| 翻訳と辞書 |
| IEEE 802.11af ： ウィキペディア英語版 |
IEEE 802.11af
IEEE 802.11af, also referred to as White-Fi and Super Wi-Fi, is a wireless computer networking standard in the 802.11 family, that allows wireless local area network (WLAN) operation in TV white space spectrum in the VHF and UHF bands between 54 and 790 MHz. The standard was approved in February 2014.〔(【引用サイトリンク】accessdate=2014-03-24 )〕 Cognitive radio technology is used to transmit on unused TV channels, with the standard taking measures to limit interference for primary users, such as analog TV, digital TV, and wireless microphones.〔
==Physical layer==
The physical (PHY) layer in 802.11af is based on the orthogonal frequency division multiplexing (OFDM) scheme specified in 802.11ac. The propagation path loss as well as the attenuation by materials such as brick and concrete is lower in the UHF and VHF bands than in the 2.4 and 5 GHz bands, which increases the possible range compared to 802.11 a/b/g/n/ac.〔 The frequency channels are 6 to 8 MHz wide, depending on the regulatory domain.〔 Up to four channels may be bonded in either one or two contiguous blocks.〔 MIMO operation is possible with up to four streams used for either space–time block code (STBC) or multi-user (MU-MIMO) operation.〔
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「IEEE 802.11af」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.
|
|