Details Title: BMA372 chapter1 Description: chapter 1 Total Flash Cards: 27 Created: 09/02/2009 15:23:32		New Users: To study from this flashcard set, or to create your own your own study flash cards, REGISTER HERE. Existing Users: CLICK HERE. Additional Computer Science Flashcards
Cards in this set: Term basic communications model Definition encoder>transmitter>channel>receiver>decoder Term telecommunications Definition transfer of data over distances via electrical, electromagnetic, or photonic means Term data communications Definition machine-to-machine communication Term channel Definition virtual connection between sender and receiver Term circuit Definition physical connection between two nodes Term network Definition consists of a pattern of circuits enabling communication among more than two nodes Term path Definition route taken by a specific signal Term simple network Definition one path to get to a specific node Term complex network Definition multiple pathes can be taken to get to a specific node Term Data transfer involves: Definition Data terminating equipment (DTE) = computer/terminal Data communications equipment (DCE)= modem Term modes of transmission Definition simplex, half duplex, full duplex Term simplex Definition one way communication Term half-duplex Definition bi-directional capability through circuit reversal (walkie-talkie, CB radio) Term full-duplex Definition simultaneos bi-directional communication; foward or reverse channels (telephone) Term serial circuit Definition bits of a character follow each other down a single wire/cable Term parallel circuit Definition bits are sent simultaneously over seperate wires Term bandwidth Definition information carrying capacity of a circuit, channel or medium Term analog is measured in Definition HZ Term digital bandwidth is measured in Definition bits Term bandwidth can be reduced if ____ Definition noise is present Term bandwidth can be increased by ___ Definition compression Term noise is caused by ___ Definition long lines, long connections Term an analog environment is susceptible to three things... Definition attenuation signal noise on the medium amplification of the signal + noise Term compression Definition reducing the amount of data by not sending redundant data -reduces the amount of storage -less bandwidth required for transmission Term redundancy, once recognized, can be recognized in two ways... Definition -using a dictionary: compression rate up to 2-1 -recreating the file: 250-1 Term NOISE: two types of signals Definition accoustic signals: noise appears as competing accoustic signals electrical signals: noise appears as static or electromagnetic pulses Term signal-to-noise ratio Definition relationship between signal and noise