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      1. 英語資訊
        News

        什么是“藍牙”技術? What is Bluetooth?

        Source:     2007-10-27  我要投稿   論壇   Favorite  
        什么是“藍牙”技術? What is Bluetooth?

         


        Bluetooth is a universal radio interface in the 2.45GHz frequency band that enables portable electronic devices to connect and communicate wirelessly via short-range, ad hoc networks. Each unit can simultaneously communicate with up to sever other units per piconet. Moreover, each unit can simultaneously belong to several piconets.

         

        What is Bluetooth Technology?

        Bluetooth technology which apart from Ericsson, has gained the support of Nokia, IBM, Toshiba, Intel and many other manufacturers

        eliminates the need for wires, cables and connectors for and between cordless or mobile phones, modems, headsets,PDAs, Computers, printers, projectors, local area networks, and so on, and paves the way for new and completely different devices and applications.Technology Characteristics

        1Ms/s symbol rate exploits maximum available channel bandwidth

        Fast frequency hopping avoids interference

        Adaptive output power minimizes interference

        Short data packets maximize capacity during interference

        Fast acknowledge allows low coding overhead for links

        CVSD (Continuous Variable Slope Delta Modulation) voice coding enables

        operation at high bit- error rates

        Flexible packet types supports wide application range

        Air interface tailored to minimize current consumption

        Basic Technical Information—Based upon a small , high performance integrated radio transceiver ,each of which is allocated a unique 48-bit address derived from the IEEE 802·standard .

        Operate in the unrestricted 2.45GHz ISM free band, Which is available globally although slight variation of location and width of band apply

        Range set at 10m to optimize for target market of mobile and business user

        Gross data rate 1Mbit/s with second generation plans to increase to 1Mbit/s

        One-to-one connections allow maximum data transfer rate of 721kbit/s (3 voice channels)

        Uses packet switching protocol based on frequency hop scheme with 1600 hops/s to enable high performance in noisy radio environments .The entire available frequency spectrum is used with 79 hops of 1Mhz bandwidth , analogous to the IEEE 802.11 standard

        Low power consumption longevity for battery powered devices . During data transfer the maximum current drain is 30mA. However during pauses or at lower data rates will be lower

        藍牙是一個頻率為2.45GHz的通用無線電通信接口,它通過一個特殊的網絡可以在各種便攜設備之間建立起無線連接并進行短程通信。在一個微微網中,每個單元都能同時與其它各單元進行通信。而且,每一個單元可以同時屬于幾個微微網。

        什么是"藍牙"技術?

        "藍牙"技術最先是由愛立信開始研制的,現在已經得到了諾基亞、IBM、東芝、因特爾及許多其它相關制造廠家的支持。其目的是為了免除在無繩電話或移動電話、調制解調器、頭套式送/受話器、PDAs、計算機、打印機、幻燈機、局域網等之間加裝電線、電纜和連接器。而且,這種技術可以延伸到那些完全不同的新設備和新應用中去。"藍牙"的技術特性—以每秒1M個碼元的字符速率傳輸,充分利用信道的最大有效帶寬.

        快速跳頻避免干擾

        可變的電源輸出使干擾減小到最小

        采用短數據包傳輸增強抗干擾能力

        快速確認允許有附加低速率的編碼被發送到鏈路上

        連續可變斜率增量調制的語音編碼可以在高誤碼率的情況下正常工作

        靈活的分組類型支持多種應用

        無線電空中接口使電耗達到最小"藍牙"基本技術概要

        每一個小型、高性能、集成的無線電收發機都有IEEE 802標準所規定的一個唯一的48比特位地址

        開放的2.45GHz ISM自由頻段,全球都可以自由使用。

        10公里是最適于移動通信市場和商業用戶的通信范圍

        總速率為1Mbit/s,計劃下一代產品將達到2Mbit/s

        點到點連接允許的最大數據傳輸速率為721kbit/s

        在無線電噪聲環境里,利用基于每秒1600跳跳頻表的分組交換協議可以提高系統性能。以1Mhz帶寬79跳來利用這個完整的可用頻譜。這類似于IEEE 802.11標準。

        低電能的消耗。在備用模式下僅需0.3mA,這能延長那些使用電池供電設備的壽命。數據傳送時電流的最大消耗為30mA。當暫停工作或低速傳送數據時電流消耗更低。

         

         


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