翻訳と辞書 Words near each other ・ Network Access Device ・ Network Access Identifier ・ Network Access License ・ Network access point ・ Network Access Protection ・ Network access server ・ Network address ・ Network address translation ・ Network administrator ・ Network Admission Control ・ Network Advertising Initiative ・ Network affiliate ・ Network Against Prohibition ・ Network agility ・ Network Aging Research ・ Network allocation vector ・ Network analysis ・ Network analysis (electrical circuits) ・ Network Analysis and Ethnographic Problems ・ Network analyzer ・ Network analyzer (AC power) ・ Network analyzer (electrical) ・ Network and Management Laboratory ・ Network Applied Communication Laboratory ・ Network arch bridge ・ Network architecture ・ Network as a service ・ Network Audio System ・ Network Automation ・ Network Automation, Inc. v. Advanced Systems Concepts, Inc. Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Network allocation vector ： ウィキペディア英語版 Network allocation vector The network allocation vector (NAV) is a virtual carrier-sensing mechanism used with wireless network protocols such as IEEE 802.11 and IEEE 802.16 (WiMax). The virtual carrier sensing is a logical abstraction which limits the need for physical carrier-sensing at the air interface in order to save power. The MAC layer frame headers contain a ''duration'' field that specifies the transmission time required for the frame, in which time the medium will be busy. The stations listening on the wireless medium read the ''Duration'' field and set their NAV, which is an indicator for a station on how long it must defer from accessing the medium. The NAV may be thought of as a counter, which counts down to zero at a uniform rate. When the counter is zero, the virtual CS indication is that the medium is idle; when nonzero, the indication is busy. The medium shall be determined to be busy when the STA is transmitting. In IEEE 802.11, the NAV represents the number of microseconds the sending STA intends to hold the medium busy (maximum of 32,767 microseconds). Wireless stations are often battery-powered, so to conserve power the stations may enter a power-saving mode. A station decrements its NAV counter until it becomes zero, at which time it is awakened to sense the medium again. The NAV virtual carrier sensing mechanism is a prominent part of the CSMA/CA MAC protocol used with IEEE 802.11 WLANs. NAV is used in DCF, PCF and HCF. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Network allocation vector」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.