هي تقنية الشيكات ذات المدى القصير وتشمل عدة تقنيات مثل Bluetooth و InfraRed وحتى WLAN لكن عندما تستخدم للربط بين جهازي كمبيوتر، وهذا هو مبدأها أي الربط بين جهازين Peer-To-Peer وهذا المصطلح (Ad Hoc) لاتيني معناه لغرض مخصص أو معنى قريبا منه (الله أعلم)
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WLAN Operational Modes
A wireless device can operate in either Ad Hoc mode or in Infrastructure mode. The following sections describe these modes.
Ad Hoc Mode
Ad Hoc is Latin for "this purpose"; in this case, it refers to a connection between wireless devices (such as two laptops, for example) for a temporary high-speed link, perhaps to share files or play a game. No AP is required; indeed, no network devices other than the two client machines are needed. Ad Hoc mode is not usually associated with business-class networks.
In Infrastructure mode, an AP is required because the client devices cannot send directly to each other; they must send through the AP. The AP, in turn, handles all the wireless client data and provides the connection to the wired LAN by way of its connection to the switch. Infrastructure mode is what you will find in business environments. With the use of an AP, many devices can connect to the network, and you can provide authentication and encryption for wireless connections to help secure the WLAN.
Within the Infrastructure mode of operation, Cisco makes a distinction between Autonomous and Lightweight modes. The difference is simple: in Autonomous mode, each AP is managed separately and sends wireless client data into the network itself. This is a suitable mode for small networks where management and security issues are not overwhelming.
Cisco has put a lot of work into making WLANs manageable and secure. In Lightweight mode, each AP associates with a WLAN controller, a special device that provides a single point for management and security of multiple APs in the network. The APs and WLAN controllers communicate using the Lightweight Access Point Protocol (LWAPP), a Cisco-proprietary protocol built for this system. In addition, all wireless client traffic from each AP is tunneled through the WLAN controller. It's more complicated and more expensive, but tremendously powerful for managing and securing many APs in a centralized fashion.