UD 5 TELECOMMUNICATIONS eng 15 16

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(1)communication technologies (4r year). INDEX 0. INTRODUCTION I. WIRED COMMUNICATION NETWORKS I.0 CABLE TYPES I.1 TELEPHONE WIRE NETWORK I.2 ELECTRICAL WIRE NETWORK II. ELECTROMAGNETIC WAVES NETWORKS II.0 ELECTROMAGNETIC WAVES TYPES. II.1 GROUND WAVES NETWORK II.2 SATELLITE NETWORK. II.3 CELLULAR NETWORK.. III-Details of the use of waves in telecommunications III.1 Electromagnetic spectrum III.2 modulation of wave signals. III.3 multitransmission of several signals simultaneously.. Luis García Molina. I.E.S. Serra Perenxisa (Torrente). 1.

(2) I.1 telephone wire network How does the phone network manage a telephone call? Call centers perform all operations required to connect two telephones. – – –. we get the dial tone and tip the phone number. It directs the call to the device that matches the code given. If the line is busy signal send "communicating".. The mobile switching centers manage the same area. To communicate different areas are connected with the transit exchanges.. Transit exchange PBX. STP or coaxial wire. Area 1. PBX fax. Area 2. 11.

(3) How data can be transmitted? Data can be transmitted by different communication networks, using different transmission media (wire, e.m waves, papers...). For traditional media (paper, air ...). Imagery (Painting, writing, photography, video, other signals). Wire telephone network. Coaxial cable network Ground waves network. Satellite waves network. Reader device. writer device. Sounds (Voice, music, other sounds). Sounds (Voice, music, other sounds). Imagery (Painting, writing, photography, video, other signals). 2.

(4) wired communication networks. 3.

(5) I.0 WIRE TYPES: a) telephone wire. a-1.PHONE TWISTED PAIR WIRE 4 wires stranded in 2 pairs. It use RJ11 connections. USE: Telephone network (telephone and internet phone). www.kenable.co.uk. Imagen: www.conetica.es.

(6) I.0. b) computer network. ETHERNET TWISTED PAIR WIRE: UTP/STP (Unshielded/Shielded) 8 wires stranded in 4 pairs. It use RJ45 connections. USE: Internal networks of computers. quierouninformatico.blogspot.com. Imagen: www.tektel.com. Imagen: articulo.mercadolibre.com.ec. 5.

(7) I.0 c) coaxial wire Coaxial Cable. Two conductors separated by an insulating layer and a metal mesh. USE: Communications "cable“ networks: (Cable TV, cable internet, cable phone).. Imagen: www.tech-faq.com. Imagen: articulo.mercadolibre.com.ve. 6 Imgen: litramfg.com.

(8) I.0 d) fibre optics wire We not only can transmit information with pulses of electricity (electrons) but also with light rays (photons). The cable transmits "informative" light . It consists of a reflective tube through which light rays advance bouncing. Very fast, very powerful, very efficient… USE: Long-distance transmission networks.. Imagen: redesdecomputadores.com.br. Imagen: https://sites.google.com/site/stigestionydesarrollo/. Hilo de rasgado. 7 Imagen: http://fibraoptica.blog.tartanga.net/.

(9) I.0 e) electric wire The electrical wire can transmit information. At the moment we can use it as transmission wire inside a building.. 8 www.dtlux.com.

(10) ACTIVITIES 1.0 •. Search the wires inside your classroom, your school, your home. Say which type they are.. •. Complete the next table about the 5 types of wire.. 9.

(11) I.1 telephone wire network with optical fiber STP cable coaxial optical fiber (Waves e.m). International Central. International Central National Central. National Central. Transit exchange PBX. Transit exchange PBX. International Central. PBX. Transit exchange PBX. PBX. PBX STP or coaxial wire 12.

(12) Parallelly to the network of telephone wires, the companies have set up networks with coaxial "cable“: These communication networks use as main wire the coaxial, but also optical fiber cables for long distances. Through these networks we also have different communication services: - Cable telephone and fax - Cable television and radio - Cable Internet - (…). COAXIAL. Microfilter (only for STP). Or STP FIBER OPTIC. decoder. Modem. 14.

(13) activities. 1.1 •. Answer:. What types of cables and wave em use the telephone wire network? What services we offer the telephone wire network? What companies operate with network? Draw a diagram of this network.. 13.

(14) actividades.1.2 •. Answer: - What types of cables used the network "cable"? - Which services network offers us the "cable"? - What companies that operate cable do you know? -Draw a diagram of this network.. 15.

(15) I.2 electrical wire network The electrical wire can transmit information. At the moment we can use it as transmission wire inside a building.. Imagen: blog.k-tuin.com. 8.

(16) communication networks by electromagnetic waves. II.0 ELECTROMAGNETIC WAVES. II.1 LAND WAVES NETWORKS II.2-WAVE SATELLITE NETWORK. 16.

(17) use of e.m waves for communication The information (voice, image, computer data ....) in our devices such as televisions, computers, mobile phones…is managed encoded into electrical signals inside the gadgets. We want to transmit this information coded into electromagnetic waves such as microwave and radio waves. How do we translate the electrical signal to an electromagnetic energy wave carrier signal? They are translated by machines that are called modulators signal. The signal to be transmitted (modulating) gives way to an electromagnetic wave (carrier). How to transmit the carrier wave? Through transmitting antennas which they send the carrier wave into the atmosphere. How do you get the wave? Receiving antennas are responsible for “listening” them. Devices called demodulators are responsible for passing them back to electrical signals which can be seen or heard on a television or radio or mobile phone.. 18.

(18) devices for a em waves communication Here's the basic outline of a media that uses radio waves. original signal. final signal. handset Apparatus 1 (electrical signal). Carrier wave Modulator. Demodulator. transmitti ng antenna. receiving antenna. Apparatus 2 (electrical signal). Amplifier. 19.

(19) antennas The antennas are made of electrically conductive materials. They create a system of em waves governed by modulator, wich obeys the the electrical signals of the device. Antennas play with positive and negative electrical charges in a system called the dipole transmission.. First. Second. + -. + 20 Imagen: www.sharetechnote.com.

(20) the way of the em waves Ground Network. 1Terrestrial-waves:. >VLF (very low frequency) >LF (low frequency), >MF (medium frequency). 2-Atmospheric waves. Ground-atmospheric Ionosphere (a layer of the network atmosphere) > MF (medium frequency) >HF (high frequency) >VHF (very high frequency) >UHF (ultra high frequency). 3-Satellite waves. Satellite network >SHF (super high frequency) >EHF (extra high frequency) Note that here we have a classification of the waves according to its frequency. 21.

(21) II.1 terrestrial e.m waves networks In the network of terrestrial electromagnetic waves information is generated at a emissor center where waves are modulated and encrypted. Information is then transmitted through em energy waves that carry information travelling by air, space, emptiness, through objects ..... The waves generated are broadcast in all directions. When find an obstacle (such as a mountain) or just arrive so far that the curvature of earth cuts the “vision” of the emissor-receptor points, then a repeater center is used. It renews the signal. Finally information is received by receiving antennas, un-encrypted and de-modulted in order to be used.. Repeater center emissor center. receiver center. 22.

(22) II.2 satellite e.m waves networks In a satellite network a emissor center modulte powerful em waves that travel outside the atmosphere. The satellites are devices that have been thrown out of the atmosphere by rockets or shuttles and are orbiting around the Earth. They have receving and transmitting antennas and processors of information.. emissor center. receiver center. Exemples of satellite telecommunication networks are: Eutelsat network , Hispasat network, Astra network, Molniya network (Russia), Intelsat network, ÒIridioÓ network (Motorola)…. ORBITS Geo-stationary: 35,700 km above the Ecuador, the satellite takes 24 hours to circle the Earth, rotating at the same speed as the rotation of the planet (seems to be still). MEO orbyt: between 8,000 and 20,000 km high. Turn on the poles. LEO orbyt: between 500 and 2,000 km in height, are rolling over an hour and a half.. LEO. GEO MEO. 24.

(23) CHARACTERISTICS OF SATELLITE COMMUNICATION: -They are widely distributed devices. - They can transmit information to thousands of antennas at the same time. - They are independent of distance, convey to all places within their reach simultaneously. - However, anyone can receive the signal and so you have to hide in a key encryption. You need a decoder to view it. -For the long distance the signals travel, they have some retardation of the signal. OTHER USES OF SATELLITES: Weather: Eg Meteosat (Europe) Remote Sensing (Mapping, uses tax ....) SPOT (France), Landsat (USA), Soyuzkarta (Russia) Positioning: GPS Network (USA), Galileo Network (Europe), network Glonass (Russia) Astronomical observations: Hubble IRAS (Infrared), NOAA (Sun), COBE (background radiation) Military: Ej.Ekran, Gorizontz (Russia) Other: COSPAS-SARSAT (Rescue people) SATELLITE SPECTRUM BANDS. C. F en e l espectro SHF. F de enlace ascendente 4 GHz. F de enlace descendente 6 GHz. Ku. SHF. 12 GHz. 14 GHz. Ka. EHF. 19 GHz. 29 GHz. Banda. Comentarios La primera en ser usada, ya está saturada. En uso actualmente. En vías de saturarse. La lluvia produce interferencias. Nueva banda. Requiere todavía equipos caros. 23.

(24) GPS and Galileo satellite networks Global positioning systems are some systems for determining with a margin of error the latitude, longitude and height from any point on earth where we are located. This uses 3 satellites emits a signal that is picked up by GPS receivers. is based on the mathematical principle of triangulation. To calculate the position of a point will be necessary for the GPS receiver to determine the exact distance to the satellites. GPS receiver detects a radio signal transmitted by a satellite from orbit, it generates a virtual sphere whose center is the satellite and whose radius is equal to the distance between the satellite receiver. Using synchronized clocks, the receiver contains the time it takes for each signal to travel from the satellites to the point where it is located and calculates the distance (knowing that the signal travels at approximately the speed of light). To correct the effects of all variables, the receiver uses complex mathematical models stored in your memory, supplemented with additional information after receiving the satellite also. The GPS system (fleet of 24 satellites) is American and the Galileo system (30 satellites) is the European equivalent. 27.

(25) Imagen: enciende.cosce.org. 28.

(26) actividades.2.2 •. Answer: - What are 3 types of orbits can have satellites? -Half Satellites are widespread. What does it mean? - What do you call the 3-band spectrum in which transmitted? - What uses are the satellites? I gave an example of each. - What do you call the main networks of satellites? - What telecommunications services offered by networks such as Hispasat satellites?. 29.

(27) II.3. mobile phone network Mobile telephony network transmit information via electromagnetic waves (UHF, VHF) in a specific network. Although it started as analog telephony from mobile terminals for voice only, it has become a internet newtork for multimedia data (voice, text, image, video, music) used in ultra-small laptops.. The main characteristic of the mobile network is that it divides the region into small areas called cells each with one antenna (base station). Why the area is divided into cells? With television or radio to transmit data are unique for ALL terminals. If there are 100 channels to transmit, the solution is to multiplex systems we have studied (different frequencies) with a single antenna to all receivers What about mobile? We have several thousands of conversations and / or transfers of personal data intended each to a particular terminal. The multiplex system does not give more of themselves. No more frequencies to use! Imagine that an antenna can process 100 calls. Valencia are insufficient for all right? Solution: Play the system on small plots of land. Now each antenna of each plot can process 100 31 calls necessary. (100 x 10 area = 1000 calls).

(28) tandléphone modvil: UMTS NETWORK The phone uses 4G technology (UMTSUniversal Mobile Telecommunications System ) with the CDMA protocol. The UMTS network is integrated into the 2nd generation GSM and consists of the following items.. Telephone company. Internet (Tv, video, radio ..). U-MSC from another company. U-MSC of a company. RNC. NODE =. RNC. =MS 4G. RNC. RNC. U-MSC: mobile switching center RNC: Radio network controller. MS: mobile station. 32.

(29) Details of the use of em waves in telecommunications. III.1 Electromagnetic Spectrum III.2 modulation wave signal transport. III.3 transmission of several signals simultaneously.. 33.

(30) What the electromagnetic waves are The electromagnetic waves are energy-matter waves originated when a electric charged particle moves. Normally electrons move around the atom in stable areas. These states have a lot of stored energy. Eventually, an electron moves from an area of high energy nearer to the core to an area of lower energy, farther from the core. Then, the electromagnetic surplus energy is ejected. Here we have a pulse of energy. When repeated in cycles we have an electromagentic regular wave, such as waves in water surface when a stone falls.. 17. Different atoms can make pulses with different energy strenghness and different frequency of the pulses..

(31) What the electromagnetic waves are Thus, an electromagnetic wave is characterized by two items: -FREQUENCY: the number of pulses per second. -AMPLITUDE: The strenghtness of the pulses.. V A = wave amplitude Is the maximum value of the signal.. Frequency F = 1 / T (the inverse of period). T = wave period. t. Is the time it takes to produce a cycle.. 38.

(32) electromagnetic spectrum There are many different types of waves of electromagnetic energy. The waves are defined by their pulse or frequency. The more frequently they are occurring faster.. Electromagnetic energy wave with HIGH FREQUENCY. Electromagnetic energy wavewith less frequency 34.

(33) electromagnetic spectrum. This table represents the electromagnetic spectrum, ie, sorting by frequency (number of vibrations per second) of the main types of electromagnetic waves used in telecommunications.. Altes frequencies. Low frequencies. HIGH FREQUENCY. LOW FREQUENCY. usades frequencies d'altes ones in altres aparells. DANYINES. es usades frequencies in Telecomunicacions * Wifi: radio: from 2.4 to 2.48 GHz. 35.

(34) divition of the spectrum into the broadcasters This applies to radio, TV, satellite, cable ... For example, the radio uses electromagnetic waves with a frequency between 10 and 100 MHz In Spain in particular, looking at the dial of our radios we can see that they emit between 87.50 MHz, and 108 MHz. Broadcasters (radio broadcast companies) share these frequencies. In each area have a dial. Eg in the area of Valencia: Issuer "Top 40": 94.2 MHz to 94.3 MHz to "Radio Nacional of Spain" from 95.1 MHz to 95.2 MHz Issuer "Europa FM" 103.2 to 103.3 MHz for 108 MHz 95.2 MHz 95.1 MHz 94.3 MHz 94.2 MHz. National Radio other The 40 ppales other. 88.5 MHz. 36.

(35) actividades.3.1 •. Answer: - What are electromagnetic waves made? - When do they occur? - Why are pulsating? - What is the frequency (f) of an electromagnetic wave? - What is the electromagnetic wave frequency of the light we see by the eyes? - And those that are used in television?. •. Draw a table where electromagnetic waves are classified according to their frequency spectrum (em) and its use in telecommunications. 37.

(36) modulation of signal into em transportation waves 1 - distinguish data with different wave amplitudes. (Amplitude modulation, AM) a) step1: Create a "dictionary" for the data with the AMPLITUDE. =C. =S. =A. b) step 2: transmission: ie. Amplitude modulation transmission for the word “CASAS” 1st 5th 3rd 4th 2nd original signal final signal. "HOMES" handset Apparatus 1 (electrical signal). Modulator. “S". "A". "S". "A". “C" Demodulator. AM Amplifier. Apparatu s2 (electrica l signal).

(37) modulation of the signal into em transportation waves 2 - distinguish data according to different wave frequencies. (Frequency modulation, FM) a) First step: Create a "dictionary" to code the data according to the frencuencia signs.. =C. =S. =A. b) Second step: transmission: ie. wave frequency modulation for transmitting the word “CASAS” original signal. 5th. 4th. 3rd. 2nd. 1st final signal. “CASAS". Apparatus 1 (electrical signal). handset. Modulator FM. “S". "A". "S". "A". “C" Demodulator. Amplifier. Apparatu 40 s2 (electrica l signal).

(38) actividades.3.2 •. Answer: - What are the two ways to encode (modulate) the data in em waves? - What is the difference between analog and digital coding ? -Explains how is coding in amplitude. -Explains how is coding in frequency.. 41.

(39) III.3 transmission of several chanels on the same wave transmission 1-distinguish messages by different wave amplitudes assignation for each channel. (MULTIPLEX SYSTEM BY AMPLITUDE DIVISION) In this system the first channel is at large amplitudes, the other channel in small "YES" Large amplitudes. "I". "S". YES. Small amplitudes "MINE". MINE "M". "YE S". "O". 2 - distinguish messages by different wave frequencies assignation for each channel. (MULTIPLEX SYSTEM BY FREQUENCY DIVISION) In this system the first frequency channel is long, the other channel at short ones. Wavelength. Shorter times. YES MINE "M". "I". "S". "O". "I". "YES". Frequency "MINE" 43 long.

(40) III.3 transmission of several chanels on the same wave transmission 3 - distinguish messages by different time interval assignations. (MULTIPLEX SYSTEM BY TIME DIVISION) We assigne different time intervals that alternate.. 1st period "YES". YES MINE. "S". "I". 1st time interval (1 second). "M". "I". "O". 2nd period. "MINE". 2 nd time interval (1 second). 44.

(41) actividades.3.3 •. Answer: - What are the three ways of transmitting multiple signals (multiplex transmission) while in an electromagnetic wave? - Explains how multiple transmission amplitude. - Explains how multiple frequency transmission. - Explain how division multiple transmission time.. 45.

(42) en fin, comunícate también con el que tienes al lado a la antigua usanza, mirando y hablando. 46.

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