 802. 11a channels Access point switch Access point arrays Client stations Figure 3-13: WLAN Tree Topology Employing Access Point Arrays create a tree topology, as shown in Figure 3-13, with multi giga-bit total WLAN capacity. Miscellaneous Wireless LAN Hardware Wireless Network Bridging Wireless bridge components that provide point-to-point WLAN or WMAN links are available from a number of manufacturers, packaged in weather proof enclosures for outdoor use (Figure 3-14). The D-Link DWL 1800 is one example which bundles a 16 dBi flat panel antenna with a 2.4 GHz radio providing a transmit power of 24 dBm (under FCC) or 14 dBm (under ETSI regulations), to deliver a range of 25 km under FCC or 10 km under ETSI. Many simple wireless LAN access points also support network bridging, or can be upgraded with a firmware upgrade to provide this capability. Configuring these devices simply involves entering the MAC address of the other endpoint into each station's access control list, SO that each station only decodes packets transmitted by the other endpoint of the bridge. Wireless Printer Servers A wireless printer server allows a printer to be flexibly shared among a group of users in the home or office without the need for the printer to be hosted by one computer or to be connected to a wired network. Chapter Three Dolitick Figure 3-14: Outdoor Wireless Bridges (courtesy of D-Link (Europe) Ltd. and Linksys (a division of Cisco Systems Inc.)) Typically, as well as wired Ethernet and wireless LAN interfaces, this device may include one or more different types of printer connections, such as USB or parallel printer ports, as well as multiple ports to enable multiple printers to be connected - such as a high-speed black and white laser and a separate colour printer. Figure 3-15: Wireless Printer Servers (courtesy of Belkin Corporation, D-Link (Europe) Ltd. and Linksys (a division of Cisco Systems Inc.)) Wireless Network Physical Architecture A printer server for home or small office wireless networking may also be bundled 