信息通信IntroductionofBluetoothTechnology英文版.pptx

,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,#,Introduction of Bluetooth Technology,History of Wireless Communications,1896 Marconi invented wireless telegraphy,1907 Trans-Atlantic wi-services was initiated,1915 Wi-voice transmission between NY and San F.was achieved,1921 Police cars in Detroit,Michigan were equipped with wireless dispatch radios,1946 First public telephone service was started in 25 US cities,1968 AT&T proposed the cellular concept to FCC,1982 European Global Systems for Mobile(GSM)Communications was established,1991 USDC was released,1994 CDMA was introduced,3G wireless systems are being deployed,Is it a Bird?.Is It a Plane?,Bluetooth is a short range wireless digital communication technology.,It was developed as a low cost,low power way of removing many of the data wires between devices.This concept is called a PAN or Personal Area Network.,It is designed to operate in the ISM band,History,In 1994,Ericsson study a low-power system for substitute cables in the short-range area,In 1998,Ericsson,Nokia,IBM,Intel,Toshiba formed the Special Interest Group(SIG),In 2000,the first Bluetooth headset appeared on the market.,Where do we need Bluetooth?,Bluetooth features at a glance,Topology,Supports up to 8 simultaneous links in a piconet,Flexibility,Goes through walls,bodies,clothes,.,Data Rate,1 MSPS,721 Kbps,Power,0.1 Watts active power,Size/Weight,25 mm 13 mm 2 mm,several grams,Cost,Long term$5 per endpoint,Range,10 meters or less;up to 100 meters with PA,Universal,Intended to work worldwide,Security,Very,link layer security,SS radio,Band,ISM 2.4GHz,Bluetooth Protocols,从协议来源分,核心协议,:SIG,开发，包括,BB,，,LMP,，,L2CAP,，,SDP,电缆替代协议,电路控制协议,选用协议,从体系结构分,底层硬件模块,:LM,BB,RF,中间协议层,高端应用层,Bluetooth Data Transmission,分组包格式,接入码用来定时同步、偏移补偿、寻呼和查询，有三种类型的接入码：,DAC,（设备），,IAC,（查询），,CAC,（信道）,Bluetooth Specifications,Core Specification,Profile Specification,Core Specification,Explanation,RF-lowest layer.,characteristic of radio,F.Bands,channel arrangements,tran.power lever,rec.sensitivity level,Baseband,carries out PHY&MAC:device discovery,link formation,synchronous and asynchronous,LMP,define control messages that configure and manage baseband connection,Explanation,Host Controller Interface(HCI),define a standard interface-independent method of communicating with the Bluetooth chip,Logic Link Control and Adaptation Protocol,can be viewed as a link layer,RFCOMM,define a method of emulating the RS-232 cable connection on top of Bluetooth airlink,Profile Specification,Explanation,Because interoperability is crucial to Bluetooths operation,SIG has defined profile specifications to support it.,Specifies controller and stack parameter settings as well as features and procedures required for interworking.,To get the Bluetooth logo,vendors must comply with the profiles.,Network Topology,A set of Bluetooth devices sharing a common channel is called a,piconet,.,Piconets and Scatternets,A bridge node can be a salve in both piconets or be a slave in one and a master in another.,For example,cordless headset and,cell phone among,several people,Specifications,ISM 2.4G band.,In EU and US,79 1MHz-wide channels are allocated,only 23 channels in Fr.,Spain,Jp.,Channels accessed using FHSS,signal rate 1Mb/s,efficient rate 721kb/s GFSK modulation,Transmission channel changes 1600/s,eq.625,us-long slots,which are identified by sequence number(sn).,Master transmits in the even sn,slave in odd,Bluetooth Devices Connection,Link Types,Asynchronous Connectionless Link(ACLs),Synchronous Connection-Oriented(SCOs),SCOs,Provide guaranteed delay and bandwidth,Provide constant-bit-rate symmetric channels,Limited reliability:no retransmission,not CRC although optional protected with 1/3 or 2/3 forward error correction(FEC)convolution code,Data rate 64kb/s in both directions,SCOs suit for voice and music,ACLs,Appropriate for non-real-time(diagram)traffic,A slave can exchange one packet at a time with the master according to a schedule between slaves,Only a single ACLs can exist between a given slave and the master,Suit for data transmission,Comparison between Bluetooth and Wi-Fi,Thank you all!,