tailieunhanh - wireless hacking projects for wifi enthusiasts phần 2

Một trong những lý do cho sự thành công của những cuốn sách này đã được chương trình solutions@ độc đáo của chúng tôi. Thông qua trang web này, chúng tôi đã có thể cung cấp cho độc giả một phần mở rộng thời gian thực để cuốn sách in. | A Brief Overview of the Wireless World Chapter 1 13 Figure Shared Key Authentication 3. challenge response 128 bytes of WEP encrypted text 4. authentication response indicating success or failure access point access point access point access point Association Once the client has been authenticated the next step is to associate with the access point see Figure .The client sends an Association Request frame including the SSID and the AP sends back an Association Response frame indicating success or failure. Figure Wireless Access Point Association access point 1. association request frame including SSID of access point access point 2. association response frame indicating success or failure 14 Chapter 1 A Brief Overview of the Wireless World FCC Regulations One of the reasons that so many enthusiasts are drawn to is because it operates in an unlicensed spectrum where a license to operate from the FCC is not required. Unlike other wireless activities such as radio or TV broadcasting we do not need to purchase frequencies or pay a monthly service fee to use the airways for Wi-Fi. While operation is free from cost it is important to remember that it is not free from regulations. The rules for operating RF equipment vary from country to country depending on the local regulatory agency involved. In the United States that agency is the Federal Communications Commission FCC .The rules for operating equipment fall under the 1985 Industrial Scientific and Medical ISM mandate while the rules for operating equipment fall under the 1997 Unlicensed - National Information Infrastructure U-NII mandate. ISM regulations actually predate the existence of . ISM provides unlicensed spectrum in the 902-928MHz and frequencies were put to work in a variety of capacities and introduced a large number of technological innovations such as pagers microwave ovens and cordless .