Term
Telecom Basic Concepts
Communications > Telecommunications > Data Communications |
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Definition
Communications
Telecommunications (TC)- Transmission of data or info over a distance between humans or machines.
Data Communictation (DC)- Specialized transmission of data between machines |
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Term
| Medium and Channel (Logical Circuit) |
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Definition
Medium: The carrier of signals between senders and receivers
Channel: A logical connection over a physical circuit to support a single conversation |
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Definition
| Two-point segment of an end-to-end circuit. A circuit can have one or more links. |
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Definition
Dedicated
Switched
Virtual |
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Definition
| Directly connects devices across a circuit w/out using a switch |
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Definition
Circuit may be temporarily established at the request of one or more of the the connected stations.
Connected through the network on a flexible basis through one or more intermediate switching devices. |
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Definition
Communications arrangement in which data from a source user may be passed to a destination user over various real circuit configurations during a single period of communication.
Logical vs. physical connection |
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Term
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Definition
Bandwidth
*Hertz
*Baud
*Bps
Narrowband (baseband)
Wideband (broadband) |
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Definition
Continuous flow (easy to recover)
Widely available
The more info the more bandwidth needed
Noise
Insecure |
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Definition
Compression
Secure
Higher quality
High cost
Upgradeable/scaleable
Lower noise |
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Term
| Converting Digital to Analog |
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Definition
Modem - Modulator/Demodulator - Delivers digital info from one digital device to another over an analog channel
Modulates outgoing signal to analog signal and then demodulates analog signal back to digital signal |
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Definition
| Converts analog signal to digital signal (i.e., analog voice signal to digital device |
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Definition
| Aggregating multiple signals in one path. |
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Definition
Frequency Division Multiplexing
Getting two or more channels from one transmission medium (simultaneously) by
sssigning a separate portion of the available frequency spectrum to each of the individual channels. |
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Definition
| Two or more channels from a given bit stream by interleaving pulses: one pulse from each followed by pulse from next and so on. |
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