SAOBRAAJNI FAKULTET

Univerzitet u Istonom SarajevuSAOBRAAJNI FAKULTET DOBOJ

SEMINARSKI RAD IZ ENGLESKOG JEZIKA NA TEMU:

INTRODUCTION TO TELECOMMUNICATIONSANALOG TRANSMISSION(prevod,transkripcija,nepoznate rijei)

MENTOR: Mr Tanja Petrovi STUDENT: Aleksandar Lazi 500/12

Doboj, februar 2014. godine

1. INTRODUCTION TO TELECOMMUNICATIONS

If we attempted to define Telecommunications, it would probably be Communications by Electronic Means. This communications could be voice, computer data or paper records (telegram, telex, etc.)Twenty-five years ago we didnt hear the word Telecommunications and now its one of the most important parts of any business. Although the term telecommunications may be new, the ideas have been with us a long time. Telecommunications used to be concerned with whether or not your phone rang when a customer called or did you even get a phone on your desk. Maybe you got to the big time by having a telephone with multiple buttons and lights (then we all learned what please hold means). Now we talk about Telecommunications as a field of specialization, a growth industry and finally we recognize it as a business resource.Have you ever heard someone say Im in business for myself! If you stop and think about that statement its impossible unless you sell a product or service to yourself and buy materials from yourself. Business, or the flow of goods and services doesnt just happen, it requires communications between two or more people. In response to the communications the goods and services will flow.Here are some ways in which telecommunications can affect your life: Airlines reservation systems allow customers to call in, book flights, arrange seating, meals and even rent cars at their final destination. These reservations can be made through telephone calls or via direct personal computer connections Large stock traders such as mutual funds use automatic computer programs to buy and sell stock. These programs track the stock prices and by using automatic margins know when to buy up and sell the stock. Some of the wild fluctuations in the 1987 market were blamed on these types of transactions. Mail order catalog services accept orders using 800 type toll free telephone numbers. At the telephone centers the orders are accepted and entered directly into computers that may be miles away.

1.1. NEPOZNATE RIJEI

means /minz/ - nain, putflow of goods /flo v gdz/ - protok robeto book flights /tu bk flajts/ - rezervisati karte za letovefluctuation /flktuen/ - fluktuacija; kolebanje, mijenjanje cijenablame on /blem n/ - okrivitimutual funds /mjutwl fndz/ - investicioni fondovi

1.2. PREVOD

UVOD U TELEKOMUNIKACIJE

Ako bi pokuali da definiemo telekomunikacije , verovatno bi definicija bila komunikacije na elektronski nain. Te komunikacije mogu biti glas, kompjuterski podaci ili zapisi na papiru ( telegram, teleks, itd. )Prije dvadeset i pet godina nismo uli za rije telekomunikacije, a sada su telekomunikacije jedan od najvanijih dijelova svakog biznisa. Iako je termin telekomunikacije moda novi, ideje telekomunikacija postoje ve dugo vremena. Telekomunikacije se koriste da se brinu za to da li je va telefon zazvonio kada je kupac nazvao, ili ak da li ste dobili telefon na vaem stolu. Moda ste doli do velikog vremena tako to imate telefon sa vie tastera i svijetla (tada smo svi nauili ta " molim zadrite " znai). Sada govorimo o telekomunikacijama kao polju specijalizacije, rastuoj industriji i konano smo je prepoznali kao poslovni resurs.Da li ste ikada uli da neko kae: "Ja sam u biznisu za sebe! " Ako stanete i razmislite o toj izjavi, ona je nemoguca, osim ako prodajete proizvod ili uslugu sebi i kupujete vae materijale od sebe. Biznis, odnosno protok robe i usluga se ne deava samo tako , on zahtijeva komunikaciju izmeu dvije ili vie osoba. Kao odgovor na komunikacije, robe i usluge e tei.Evo nekoliko naina na koji telekomunikacije mogu uticati na va ivot:- Sistemi rezervacija aviokompanija omogucavaju korisnicima da pozovu , rezerviu karte za letove, organizuju raspored sjedita, obroke, pa ak i iznajme automobile u svom konanom odreditu. Ove rezervacije se mogu obaviti putem telefonskih poziva ili putem direktnih linih kompjuterskih konekcija.- Veliki trgovci akcija , kao to su investicioni fondovi koriste automatske kompjuterske programe da kupuju i prodaju akcije . Ovi programi prate cijene akcija i pomocu automatskih margina znaju kada da kupuju i prodaju akcije . Ove vrste transakcija su okrivljene za neke od divljih fluktuacija na tritu 1987. godine.- Potanski servisi za naruivanje kataloga primaju narudbe koristeci 800 vrsta besplatnih telefonskih brojeva. Narudbe se primaju u telefonskim centrima i unose direktno u kompjutere koju mogu biti miljama udaljeni.

2. ANALOG TRANSMISSION

Using analog transmission techniques, such as those found on the existening telephone networks has presented a problem as newer services are brought into the network. This section will explore some of those problems and contrast them to the advantages of providing digital services.To begin, we must understand that for most of its first one hundred years the worldwide telephone network was concerned with only carrying voices. This meant that the network was built to connect telephones across the world and carry a voice between two points. Although the network architecture worked well for voice transmission, the newer services like computer data, fascimile and video transmission have been constrained by the analog voice network design.

Figure 1.1 Analog Telephone Services

Looking at Figure 1.1 (above), we can see how the existing telephone network is used to provide a variety of office communications. This drawing shows one key problem with the telephone network. Each of the various lines for telephone or data communications requires a separate line of circuit. The telephone systems have tie-lines and trunks to the outside world, computers use high speed analog or digital circuits and video systems use high speed or broadband circuits. Each type of circuit has it own problems related to installation, support and maintenance. In many cases the telephone companies had different service organizations to handle each service creating confusion for the customers.Telephone companies also found problems with voice quality as it was transmitted across long distances. Analog transmission and amplification had limits, since noise was usually amplified along with the voice signal. This meant there was a limit to how many times an analog signal could be amplified and still be recognized.Analog transmission systems were also difficult to test and service. Usually, the telephone company technicians had to take an analog transmission system out of service before doing any testing or maintenance.In addition to the analog transmission problems, telephone companies were faced with increased pressure from customers for more services and greater bandwidths. Growth in telephone usage in the 1950s and 1960s also added to the telephone companies requirements to provide more voice circuits globally.

2.1. NEPOZNATE RIJEI

transmission / trnsmn/ - prenosconstrained / knstrend / - ogranienbroadband /brdbnd/ - irokopojasniamplification /mplfken/ - pojaanjebandwidth /bndwd/ - propusni opseg

2.2. PREVOD

ANALOGNI PRENOS

Koritenje analognih tehnika prenosa, kao to su one koje se nalaze na postojeim telefonskim mreama se predstavilo kao problem poto su nove usluge uvedene u mree. Ovaj odjeljak ce istraiti neke od tih problema i uporediti ih sa prednostima pruanja digitalnih usluga .Za poetak, moramo shvatiti da je za veinu od prvih sto godina svjetska telefonska mrea bila usmjerena samo na prenoenje glasova. To je znailo da je mrea izgraena za povezivanje telefona irom svijeta i za prijenos glasa izmeu dvije take. Iako je mrena arhitektura radila dobro za prijenos glasa , novije usluge kao to su raunarski podaci , faks i prenos video signala su bile ograniene dizajnom za analognu glasovnu mreu.

Slika 1.1 Analogne telefonske usluge

Gledajuci sliku 1.1 (gore) , moemo videti kako se postojeca telefonska mrea koristi za pruanje razliitih poslovnih komunikacija . Ovaj crte prikazuje jedan kljuni problem telefonske mree. Svaka od raznih linija za telefonsku komunikaciju ili komunikaciju podataka zahtijeva posebnu liniju ili kolo. Telefonski sistemi imaju povezane linije i linije za spoljni svijet, raunari koriste analogna ili digitalna kola sa velikim brzinama i video sistemi koriste kola sa velikim brzinama ili irokopojasna kola. Svaka vrsta kola ima svoje probleme vezane za instalaciju, podrku i odravanje. U mnogim sluajevima telefonske kompanije imaju razliite uslune organizacije za rukovanje svakom uslugom koja stvara konfuziju za kupce.Telefonske kompanije takoe imaju problema sa kvalitetom zvuka jer se zvuk prenosi preko velikih razdaljina . Analogni prenos i pojaanje imali su ogranienja, jer se um obino pojaavao zajedno sa signalom glasa. To je znailo da postoji ogranienje koliko puta analogni signal moe biti pojaan a da se i dalje moe prepoznati.Analogni sistemi prenosa bili su takoe teki za testiranje i odravanje. Obino, tehniari telefonske kompanije su morali staviti van funkcije analogni sistem prenosa prije nego to bilo ta testiraju ili poprave.Pored problema analognog prenosa, telefonske kompanije su bile suoene sa povecanim pritiskom kupaca za vie usluga i vecim propusnim opsegom. Rast upotrebe telefona u pedesetim i ezdesetim godinama 20. vijeka je takoe dao zadatak telefonskim kompanijama da obezbijede golobalno vie glasovnih kola.

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