Means of information transmission. Modern means and methods of information transmission and their features

12.08.2019 News

The concept of “communication” is derived from the Latin communicatio, which means “message; broadcast; common, shared with everyone; communication". In other words, communication–this is the transfer of this or that content from one consciousness (individual or collective) to another through signs; This is a connection during which information is exchanged between systems in both living and inanimate nature.

Communication between people has a number of specific features:

1. Existing relations between two individuals, each of whom is an active subject. At the same time, their mutual informing presupposes the establishment of joint activities.

The specificity of human information exchange lies in the special role for each participant in the communication of this or that information and its significance.

2. The possibility of mutual influence of partners on each other through a system of signs.

3. Communicative influence only if there is a single or similar system of codification and decodification between the communicator (the person sending the information) and the recipient (the person receiving it).

4. The possibility of communication barriers (social or psychological). In this case, the connection that exists between communication and attitude becomes clear.

Distribution media. The dissemination of information in society passes through a kind of “trust-distrust filter.” Such a filter acts in such a way that true information may not be accepted, but false information may be accepted.

Content and type of information. In the process of communication, the participants in communication are faced with the task of not only exchanging information, but also achieving its adequate understanding by partners. That is, in interpersonal communication, the interpretation of the message coming from the communicator to the recipient stands out as a special problem. Barriers may arise during communication. Communication barrier- this is a social or psychological obstacle to the adequate transfer of information between communication partners.

Communication process model usually includes five elements: communicator - message (text) - channel - audience (recipient) - feedback. The main goal of information exchange in communication is to develop a common meaning, a common point of view and agreement regarding various situations or problems. It is characterized by a mechanism reversecommunications. The content of this mechanism is that in interpersonal communication the process of information exchange is, as it were, doubled and, in addition to the substantive aspects, the information coming from the recipient to the communicator contains information about how the recipient perceives and evaluates the behavior of the communicator.

The information itself coming from the communicator can be of two types: motivating and stating. Incentive information expressed in an order, advice, request. It is designed to stimulate some action. Ascertaining information appears in the form of a message, it takes place in various educational systems and does not imply a direct change in behavior, although it indirectly contributes to this. The message option is specified by the communicator, i.e. the person from whom the information comes.

The transmission of any information is possible only through signs, or rather sign systems. There are several sign systems that are used in the communication process. In a rough division, a distinction is made between verbal and nonverbal communications that use different sign systems. Accordingly, verbal and non-verbal means of communication are distinguished.

Verbal communication uses human as a sign system speech, natural sound language, i.e. a system of phonetic signs that includes two principles: lexical and syntactic.

Speech is the most universal means of communication, since when transmitting information through speech, the meaning of the message is least lost. With the help of speech, information is encoded and decoded: the communicator encodes while speaking, and the recipient decodes this information while listening.

The main purpose of verbal communication is to establish, maintain, and develop meaningful information contact.

Types of Verbal Communication:

Written: certainty of source; consistency of information; possibility of adequate reporting.

Verbal: non-verbal reinforcement possible; can be edited and clarified. Information can be substantive (depending on the subject) and modal (shows whether what is being said is essential, desirable, necessary, possible).

Nonverbal communication. Nonverbal means of communication are needed in order to: regulate the flow of the communication process, create psychological contact between partners; enrich the meanings conveyed by words, guide the interpretation of the verbal text; express emotions and reflect the interpretation of the situation, i.e. their functions: supplementation of speech, replacement of speech, representation of the emotional states of partners in the communicative process.

Types of nonverbal means of communication:

1. Visual means of communication are:

kinesics (gestures) – movements of the arms, legs, head, torso;

direction of gaze and eye contact;

eye expression;

facial expression (facial expressions);

pose (pantomime), in particular, localization, changes of poses relative to the verbal text;

skin reactions (redness, sweating);

distance (distance to the interlocutor, angle of rotation towards him, personal space);

auxiliary means of communication, including body features (gender, age) and means of their transformation (clothing, cosmetics, glasses, jewelry, tattoo, mustache, beard, cigarette, etc.).

2. Acoustic (sound) means of communication are:

paralinguistic, i.e. related to speech (intonation, volume, timbre, tone, rhythm, pitch, speech pauses and their localization in the text);

extralinguistic, i.e. not related to speech (laughter, crying, coughing, sighing, gnashing of teeth, sniffling, etc.).

3. Tactile-kinesthetic (related to touch) means of communication are:

physical influence (leading a blind person by the hand, etc.);

takeshika (hand shake, pat on the shoulder).

4. Olfactory means of communication are:

pleasant and unpleasant odors of the environment;

natural and artificial human odors, etc.

All non-verbal means are complementary to verbal communication, i.e. They report their readiness to support communication or stop it, encourage the partner to continue the dialogue, and finally, contribute to discovering their “I” more fully, or, on the contrary, hiding it.

5 unusual ways of transmitting information in ancient times

Editor's response

The history of mankind knows examples of amazing ways of transmitting information, such as knotted writing, Indian tribes called wampum and encrypted manuscripts, one of which cryptologists still cannot solve.

Knotted writing in China. Photo: Commons.wikimedia.org

Knot writing, or a method of writing by tying knots on a string, presumably existed before the advent of Chinese characters. Knotted writing is mentioned in the treatise Tao Te Ching (“Book of Path and Virtue”), written by the ancient Chinese philosopher Lao Tzu in the 6th-5th centuries. BC. Interconnected cords act as information carriers, and the information itself is carried by the knots and colors of the laces.

Researchers put forward different versions of the purpose of this type of “writing”: some believe that the knots were supposed to preserve important historical events for their ancestors, others believe that ancient people kept accounting in this way, namely: who went to war, how many people returned, who was born and who died, what is the organization of the authorities. By the way, knots were woven not only by the ancient Chinese, but also by representatives of the Inca civilization. They had their own knotted writing “kipu”, the structure of which was similar to the Chinese knotted writing.

Wampum. Photo: Commons.wikimedia.org

This writing of the North American Indians is more reminiscent of a multi-colored ornament than a source of information. The wampum was a wide belt made of shell beads strung on cords.

To convey an important message, the Indians of one tribe sent a wampum-carrying messenger to another tribe. With the help of such “belts”, treaties were concluded between whites and Indians, and the most important events of the tribe, its traditions and history were recorded. In addition to the informative load, wampums carried the burden of a currency unit, sometimes they were simply used as decoration for clothing. People who "read" wampum had a privileged position in the tribe. With the advent of white traders on the American continent, shells were no longer used in wampum, replacing them with glass beads.

Rubbed iron plates

The glare from the plates warned the tribe or settlement of the danger of attack. However, such methods of transmitting information were used only in clear sunny weather.

Stonehenge and other megaliths

Megalithic burial in Brittany. Photo: Commons.wikimedia.org

Ancient travelers knew a special symbolic system of stone structures or megaliths, which showed directions of movement towards the nearest settlement. These stone groups were intended primarily for sacrifices or as a symbol of the deity, but they were also practically road signs for the lost. It is believed that one of the most famous monuments of the Neolithic era is the British Stonehenge. According to the most common version, it was built as a large ancient observatory, since the position of the stones can be associated with the location of the celestial sanctuaries in the sky. There is also a version, which does not contradict this theory, that the geometry of the location of stones on the ground carried information about the lunar cycles of the Earth. Thus, it is assumed that ancient astronomers left behind data that helped their descendants deal with astronomical phenomena.

Encryption (Voynich Manuscript)

Voynich manuscript. Photo: Commons.wikimedia.org

Data encryption has been used since ancient times until now, only the methods and methods of encryption and decryption are being improved.

Encryption made it possible to transmit a message to the person to whom it was intended in such a way that no one else would be able to understand it without the key. The forefather of encryption is cryptography - mono-alphabetic writing, which could only be read with the help of a “key”. One example of a cryptographic script is the ancient Greek scytale, a cylindrical device with a parchment surface whose rings moved in a spiral. The message could only be deciphered using a stick of the same size.

One of the most mysterious manuscripts recorded using encryption is the Voynich manuscript. The manuscript received its name in honor of one of the owners, the antiquarian Wilfried Voynich, who acquired it in 1912 from the Roman College, where it had previously been kept. Presumably, the document was written at the beginning of the 15th century and describes plants and people, but it has not yet been deciphered. This made the manuscript famous not only among cryptographers, but also gave rise to all sorts of hoaxes and speculation among ordinary people. The bizarre texts of the manuscript are considered by some to be a skillful forgery, by others as an important message, by others as a document in an artificially invented language.

The history of the development of means of information transmission is an integral part of the history of the development of society, and the needs for information exchange have always exceeded the existing technical capabilities of satisfying them.

Information has always played a huge role in the life of society and the individual. Since ancient times, possession of information and dominance in the information field have been a necessary condition for the dominant social group to have power.

The need for communication, transmission and storage of information arose and developed along with the development of human society. At present, it can already be argued that the information sphere of human activity is a determining factor in the intellectual, economic and defense capabilities of human society and the state. Originating at a time when the earliest signs of human civilization began to appear, the means of communication between people (means of communication) were continuously improved in accordance with changing living conditions, with the development of culture and technology.

The same applies to the means of recording and processing information. Today, all these tools have become an integral part of the production process and our everyday life.

Since ancient times, sound and light have served people to transmit messages over long distances.

At the dawn of his development, man, warning his fellow tribesmen about danger or calling for a hunt, gave signals by shouting or knocking. Sound is the basis of our speech communication. But if the distance between the interlocutors is large and the strength of the voice is not enough, auxiliary means are required. Therefore, man began to use “technology” - whistles, animal horns, torches, fires, drums, gongs, and after the invention of gunpowder, shots and rockets. Special people appeared - messengers, heralds - who carried and transmitted messages, announced the will of the rulers to the people. In southern Italy, here and there along the seashore, until recently, the ruins of outposts remained, from which news of the approach of the Normans and Saracens was transmitted through the ringing of bells.

Since time immemorial, light has also been used as a carrier of information. The first communication “systems” were guard posts located around settlements on specially built towers or towers, and sometimes simply on trees. When an enemy approached, an alarm fire was lit. Seeing the fire, the guards at the intermediate post lit a fire, and the enemy was not able to take the residents by surprise. Horse changing stations are created for messengers. Lighthouses and rockets still carry out their “information service” at sea and in the mountains.

The need to transmit not only individual alarm signals, but also various messages led to the use of “codes”, when different messages differed, for example, in the number and location of fires, the number and frequency of whistles or drum beats, etc. The Greeks in the second century BC used combinations of torches to convey messages "by letter." At sea, signal flags of various shapes and colors have found widespread use, and the message is determined not only by the flags themselves, but also by their relative position, as well as “semaphore” - the transmission of messages by changing the position of hands with flags (day) or lanterns (at night). People were needed. , who know the “language” of flags or semaphore, and are able to transmit and receive transmitted messages.

Along with the development of methods for transmitting signals using sound and light, there was a development of methods and means of recording and storing information. At first it was just various notches on trees and cave walls. From the drawings carved on the walls of caves more than three thousand years ago, we can now get an idea of certain aspects of the life of our ancestors in those distant times. Both the form of recording and the means of its implementation were gradually improved. From a series of primitive drawings, man gradually moves on to cuneiform writing and hieroglyphs, and then to phonetic letter writing.

Sound and light have been and remain important means of transmitting information, and despite their primitiveness, fire and sound signaling have served people for many centuries. During this time, attempts were made to improve signaling techniques, but they did not receive widespread practical application.

The development of means of storing, transmitting and processing information in the history of human society has been uneven. Several times in human history there have been radical changes in the information field, which are called “information revolutions.”

The first information revolution is associated with the invention of writing. Writing created the opportunity for the accumulation and dissemination of knowledge, for the transfer of knowledge to future generations. Civilizations that mastered writing developed faster than others and reached a higher cultural and economic level. Examples include ancient Egypt, the countries of Mesopotamia, and China. Within this revolution, the stage of transition from pictographic and hieroglyphic writing to alphabetic writing turned out to be very significant; this made writing more accessible and, to a large extent, contributed to the shift of the centers of civilization to Europe.

The second information revolution (mid-16th century) was associated with the invention of printing. It has become possible not only to save information, but also to make it widely available. Literacy is becoming a mass phenomenon. All this accelerated the growth of science and technology and helped the industrial revolution. Books crossed the borders of countries, which contributed to the beginning of the creation of a universal civilization.

The third information revolution (late 19th century) was caused by the progress of communications. The telegraph, telephone, and radio made it possible to quickly transmit information over any distance. It was during this historical period that the germs of the process that today is called “globalization” appeared. The progress of information transmission media has greatly contributed to the rapid development of science and technology, which required reliable and high-speed communication channels.

The fourth information revolution (70s of the XX century) is associated with the emergence of microprocessor technology and, in particular, personal computers. Note that it was not the appearance of computers in the mid-twentieth century in itself, but precisely microprocessor systems that had a decisive influence on the information revolution. Soon after, computer telecommunications emerged, radically changing information storage and retrieval systems. It was the fourth information revolution that gave impetus to such significant changes in the development of society that a new term appeared to describe it? "Information society".

Throughout the 20th century, signalmen sought to increase the speed of information transmission. The need for more transmitted information caused the transition from the telegraph first to the telephone, and then to radio.

In the 20th century, railroads revolutionized the world by providing a transportation network that moved materials and manufactured products. They made the development of industrial society possible.

Digital communications networks have ushered in a new revolution by providing technology that transports the data required by a society in which information plays a key role. Networks have already penetrated industry, education and government. They have already begun to change our understanding of the world, reducing geographical distances and forming new communities of people who interact frequently and effectively. More importantly, the growth of networks is explosive. The revolution has already begun.

The development of fiber-optic communication networks is characterized by a very rapid increase in the speed of information transfer. The transmission speed achieved experimentally in laboratory conditions and the transmission speed of highly reliable commercial networks are growing exponentially, doubling approximately every 2 years. This trend is ensured by both a steady increase in the speed of information transmission over one channel and an increase in the number of channels simultaneously transmitted over one fiber in systems with spectrum division of channels. Simultaneously with the increase in information transmission speed, the transmission range is steadily increasing.

Electronic mail (E-mail) is the most common use of the Internet. E-mail provides the ability to send messages over the network at a speed that is incomparably higher than that of regular mail. You can receive messages, place them in your email inbox, reply to letters automatically using the sender's address, send a letter to several recipients at once, and forward letters.

E-mail is one of the most important information resources on the Internet, the most widespread means of electronic communications. Any Internet user can get their own mailbox on the network. If you consider that via the Internet you can receive or send messages to another two dozen international computer networks, some of which do not have an on-line service at all, then it becomes clear that mail provides opportunities in some sense even broader than just the Internet information service .

Email allows you to compose a text message on your computer and send it over the network to another user. All over the world, the main resource of networks is people. Using such familiar means of communication as telephone, fax and regular mail can often be difficult for technical, financial and other reasons. Email provides a relatively simple and inexpensive solution to the problems of maintaining regular contact between people.

The advantages of using e-mail compared to other types of transmission media are many enough to evaluate the convenience of exchanging information in this particular way. Let's list at least a few, first of all - cost savings. For connecting to the Internet, the provider is paid a more or less fixed amount, and unlike regular mail and telephone, you do not have to pay for sending each message.

This applies not only to messages you send, but also to messages you receive. Recipients of messages can save money that was previously spent on postage and telephone calls.

The significant difference in price between paper and electronic versions allows you to issue emails much more frequently, thereby increasing their effectiveness.

However, saving money is not the only reason to use email. The main advantage of email is that it is ultimately more effective than all other means of communication. Email delivery is faster because there are no delays in printing and copying documents. Instead of several days, it takes minutes or even seconds to deliver one letter, no matter how far away the recipient is.

People perceive email as more urgent and important than traditional email. Regular correspondence can sit unopened for days or even weeks, but emails are usually read as soon as they are received. This is very important if you have to disseminate urgent information.

Another advantage of e-mail arises from the features of modern document management. An electronic message can be inserted into a text document or spreadsheet much more easily than a paper message. This feature is very important if documents are often exchanged.

WAP can be briefly described as follows: access to information located on the Internet directly from a mobile phone. With its help, you can view specially prepared Web pages with news, exchange rates, jokes and more. You can also download for your phone: new ringtones, screensavers and games.

WAP is a means of gaining access to Internet resources via a mobile phone. In this case, the user does not resort to the help of any additional devices, such as a computer or modem. WAP (Wireless Application Protocol) is a protocol, or technical standard, that describes the way information from the Internet is transferred to a small mobile phone display. This is the main difference between WAP and the usual methods of access to the World Wide Web, which provide information exchange and viewing of Web sites (HTTP and TCP/IP protocols). Theoretically, if a mobile phone screen could display as much information as a computer display, then WAP would not exist in the form in which it is provided now. But the displays of mobile phones, even those with high resolution, cannot “accommodate” ordinary Web pages. This is what led to the creation of special ways to allow mobile phone users to use the Internet. With the advent of the WAP protocol, subscribers of cellular networks were able to use a number of services on special WAP sites: such as e-mail, electronic stores, booking tickets and hotel rooms, access to their bank account, information channels (news, weather forecast , exchange rates, etc.) and even an electronic guide. More and more WAP resources appear on the World Wide Web every day. Many popular Web sites have WAP twins that provide mobile users with the same set of services. One example: the email site www.mail.ru has a WAP version of wap.mail.ru. A list of popular WAP sites and their brief description can be viewed in the "WAP sites" menu. For those who want to evaluate this or that WAP site without leaving their computer, there are WAP emulators that allow you to reproduce the work with WAP on the display of your mobile phone. With the introduction of WAP, its advantages and disadvantages were revealed. WAP as it currently exists needs major improvement. Due to the small size of the displays, the WAP interface leaves much to be desired. While small messages can be read fairly quickly, those containing up to a hundred characters take a long time to scroll through. The speed of data exchange from mobile terminals is also relevant, especially since you have to pay for the time you work with WAP. The last drawback is eliminated by the new GPRS data transmission technology, which not only increases the exchange speed several times, but also allows you to pay not for time, but for the volume of received information. For specialists servicing WAP, the following problems arise: sites that users can visit from mobile phones must be constantly adapted. In other words, a WAP site that can be viewed on an 8-line display is no longer suitable for a 4-line display, and it must be rewritten in a special version. WAP technology in its modern form is still a transitional solution. The developers are already modernizing it, eliminating the original shortcomings. The goals achieved by using WAP may change. However, the general idea of providing information from the Internet to a mobile phone will only continue to evolve. While traveling, a person may need access to his usual e-mail, his financial data, and information about institutions of interest in the area where the user is located.

Transfer of information

Transfer of information- the physical process by which information is transferred in space. We recorded the information on a disk and moved it to another room. This process is characterized by the presence of the following components:

A source of information.
Information receiver.
Information carrier.
Transmission medium.

transfer of information- a technical event organized in advance, the result of which is the reproduction of information available in one place, conventionally called the “source of information,” in another place, conventionally called the “receiver of information.” This event assumes a predictable time frame for obtaining the specified result.

“Information” here is understood in a technical aspect, as a meaningful set of symbols, numbers, parameters of abstract or physical objects, without a sufficient “volume” of which the problems of management, survival, entertainment, crime or monetary transactions cannot be solved.

To implement p.i. It is necessary to have, on the one hand, a so-called “storage device” or “carrier” that has the ability to move in space and time between the “source” and the “receiver”. On the other hand, rules and methods for applying and removing information from the “media” are required in advance, known to the “source” and “receiver”. On the third hand, the "carrier" must continue to exist as such upon arrival at the destination. (by the time the “receiver” finishes removing information from it)

At the present stage of technology development, both material-subject and wave-field objects of a physical nature are used as “carriers” at the present stage of technology development. Under certain conditions, the transmitted “information” “objects” themselves (virtual media) can be carriers.

P.i. in everyday practice, it is carried out according to the described scheme, both “manually” and using various automatic machines. In many varieties of technical implementation.

When constructing p.i. systems Not only information about physical objects can be “transmitted,” but also information about media prepared for transmission. In this way, a hierarchical “transmission medium” with any depth of nesting is organized. (Not to be confused with the propagation medium of wave carriers.)

Literature

Richard Read Fundamentals of the theory of information transmission = The Essence of Communication Theory (Essence of Engineering). - M.: “Williams”, 2004. - P. 304. - ISBN 0-13-521022-4

Links

Wikimedia Foundation. 2010.

See what “Transfer of Information” is in other dictionaries:

transfer of information- Transfer of digitized information in accordance with the protocol. [GOST R 41.13 2007] information transfer The process of transferring information (data) from its source to the consumer. In general, it can be represented by the following diagram (Fig. A.3). This diagram... ...

A useful function of speculation, which is the dissemination of information by entering into public transactions based on unknown information. In English: Transmission of information See also: Exchange speculative operations Financial dictionary ... Financial Dictionary

Transfer of information- the process of transferring information (data) from its source to the consumer. In general, it can be represented by the following diagram (Fig. A.3). This diagram shows that for P.i. it must be encoded (see Encoding), i.e. turn into...

transfer of information- 2.25 data communication: Transfer of digitized information in accordance with a protocol. Source: GOST R 41.13 2007: Uniform regulations concerning vehicles of categories M, N and O regarding braking... Dictionary-reference book of terms of normative and technical documentation

transfer of information- informacijos perdavimas statusas T sritis automatika atitikmenys: engl. information transfer; information transmission vok. Informationsübertragung, f rus. transfer of information, f pranc. transmission d information, f … Automatikos terminų žodynas

Transfer of information constituting a trade secret- (commercial secret information transfer) transfer of information by its owner to a counterparty on the basis of a condition that the counterparty takes measures to protect its confidentiality... Economic and mathematical dictionary

transfer of information constituting a trade secret- Transfer of information by its owner to the counterparty on the basis that contains the condition that the counterparty takes measures to protect its confidentiality. Topics: economics EN commercial secret information transfer… Technical Translator's Guide

TRANSFER OF INFORMATION CONTAINING A TRADE SECRET- TRANSFER OF INFORMATION CONTAINING A TRADE SECRET transfer of information constituting a trade secret and recorded on a tangible medium by its owner to the counterparty on the basis of an agreement to the extent and on the terms provided for... ... Legal encyclopedia

The movement of information from one unit to another within an organization...

The movement of information from the upper levels of the organization to the lower... Glossary of crisis management terms

Books

Transfer of information. Statistical theory of communication, Fano R.M.. The book of the famous American scientist R. Fano systematically sets out the foundations of information theory; Along with the fundamental results of Shannon coding theory, a number of...

This applies not only to messages you send, but also to messages you receive. Recipients of messages can save money that was previously spent on postage and telephone calls.

The significant difference in price between paper and electronic versions allows you to issue emails much more frequently, thereby increasing their effectiveness.

3.2. IP telephony

Internet Telephony (IP telephony) is a technology that is used on the Internet to transmit voice signals.

There are two basic types of Internet Telephony telephone requests:

1. From computer to computer

2. From computer to phone

In a normal telephone call, the connection between both interlocutors is established through the telephone exchange for the sole purpose of conversation. Voice signals are transmitted over specific telephone lines, through a dedicated connection.

When a request is made over the Internet, compressed data packets arrive on the Internet with a destination address. Each data packet travels its own path to the destination, along different routes. For the destination, the data packets are regrouped and decoded into the original voice signals

The significantly lower cost of IP telephony is due to the fact that ordinary telephone calls require an extensive communication network of telephone exchanges connected by fixed telephone lines, the supply of fiber-optic cables and communication satellites. The high costs of telephone companies result in expensive long distance calls for us. A dedicated telephone exchange connection also has a lot of overhead or downtime during a voice session. IP telephony relies in part on an existing network of fixed telephone lines. But most importantly, it uses the most advanced compression technology for our voice signals, and fully utilizes the capacity of telephone lines. Therefore, data packets from different requests, and even different types of them, can move along the same line at the same time.

Today, IP telephony is very popular, which is explained by its low cost, high speed, excellent sound quality and ease of use. It uses all the capabilities of telephone lines, allowing you to simultaneously make calls and transfer data over the Internet. The advantages of IP telephony include: its low cost, reliability, high communication speed, complete independence and ease of use.

3.3. NMT

NMT is one of the oldest cellular communication standards, developed in 1978 and first put into operation in 1981. Initially, the standard was developed for Scandinavia with its large territory and low population density, so it was perfectly suited for the “mobilization” of Russia. To this day, in our country the NMT network has significantly greater coverage even compared to the total coverage of networks of other standards. And this situation is unlikely to change in the coming years. The NMT standard is analog and belongs to the FDMA (Frequency Division Multiplie Access) group of cellular communication standards. This group of standards has many disadvantages, but also quite a lot of advantages compared to other groups (TDMA and CDMA). The main advantage is the large range of the base station. The main problem with the NMT-450 is the significant level of interference in the 450 MHz range in large industrial cities. But as soon as you move away from the city, the quality of communication improves greatly and often surpasses the quality of wired telephone networks. Over time, various services were added to the standard and today NMT looks no worse than its younger competitors. This includes number identification, voice mail, fax mail, conference calling, call forwarding, SMS, clock synchronization, etc.

3.4. GSM

Global Mobile Communications (GSM) - global mobile communications system; European digital standard; frequency range 890 - 960 MHz and 1710-1880 MHz.

Today, the abbreviation GSM stands for Global System for Mobile Communications, and the GSM standard and its versions are accepted for use in approximately 80 countries around the world.

The technology reached Russia with a traditional delay: the first cellular communication system appeared in Russia only in 1991. Despite this, the pace of development of cellular communications in our country is so high that in just a few years this service has turned from a “privilege of the elite” into an urgent need for people with average incomes. Instead of a symbol of prosperity, cellular communications are becoming what they should be - a means of communication, already competing in certain areas with wired networks.

The GSM standard belongs to the second generation of cellular communication standards based on digital technology. Full-speed speech coding implemented in GSM systems makes its quality comparable to the quality of landline telephone networks. A GSM radiotelephone can be divided into two parts: a SIM subscriber module (SIM card) and the phone itself, containing hardware and software. The SIM card serves as confirmation of the subscriber's authenticity and contains in its memory all the necessary data related to the credentials of a particular subscriber. To prevent the thief from using it, a special identification number (PIN code) is entered into it. Using a SIM card is also convenient because when changing a device, the subscriber does not need to change his mobile number, he simply rearranges the card, and all the data saved on it, including the address book, becomes available in the new device. When the SIM card is not in the device, access to the vast majority of services is blocked, with the exception of emergency calls (if the network allows). It is very difficult to duplicate a SIM card and, combined with security functions, it provides a high level of protection for users and networks from unauthorized access. The GSM standard introduces several security functions. First of all, this is encryption of the radio channel, which prevents eavesdropping by third parties, as well as protection of the subscriber’s number (to prevent disclosure of his location). In addition to the standard capabilities provided by cellular operators - local, long-distance and international communications, call forwarding and others, GSM phones provide their owners with a number of additional functions: saving voice messages received during the period when the subscriber was unavailable (voice mail), receiving messages about an incoming fax (fax-mail), identifying the caller's number. It is possible to transmit short messages “from point to point” (paging), that is, subscribers can, if desired, exchange simple short (several dozen characters) messages (tariffs for this service are slightly lower than for regular conversations). Mobile modem/fax functionality, coupled with the ubiquity of laptop computers, makes it possible to access the Internet and email via GSM networks. These services greatly increase the attractiveness of using GSM phones for users. So, for example, fax mail can be very useful for a business person, because it allows you not to miss information about a fax at any time, regardless of the location of the subscriber. The mobile phone will notify its owner, and he can receive the fax anytime and anywhere, since the fax is automatically sent to his electronic mailbox.

The advantages of the standard include the smaller size and weight of telephones compared to analog standards and longer operating time without recharging the battery. This is mainly achieved through the base station equipment, which constantly analyzes the level of the signal received from the subscriber's device. In cases where it is higher than required, the emitted power is automatically reduced. There is also a relatively high network capacity, a low level of industrial interference in this frequency range and a somewhat unnatural sound of speech, but there is no hissing or crackling

Maximum protection against eavesdropping and illegal use, which is achieved through the use of public key encryption algorithms. EFR technology is an advanced speech coding system. This system was developed by Nokia and subsequently became the industry standard encoding/decoding for GSM technology. One of the significant disadvantages of GSM cellular networks today is the low data transfer speed.

3.5. WAP

3.6. GPRS

The GPRS standard - General Packet Radio Service for GSM networks provides mobile access and data services within the framework of a new economic model. With the introduction of the GPRS standard for today's voice-centric GSM networks, the era of wireless information business began. GPRS provides a new, packet-based network architecture (Internet compatible) that will enable cellular operators and other companies to offer a wide range of profitable and valuable services to their customers. As mobile communications increasingly become the norm, mobile subscribers have a growing need to access information in real time. The Internet phenomenon, as well as the possibility of simultaneous voice and data transmission, make the introduction of GPRS the next revolutionary step in the development of wireless communications.

GPRS is a wireless standard designed to provide the basis for a wide range of data transfer functions using packet transmission. These are new, unique services of GSM operators, whose subscribers will pay for the use of only those resources that they use. The main resource of a cellular operator - the frequency range - can be divided between many users at the same time, since the GPRS standard supports simultaneous data transmission for a much larger number of users. GPRS is designed to enhance end-user mobile data access by making always-on connectivity possible, affordable and with significantly faster data transfer speeds. GPRS will not only complement the existing data transfer capabilities provided by GSM operators, but will also ensure the introduction of data transfer services characteristic of third generation cellular networks several years before their availability.

The main purpose of GPRS is to provide efficient, cheap, packet-based access to Internet services on the “from sender to recipient” principle. GPRS allows subscribers to use radio channels simultaneously and creates an overlapping packet network with Internet access service nodes.

Among the advantages of GPRS are:

· permanent virtual connection

Frequency bandwidth is determined by needs

· tariff per unit of transmitted information

The GSM standard, which already employs 230 networks around the world, has achieved impressive success. Today it is obvious that a new large market is emerging: the mobile data market. This market will reflect the extraordinary growth of fixed local area networks (LANs) and regional networks (WANs). For example, today there are more than 100 million Internet users in the world, and the need for network services is growing very quickly.

As the number of wireless computers grows just as rapidly, there is a clear, market-driven opportunity for the development of wireless connection systems to data networks. Some operators are already aware of the potential benefits of providing data services. In addition to direct commercial benefits, there are also indirect benefits: for example, a reduction in the proportion of high-level users. With the growth of the range of services provided by the operator, the issue of maximum service efficiency is becoming increasingly important for the network. SMS messaging and standard round-robin technology are becoming increasingly expensive in terms of planning and network resources. The GPRS standard provides technology solutions that provide optimal compliance for the full range of possible applications. It is clear that higher data rates, demand-based frequency allocation, virtual permanent connections, fast call setup and per-volume pricing may be required to meet the needs of advanced users and effectively compete with landlines.

GPRS allows you to transmit data over a wide frequency band. Packet switching technology provides a complete and instantaneous connection between a wireless device or laptop computer and the Internet or corporate network, allowing you to freely use all existing Internet applications such as email and web search engines. The high capacity of GPRS networks will make it possible to introduce wireless multimedia applications into practical use.

Advantages:

· High data transfer speed;

· Quick call setup;

· Users can be “online” for days, loading system resources less;

· The user pays for the volume of transmitted information, in addition, it is possible to combine payment by volume with payment by time;

· Highly efficient system capacity for data transmission - from 2 to 10 times increased compared to networks with cyclic switching;

· SMS applications can be switched to GPRS for optimal performance;

· The technology is applicable to a wide range of data transmission applications - both pulsed and continuous, both low and high speed;

· Compatible with the IP protocol: connection to the Internet and corporate networks;

· A stepping stone towards UMTS architecture and functionality.

In addition to the inherent capabilities of packet technology, GPRS allows optimal use of the available frequency range through the ability to allocate radio channels. This capability helps protect resource investments by giving operators the freedom to set thresholds for channel resource allocation between voice and data. For example, some channels can be allocated only for the transmission of voice and/or data, while on other channels the operator can transmit both data and sound, determining the relationship between them at his own discretion.

GPRS is based on the use of Internet Protocol (IP). IP support may be especially important as some companies are now interested in Internet access that allows remote access to corporate networks. Thanks to IP support, any application operating using this protocol will be able to work over a GSM cellular network. Cellular communications providing GPRS services are intended to become wireless extensions of the Internet and corporate networks.

The purpose of GPRS is to provide technological solutions that can be used in any application. The main advantages of networks operating using the GPRS standard (high data transfer speed, allocation of frequency resources according to needs, virtual permanent connection, quick call setup and the ability to charge per volume unit) are the key to the successful implementation of a whole bunch of services. Here are just a few of them:

· Email

· electronic commerce

local service

· information Services

· synchronization

3.7. Internet (modem connection)

Let's consider this type of connection to the Internet as Dial-up. Parallel signals sent by the computer are converted into serial signals by the modem and transmitted over telephone lines. The maximum speed achieved with dial-up is 55.6 kbit/s, which is, of course, quite a bit. Moreover, 55.6 kbit/s is the ideal case, usually this parameter is much lower. For communication speed with dial-up “It is influenced by a huge number of different factors, both constant and changing over time. For example, the type of telephone exchange plays a huge role. If a telephone number is served by an old turn-by-turn PBX, then the maximum communication speed is unlikely to exceed 28.8 kbit/s. In addition, the condition of the telephone line to the PBX, the cable in the apartment, the load on the station at a given time, external interference, the speed of your modem and much, much more are important. In addition to speed, dial-up has other disadvantages. Firstly, the phone is busy while working on the Internet. Secondly, the connection reliability is extremely low. The problem is that the connection is often lost due to unknown reasons (problems on the PBX, interference on the line, etc.) The quality of the connection is affected by the type of modem, the quality of the telephone line, the protocol with which this connection is established (HST - specially designed for very noisy lines). The data transfer speed is determined by the modems installed for the user and the provider, and is 28.8 - 56 kBit/s. The transmission speed is affected by the load on the server with which the user is working, as well as the data transmission channels “leading” to this server.

And yet, despite serious problems with speed, dial-up also has a number of invaluable advantages. Firstly, the connection cost is low. Since the communication channel itself (telephone line) is already ready, you only need to buy a modem. There are a huge number of providers now, all of them are connected completely free of charge. The next plus of dial-up is the low cost of working on the Internet. And indeed, since there are many providers, it means there is competition, thanks to which prices are constantly falling. Thus, despite all its disadvantages, dial-up remains in Russia, and , perhaps, will remain one of the most common methods of connecting to the Internet for a long time.

3.8. Satellite connection

Data from the Internet arrives at the user's computer via satellite at a speed of 400 Kbps, and in the opposite direction via a modem. Disadvantages: uneven data transfer speed excludes the possibility of video conferencing, high connection cost.

Today, the process of “multimediatization” is in full swing on the Internet. Flash technologies, video inserts, and voiceovers are increasingly being used on websites. Also, audio and video conferencing are becoming more and more widespread, which facilitate full communication between people who are far from each other. In addition, users are now downloading much more information from the World Wide Web onto their computers. Regular Internet access via telephone line is no longer enough. And even many leased lines, as they exist, often do not meet the needs of users. Let's consider satellite Internet as one of the ways to solve this kind of problem.

More recently, this method of accessing the global network was available only to residents of the western regions of our country. Today, the broadcast zone of satellites of various companies covers almost the entire territory of Russia. This means that when connecting to the Internet, this access option should not be considered as some abstract possibility, but as a real alternative to other, more traditional methods.

Satellite Internet has several advantages. Firstly, it is a very high data transfer speed. On good equipment it rarely drops below several hundred or even thousands of kilobytes per second and is usually determined not by physical parameters, but by the cost of the contract with the provider (the higher the speed, the more expensive). It is almost impossible to achieve this “on earth”. The second advantage of Internet access via satellite is the price. Approximately a gigabyte of information will cost less than a thousand rubles. Moreover, most satellite providers charge traffic depending on the time of day, and therefore at night the price of one gigabyte drops to 150-200 rubles. The third advantage is the ability to quickly switch to another provider if for some reason you are no longer satisfied with it. And in the case, for example, with a leased line, this is impossible without laying a new cable with all the ensuing costs.

But, of course, accessing the Internet via satellite has its drawbacks. And the most important of them is that the dish installed by the user can only receive signals, but not send them in any way. This means that to work on the Internet you will have to use any other traditional access method, in addition to satellite. At first glance, it seems that this negates all the advantages considered. However, in reality this is not the case at all. The fact is that incoming traffic is usually tens of times greater than outgoing traffic. And if a user downloads, for example, movies or music from the Internet, then this difference can be an order of magnitude greater. In addition, when communicating via a dedicated line, outgoing traffic is free. Thus, if the user’s computer receives data from a satellite and sends it via a “dedicated” network, then for the money the user will not even feel any “duplication”.

The second disadvantage is the high price of the initial equipment. The third disadvantage of satellite Internet is the dependence of communication quality on weather conditions.

Satellite access can make life much easier for private or business users who need high-speed access but are unable to use a leased line or ADSL. In this case, you can use dial-up for outgoing traffic. True, this will be more expensive, since you will have to pay for both connection methods, but it allows you to achieve a very decent download speed of information.