What is the hidden node problem on Wi-Fi networks and what can be used to counteract the problem?
What will be an ideal response?
It's quite possible that in a three-station wireless network, all workstations can communicate with the AP: For example, workstation A can hear workstation B and workstation B can hear workstation C, but workstation A can't hear workstation C, perhaps because the two are out of range. This situation is called the hidden node problem. CSMA/CA doesn't work because workstation A never knows whether workstation C is sending, and vice versa. To counteract this problem, the 802.11 standards specify another feature that uses handshaking before transmission. If this feature is enabled, a station must send the AP a request-to-send (RTS) packet requesting transmission. If it's okay to transmit, the AP sends a clear-to-send (CTS) message, and the workstation starts its communication. All other devices communicating with the AP hear the exchange of RTS and CTS messages, informing them that another device has control of the medium.
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Rewrite the XML document in Fig. 5.10 such that each note element has year, month, day and time attributes rather than child elements. The solution should contain only the root element and note child elements.
What will be an ideal response?
The OS X file system uses ________
A) DoS B) HFS+ C) FAT D) NTFS
________ menus appear when the user right-clicks on a database object such as a form
Fill in the blank(s) with correct word
Field names and data types need to be the same in both the source table and the destination table to append all records
Indicate whether the statement is true or false