máy tính để bàn sử dụng các thiết bị phần cứng mà thực hiện theo tiêu chuẩn Peripheral Component Interconnect (PCI). Các thiết bị này có chứa các mạch điện tử trên circuitboards in và có kết nối trên một cạnh. Một ví dụ của một PCI adapter mạng LAN không dây được hiển thị trong | Figure A wireless LAN adapter based on the Compact Flash technology. Peripheral Component Interconnect PCI Wireless LAN Adapters New hardware functionality is added to desktop computers using hardware devices that comply with the Peripheral Component Interconnect PCI standard. These devices contain electronic circuits on the printed circuitboards and have connectors on one edge. An example of a PCI wireless LAN adapter is shown in Figure . Figure PCI wireless LAN adapter. Wireless LAN Access Points APs Wireless LAN access points APs are wireless LAN devices that make up the central portion of a wireless LAN that operate in the infrastructure mode. All LAN traffic in a wireless LAN operating in infrastructure mode must go through an access point see Chapters 2 and_3 for more information on wireless LAN access points . Most wireless LAN APs are standalone devices and do not need to be installed or physically interfaced with a computer. Physically APs normally have one or two antennas small light indicators showing the status of the AP a power jack for providing the electric current necessary to operate the device and a few wired LAN jacks typically RJ45 to connect the AP to a wired LAN. Figure shows a wireless LAN AP. 138 Figure A wireless LAN access point. Wireless LAN Antennas Most wireless LAN devices like APs and PC Card adapters come with built-in antennas. However if you feel that you are not receiving a strong enough signal using regular antennas often you can add external antennas to wireless LAN devices. Also if you are connecting two physically separated LAN sites using wireless LAN equipment you will most probably need external antennas. You should contact the manufacturer of your wireless LAN equipment for more information on antennas that will be suitable for your needs. Networking Support Servers The networking support servers include the computers that play key roles in a LAN. For example file servers include large capacity disks and
