Appliances may interfere on the unregulated signal

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Appliances may interfere on the unregulated signal frequency. 7. There is another mechanism besides RTS/CTS that helps the incompatibility. Explain briefly the difference between RTS/CTS and CTS-to-self and when each is used. RTS/CTS exchange is a way for the client to tell the AP, "hey I'm going to transmit, please let everyone know" and the CTS is then sent by the AP to tell everyone else, "hey, be silent while this other node transmits." The difference is that CTS-to-self is a way for the AP to protect its own transmissions from disruption. 8. What is the protection scheme talked about in the standard? In short, how do 11g nodes know that an 11b node is associating and how is CCK involved? RTS/CTS and CTS-to-self are called protection mechanisms. They protect one transmission from being broken up by someone else. The original purpose of RTS/CTS was basically a way for 802.11g stations to tell 802.11b stations to be silent. 802.11b specifies Complementary Code Keying (CCK), which consists of a set of 64 eight- bit code words. As a set, these code words have unique mathematical properties that allow them to be correctly distinguished from one another by a receiver even in the presence of substantial noise. 10
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MIXED 11B/11G WLAN PERFORMANCE 11 9. In addition to the added overhead of the RTS/CTS scheme, what else causes the drop in throughput you see? Are there other factors that can affect the throughput? If you don't have any hidden nodes, then the use of RTS/CTS will only increase the amount of overhead, which reduces throughput. A slight hidden node problem may also result in performance degradation if you implement RTS/CTS. In this case, the additional RTS/CTS frames cost more in terms of overhead than what you gain by reducing retransmissions.
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