller and reporting functions at its own data center. For more information on cloud computing and virtu- alization, see Chapter 1, "Computing and Enabling Technologies." Wi-Fi Standards, Architecture, and Use in Cellular Networks Internet Miami Cincinnati headquarters Internet Management console Kansas City Usage statistics Information about congestions Security reports Internet Identities of allowed users Dallas Figure 7-7 A wireless network management console can be situated at the provider's location, in the cloud, or at the enterprise site. Central controller in data center Controllers in wiring closets Building 1 Floor 2 in Building 3 Controllers in wiring closets Building 2 Floor 1 in Building 3 Figure 7-8 An example of Wi-Fi architecture with controllers at each build- ing, and a central controller for overall management of the Wireless Local Area Network (WLAN). Mobile and Wi-Fi Networks Decreasing Errors and Improving Productivity in Hospitals by Using Wireless Service A 400-bed acute care rehabilitation hospital, one with facilities to diagnose and treat patients on an inpatient basis, is planning to implement additional wireless applications on its existing Wi-Fi network. The overarching goals of this project are to increase productivity by getting information to mobile workers more efficiently and to reduce medication dosing errors. These applications will use the existing Wi-Fi network that will be expanded as required to support use for visitors, existing applications, and new applications. Most of the rehabilitation facility's employees are mobile and not assigned to a fixed desk with a telephone and computer. Doctors and nurses are more produc- tiv