.11a) provide an the marketplace. However, even if never deployed, these evolution path to support more users and applications; proposals provide an indication of the likely approaches WPA and eventually 802.11i enable a more robust en- for future high-rate short-range radio technologies. cryption and authentication environment for protecting sensitive information. Contemporaneous with the evolution of WLANs, 5.1.6 Capsule summary: Chapter 5.1 WPANs have been developed to replace local cables. For historical and technical reasons, a distinct PAN architec- WLANs are constructed to extend LANs and share some ture has evolved, using master/slave self-organizing pico- of the properties of their wired forebears. However, the nets. WPAN radios are targeted for short-range wireless transition places requirements on any WLAN communications and require modest transmit power and protocol for connection management, medium alloca- limited receiver sensitivity. Support for time-sensitive tion, error detection and correction, and additional link traffic is provided in the design. WPANs are evolving security. IEEE 802.11 WLANs provided a good com- toward higher data rates and in a possible UWB imple- bination of range and data rate at low cost and easy in- mentation may provide the basis for the long-envisioned tegration with popular Ethernet-based wired LANs; the convergence of the various home entertainment/ in- successful WECA consortium also provided assurance of formation media into a single short-range wireless network. Further reading 802.11 Networks in Cryptography conference, Toronto, also available on the respective task Canada, 16-17 August 2001 group web pages. Draft standards that 802.11 Networks: The Definitive "Using the Fluhrer, Mantin and Shamir are not yet available for free download Guide, Matthew Gast (cited in chapter Attack to Break a WEP," A. Stubble- can be purchased from the IEEE store 1): The best overall introduction. Goes field, J. Ioannidis, and A. Rubin, Net- (but beware of awkward digital-rights- 