The Science of Radio Astronomy

One of the earliest modern investigations into extraterrestrial sources of radio waves was by Karl Guthe Jansky, an engineer with Bell Telephone Laboratories, in the early 1930s. The first object actually detected was the center of the Milky Way, followed by the sun. These early discoveries were confirmed by Grote Reber by 1938.

What was the nature of the discrete radio sources, or "radio stars'? Where were they, what were they, what were their properties, how many were there, how did they work and what was their significance in the Universe? Of parallel importance was the puzzle of how to devise new kinds of radio telescope which would elucidate these astronomical questions. Nikola Tesla in the Colorado Springs lab recorded cosmic waves emitting from interstellar clouds and red giant stars. He observed repeating signals conducted by his transceiver. He announced that he received extraterrestrial radio signals. But the scientific community did not believe him, and rejected Tesla's data. Tesla spent the latter part of his life trying to signal Mars.

Modern Radio Astronomy is a universally recognized subfield of astronomy. Just like in the visible, at low radio frequencies the sky is dominated by small bright sources, but the sources are typically active galaxies and supernova remnants rather than stars. Radio astronomy is the study of celestial phenomena through measurement of the characteristics of radio waves emitted by physical processes occurring in space. Radio waves have a much greater wavelength than light waves. In order to receive good signals, radio astronomy requires large antennas, or arrays of smaller antennas all working together. Most radio telescopes use a parabolic dish to reflect the waves to a receiver which detects and amplifies the signal into usable data. This allows astronomers to see a region of the radio sky. If they take multiple scans of overlapping strips of the sky they can piece together an image ('mosaicking').

Radio astronomers use different types of techniques to observe objects in the radio spectrum. Instruments may simply be pointed at an energetic radio source to analyze what type of emissions it makes. The types of instruments being used depends on the weakness of the signal and the amount of detail needed. Radio telescopes may need to be extremely large in order to receive signals with large signal-to-noise ratio. Also since angular resolution is a function of the diameter of the "objective" in proportion to the wavelength of the electromagnetic radiation being observed, radio telescopes have to be much larger in comparison to their optical counterparts. For example a 1 meter diameter optical telescope is two million times bigger than the wavelength of light observed giving it a resolution of a few arc seconds, whereas a radio telescope "dish" many times that size may, depending on the wavelength observed, may only be able to resolve an object the size of the full moon (30 minutes of arc).

Radio astronomy has led to substantial increases in astronomical knowledge, particularly with the discovery of several classes of new objects, including pulsars, quasars and radio galaxies. This is because radio astronomy allows us to see things that are not detectable in optical astronomy. Such objects represent some of the most extreme and energetic physical processes in the universe. Radio astronomy is also partly responsible for the idea that dark matter is an important component of our universe; radio measurements of the rotation of galaxies suggest that there is much more mass in galaxies than has been directly observed. The cosmic microwave background radiation was also first detected using radio telescopes. However, radio telescopes have also been used to investigate objects much closer to home, including observations of the Sun and solar activity, and radar mapping of the planets. And still there is a lot to be discovered. ~ 3299

red giant – красный гигант - звезда, в конце своей жизни, относительно холодная (ее температура 2000-4000 K), она обладает высокой красной светимостью.

supernova – сверхновая (звезда), заканчивающая свою эволюцию в катастрофическом взрывном процессе. Вспышка при этом может быть на несколько порядков больше чем в случае новой звезды. Столь мощный взрыв – это следствие процессов, протекающих в звезде на последний стадии эволюции.

to overlap – перекрывать, нахлестывать, покрывать

an arc second – угловое разрешение — минимальный угол между объектами, который может различить телескоп.

pulsar – пульсар - астрономический объект, испускающий мощные, строго периодические импульсы электромагнитного излучения.

quasar – квазар - класс внегалактических объектов, отличающихся очень высокой светимостью и малым угловым размером.

radio galaxy радиогалактика — тип галактик, который обладает намного большим радиоизлучением, нежели обычные галактики. Радиоизлучение наиболее «ярких» радиогалактик превышает их оптическую светимость..

dark matter – скрытая масса (также тёмная материя, тёмное вещество, тёмная энергия)— общее название совокупности астрономических объектов, недоступных прямым наблюдениям современными средствами астрономии (то есть не испускающие электромагнитного излучения достаточной для наблюдений интенсивности), но наблюдаемым косвенно по гравитационным эффектам, оказываемым на наблюдаемые объекты.

The oldest form of digital broadcast was spark gap telegraphy, used by pioneers such as Marconi. By pressing the key, the operator could send messages in Morse code by energizing a rotating commutating spark gap. Spark gap transmitters are now illegal, because their transmissions span several hundred megahertz. This is very wasteful of both radio frequencies and power.

The next advance was continuous wave telegraphy, or CW, in which a radio frequency produced by a vacuum tube electronic oscillator was switched on and off by a key. CW uses less than 100Hz of bandwidth. CW is still used, these days primarily by amateur radio operators (hams). Strictly, on-off keying of a carrier should be known as Interrupted Continuous Wave or ICW.

Radio teletypes usually operate on short-wave (HF) and are much loved by the military because they create written information without a skilled operator. They send a bit as one of two tones. Groups of five or seven bits become a character printed by a teletype. From about 1925 to 1975, radio teletype was how most commercial messages were sent to less developed countries. They are still used by the military and weather services.

Aircraft use a 1200 Baud radio teletype service over VHF to send their ID, altitude and position, and get gate and connecting-flight data.

Microwave dishes on satellites, telephone exchanges and TV stations usually use quadrature amplitude modulation (QAM). QAM sends data by changing both the phase and the amplitude of the radio signal. QAM packs the most bits into a radio signal. Usually the bits are sent in "frames" that repeat. A special bit pattern is used to locate the beginning of a frame.

Systems that need reliability, or that share their frequency with other services may use corrected orthogonal frequency-division multiplexing or COFDM. COFDM breaks a digital signal into several hundred slower subchannels. The digital signal is often sent as QAM on the subchannels. Modern COFDM systems use a small computer to make and decode the signal with digital signal processing which is more flexible and far less expensive than older systems that implemented separate electronic channels. COFDM resists fading and ghosting because the narrow-channel QAM signals can be sent slowly. An adaptive system or one that sends error-correction codes can also resist interference, because most interference can affect only a few of the QAM channels. COFDM is used for Wi-Fi, some cell phones and many other local area network, digital TV and radio standards. ~2123

a spark gap telegraphy – искровое телеграфирование

a continuous wave telegraphy – однополосное телеграфирование

Interrupted Continuous Wave – короткая (электромагнитная) волна; прерывистая незатухающая волна.

Baud (Emile Baudot) – Эмиль Бодо, создатель кода Бодо

a quadrature amplitude modulation – квадратурная амплитудная манипуляция

a corrected orthogonal frequency-division multiplexing – мультиплексирование на основе ортогонального разделения частот

a digital signal processing – цифровая обработка сигналов (ЦОС)

Wi-Fi -Wireless Fidelity - беспроводная точность. Стандарт на оборудование Wireless LAN (Wireless Loсal Area Network; WLAN — беспроводная локальная вычислительная сеть). Он разработан консорциумом Wi-Fi Alliance на базе стандартов IEEE 802.11, «Wi-Fi» — торговая марка «Wi-Fi Alliance».

HD Radio offers a new and better way to broadcast radio programs. The "HD" in HD radio is a trademarked brand name that's given by its developer and that doesn't stand for anything. HD Radio technology is developed without any intention to replace traditional FM and AM radio broadcast. HD Radio is currently being broadcast along with conventional FM and AM signals.

The main difference of HD Radio compared to Amplitude Modulation (AM) and Frequency Modulation (FM) is the form of signal that it uses to carry information. Both AM and FM signals are analog radio waves while HD Radio signals are in the compressed digital form.

Digitizing radio broadcast has provided a lot of improvements to sound quality and broadcast signal quantity. With an HD radio, sounds produced are a lot better in quality as compared to conventional radio broadcast. AM and FM signals carry little amount of information. HD Radio signals carry a lot more. More information-carrying capability means better sound quality.

If one is familiar with audio and video compression, he should be able to understand why HD Radio produces better sounds that traditional AM and FM broadcast. One usually sees videos and audio with the same content and length but with different sizes. Once these files are played or viewed, one immediately notices the difference in quality between the two. The larger file plays better that than the smaller one. The smaller file has been reduced to a form where it only contains enough information to be viewed fairly.

Aside from better sound quality, HD Radio has multicasting or multiplexing capability. Multicasting refers to the ability of HD radio to carry multiple channels in one frequency. For example, if one tune in to a certain radio frequency and this frequency is multicasting, the HD Radio will tell you so. One could then access the other channels on the said frequency through a separate dial on the HD Radio.

In addition to this, HD Radio also has the ability to carry information like text that could display song data, lyrics and many more options through the HD Radio display.

There is very little difference between how HD radio and conventional radio work. A radio station is contracted to broadcast both HD and conventional radio signals. Once a radio station agrees to broadcast HD signals, it is then required to transmit both digital and analog audio broadcast. The digital signal passes through a computer system which compresses digital information. The analog signal is broadcast unaffected by the compression. Both signals are then transmitted at the same time. During broadcast, digital signals for HD Radio are less prone to interference, reflections and dropout. This eliminates the static and hissing sound from the audio produced.

Conventional radio is not equipped with the capability to receive HD Radio signals. Thus, to be able to enjoy the benefits of HD Radio one should purchase an HD Radio receiver. This receiver lets one enjoy FM, AM and HD Radio broadcast. ~ 2509

The crystal radio is a rudimentary radio receiver that can be made from a few easy-to-obtain and inexpensive parts. It is unique for this type of radio does not require a battery pack, has no moving parts, and can be built using ordinary household materials, yet it actually works. The only power it receives comes from the radio signals.

The basic properties and mechanics of radio broadcasting had been discovered and worked out in the early 1900s and radio stations began broadcasting news and other information to the general public. However, the cost of factory-manufactured radios was prohibitive. The US government therefore taught the general public how to make crystal radios.

Later, radios with amplifiers and speakers became much more inexpensive so more people could afford to purchase a unit. This brought an end to the popularity of crystal radios. Hobbyists, however, still continue to build crystal radios.

It should not be surprising that crystal radios work. The basic principles of radio broadcasting make radio crystal operations more than possible. First, the function of a radio broadcasting station (with all its equipment, transmission tower, power supply, etc.) is to convert sounds produced within the studio (whether from CDs, DJs talking, or live bands) into radio signals. These radio signals are then transmitted from the tower outwards, after which they will be picked up by radio receivers.

In the case of crystal radio receivers, the antenna picks up radio signals from the air. The ground wire creates a continuum - a point of entry (the antenna) and a point of exit (the ground) so radio signal electricity is generated. This low-voltage electricity flows through to the radio and is adjusted through the radio crystal tuner to choose a particular radio station's broadcast.

The electricity is then directed to the apparatus that converts radio signal electricity into sound energy. This converter is the crystal detector, composed of a slender wire touching a semi-conducting crystal; primitive radio crystals used galena but more recent models made use of germanium diodes.

At this point, electrical energy is successfully converted into sound energy that humans can hear.

Conventional radio receivers have an antenna and ground wire, too. The process of picking up a certain station's broadcast and the process of conversion from radio signal electricity into sound energy follows the same basic pattern as that of radio crystals.

However, conventional radios require an external power source because they add another process to sound production. This process is amplification. Amplification boosts the electrical signal to the point that it can be heard through speakers.

A basic crystal radio receiver does not have an amplifier. Thus, it requires the use of an earphone or other such device so that the sound it produces can be heard by the user. Crystal radio receivers also require a long antenna to function properly (standard antenna length is from 30 to 50 feet). ~ 2529

a battery pack – портативный батарейный источник питания

galena – свинцовая руда, сернистый свинец, галенит

Internet radio is essentially the same as regularly broadcast radio, with a few distinguishing characteristics. Whereas there is a minimal lag time with regular radio because it broadcasts through the air, Internet radio has a lag time of 2.5 to 10 seconds or so, depending on the server. Internet radio is streamed, and so does not involve downloading. You simply log on to the particular site and in it comes.

Receiving the stream is much like listening to your MP3 player, as the format is the same. Several formats are on offer, but the MP3 and ACC formats are currently the most frequently used. As the medium continues to find its footing, there will likely be modifications, which are difficult to predict today.

Anybody with the content, software, and hardware can run an Internet radio station. Because of this, most Internet radio stations are existing radio stations that are simply simulcasting their regular programming. The fact that it is separate, however, allows for a certain amount of variation if the station would like to change things a bit during the course of the day.

One of the more positive aspects of Internet radio is that it is international in flavor. Anybody around the world can get international access to Internet radio. Expatriates can keep up on news from home and revolutionaries can get their word out. The recent events in Burma are an example in this regard.

Unfortunately, there is one limiting factor in the United States, particularly with regard to music programming and generally getting started. As the digital age was really getting going, the United States government started imposing copyright fees and license fees on Internet broadcasters. A minimum fee of $500 was imposed, and a royalty fee structure in excess of the budgets of many Internet radio stations' business models was added.

Needless to say, this did not sit well with many Internet radio operators in the United States. It also did not sit well with many recording artists who had their own business models relying on play time to build a following. They felt the new structure would drive stations away, and it appears that this may be true. Several Internet radio concerns are now moving to international locations where fee structures are more favorable or nonexistent.

One of the features that bring many listeners to Internet radio is the fact that they can hear such a varied mix of formats from around the world. If you would like to hear the surf report in Australia from London, you can. The fact that the Voice of America was one of the very first broadcasters to adopt Internet radio speaks to its international appeal. Unfortunately, many countries are beginning to impose limitations on Internet radio. They would like to keep streams within their borders or keep streams out. Fortunately, hackers enjoy these types of challenges, so the future is a question mark in this regard. ~ 2473

ACC -Advanced Audio Coding — собственнический (патентованный) формат аудиофайла с меньшей потерей качества при кодировании, чем MP3 при одинаковых размерах.

t o simulcast - транслировать одновременно по радио и телевидению

More than three million people enjoy ham radio hobbies, which is basically amateur radio. These enthusiasts create a network of people that enjoy communicating with one another over different frequencies. However, ham radio operators do use a variety of methods to communicate with one another.

The amateur radio operators are known as Hams, and they communicate with one another for fun, self-improvement, or even public service. These operators communicate by transmitting messages by voice, Morse code, or even messages through computers. There are some new ways that allow hams to communicate via television with pictures that are transmitted around the world.

Ham radio is something that everyone can enjoy. There are people from all walks of life that enjoy this hobby such as homemakers, students, doctors, engineers, and drivers. All of these people have an interest and enjoyment in communicating with others through wireless technology. Many hams get together so that the younger generations can learn from those that have a lot of experience. Licensed hams actually communicate with one another from regional locations such as across town, across the country, although they can even communicate when they are across the world from one another if they so choose.

Hams have different reasons for participating. Many ham radio operators simply enjoy talking to friends, while others enjoy volunteering to help assist people in emergency situations, and are able to transmit messages if normal communications are not possible. Many hams are available to emergency medical teams, specialize in spotting severe weather, and disaster response. Ham radios can even be used to communicate with astronauts in outer space! Astronauts have communicated with many operators such as teachers, parents, and children while they have been in the space station and in orbit.

More than 600,000 Americans have a ham radio license. The Federal Communications Commission must license all people that use ham radios in the United States. To receive the license one must pass an exam. Most of these hams will tell you that they have a dedicated area of their home for their radio and other equipment, this room is often known as the "shack" in ham slang.

Hams enjoy meeting one another and often hold organized events to get together and have a great time. These gatherings are usually called Hamfest, with the largest Hamfest gathering being held in Dayton, Ohio. This is always an exciting event for most ham radio enthusiasts because they get to meet other with similar interests, talk shop, and meet new friends.~2188

a dedicated area – предназначенное пространство

On March 10, 1876, Alexander Graham Bell changed the course of history. After years of experiments with home-made inventions and just three days after the patent office granted a patent for his telephone, he finally stumbled upon the secrets of sending human speech over the wires by electrical means. In his attic laboratory in Boston, Bell worked day and night with his assistant, Thomas A. Watson, trying to develop a working telephone. Like most people, he knew little about electricity, so he learned as he went along. Because electricity was such a new phenomenon, he had to make all of his own equipment, including batteries.

While Bell sat in his attic with a cone-shaped telephone that looked like a small upright megaphone, Watson waited on the ground floor with the receiver. As he adjusted the wire connecting the two devices, Watson was taken aback when he heard Bell's clear voice Mr. Watson, come here, I want you." According to legend, Bell spilled a dish of acid and was calling for Watson to help him clear up the mess. Watson rushed upstairs and burst into attic to deliver the fantastic news:" - Mr. Bell, I understood what you said!"

They continued experimenting with the machine, each taking turns speaking into the telephone while the other listened at the receiver. Bell's fascination with the telephone started many years earlier while working on the "harmonic telegraph". This invention made it possible to send multiple messages over the same telegraph wire at the same time, and it brought Bell to the realization that it should also be possible to send speech over the telegraph wires.

In addition Bell, a small group of other scientists in the United States understood the concept of how a telephone should work. The problem they all faced was creating a working model, and as the month progressed, the competition became intense. Each inventor was in desperate race against the others.

When Bell finally succeeded, he proudly unveiled his invention at the 1876 Centennial Exposition in Philadelphia, which was the year's most important display-case for new invention and discoveries. At the exposition, Bell demonstrated the wonders of his telephone to eager and attentive audiences. With the transmitter and receiver set up 100 yards apart in different halls, he astounded everyone and walked away with first prize for the best new invention.

Bell envisioned his telephone as a more practical alternative to the telegraph, because telephones could provide two-way communication. In fact, he saw no limits to stop it from spreading to every home and business in the nation.

Despite the excitement the telephone caused at public demonstration, not everyone was impressed. The first telephones were large and bulky. People had to shout in order to be heard at the other end, and static often made the words impossible to hear. Many people did not believe that such a machine would ever become practical for everyday use. Newspapers ridiculed the telephone as a passing novelty, and Western Union Telegraph failed to recognize its importance and even rejected an offer to buy Bell's patent for only $100,000.

Thanks in part to the rejection by Western Union, Bell and Watson formed the Bell Telephone Company, through which they promoted their telephone. By August of 1877, there were 600 telephones in use in Boston alone, all with private lines. Telephone systems grew in cities and towns across the United States, and soon, operators at switchboards were busy fielding an ever-increasing number of calls from more subscribers. Bell's invention was literally changing the face of America. It also threatened to make the telegraph obsolete, because people realized the convenience and necessity of being able to talk directly to one another. Each year, thousand of new telephones were installed in homes, and businesses started to replace old fashioned telegraphs with new telephones. What's more, dozen of companies joined the competition for customer with their own patented telephone design.

Famous people gave the telephone added publicity. Congressman James A Garfield was the one of the first to have a telephone installed in his home. Writer Mark Twain also had in his home in Hartfort, and when Bell visited England on his honeymoon, he made a personal demonstration for Queen Victoria. The Queen was so impressed that she asked for her own telephone set.

Eventually, Western Union realized its mistake and joined the frenzy by establishing its own telephone system. At this time, each telephone company had its own wires, its own operators, and its own telephones, which often caused confusion and frustration for customers.

After the national telephone network was in place, it was time to rich beyond the border of the United States. Telegraph messages could already be sent to Europe over Atlantic Cable, but telephones calls were sent overseas by radio signal because the electric current was not strong enough to carry voices the entire length of the cable. As a result, international telephone calls were usually of poor quality. Starting in 1956, the first specially-designed telephone cable were laid on Atlantic Ocean's floor to give the United States a direct telephone connection with England. The improvement in quality was dramatic. Other cable quickly followed across both the Atlantic and Pacific Oceans, and soon it was possible to call directly to most telephones in Europe as well as in Asia and around the world. The telephone was making global communication a reality.

To make overseas calling faster and ever more efficient, NASA launched the first communications satellite in 1960. Known as Echo 1, it was a giant silver balloon which orbited the Earth and simply reflected telephone transmission from a sending station to a receiving station. Two years later, the more powerful TelStar 1 became the first two-way communications satellite and was a vital step towards the future of a true global telephone system.

By the time it reached its 100th anniversary in 1976, the telephone was already an essential part of business life, and a few homes were without at least one telephone. Today, the world wide network of computers and satellite makes the modern telephone system a far cry from the primitive machine first pioneered by Alexander Graham Bell in 1876.~5293

to envision -воображать что-л., рисовать в своем воображении, представлять себе, предвидеть

a switchboard – коммутатор, распределительный щит

Mobile (also called cellphone and handphone, as well as cell phone, wireless phone, cellular phone, cell, cellular telephone, mobile telephone or cell telephone) is a long-range, electronic device used for mobile voice or data communication over a network of specialized base stations known as cell sites.

In addition to the standard voice function of a mobile phone, telephone, current mobile phones may support many additional services, and accessories, such as SMS for text messaging, email, packet switching for access to the Internet, gaming, Bluetooth, infrared, camera with video recorder and MMS for sending and receiving photos and video, MP3 player, radio and GPS. Most current mobile phones connect to a cellular network consisting of switching points and base stations owned by a mobile network operator (the exception is satellite phones, which are mobile but not cellular).

A mobile phone, as opposed to a radio telephone, offer full duplex-communication, automatised calling to and paging from a public switched telephone network (PSTN), handoff (am. English) or handover (European term) during a phone call when the user moves from one cell (base station coverage area) to another. A cell phone offer wide area service, and should not be confused with a cordless telephone, which also is a wireless phone, but only offer telephony service within a limited range, e.g. within a home or an office, through a fixed line and a base station owned by the subscriber.

The International Telecommunication Union estimated that mobile cellular subscriptions worldwide had reached approximately 4.1 billion by the end of 2008. Mobile phones have gained increased importance in the sector of Information and communication technologies for development in the 2000s and have effectively started to reach the bottom of the economic pyramid

In 1908, U.S. Patent 887,357 for a wireless telephone was issued in to Nathan B. Stubblefield of Murray, Kentucky. He applied this patent to "cave radio" telephones and not directly to cellular telephony as the term is currently understood. Cells for mobile phone base stations were invented in 1947 by Bell Labs engineers at AT&T and further developed by Bell Labs during the 1960s.

Radiophones have a long and varied history going back to Reginald Fessenden's invention and shore-to-ship demonstration of radio telephony, through the Second World War with military use of radio telephony links and civil services in the 1950s, while hand-held cellular radio devices have been available since 1973. A patent for the first wireless phone as we know today was issued in US Patent Number 3,449,750 to George Sweigert of Euclid, Ohio on June 10, 1969.

In 1945, the zero generation (0G) of mobile telephones was introduced. Like other technologies of the time, it involved a single, powerful base station covering a wide area, and each telephone would effectively monopolize a channel over that whole area while in use. The concepts of frequency reuse and handoff, as well as a number of other concepts that formed the basis of modern cell phone technology, are first described in U.S. Patent 4,152,647, issued May 1, 1979 to Charles A. Gladden and Martin H. Parelman, both of Las Vegas, Nevada and assigned by them to the United States Government.

This is the first embodiment of all the concepts that formed the basis of the next major step in mobile telephony, the Analog cellular telephone. Concepts covered in this patent (cited in at least 34 other patents) also were later extended to several satellite communication systems. Later updating of the cellular system to a digital system credits this patent.

Martin Cooper, a Motorola researcher and executive is widely considered to be the inventor of the first practical mobile phone for hand-held use in a non-vehicle setting. Cooper is the inventor named on "Radio telephone system" filed on October 17, 1973 with the US Patent Office and later issued as US Patent 3,906,166. Using a modern, if somewhat heavy portable handset, Cooper made the first call on a hand-held mobile phone on April 3, 1973 to a rival, Dr. Joel S. Engel of Bell Labs.

The first commercial citywide cellular network was launched in Japan by NTT in 1979. Fully automatic cellular networks were first introduced in the early to mid 1980s (the 1G generation). The Nordic Mobile Telephone (NMT) system went online in Denmark, Finland, Norway and Sweden in 1981.

In 1983, Motorola DynaTAC was the first approved mobile phone by FCC in the United States. In 1984, Bell Labs developed modern commercial cellular technology (based, to a large extent, on the Gladden, Parelman Patent), which employed multiple, centrally controlled base stations, each providing service to a small area (a cell). The cell sites would be set up such that cells partially overlapped. In a cellular system, a signal between a base station (cell site) and a terminal (phone) only need be strong enough to reach between the two, so the same channel can be used simultaneously for separate conversations in different cells.

Cellular systems required several leaps of technology, including handover, which allowed a conversation to continue as a mobile phone traveled from cell to cell. This system included variable transmission power in both the base stations and the telephones (controlled by the base stations), which allowed range and cell size to vary. As the system expanded and neared capacity, the ability to reduce transmission power allowed new cells to be added, resulting in more, smaller cells and thus more capacity. The evidence of this growth can still be seen in the many older, tall cell site towers with no antennae on the upper parts of their towers. These sites originally created large cells, and so had their antennae mounted atop high towers; the towers were designed so that as the system expanded—and cell sizes shrank—the antennae could be lowered on their original masts to reduce range.

The first "modern" network technology on digital 2G (second generation) cellular technology was launched by Radiolinja (now part of Elisa Group) in 1991 in Finland on the GSM standard which also marked the introduction of competition in mobile telecoms when Radiolinja challenged incumbent Telecom Finland (now part of TeliaSonera) who ran a 1G NMT network.

The first data services appeared on mobile phones starting with person-to-person SMS text messaging in Finland in 1993. First trial payments using a mobile phone to pay for a Coca Cola vending machine were set in Finland in 1998. The first commercial payments were mobile parking trialled in Sweden but first commercially launched in Norway in 1999. The first commercial payment system to mimic banks and credit cards was launched in the Philippines in 1999 simultaneously by mobile operators Globe and Smart. The first content sold to mobile phones was the ringing tone, first launched in 1998 in Finland. The first full internet service on mobile phones was i-Mode introduced by NTT DoCoMo in Japan in 1999.

In 2001 the first commercial launch of 3G (Third Generation) was again in Japan by NTT DoCoMo on the WCDMA standard.

Until the early 1990s, following introduction of the Motorola MicroTAC, most mobile phones were too large to be carried in a jacket pocket, so they were typically installed in vehicles as car phones. With the miniaturization of digital components and the development of more sophisticated batteries, mobile phones have become smaller and lighter.~6277

GPS -Global Positioning System - глобальная система позиционирования

full duplex -полнодуплексный (канал или устройство, выполняющее одновременно прием и передачу данных)

a handoff -передача обслуживания при использовании помощи самой мобильной станции. Вариант эстафетной передачи, при котором решение о выборе наилучшей доступной ячейки принимается с помощью мобильной станции. Критерием такого выбора является качество канала связи.

a cordless telephone -беспроводный телефон, радиотелефон

Bell Labs -Bell Laboratories - бывшая американская корпорация, крупный исследовательский центр в области телекоммуникаций, электронных и компьютерных систем.

AT&T -компания American Telephone and Telegraph, одна из крупнейших американских телекоммуникационных компаний.

an embodiment – интеграция, объединение, слияние

Nordic Mobile Telephone (NMT) -аналоговый стандарт мобильной связи в диапазоне частот от 453 до 468 МГц.

TeliaSonera -телекоммуникационная компания, лидер рынков сотовой связи Швеции и Финляндии. Штаб-квартира — в Стокгольме.

NTT DoCoMo — крупнейший японский оператор мобильной связи.

WCDMA – Wideband Code Division Multiple Access — широкополосный множественный доступ с кодовым разделением. Технология радиоинтерфейса, избранная большинством операторов сотовой связи для обеспечения широкополосного радиодоступа с целью поддержки услуг 3G.

Bluetooth is a radio standard and communications protocol designed for wireless personal area networks (PANs), also known as IEEE 802.15.1. Bluetooth provides a way to connect and exchange information between devices such as mobile phones, laptops, PCs, printers, digital cameras, and video game consoles over a secure, globally unlicensed short-range radio frequency (power class dependent: 1metre, 10 metres, 100 metres). Using a radio communication system, the devices don’t have to be in line of sight of each other and can even be in other rooms, so long as the received transmission is powerful enough.

Bluetooth was named after the 10^th century king of Denmark and Norway Harald Bluetooth. He is known for his unification of previously warring tribes from Denmark and Norway. Bluetooth likewise was intended to unify different technologies, such as computers and mobile phones. The Bluetooth logo merges the Nordic runes analogous to the modern Latin H and B: Haglaz and Berkanan forming a bind rune.

Bluetooth wireless technology is a short-range communication technology intended to replace the cables connecting portable and/or fixed devices while maintaining high levels of security. The key features of Bluetooth technology are robustness, low power, and low cost. The Bluetooth specification defines a uniform structure for a wide range of devices to connect and communicate with each other.

Bluetooth technology has achieved global acceptance such that any Bluetooth enabled device, almost everywhere in the world, can connect to other Bluetooth enabled devices in proximity. Bluetooth enabled electronic devices connect and communicate wirelessly through short-range, radio networks known as piconets. Each device can simultaneously communicate with up to seven other devices within a single piconet. Each device can also belong to several piconets simultaneously. Piconets are established dynamically and automatically as Bluetooth enabled devices enter and leave radio proximity.

A fundamental Bluetooth wireless technology strength is the ability to simultaneously handle both data and voice transmissions. This enables users to enjoy variety of innovative solutions such as a hands-free headset for voice calls, printing and fax capabilities, and synchronizing PDA, laptop, and mobile phone applications to name a few.

• Wireless control and communication between a cell phone and a hands-free headset. This is the most popular use.

• Wireless networking between PCs in a confined space and where little bandwidth is required.

• Wireless communications with PC input and output devices, the most common being the mouse, keyboard and printer.

• Replacement of traditional wired serial communications in test equipment, GPS receivers and medical equipment.

• Sending small advertisements from Bluetooth enabled advertising hoardings to other Bluetooth devices.

• Wireless control of a games console, Nintendo and Sony PlayStation will both use Bluetooth technology for their wireless controllers.

These days there are a lot of problems in the Bluetooth kingdom. The promises of a Bluetooth-united world have become hyperbole, diminished expectations, and security loopholes. These so-called Bluetooth cavities have generated a vocabulary of new words and phrases to name and describe them.

First of all it is the practice of bluejacking: temporarily hijacking another person’s cellphone by sending it an anonymous text message using the Bluetooth wireless networking system. In this way people bluejack nearby devices to send them unsolicited commercial messages, a practice called, inevitably, bluespamming.

Then it is warchalking, using chalk to place a special symbol on a sidewalk or other surface that indicates a nearby wireless network, especially one that offers Internet access. Now hackers are wandering around neighborhoods looking for vulnerable Bluetooth devices. Randomly searching for hackable Bluetooth devices is called bluestumbling; generating an inventory of the available services on the devices – such as voice or fax capabilities – is called bluebrowsing. When they find them, they’re chalking the Bluetooth symbol (the Nordic runes for the letters H and B, for Harald Bluetooth) on the sidewalk, a practice known as bluechalking.

Bluetooth crackers have recently learned to exploit problems in the OBEX Protocol, used to synchronize files between two Bluetooth devices – a practice called pairing, which is a normal part of the connection process, but in this case it’s done without the other person’s permission. Once pairing is achieved, the crackers can copy the person’s e-mail messages, calendar, and so on. This is known as bluesnarfing, and the criminals are called bluesnarfers. (The verb to snarf means to grab or steal something.)

A different Bluetooth security breach enables miscreants to perform bluebugging. This lets them not only read data on a Bluetooth-enabled cellphone but also eavesdrop on conversations and even send commands to the phone to initiate phone calls, send text messages, connect to the Internet, and more.

Perhaps the worst of the Bluetooth hacks is the Bluesniper, a Bluetooth scanning device that looks like a sniper rifle. Point the Bluesniper in any direction and it picks up the signals of vulnerable devices up a kilometer away (compared with the usual Bluetooth scanning distance of 10 meters). And, of course, the Bluesniper also lets you attack those distant devices with your favourite Bluetooth hack. ~ 4829

a communications protocol – протокол обмена данными, протокол связи

IEEE 802.15.1 – стандарт, разработанный для технологии беспроводной ближней коротковолновой радиосвязи Bluetooth, получил обозначение IEEE 802.15. Он определяет работу на частоте 2,4 ГГц, со скоростями передачи 722-784 Кбит/с.

IEEE ( The Institute of Electrical and Electronics Engineers, Inc.) –Институт инженеров по электротехнике и радиоэлектронике США. Крупнейшая в мире организация (www.ieee.org), объединяющая более 300 тыс. технических специалистов из 147 стран, ведущая организация по стандартизации, отвечающая также за сетевые стандарты.

an unification -консолидация, слияние; объединение, союз

Nordic runes – скандинавские руны (буквы рунического алфавита)

to merge -сливать(ся), соединять(ся) (into, with), поглощать

a piconet -беспроводная персональная сеть, которая может соединить без использования проводов минимум – 2, и максимум – 8 устройств.. a robustness – надёжность, ошибкоустойчивость

OBEX ( Object Exchange Technology ) – технология обмена объектами внутри рабочей группы

a loophole (=cavity, breach) – дыра, лазейка (в защите компьютерной системы)

bluejacking (блюдже́кинг) — атака с использованием особенностей профиля Object Exchange (OBEX). Этот профиль предназначен для обеспечения обмена данными (скажем, электронными визитными карточками или записями в календарях) между двумя оснащенными средствами Bluetooth устройствами без обязательной аутентификации. Когда одно устройство направляет некоторые данные на другое, получающее устройство отображает эту информацию в своем формате и затем спрашивает пользователя, нужно ли сохранять эту информацию. При совершении атаки Bluejacking отправитель изменяет содержимое поля «Имя» отправляемого сообщения, помещая в нем короткий текст. Bluejacking можно определить как спам на платформе Bluetooth.

unsolicited – незапрашиваемый, представленный без просьбы

spamming -рассылка коммерческой, политической и иной рекламы или иного вида сообщений лицам, не выражавшим желания их получать.

warchalking -Оставление простых условных знаков, в основном мелом, на тротуаре, стене или другой поверхности в местах близкого расположения точек доступа Wi-Fi (802.11) и местах частого появления пользователей Wi-Fi-устройств. Символ определяет, какой тип интернет-доступа возможен и используются ли средства защиты беспроводной сети (WEP или др.). Идея уорчокинга основана на языке символов странствующих рабочих начала 20 века в США.

bluestumbling -процесс, позволяющий хакеру обнаруживать устройства Bluetooth, расположенные в непосредственной близости, и в первую очередь устройства, функционирующие в режиме безопасности 1, либо дефектные устройства, допускающие обращения к службам без прохождения аутентификации.

browsing -просмотр (напр., файла), оиск путем просмотра

bluechalking -это способ знакомиться и общаться с людьми, пользоваться сервисами сетей (игра по сети, доступ к файл серверам, интрнет) при помощи устройств оборудованных беспроводным интерфейсом Bluetooth. Им оснащаються многие современные мобильные телефоны, КПК, ноутбуки.

a cracker -программа взлома (чужого ПО), взломщик (человек или программа, взламывающие фирменную защиту от копирования)

bluesnarfing -получение информации от устройства Bluetooth без предварительного образования пары. Целью первых атак Bluesnarfing было получение информации о контактах, которая хранилась на мобильных телефонах различных марок, изготовленных известными производителями. Злоумышленники пользовались недостатками в реализации стандарта Bluetooth в этих устройствах — недостатками, которые позднее были признаны изготовителями и устранены.

bugging -тайное наблюдение (подслушивание) с помощью малогабаритных электронных устройств; установка аппаратуры для тайного наблюдения (подслушивания)

to eavesdrop – подслушивать, перехватывать сообщения

During the early 1980s, cellular telephone systems were experiencing rapid growth in Europe, particularly in Scandinavia and the United Kingdom, but also in France and Germany. Each country developed its own system, which was incompatible with others in equipment and operation. This was an undesirable situation.

The Europeans realized this and in 1982 the Conference of European Posts and Telegraphs formed a study group called the Groupe Spécial Mobile (GSM) to study and develop an all-European public land mobile system.

Commercial service was started in 1991, and by 1993 there were 36 GSM networks in 22 countries. Although standardized in Europe, GSM is not only a European standard. Over 200 GSM networks operate in 110 countries around the world. With North America with a derivative of GSM called PCS 1900, GSM systems exist on every continent, and the acronym GSM now stands for Global System for Mobile communications.

A GSM network is composed of several functional entities with specific functions and interfaces. The GSM network can be divided into three broad parts.

The Mobile Station (MS) is carried by the subscriber. It consists of the mobile equipment and a smart card called the Subscriber Identity Module (SIM). The SIM provides personal mobility. By inserting the SIM card into another GSM terminal, the user is able to receive calls at that terminal, make calls from that terminal, and receive other services. The SIM card may be protected against unauthorized use by a password or personal identity number.

The Base Station Subsystem (BSS) controls the radio link with the Mobile Station. The Base Station Subsystemis composed of two parts, the Base Transceiver Station (BTS) and the Base Station Controller (BSC). These communicate across the standardized Abis interface allowing operation between components made by different suppliers. The BTS contains the radio transceivers that define a cell and handles the radio-link protocols with the Mobile Station. The BSC manages the radio resources for one or more BTSs. It is the connection between the Mobile Station and the Mobile service Switching Center (MSC).

The Network Subsystem (NSS), the main part of which is the Mobile services Switching Center (MSC), performs the switching of calls between the mobile users, and between mobile and fixed network users. The central component of the Network Subsystem is the Mobile services Switching Center (MSC). It acts like a switching node of the PSTN or ISDN, and provides all the functionality needed to handle a mobile subscriber, such as registration, authentication, location updating, handovers, and call routing to a roaming subscriber.

The Mobile Station and the Base Station Subsystem communicate across the Um interface, also known as the air interface or radio link.

GSM is a cellular network which means that mobile phones connect to it by searching for cells in the immediate area. GSM networks operate on four different frequency ranges. Most GSM networks operate on the 900 MHz or 1800 MHz bands. Some countries in the Americas (including the USA and Canada) use the 850 MHz and 1900 MHz bands because the 900 and 1800 MHz frequency bands were already allocated. The International Telecommunication Union, which manages the international allocation of radio spectrum, allocated the bands 890-915 MHz for the uplink (mobile station to base station) and 935-960 MHz for the downlink (base station to mobile station) for mobile networks in Europe.

Since radio spectrum is a limited resource shared by all users, a method must be devised to divide up the bandwidth among as many users as possible. The method chosen by GSM is a combination of Time- and Frequency-Division Multiple Access (TDMA/FDMA). The FDMA part involves the division of the 25 MHz bandwidth into 124 carrier frequencies spaced 200 kHz apart. One or more carrier frequencies are assigned to each base station. Each of these carrier frequencies is then divided in time, using a TDMA scheme. The fundamental unit of time in this TDMA scheme is called a burst period which lasts 15/26 ms (or approx. 0.577 ms). Eight burst periods are grouped into a TDMA frame (approx. 4.615 ms). One physical channel is one burst period per TDMA frame. ~ 3557

a roaming -роуминг (автоматическое подключение к местной сети связи)

a derivative -дериват, производное (происшедшее от чего-л. ранее существовавшего)

TDMA (Time Division Multiple Access) – множественный доступ с временным разделением каналов (временное разделение каналов с многостанционным доступом).

FDMA (Frequency Division Multiple Access) – множественный доступ с разделением частот.

A smartphone is a mobile phone offering advanced capabilities, often with PC-like functionality. There is no industry standard definition of a smartphone. For some, a smartphone is a phone that runs complete operating system software providing a standardized interface and platform for application developers. For others, a smartphone is simply a phone with advanced features like e-mail, Internet and e-book reader capabilities, and/or a built-in full keyboard or external USB keyboard and VGA connector. In other words, it is a miniature computer that has phone capability.

Growth in demand for advanced mobile devices boasting powerful processors, abundant memory, large screens and open operating systems has outpaced the rest of the mobile phone market for several years.

The first smartphone was called Simon; it was designed by IBM in 1992 and shown as a concept product that year at COMDEX, the computer industry trade show held in Las Vegas, Nevada. It was released to the public in 1993 and sold by BellSouth. Besides being a mobile phone, it also contained a calendar, address book, world clock, calculator, note pad, e-mail, send and receive fax, and games. It had no physical buttons to dial with. Instead of customers used a touch-screen to select phone numbers with a finger or create facsimiles and memos with an optional stylus. Text was entered with a unique on-screen "predictive" keyboard. By today's standards, the Simon would be a fairly low-end product, however its feature set at the time was incredibly advanced.

The Nokia Communicator line was the first of Nokia's smartphones starting with the Nokia 9000, released in 1996. This distinctive palmtop computer style smartphone was the result of a collaborative effort of an early successful and expensive PDA model by Hewlett Packard combined with Nokia's bestselling phone around that time and early prototype models had the two devices fixed via a hinge; the Nokia 9210 as the first color screen Communicator model which was the first true smartphone with an open operating system; the 9500 Communicator that was also Nokia's first cameraphone Communicator and Nokia's first WiFi phone; the 9300 Communicator was the third dimensional shift into a smaller form factor; and the latest E90 Communicator includes GPS. The Nokia Communicator model is remarkable also having been the most expensive phone model sold by a major brand for almost the full lifespan of the model series, easily 20

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