01-04-2020-Oxford_English_for_Infomation_Technology (1171844), страница 28
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The brainchildof Ericsson, IBM, Intel, Nokia and Toshiba,Bluetooth is a microwave high-speed wireless linksystem that's designed to work with portableequipment. To that end, it's low power, very smalland very low cost. It uses the same frequencies asexisting radio LANs (and, incidentally, microwaveovens) to create a secure 1 Mbit/s link betweendevices within 1 Om of each other. These devicescan be laptops, PDAs, cellphones, wiredtelephone access points, even wristwatch devices,headphones, digital cameras and so on.
Withthem, your notebook PC will be able to accessyour cellular phone — and thus the Internet —without your having to take the phone out of yourpocket. Files can be exchanged andcommunications set up for voice and databetween just about any device capable of handlingthe information.Bluetooth operates in the unlicensed SM(Industrial, Scientific and Medical) band at2.45GHz, which is globally available for products.There's 89MHz of bandwidth allocated here, andsince Bluetooth is very low power, it actuallyradiates less than most national and internationalstandards allow non-transmittinpo devices to leakas part of their normal operation. This is key, as itallows the technology to operate withoutrestriction on aircraft.As befits their status as radio frequency experts,Ericsson and Nokia developed the RF side ofBluetooth.
The link works in a similar way to theIEEE 802.11 wireless networking system, with apacket-switching protocol based on fast-frequencyhopping direct sequence spread spectrum. Inother words, it constantly switches channel toavoid interference. It changes frequency 1,600times a second through 79 frequency bands. It'sexpected that this will be so good at avoidingconflicting signals from other sources that thetransmission power can be kept very low.OJUNIT 23 Recent Developments in ITSecurity is taken care of through the frequencyhopping and 40-bit encryption. As the system usesradio, it can work through some barriers —briefcases, shirt pockets and desktops, forexample — but it won't carry through officebuildings.
The power level of the transmitter canbe varied, with feedback from the remote side ofthe link used to set the output to the lowest levelcommensurate with error-free operation. Thissaves power and increases the usable density ofdevices. The device can operate at up to 1mW (anoptional power amplifier can increase this to100mW) and the whole lot consumes between8mA and 30mA at 2.7V. Various power-savingmodes can be used when a device isn'ttransmitting, trading off speed of response forbattery life.
These work with current levelsbetween 3OOpA and 60pA.BThe standard is open and royalty-free to membersof the Bluetooth special interest group.[Adapted from 'Fast Forward' by Rupert Goodwins, PC Magazine,August 1998]Re-read the text to find the answers tothese questions.1 Match the terms in Table A with thestatements in Table B.Table AaBluetoothb SMbandcRFdIEEE802.11eFrequency hoppingfUsable densityg piconetTable BiRadio frequencyii The number of devices that can be used irthe same areaWithin the 10m radius of a unit, up to 10independent full-speed piconets can operate, withbandwidth reduced proportionately if more thanthis are in use. Each can handle up to eightdevices, and can be further subdivided intoseparate services: 432Kbit/s full-duplex data,721/S6Kbit/s asymmetric duplex, or 384Kbit/sthird-generation GSM.
Each channel can alsosupport three 64Kbit/s full-duplex voicechannels. An optional variation in modulationtechnique would double the basic data rate to2Mbit/s.Power consumption and cost were very significantFactors in Bluetooth's design, and it was decidedlot to make the system a fully-fledged LAN. As aresult, there's no collision detection.
All deviceson a piconet are synchronized to a master deviceand are controlled by it to prevent simultaneousjperation on the same frequency. Any device canbe a master, and is elected dynamically when thelink starts up.171iii A microwave high-speed wireless linksystem designed to work with portableequipmentiv Very low power network links betweenBluetooth devicesvAn unlicensed frequency range at2.45GHZvi A standard for networking systems with apacket-switching protocolvii Constantly switching channels2Mark the following as True or False:a Bluetooth is an expensive system.b Bluetooth devices can communicate at adistance of up to 20m.c The SM band is available throughout theworld.d Bluetooth has a very low radiation level.e Each Bluetooth connection operates at onefixed frequency.f Bluetooth signals will pass through walls ofbuildings.g The master Bluetooth device is determinedwhen a link is first established.UNIT 24The Future of ITSTARTERHow do you think developments in IT will affect these areas oflife in the next ten years?123commerceworkthe relationship between humans and computersCompare your predictions with others in your group.
Try toagree on a ranking from most likely to least likely.Read the three opening paragraphs of the text below andanswer these questions:12345How does the author justify his claim that we are 'in the midst ofconvergence'?What will be the difference between computers and humansafter 2015?What does he mean by a 'positive feedback loop' in computerdevelopment?Why will knowledge of a major language be the only IT skillneeded?Which of the author's predictions do you accept?The future ofInformationTechnologyWe are in the midst ofconvergence.
At the hardwarelayer, computers, phones andconsumer electronics areconverging. At the applicationslayer, we see convergence ofinformation, entertainment,communications, shopping,commerce, and education.Computers have come fromnowhere 50 years ago and arerapidly catching up in capabilitywith the human brain. We canexpect human:machineequivalence by about 2015. Butafter this, computers willcontinue to get smarter. There isa noticeable positive feedbackloop in technology development,with each generation ofimproved computers giving usmore assistance in the design anddevelopment of the next.Ultimately, they will design theiroffspring with little or no humaninvolvement. This technologydevelopment will push everyfield of knowledge forwards, notjust computing.
It will be almostas though extraterrestrials hadlanded in 2020 and given us alltheir advanced technologyovernight.But we will never get far unlesswe can solve the interfaceproblem. In the near future wemay have electronic pets, withvideo camera eyes andmicrophone ears, linked by radioto the family computer. Withvoice and language recognitionwe will have easy access to allthat the Internet can provide.
Wecan tell the pet what we want andit will sort it out for us. It will beimpossible to be technophobicabout such an interface, and theonly IT skill needed will be tospeak any major language.Now work in groups of three, A, B and C. Read your text extractand complete parts 1 and 2 of this table.1Area of IT2Predictions3CommentsTelecoms applications will soon be bundledtogether in much the same way as officeapplication suites are today.
A major example isthe electronic marketplace, which will bringcustomers and suppliers together in smartdatabases and virtual environments, with IDverification, encryption and translation. It willthen implement the billing, taxation andelectronic funds transfer, while automaticallyproducing accounts and auditing. The whole suiteof services will be based on voice processing,allowing a natural voice interface to talk to thecomputer, all the AI to carry out the request, andvoice synthesis and visualisation technology to getthe answer out.Electronic money will be very secure but muchmore versatile than physical alternatives. E-cashcan be completely global and could be used as a defacto standard.
It does not have to be linked to anynational currency, so can be independent of localcurrency fluctuations. Its growing use on the Netwill lead to its acceptance on the street and wemay hold a large proportion of our total funds inthis global electronic cash.
People willincreasingly buy direct from customisedmanufacturers. Shops will be places where peopletry on clothes, not buy them. Their exactmeasurements can be sent instantly to themanufacturer as soon as they have chosen anoutfit. The shops may be paid by the manufacturerinstead.Employment patterns will change, as many jobsare automated and new jobs come into existenceto serve new technologies. Some organisationswill follow the virtual company model, where asmall core of key employees is supported bycontractors on a project by project basis, bringingtogether the right people regardless of where theylive. The desks they will use will have multiple flatscreens, voice interfaces, computer programs withhuman-like faces and personalities, full-screenvideoconferencing and 3D sound positioning.
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