外文翻译--蓝牙技术毕业论文外文翻译.doc

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1、译文题目：蓝牙技术外文题目：bluetooth projectBluetoothIntroductionBluetooth is a forever, limited radio connect that resides on a microchip. It was originally expanded through Swedish mobile phone creator Ericsson in 1994 as a method to let laptop computers make calls above a mobile phone. As then, numerous organ

2、izations have signed on to create Bluetooth the low-power thoughtless wireless average for a broad variety of devices (LeVitus, 216-220). Industry spectators anticipate Bluetooth to be fitted in billions of devices through 2005.DiscussionDeveloped by engineers at Ericsson in the late 1990s, Bluetoot

3、h is more and more special technology that facilitates thoughtless wireless communication among a diversity of electronic devices. Its mainly important aspect is that it permits devices to “talk” (relocate and orchestrate data) wirelessly with each other, terminating the requirement for the outwardl

4、y continuous tangle of cables, cords, and adapters important for numerous todays expertise.The Bluetooth Special Interest Group (SIG) was formed in 1998 to manage the expansion and prologue of Bluetooth knowledge (LeVitus, 216-220). IBM, Intel, Toshiba and Nokia connected with Ericsson as the beginn

5、ing associates of the SIG, and in excess of 8,000 organizations have contracted since. So as to trade products with the Bluetooth requirement and logo, manufacturers should be associates of the SIG and the devices should meet well-outlined credentials. These procedures make sure that Bluetooth wirel

6、ess devices international may converse with each other, apart from company or nation of derivation.Speed and RangeRange is application specific and although a minimum range is mandated by the Core Specification, there is not a limit and manufacturers can tune their implementation to support the use

7、case they are enabling. Range may vary depending onclass of radio used in an implementation: Class 3 radios have a range of up to 1 meter or 3 feet Class 2 radios most commonly found in mobile devices , have a range of 10 meters or 33 feet Class 1 radios used primarily in industrial use cases , have

8、 a range of 100 meters or 300 feetThat creates Bluetooth technology appropriate for transporting lesser files for example cell phone contracts and text documents, also as lower-quality pictures and audio (Kumkum, 160-162). At these relocate speeds; Bluetooth may not actually deal streaming video or

9、high-quality pictures and audio at this end, except this possibly will alter in the future when fresh Bluetooth standards are initiated.Simple and Competent to UtilizeCreating and configuring Bluetooth allowed devices is moderately uncomplicated, with little extra commotion than acquire the two devi

10、ces close to one another and twist them on. There is no requirement to mount drivers or further software to complex an ad-hoc, personal wireless network (Kumkum, 160-162). It has a uniform organization, meaning that some two wireless products attributing Bluetooth technology, despite of product or n

11、ation of origin, have the ability to converse faultlessly with each other.Common ApplicationsOne of the mainly ordinary applications of Bluetooth is hands-free cell phone procedure. About each cell phone fashioned in our day has constructed Bluetooth (Meier, 15-20). Only pair phone with a Bluetooth

12、headset, and he may talk whereas his phone is in his purse or pocket. Several of todays car stereos as well have fitted Bluetooth for hands-free calling in his vehicle. And if his vehicle has a plant stereo or grown-up aftermarket one that he merely doesnt wish to restore, he may yet like hands-free

13、 identifying with a Bluetooth car kit.Bluetooth 3.0Bluetooth 3.0 is the fresh Bluetooth wireless typical adopted through the Bluetooth SIG on April 21, 2009. The fresh standard supports elevated data remove speeds and constructs ahead the preceding standards (Meier, 15-20). With its superior speed,

14、the technology has the probable to transfigure the consumer electronics industry.TechnologyPROTOCOLThe Bluetooth technology standard is set to make different applications can “communicate” with each other. Remote devices in communication use the same protocol stacks, while different applications nee

15、d different protocol stacks. But, every application needs the data link layer and physical layer of the Bluetooth technology. The whole Bluetooth protocol stacks is shown as blow. Not any application should use all of the protocols, but one or some lists of these. The chart below shows the relations

16、hip between protocols, but the relationship may change in some applications.The completely protocol stacks include Bluetooth special protocols (like LMP and L2CAP) and not special ones (such as OBEX and UDP). The basic principle for designing protocol and protocol stacks is that use existing high le

17、vel protocol as possible, ensure the combination of protocols and Bluetooth technology, and take the best advantage of the software and hardware which adapt to the Bluetooth technology standards. The open Bluetooth technology makes device manufacturers can choose protocols freely as they like or use

18、d to.The protocols in Bluetooth protocol systemThere are four layers in Bluetooth protocol system according to the SIG Core protocols Cable replacement protocols Telephony control protocols Adopted protocolsExcept the protocol layers above, the standard also defines Host/Controller Interface (HCI),w

19、hich provides command interface for baseband controller, connection manager, hardware state and control register.Bluetooth core protocols consist of the special protocols made by SIG. Most Bluetooth devices need core protocols, while other protocols are used depend on needs of the application. After

20、 all, cable replacement protocols, technology control protocols and adopted protocols based on the core protocols constitute the object-oriented protocols. Core protocols LMP (Link Management Protocol)Used for control of the radio link between two devices. Implemented on the controllers.It identifie

21、s and encrypts through launching, exchanging and checking the connection, and decides the size of baseband data packets through conference. It also controls the power mode and work cycle of wireless equipment, and connection status of unit equipment in piconet. L2CAP (Logical Link Control & Adaptati

22、on Protocol)This protocol is used to multiplex multiple logical connections between two devices using different higher level protocols, and provides segmentation and reassembly of on-air packets.In Basic mode, L2CAP provides packets with a payload configurable up to 64kB, with 672 bytes as the defau

23、lt MTU, and 48 bytes as the minimum mandatory supported MTU.In Retransmission & Flow Control modes, L2CAP can be configured for reliable or isochronous data per channel by performing retransmissions and CRC checks.Bluetooth Core Specification Addendum 1 adds two additional L2CAP modes to the core sp

24、ecification. These modes effectively deprecate original Retransmission and Flow Control modes: Enhanced Retransmission Mode (ERTM): This mode is an improved version of the original retransmission mode. This mode provides a reliable L2CAP channel. Streaming Mode (SM): This is a very simple mode, with

25、 no retransmission or flow control. This mode provides an unreliable L2CAP channel.Reliability in any of these modes is optionally and/or additionally guaranteed by the lower layer Bluetooth BDR/EDR air interface by configuring the number of retransmissions and flush timeout (time after which the ra

26、dio will flush packets). In-order sequencing is guaranteed by the lower layer.Only L2CAP channels configured in ERTM or SM may be operated over AMP logical links. SDP (Service Discovery Protocol)Service Discovery Protocol (SDP) allows a device to discover services supported by other devices, and the

27、ir associated parameters. For example, when connecting a mobile phone to a Bluetooth headset, SDP will be used for determining which Bluetooth profiles are supported by the headset (Headset Profile, Hands Free Profile, Advanced Audio Distribution Profile (A2DP) etc.) and the protocol multiplexer set

28、tings needed to connect to each of them. Each service is identified by a Universally Unique Identifier (UUID), with official services (Bluetooth profiles) assigned a short form UUID (16 bits rather than the full 128)/vichitra Cable replacement protocols(RFCOMM)Radio frequency communications (RFCOMM)

29、 is a cable replacement protocol used to create a virtual serial data stream. RFCOMM provides for binary data transport and emulates EIA-232 (formerly RS-232) control signals over the Bluetooth baseband layer.RFCOMM provides a simple reliable data stream to the user, similar to TCP. It is used direc

30、tly by many telephony related profiles as a carrier for AT commands, as well as being a transport layer for OBEX over Bluetooth. Telephony control protocols (TCP).Telephony control protocol-binary (TCS BIN) is the bit-oriented protocol that defines the call control signaling for the establishment of

31、 voice and data calls between Bluetooth devices. Additionally, TCS BIN defines mobility management procedures for handling groups of Bluetooth TCS devices.TCS-BIN is only used by the cordless telephony profile, which failed to attract implementers. As such it is only of historical interest. Adopted

32、protocolsAdopted protocols are defined by other standards-making organizations and incorporated into Bluetooths protocol stack, allowing Bluetooth to create protocols only when necessary. The adopted protocols include: Point-to-Point Protocol (PPP): Internet standard protocol for transporting IP dat

33、agrams over a point-to-point link. TCP/IP/UDP:For communicating with the device connected to Internet. Object Exchange Protocol (OBEX): Session-layer protocol for the exchange of objects, providing a model for object and operation representation. It uses the client-server mode. Wireless Application

34、Environment/Wireless Application Protocol (WAE/WAP):WAE specifies an application framework for wireless devices and WAP is an open standard to provide mobile users access to telephony and information services.TechnologySPECTRUM AND INTERFERENCEBluetooth technology operates in the unlicensed industri

35、al, scientific and medical (ISM) band at 2.4 to 2.485 GHz, using a spread spectrum, frequency hopping, full-duplex signal at a nominal rate of 1600 hops/sec. The 2.4 GHz ISM band is available and unlicensed in most countries.SIM frequency band is open to all radio system, So the use of a certain fre

36、quency band will meet unpredictable interference sources. Therefore, Bluetooth designs special fast acknowledge and frequency hopping technique to ensure the stability of link. Frequency hopping technique to divide the band into many frequency hopping channels, in a connection, radio transceiver “ju

37、mp” from a channel to another constantly according to certain code sequence. Only sender and receiver communicate according to this law, and the rest of interference may not press the same rule. The instantaneous bandwidth of Frequency hopping is very narrow, but through the spread spectrum technolo

38、gy it can make the narrow bandwidth one hundred times expanded into wideband, making the influence of interference may become very small. Comparing to other systems that work in the same frequency band, frequency hopping of Bluetooth works faster, data packet of Bluetooth is shorter, which make it m

39、ore stable than the otherERROR CORRECTIONBluetooth supports circuit switching and packet switching two techniques, and defines two types of link connection, namely connection-oriented synchronous link (SCO) and connectionless-oriented asynchronous link (ACL)Bluetooth use three error correction model

40、s: 1/3 Forward Error Correction (FEC), 2/3forward Forward Error Correction and Automatic Repeat Request (ARQ). Purpose to the error correction is to reduce the possibility of retransmission, while at the same time increase the extra expenses, but in a reasonable errorless environment, redundant bids

41、 will reduce output. So the packet definition itself also keeps flexible ways. Hence the software can be defined whether to adopt FEC. In general, when the channel noise is large, Bluetooth system will uses FEC, in order to ensure the quality of communication: as to SCO link, 1/3 FEC is used; 2/3 FE

42、C is used in ACL link. In unnumbered ARQ, the data send in a time slot must receive a confirmation of receipt in the next time slot. Only when the data is checked to be without mistake after header error detection and CRC at receiver will the confirmation sent to sender, or an error message will be

43、sent back.RANGERange is application specific and although a minimum range is mandated by the Core Specification, there is not a limit and manufacturers can tune their implementation to support the use case they are enabling. Range may vary depending onclass of radio used in an implementation: Class

44、3 radios have a range of up to 1 meter or 3 feet Class 2 radios most commonly found in mobile devices , have a range of 10 meters or 33 feet Class 1 radios used primarily in industrial use cases , have a range of 100 meters or 300 feetPOWERIn order to make a Bluetooth equipment can also be in connec

45、tion even in a very low power state, Bluetooth stipulates three energy saving state: Park state, Hold state and Sniff state. The energy saving efficiency of these states declines one by one. The most commonly used radio is Class 2 and users 2.5mW of power. Bluetooth technology is designed to have ve

46、ry low power consumption. This is reinforced in the specification by allowing radios to be powered down when inactive.The Generic Alternate MAC/PHY in Version 3.0 HS enables the discovery of remote AMPs for high speed devices and tums on the radio only when needed for data transfer giving a power op

47、timization benefit as well as aiding in the security of the radios.Bluetooth low energy technology, optimized for devices requiring maximum battery life instead of a high data transfer rate, consumers between 1/2 and 1/100 the power of classic Bluetooth technology.SECURITYMobility and open of Blueto

48、oth system makes safety problems extremely important. Although the frequency modulation technique used by Bluetooth system has already provided a certain security, but Bluetooth system still need safety management to link layer and application layer. In link layer, Bluetooth system provides authenti

49、cation, encryption and key management, and other functions. Each user has a Personal Identification Number (PIN), which will be translated into 128 bit link key for one-way or both-way certification. Once the authentication finished, link will use encryphon key to encrypt. The link layer security mechanism provides a great deal of certification schemes and