Presentation on physics cellular communications. Presentation "principles of cellular communications". Phone operation on a cellular network

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Popov Alexander Stepanovich

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In July 1947, Bell Laboratories employees W. Shockley, J. Bardeen and W. Brattain invented

transistor.

D. Ring's idea - Base stations with their coverage areas form cells, the size of which is determined by the territorial density of network subscribers. Frequency channels used for the operation of one of the base stations of the network can be used by other base stations of this network.

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Martin Cooper

Taking the Motorola Dina-TAC in his hands, Martin Cooper went outside and made the world's first cell phone call.

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First generation cellular communications (1G).

Standard CDMA, TDMA, iDEN, PDS, PHS

Data in such networks could only be transmitted at low speeds of up to 2.4 kbit/s, and the spectrum was limited above by a frequency of 900 MHz.

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Second generation cellular communications (2G).

GSM standard

The main difference between second-generation systems is that they are “digital”, i.e. voice is transmitted digitally.

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Third generation cellular communications (3G).

The systems operate at the following data transfer rates: for subscribers with high mobility (up to 120 km/h) - at least 144 kbit/s, for subscribers with low mobility (up to 3 km/h) - 384 kbit/s, for stationary objects at short distances - 2.048 Mbit/s.

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Base stations.

A base station (in relation to cellular communications) is a complex of radio transmitting equipment (repeaters, transceivers) that communicates with the end user device - a cell phone.

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Communication between the phone and the station can be via an analog protocol (AMPS, NAMPS, NMT-450) or digital (DAMPS, CDMA, GSM, UMTS).

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1. Graphics manipulator button2. Call button3. Phone book4. Keyboard5. Antenna6. Sound speaker7. LCD display8. On/off and call reset key9. Cancel key10. Microphone (located at the bottom)

Mobile phone appearance

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Block diagram of a cell phone

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Encoding and decoding processes in a cellular GSM phone

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Phone operation on a cellular network

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A cell phone is different in that it deals a “triple blow” to our body. Here we mean three sources of radiation of microwave fields located in one device and generating different EMFs, in various modes his works.

1. The first of these is the cell phone antenna, which emits EMF, the power of which is determined in units of watts.

2. This radiation is carried out in transmission mode, and a significant part of the EMR, partially attenuated by the cranium, penetrates our brain. In standby mode, a cell phone is similar to other electronic devices and emits weak fields of non-thermal intensity, which, when accumulated in the body, can lead to negative consequences.

3. In reception mode, microwave radiation penetrates directly into the brain through the ear canal.

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As a result of numerous studies in the field of biological effects of electromagnetic radiation, it was established:

1. that they have the property of accumulating over time in the human body, thereby disturbing its bioenergetic balance and, first of all, the structure of the so-called. energy information exchange (ENIO), which ensures the normal functioning of information exchange processes between all organs and systems, at all levels of organization of the human body, including those between the body and the external environment.

2. The most sensitive systems of the human body are: nervous, immune, endocrine and reproductive (sexual).

3. The biological effect of EMF under conditions of long-term, long-term exposure can lead to the development of long-term consequences, including degenerative processes of the central nervous system, blood cancer (leukemia), brain tumors, hormonal diseases, etc.

4. EMFs are especially dangerous for children and pregnant women, since the child’s body, which has not yet formed, is highly sensitive to the effects of such fields.

5. People with diseases of the central nervous, hormonal, cardiovascular systems, allergy sufferers and people with weakened immune systems are also very sensitive to the effects of EMFs.

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A cell phone interferes with healthy sleep.

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Children are slowing down...

Alan Preece, head of the biophysics department at the Bristol Cancer Centre, gave phones to 10- and 11-year-olds for half an hour. For half they worked in talk mode, for others they were disabled. And then the scientist conducted neurophysiological tests. For those who had mobile phones turned on, all reactions were slow. Another experiment showed that even after a two-minute conversation, the bioelectrical activity of the brain changes in adolescents aged 11-13 years. It returns to normal only after two hours. What does it mean? The child’s mood changes, he perceives the material in class worse if he was chatting on his cell phone during the break.

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And adults' blood boils

Hungarian biologist Turocsi asked 76 volunteers to make two calls, each lasting 7.5 minutes. The body trembled with all its fibers: the biocurrents of the brain changed, cerebral circulation slowed down, and blood pressure dropped. Doctors recorded anxiety and stress in the subjects.

And Russian professor Igor Belyaev, working at Stockholm University, turned on the phone next to test tubes with human blood. An hour later, the blood in several of them “boiled”! “No, it didn’t heat up,” explains the researcher. “But the blood cells, lymphocytes, behaved as if the person had a very high fever - 44 degrees.” The heat shock effect lasted 72 hours.

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Embryos die...

At the Moscow Institute of Biophysics, Professor Yuri Grigoriev made two incubators. I put 63 chicken eggs in each. A GSM mobile phone was suspended above one “bird house” at a height of 10 cm. The phone worked in this mode: 1.5 minutes on, half a minute off. Embryonic development disorders began on the third day. Only 16 birds hatched and “listened” to the phone! But they also turned out to be unviable. For comparison: in an incubator where the eggs were not pestered with calls, 51 chicks were born without any problems.

Scientists from Moscow State University discovered that cell phones kill yeast and acetic acid bacteria. This means that a device on a belt or in a pocket - next to the intestines - can ruin the life of one of the 500 microorganisms living there! And they will take revenge on the careless owner.

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SAR - Specific Absorption Rate - a unit of measurement showing the maximum specific power absorbed by the human body (W/kg) during a normal conversation on a cell phone.

The maximum safe level is 2.0, most modern phones have an SAR between 0.5 and 1.0.

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• At what age did you start using a cell phone?
• How much time a day do you talk on your cell phone?
• What phone model do you have now?
• Where do you usually keep your cell phone?
• Where is your cell phone at night?
• Do you know the device of a cell phone?
• Do you know about the harmful effects cell phones on the human body?

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At what age did you get a cell phone?

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2. How much time a day do you talk on your cell phone?

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3. What phone model do you have now?

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SAR LEVEL MEASUREMENT RESULTS - THE SAFEST

You are given the opportunity to get acquainted with the list mobile phones, having the lowest level SAR emissions. All data is provided for phones operating in the GSM 900 standard. The table shows SAR values ​​determined for 10 g of fabric. Remember: the lower the SAR value, the less impact a mobile phone has on a person! More about SAR

• SAR model
• MagComMagCom 0.04
• Motorola StarTac 130? 0.07
• Samsung SGH-F700v Qbowl 0.07
• Motorola V100 0.09
• Samsung SGH-Z560 0.10
• Swisscom XPA v1615 0.10
• Motorola MPx200 0.12
• Philips 362 0.12
• TelefoonTotaalBasicPhone 0.12
• Mitac Mio A501 0.12
• Samsung SGH-X830 0.12
• LG S5200 0.12
• Audiovox XV6600 0.12
• LG KG320S 0.13
• Sagem myMobileTV2 0.13
• Motorola V101 0.14
• Sony Ericsson T292a 0.15
• Nokia 8810 0.15
• E-ten M500 0.16
• Vodafone VPA IV 0.17
• BlackBerry 7280 0.17
• Samsung GT-I8000 Omnia II 0.17
• T-Mobile MDA Pro 0.17
• BlackBerry 6280 0.18
• Samsung SGH-s105 0.18

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Conclusion: the influence of electromagnetic fields on human health is a research problem of science. A person can ensure his own safety if he has the necessary information. Each of us can and even must take simple precautions. A cell phone is only safe if you use it wisely.

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List of sources and literature used

A. Gridin, K. Romanov, I. Zubik “MOBILE FOR EVERYONE. Design and operation of mobile phones"

Malyarevsky A., Olevskaya N. Your mobile phone (popular tutorial). M, "Peter", 2004

Zakirov Z.G., Nadeev A.F., Faizullin R.R. Cellular communication standard GSM. Current state, transition to third generation networks (“MTS Library”). M., “Eco-Trends”, 2004

Popov V.I. Fundamentals of cellular communications of the GSM standard (“Engineering Encyclopedia of the Fuel and Energy Complex”). M., “Eco-Trends”, 2005

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Cell phone device

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Over the course of the century and a half that has passed since the invention of the telephone, telephone communication has become so firmly established in the everyday life of modern people that the absence of a telephone in an apartment has practically become an exception. The advantages of wired telephone networks include reliable communication and a developed system of subscriber networks, which allows the user to contact a subscriber in almost any country in the world.

However, the “rigid binding” of the subscriber to a landline telephone, “limited” also by the length of the handset wire, did not allow the user to be mobile, i.e., move freely in space during conversations or between them.

In the second half of the last century, as technology and technology improved, the idea of ​​​​creating a worldwide (global) network began to develop mobile (cellular) telephony, allowing the user to have access to a developed subscriber network using a portable portable (mobile) handset-telephone with a significant (tens of kilometers) range.

The implementation of this idea would allow telephony to be brought to a new level of popularity and accessibility from the point of view of the user, who would have his own individual phone number and virtually unlimited freedom of movement (mobility) during or between conversations.

The proposed operating principle of mobile telephony is quite simple: using a handset (mobile phone), the subscriber communicates with the nearest base station (transmitter) of the network (Fig. 224).

Rice. 224. Cellular network base station (transmitter)

This base station, in turn, communicates with the next transmitter in the network, etc. as required by the subscriber (Fig. 225).

Rice. 225. Cellular network of transmitters

The described principle of creating a developed subscriber network is called cell phone principle, since bees build honeycombs inside the hive using the same principle. In this case, each created cell serves as the basis for creating the next exactly the same cell, etc.

Due to this circumstance, mobile telephony is also called cell phone communication When a subscriber moves (for example, in a car) (see Fig. 225), the base stations independently monitor him and “transmit” to each other, which happens with virtually no loss of communication quality, quickly and completely unnoticed by the user.

The simplest part of the block diagram of cellular communications - a mobile (portable) telephone, consists of two parts: the actual “handset” or ME (Mobile Equipment) and the subscriber identification module, or smart cards SIM (Subscriber Identity Module), obtained upon concluding a contract with a particular operator.

Each cell phone is assigned its own number or international identifier during production. mobile deviceΙΜΕΙ (International Mobile Equipment Identity), allowing you to distinguish it from the second one exactly the same.

Our country uses the second generation network standard GSM (Global System for Mobile Communications), which was developed in 1990. This standard uses an operating frequency of ν = 900 MHz, which can significantly improve communication quality compared to first generation standards.

The first GSM operator accepted subscribers in 1991, and by the beginning of 1994, global networks based on this standard, had 1.3 million subscribers. By the end of 1995, their number increased to 10 million!

When you turn on a mobile phone with an activated smart card, it “itself” finds the nearest base station of the corresponding cellular network, after which the entire package telephone services of this network becomes available to the subscriber.

Each transmitter provides radio coverage on average at a distance of up to two tens of kilometers from it (Fig. 226). For the rational use of the cellular network of transmitters, optimal schemes for their relative location on the ground are being developed, taking into account its topography.

“Physics of Radiation” - There are currently 10 nuclear power plants in operation in our country. This definition of radioactivity was given by Marie Curie, the famous physicist. Completed by: Nalivaiko G.G. Negramotnov I.A. Small doses of radiation are not dangerous, quite the opposite. Radioactivity helps people in real life. This source is the energy of atoms.

“Rutherford’s experiment on the structure of the atom” - Dispersion mechanism. Facts indicating the complexity of the structure of the atom. Models of atomic structure. Rutherford's experience. The structure of the atom. Ancient scientists about the structure of matter. All models were speculative and were not the result of an experiment. The charge of the nucleus is equal in magnitude to the charge of all electrons, so the atom is neutral.

“Thermonuclear reaction” - Of particular great practical importance is the fact that during a thermonuclear reaction, much more energy is released for each nucleon than during a nuclear reaction, for example, during the fusion of a helium nucleus from hydrogen nuclei, an energy equal to 6 MeV is released, and during the fission of a uranium nucleus per nucleon there is »0.9 MeV. What a huge and “inexhaustible” source of energy a person has!

“Biological effect of radioactive radiation” - A person with the help of his senses is not able to detect any doses of radioactive radiation. Radioactive radiation has a strong biological effect on the tissues of a living organism, consisting in the ionization of atoms and molecules of the environment. Completed: 2009.

“The influence of radiation on humans” - - “The hormone of vivacity.” A cell phone affects the entire cardiovascular system as a whole. How to protect yourself from EMF. Ozone layer. How does the state help? Fundamental Question: How do radiation and electromagnetic radiation affect human health?

“Model of the atom” - 7. , Where?0 = const, n = 3, 4, 5,… 7.1. Regularities in atomic spectra. 7.3. Bohr's elementary theory. When moving in a circle, there is centripetal acceleration. Hydrogen atom according to Bohr's theory. Where k = 1, 2, 3,…; n = k + 1, k + 2,…. In physics, the Rydberg constant is also called another quantity equal to R = R?·с.

There are 11 presentations in total

Research work in physics On the topic: “Cellular communications. From origins to modern times. The influence of electromagnetic radiation from a cell phone on the human body. Completed by: student of grade 11 “a” of Municipal Educational Institution Secondary School 2 Voronova Elena Voronova Elena Teacher: Borshchenko I. B.

Plan Introduction. Introduction. Goal of the work. Goal of the work. The first mobile phones. The first mobile phones. Modern phones. Modern phones. mobile connection in Russia. Mobile communications in Russia. Not a means of communication. Not a means of communication. The influence of a cell phone on the human body. The influence of a cell phone on the human body. Health. Mobile phone damage. Health. Mobile phone damage. Conclusion. Conclusion. Bibliography. Bibliography.

Purpose of the work: Research: Research: 1. development of cellular communications; 1. development of cellular communications; 2. harm caused to the human body by electromagnetic radiation from a cell phone. 2. harm caused to the human body by electromagnetic radiation from a cell phone.

Introduction Today's electromagnetic radiation is 100 million times greater than what our forefathers experienced. Long-term exposure to artificial electromagnetic radiation seriously affects health. Epidemiologists have found that cancer is more common among people living in close proximity to sources of strong electromagnetic fields, such as high-voltage power lines. Today, electromagnetic radiation is 100 million times greater than what our forefathers experienced. Long-term exposure to artificial electromagnetic radiation seriously affects health. Epidemiologists have found that cancer is more common among people living in close proximity to sources of strong electromagnetic fields, such as high-voltage power lines.

The first “mobile” phones This is the great-great-grandfather of the mobile phone: This is the great-great-grandfather of the mobile phone: The 1912 telegraph device. The so-called Morse apparatus. To send a telegram, its text must be converted into dots and dashes. Telegraph device model 1912. The so-called Morse apparatus. To send a telegram, its text must be converted into dots and dashes.

The first "mobile" phones Completely automatic system Mobile Telephony A (MTA), operated since 1956 in Stockholm and Gothenburg on 160 MHz Fully automatic Mobile Telephony A (MTA), operated since 1956 in Stockholm and Gothenburg on 160 MHz

The first "mobile" phones American Martin Cooper created the first mobile phone - Motorola DynaTec, which weighed 1 kg. But it took another five years of research before the first commercial cellular operator appeared. It was the Bahrain Telephone Company. American Martin Cooper created the first mobile phone - Motorola DynaTec, which weighed 1 kg. But it took another five years of research before the first commercial cellular operator appeared. It was the Bahrain Telephone Company.

Not a means of communication Many people know that a mobile phone has ceased to be just a means of communication!!! Now, for example, in front of you is a connection diagram between a mobile phone and a car alarm. Many people know that a mobile phone is no longer just a means of communication!!! Now, for example, in front of you is a connection diagram between a mobile phone and a car alarm.

How does a cellular radiotelephone affect the human body? In 1994, as part of the European project "Biomedical effects of electromagnetic fields", scientists in Europe, including Russia and Ukraine, Japan and the USA, began special research into the possible impact of cell phone radiation on the health and life of their users. In 1994, as part of the European project "Biomedical effects of electromagnetic fields", scientists in Europe, including Russia and Ukraine, Japan and the USA, began special research into the possible impact of cell phone radiation on the health and life of their users. In 1996, the first stage of collective work was completed. The results were more than disappointing. For radiotelephones and specifically cellular ones with a carrier frequency of MHz, they have a negative impact on the physical condition and health of their users. The brain (hypothalamus region), peripheral analyzers in the middle ear, vestibular and auditory analyzers are most affected. All this leads to mental disorders, including changes in conditioned reflex activity, behavioral reactions, states of short-term and long-term memory loss, changes in the bioelectrical activity of various brain structures. In 1996, the first stage of collective work was completed. The results were more than disappointing. For radiotelephones and specifically cellular ones with a carrier frequency of MHz, they have a negative impact on the physical condition and health of their users. The brain (hypothalamus region), peripheral analyzers in the middle ear, vestibular and auditory analyzers are most affected. All this leads to mental disorders, including changes in conditioned reflex activity, behavioral reactions, states of short-term and long-term memory loss, changes in the bioelectrical activity of various brain structures. Research is still ongoing, but today it is reliably known that electromagnetic radiation has a harmful effect on the endocrine and immune systems, reproductive organs, and genetic apparatus. Research is still ongoing, but today it is reliably known that electromagnetic radiation has a harmful effect on the endocrine and immune systems, reproductive organs, and genetic apparatus.

Health. Harm from a mobile phone Prolonged use of a mobile phone can heat a person's brain by up to one degree. Prolonged use of a mobile phone can heat a person's brain by up to one degree. Wireless technologies WiFi data transmissions can have a negative effect on the cerebral cortex, and the lack of legislation in this area does not prevent the terrible consequences of the effects of mobile phones on the human body. Wireless WiFi data transmission technologies can have a negative impact on the cerebral cortex, and the lack of legislation in this area does not prevent the terrible consequences of the influence of mobile phones on the human body. Scientists have repeatedly said that constant exposure to radio frequency signals can negatively affect human health. Many phone owners complain of various side effects from cellular communications: frequent headaches, loss of memory and concentration, tension in the eardrums and sudden attacks of fatigue. Scientists have repeatedly said that constant exposure to radio frequency signals can negatively affect human health. Many phone owners complain of various side effects from cellular communications: frequent headaches, loss of memory and concentration, tension in the eardrums and sudden attacks of fatigue.

Health. Harm from a mobile phone According to studies conducted by European scientists, 3% of people suffer from so-called “hyperelectric sensitivity,” that is, the body of these people is extremely sensitive to electromagnetic fields. According to studies conducted by European scientists, 3% of people suffer from so-called “hyperelectric sensitivity,” that is, the body of these people is extremely sensitive to electromagnetic fields. Among possible diseases in connection with the use of mobile phones, scientists name childhood leukemia, eye cataracts, brain tumors, cardiovascular diseases, and disruption of the nervous system, which can lead to DNA damage. Among possible diseases in connection with the use of mobile phones, scientists name childhood leukemia, eye cataracts, brain tumors, cardiovascular diseases, and disruption of the nervous system, which can lead to DNA damage. Now in the world more than two billion people are users of cell phones, of which more than 500 million use GSM phones. At the same time, scientists note that analogue phones are much more harmful to human health than digital ones. Now in the world more than two billion people are users of cell phones, of which more than 500 million use GSM phones. At the same time, scientists note that analogue phones are much more harmful to human health than digital ones.

Conclusion For its part, the World Health Organization recommends caution when using wireless systems. In turn, the director of research of the International GSM Association (a trade organization of more than 700 mobile operators) Jack Rowley believes that scientists' fears are too exaggerated. For its part, the World Health Organization recommends caution when using wireless systems. In turn, Jack Rowley, director of research at the International GSM Association (a trade organization that includes more than 700 mobile operators), believes that scientists' concerns are too exaggerated. "Single studies don't say much. Claims that mobile phone technology is harmful are unfounded," Rowley said, adding that five studies found no evidence of an effect of WiFi on cancer. "Single studies don't say much. Claims that mobile phone technology is harmful are unfounded," Rowley said, adding that five studies found no evidence of an effect of WiFi on cancer.

List of used literature. 1.Big technical encyclopedia. Moscow 2007 1. Big technical encyclopedia. Moscow 2007 2. Great Encyclopedia of Cyril and Methodius Great Encyclopedia of Cyril and Methodius Internet resources: 3. Internet resources: Brilliant inventors. M.: Tera - book club 4. Brilliant inventors. M.: Tera - book club of the city.