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In communications, a system is wideband when the message bandwidth significantly exceeds the coherence bandwidth of the channel. Some communication links have such a high data rate that they are forced to use a wide bandwidth; other links may have relatively low data rates, but deliberately use a wider bandwidth than "necessary" for that data rate in order to gain other advantages; see ''spread spectrum''. A wideband antenna is one with approximately or exactly the same operating characteristics over a very wide passband. It is distinguished from broadband antennas, where the passband is large, but the antenna gain and/or radiation pattern need not stay the same over the passband. The term Wideband Audio or (also termed HD Voice or Wideband Voice) denotes a telephony using a wideband codec, which uses a greater frequency range of the audio spectrum than conventional voiceband telephone calls, resulting in a clearer sound. Wideband in this context is usually considered to cover frequencies in the range of 50–7,000 Hz, therefore allowing audio with richer tones and better quality.〔(【引用サイトリンク】title= Unified Communications Architecture Basics )〕 According to the United States Patent and Trademark Office, WIDEBAND is a registered trademark of WideBand Corporation, a USA-based manufacturer of Gigabit Ethernet equipment.〔(【引用サイトリンク】title= US Trademark Search )〕〔(【引用サイトリンク】title= WideBand Corporation web site )〕 Within Australia and New Zealand, the word WIDEBAND is a registered trademark of "Wideband Technology Pty Ltd", an Australian-based company specialising in data and communication equipment.〔http://www.widebandtechnology.com〕 In some contexts wideband is distinguished from broadband in being broader.〔(Forester research ) Shift from broadband to wideband〕 ==See also== *Narrowband *Broadband *Broadband Internet access *Ultra-wideband *Wideband Audio 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「wideband」の詳細全文を読む スポンサード リンク
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