什么是“蓝牙”技术? What is Bluetooth?1

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

蓝牙是一个频率为2.45GHz的通用无线电通信接口，它通过一个特殊的网络可以在各种便携设备之间建立起无线连接并进行短程通信。在一个微微网中，每个单元都能同时与其它各单元进行通信。而且，每一个单元可以同时属于几个微微网。

什么是"蓝牙"技术?

"蓝牙"技术最先是由爱立信开始研制的，现在已经得到了诺基亚、IBM、东芝、因特尔及许多其它相关制造厂家的支持。其目的是为了免除在无绳电话或移动电话、调制解调器、头套式送/受话器、PDAs、计算机、打印机、幻灯机、局域网等之间加装电线、电缆和连接器。而且，这种技术可以延伸到那些完全不同的新设备和新应用中去。"蓝牙"的技术特性—以每秒1M个码元的字符速率传输，充分利用信道的最大有效带宽.

快速跳频避免干扰

可变的电源输出使干扰减小到最小

采用短数据包传输增强抗干扰能力

快速确认允许有附加低速率的编码被发送到链路上

连续可变斜率增量调制的语音编码可以在高误码率的情况下正常工作