Loopcomm LP-9327H, Руководство пользователя

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members is to enhance the user experience through product interoperability. The organization is formerly
known as WECA.
21. Wi-Fi Protected Access (WPA)
The Wi-Fi Alliance put together WPA as a data encryption method for 802.11 wireless LANs. WPA is an
industry-supported, pre-standard version of 802.11i utilizing the Temporal Key Integrity Protocol (TKIP),
which fixes the problems of WEP, including using dynamic keys.
22. Wide Area Network (WAN)
A WAN consists of multiple LANs that are tied together via telephone services and / or fiber optic cabling.
WANs may span a city, a state, a country, or even the world.
23. Wired Equivalent Privacy (WEP)
Now widely recognized as flawed, WEP was a data encryption method used to protect the transmission
between 802.11 wireless clients and APs. However, it used the same key among all communicating devices.
WEP’s problems are well-known, including an insufficient key length and no automated method for
distributing the keys. WEP can be easily cracked in a couple of hours with off-the-shelf tools.
24. Wireless LAN (WLAN)
A wireless LAN does not use cable to transmit signals, but rather uses radio or infrared to transmit packets
through the air. Radio Frequency (RF) and infrared are the commonly used types of wireless transmission.
Most wireless LANs use spread spectrum technology. It offers limited bandwidth, usually under 11Mbps,
and users share the bandwidth with other devices in the spectrum; however, users can operate a spread
spectrum device without licensing from the Federal Communications Commission (FCC).
25. Fragment Threshold
The proposed protocol uses the frame fragmentation mechanism defined in IEEE 802.11 to achieve parallel
transmissions. A large data frame is fragmented into several fragments each of size equal to fragment
threshold. By tuning the fragment threshold value, we can get varying fragment sizes. The determination of
an efficient fragment threshold is an important issue in this scheme. If the fragment threshold is small, the
overlap part of the master and parallel transmissions is large. This means the spatial reuse ratio of parallel
transmissions is high. In contrast, with a large fragment threshold, the overlap is small and the spatial reuse
ratio is low. However high fragment threshold leads to low fragment overhead. Hence there is a trade-off
between spatial re-use and fragment overhead. Fragment threshold is the maximum packet size used for
fragmentation. Packets larger than the size programmed in this field will be fragmented If you find that your
corrupted packets or asymmetric packet reception (all send packets, for example). You may want to try
lowering your fragmentation threshold. This will cause packets to be broken into smaller fragments. These
small fragments, if corrupted, can be resent faster than a larger fragment. Fragmentation increases overhead,
so you'll want to keep this value as close to the maximum value as possible.
26. RTS (Request To Send) Threshold
The RTS threshold is the packet size at which packet transmission is governed by the RTS/CTS transaction.
The IEEE 802.11-1997 standard allows for short packets to be transmitted without RTS/ CTS transactions.
Each station can have a