Bluetooth(专业英语论文).doc

bluetooth abstract: bluetooth has been the most advanced technology in our world. but not all of us know what exactly bluetooth is, how dose bluetooth work and what advantage bluetooth has? today or in the future, bluetooth will bring us a great many riches, so all of us should know something about bluetooth now. in my academic discourse, you will know more about bluetooth: why we need bluetooth? how dose bluetooth come out? how dose bluetooth work? in what aspect can bluetooth be used? how will bluetooth develop? with all of these questions, let us read this discourse and go into the bluetooth world.keyword:bluetooth 蓝牙cable 电缆, 海底电报, 缆, 索frequency 频率, 周率, 发生次数mobile phones 可移动电话，手机microchip 微芯片synchronous 同步的，同时的ieee 电气和电子工程师协会broadband 宽带wireless 无线的snap smart network access points（智能网络接入点）polyphony server 复音服务器constellation partners 星级伙伴virtual private networks 虚拟专用网ethernet 以太网look around you at the moment, you have your keyboard connected to the computer, as well as a printer, mouse, monitor and so on. what joins all of these together? of course, they are connected by cables. cables have become the bane of many offices, homes etc. most of us have experienced the joys of trying to figure out what cable goes where, and getting tangled up in the details. today, you will not be worried about this, bluetooth essentially aims to fix this， it is a cable-replacement technology .but what exactly is bluetooth? well it isnt some strange form of tooth decay as you might initially imagine. bluetooth is the name of a new technology, set to commercially come out in bulk around 2002. it promises to change significantly the way we use machines.bluetooth technology, which was conceived initially by ericsson, has gained the support of nokia, ibm, toshiba, intel and many other manufacturers today. before being adopted by these companies, bluetooth is a standard for a small, cheap radio chip to be plugged into computers, printers, mobile phones, etc. a bluetooth chip is designed to replace cables by taking the information normally carried by the cable, and transmitting it at a special frequency to a receiver bluetooth chip, which will then give the information received to the computer, phone whatever. that was the original idea, but the originators of the original idea soon realized that a lot more was possible. they thought, if you can transmit information between a computer and a printer, why not transmit data from a mobile phone to a printer, or even a printer to a printer? the projected low cost of a bluetooth chip, and its low power consumption, means you could literally place one anywhere. how does bluetooth works? bluetooth uses a short-range radio link built into a 9 mm x 9 mm microchip. the protocol enables the exchange of information between many devices, including mobile telephones, pdas, notebook pcs, handheld pcs, associated peripherals, and home hubs, which may include home rf. the radio will operate on the globally available 2.45 ghz ism free band, meaning there will be no hindrance for international travelers using bluetooth-enabled equipment. bluetooth does not require line of sight for connection, provided they are within operational range of other bluetooth-enabled devices. the bluetooth base band protocol is a combination of circuit- and packet-switching, making it suitable for both voice and data. each voice channel supports a 64 kbit/s synchronous link, and the asynchronous channel can support an asymmetric link of up to 721 kbit/s in either direction, while permitting 57.6 kbit/s in the return direction. all in all, this is fast enough to cope with the vast majority of proposed data rates over cellular systems. the nominal link range is 10 cm to 10 m, but links can be extended to more than 100 m by increasing the transmit power. the software framework in the proposed specification would require bluetooth-compliant devices to support a basic level of interoperability. the level of compliance will vary depending on the device application.now we can say that bluetooth has a lot of advantage.1fast frequency hopping avoids interference.2adaptive output power minimizes interference.3short data packets maximize capacity during interference.4fast acknowledge allows low coding overhead for links.5cvsd(continuous variable slope delta modulation) voice coding enables operation at high bit-error rates.6flexible packet types supports wide application range.7air 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 form the ieee 802.standard.8operate in the unrestricted 2.45ghz ism free band, which is available globally although slight variation of location and width of band apply.9range set at 10m to optimize for target market of mobile and business user.10gross data rate 1mbit/s with second generation plans to increase to 1mbit/s.11one-to-one connections allow maximum data transfer rate of 721kbit/s (3 voice channels). 12uses packet switching protocol based on frequency hop scheme with 1600hops/s enable high performance in noisy radio environments. the entire available frequency spectrum id used with 79 hops of 1mhz bandwidth, analogous to the ieee 802.11 standard.13low 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 lover.because of all the things we have inferred above, a lot of people become interested in bluetooth. with this viewpoint interest in bluetooth is soaring, lots of ideas are constantly emerging, some practical and feasible e.g.: bluetooth chips in freight containers to identify cargo when a lorry drives into a storage depot, or a headset that communicates with a mobile phone in your pocket, or even in the other room, other ideas not so feasible: refrigerator communicating with your bluetooth-enabled computer, informing it that food supply is low, and to inform the retailer over the internet. if we want to know more about bluetooth, we should know some new bluetooth products. there are some new bluetooth products here, we can see the big advantage it has.1. the racewood technology co., ltd. bluetooth headset rbths001. it can be used with any application requesting personal audio through a lightweight, easy- to-use and easy-to-wear device, offering enhanced mobility through the use of true wireless technology. the rbths001 allows for the host headset to be worn and used freely up to a distance of 10 meters from the connecting device. the headset can be operated and linked to the audio gateway at most 3 seconds after being turned on.2. the racewood technology co., ltd. universal class 1 and class 2 bluetooth usb dongle rbtpu001. it is compact and qualified module that provide a complete 2.4ghz bluetooth system for wireless data and voice communications. the rbtpu001 includes an integrated antenna and a usb connector interface, offering a simple bluetooth solution for electronic devices with a usb interface.3. the racewood technology co, ltd universal class 2 bluetooth compact flash card rbtcf001. it is bluetooth v1.1 compliant that will be used with personal digital assistant products to allow you to wirelessly connect with other bluetooth-enabled devices. the bluetooth compact flash card can plug into pda, handheld pc through a type 1 compact card slot, features a class 2 radio, an integral antenna and operation range of 10m.the bluetooth compact flash card can be plug_and_play under windows ce and pocket pc 2000/2002 operating systems.use bluetooth compact flash card in your pda, pocket or handheld pc to wirelessly synchronize data with your bluetooth pc or other bluetooth device. also, this single wireless product can be used for many purposes, whether connecting to the internet via an access point or sending files to others.now let us talk about the hotel and bluetooth. the rapid adoption of bluetooth technology by the hotel industry would appear to provide early evidence of its potential. however, there are many questions as to the real viability of wireless systems in this business environment. the hotel industry is not one that you would normally associate with leading edge, high technology. however, in this age of the international business park, the demands of the business travelers are changing the face of hotel services. hotels catering for business travelers have flourished and to keep its increasingly essential business clientele, the hotel industry is embracing new technologies to help deliver increased services to guests. the idea is a relatively simple one. there is a sort of service war going on and some hotels, particularly the larger chains, have grown hungry for new technologies. this hunger is manifesting itself in the take-up of wireless technologies and in particular, bluetooth.the main reasoning behind this is to offer guests services such as email, internet access, greater in-hotel control of facilities, and access to local attraction information, remote checking in or out, use of hotel printing facilities and so on. while anyone can see that additional services in hotels could be extremely beneficial to the business travelers in particular, given that bluetooth is still a new technology there remains an air of uncertainty around the validity of such services. and one question that is always thrown about when a new technology comes along is whether or not it is technology for technologys sake. there are enough worthy applications around to suggest this is not the case, although this is still something to be wary of. it is important to decipher whether hotels are embarking on a technology game or if there is something of real value to hotel guests here.one company that is about to embark on a trial of a bluetooth-based hotel network is bluetooth software developer, classwave wireless. the trial, to take place in june this year, follows a partnership deal with the starwood hotel chain. the potential of the application is full of optimism. we could say that working with a partner like classwave will enable starwood to deliver a new level of information and service to its guests and employees. classwave ceo, tom sweeney, claimed that its polyphony server will enable starwood to easily create new revenue streams and business models by delivering mobile personal networks for the dynamic delivery of content within their properties worldwide. starwood, which boasts 725 properties in 80 countries including the sheraton, st regis and westin brands, will install classwaves polyphony server in one of its new york hotels. this, it claims, will offer guests access to the internet and email, mobile registration and personalized information via mobile devices, electronic concierge and in-hotel m-commerce. classwave, a specialist in what it terms bluetooth network infrastructure solutions, will initially set up a system that will deal with guest reservation and registration information. business travelers will be able to check-in and check-out where they want and when they want, according to the company.but it doesnt stop there. according to classwave, there are greater benefits in terms of both functionality and cost. as well as offering guests wireless services, the system will enable a number of other functions for the hotel back office including mobile management systems, employee service logistics, employee chat services, instant messaging and access to corporate data.the hotel could also have its own mobile portal extending localized content to guests, voice services and access to starwoods constellation partners for m-commerce and convention services. the wireless server platform enables companies like starwood to easily create new revenue streams and business models by delivering mobile portals for the dynamic delivery of content, says a classwave spokeswoman. we are finding three primary reasons for deploying polyphony server in hotels: to generate revenue; reduce registration staff; and reduce call centre staff. the revenue generation comes from an increase in fee-based services such as high-speed internet usage, email and fax, while the reduction in traditional staff is undoubtedly a long-term cost saver. a reduction in registration staff by providing automated check-in and a reduction in call centre staff through extension of website reservation system to wireless devices will be attractive propositions to the budget sensitive hotelier. it will also have the added benefit of reducing waiting times for check-in and reservation changes.the system works by deploying a number of snaps around the hotels to allow for transfer of information from kiosks to customer mobile devices. it is controlled by classwaves polyphony server, which provides the backbone intelligence for the bluetooth network by managing the devices media format and content delivery through the snaps and other wireless channels including cellular networks. while the network is based on the bluetooth standard, classwaves application itself is not dependent on bluetooth. classwave also supports 802.11 but claims, due to the form factor of pdas and phones expected to embrace bluetooth, we are using it in the hotel trials, adds the spokeswoman. the main reasoning given is the lower power usage, reasonable speed and the support for both data and voice.let us have a look at the five-star treatment. the holiday inn wall street is another hotel striving to offer its clientele leading edge technology services. it has teamed up with registry magic to deliver what it claims is the worlds first full service bluetooth-enabled hotel, a statement that may raise a few eyebrows at starwood. registry magics involvement with the holiday inn is to initially provide its bluetooth-based consumer payment network and bluetooth cell phones and mobile devices to enable guests to access a host of wireless services. these services include check-in and check-out, making payments at in-house restaurants, secure access to rooms, internet access and picking up phone messages.like classwave and starwood, registry magic and the holiday inn are quick to dismiss any suggestion of gimmick. john falcone, registry magics senior vice president of technology and business development believes that the hotel application is one of the true commercial bluetooth applications and therefore a valid investment for the hotel industry.of course, if you dont spend your time frequenting hotels then this application is highly unlikely to impact your everyday life, but we kind of see the point. for so long bluetooth has just been a technology with visions attached to it and now here is an application with a willing commercial audience in the hotel trade.in fact, for the past 18 months, hotel chains have been, or are now starting to install technology as a means to offer greater services to guests in what is fast becoming a services war in the industry. hyatt hotels and resorts last year teamed-up with i-quest to install a broadband plug_and_play internet connection in its rooms using worldroom connects virtual private networks (vpns). although the system is based on a standard ethernet cable network, it demonstrates that the demand for internet access in hotel rooms is sufficient enough to warrant the investment from the hotel groups. while it could be argued that guests only really work and want to access the internet in their rooms, it may be because that is the only option that is open to them. the trouble here is that we are dabbling in a yet-to-be-proven use of mobile devices where words such as potential and if are regularly applied. so could this drive towards wireless infrastructures be misplaced? the answer is not. a bluetooth-based network service should just provide guests with greater flexibility. if they want to use their mobile devices and notebook pcs in their rooms they can still use the system but it just provides greater flexibility of movement. if a guest wants to peruse the web while sitting in the bar sipping his favourite cocktails, why shouldnt he?of greater concern are the still inherent problems encountered with bluetooth. interoperability is still causing some problems especially as the technology and subsequent bluetooth-enabled devices are still in their infancy. could classwave risk interoperability problems in the trials? it seems not, as the company admits it is sourcing devices from a single vendor in an attempt to mitigate the risks.for bluetooth to also take-off in the hotel trade it will have to be very reliable. it is one thing saying that a bluetooth application will reduce check-in times and ease the registration process but it is another thing to actually deliver it, especially at the cost of front desk staff. it is almost possible to imagine the scene where the system breaks down and the hotel lobby is full of suited guests queuing to speak to one or two receptionists while staring blankly into their bluetooth devices.the optimism in the hotel industry