Level 52 Level 54
Level 53

Data Communications & Computer Networks


52 words 0 ignored

Ready to learn       Ready to review

Ignore words

Check the boxes below to ignore/unignore words, then click save at the bottom. Ignored words will never appear in any learning session.

All None

Ignore?
Digitization
The process of converting an analog signal or data into digital data.
data
Business __________ theft involves stealing proprietary business INFORMATION such as research for a new drug or a list of customers that competitors are eager to acquire.
Signals
The electric or electromagnetic encoding of data. Signals are used to transmit data.
Analog Data
Data that is represented by continuous waveforms, which can be at an infinite number of points between some given minimum and maximum.
Analog Signal
Signals that are represented by continuous waveforms, which can be at an infinite number of points between some given minimum and maximum.
Noise
Unwanted electrical or electromagnetic energy that degrades the quality of signals and data.
Digital Data
Entities that are represented by discrete waveforms, rather than continuous waveforms. Between a minimum value X and a maximum value Y, the discrete waveform takes on only a finite number of values.
Digital Signals
The electric or eletromagnetic encoding of data that is represented by discrete waveforms rather than continuous waveforms. Between a minimum value X and a maximum value Y, the discrete waveform takes on only a finite number of values.
Amplitude
The height of the wave, above or below a given reference point.
Frequency
The number of times a signal makes a complete cycle within a given time frame.
Period
The length, or time interval of one cycle.
Hertz (Hz)
Cycles per second, or frequency.
Spectrum
The range of frequencies that a signal spans from minimum to maximum.
Bandwidth
A measure for the speed (amount of data) you can send through an Internet connection. The more __________, the faster the connection
Effective Bandwidth
The bandwidth of a signal after noise and other factors such as environmental conditions have been applied.
Phase
Single step in a lifecycle
Attenuation
The continuous loss of strength (power) that a signal experiences as it travels through a medium.
Decibel (dB)
A relative measure of signal loss or gain that is used to measure the strength of a signal.
Amplification
The gain of the signal strength (power) of an analog signal.
Modulation
The process of converting digital data into an analog signal.
Non-return to Zero-Level (NRZ-L) Code
A digital encoding technique that assigns a binary 1 or binary 0 to a low or high voltage level.
Non-return to Zero inverted (NRZI) Code
A digital encoding technique that assigns a binary 1 or a binary 0 by the voltage change or lack of voltage change at the beginning of the bit.
Manchester Code
A digital encoding scheme that ensures that each bit has a signal change in the middle of the bit and thus solves the synchronization problem.
Differential Manchester Code
A digital encoding technique that transmits a binary 0 when there is a voltage change at the beginning of the bit frame, and transmits a binary 1 when there is no voltage change at…
Self-Clocking
A characteristic of a signal in which the signal changes at a regular pattern, which allows the receiver to stay synchronized with the signal's incoming bit stream.
Baud Rate
The number of signal elements or signal level changes per second.
Data Rate
The speed at which data is transmitted between two devices; often refered to in bits per second (bps).
Bits Per Second (bps)
The number of bits that are transmitted across a medium in a given second.
Bipolar-AMI
A digital encoding technique with no DC-component; logic 9s are denoted by zero voltage, and logic 1s are denoted by alernating positive and negative voltages.
4B/5B
A digital encoding scheme that takes 4 bits of data, converts the 4 bits in to a unique 5-bit sequence, and encodes the 5 bits using NRZI.
Shift Keying
A technique in which digital data is converted to an analog signal for transmission over a telephone line.
Amplitude Shift Keying
A modulation technique for endcoding digital data using various amplitude levels of an analog signal.
Frequency Shift Keying
A modulation technique for encoding digital data using various frequencies of an analog signal.
Intermodulation Distortion
The noise that occurs when the frequencies of two or more signals mix together and create new frequencies.
Phase Shift Keying
A modulation technique for encoding digital data using various phases of an analog signal.
Quadrature Phase Shift Keying
A modulation technique that incorporates four different phase angles, each of which represents 2 bits.
Quadrature Amplitude Modulation
A modulation technique that incorporates multiple phase angles with multiple amplitude levels to produce numerous combinations, creating a bps that is greather than the baud rate.
Pulse Code Modulation (PCM)
An encoding technique that converts analog data to a digital signal. Also known as digitization.
Codec
A device that accepts analog data and converts it into digital signals. This process is also known as digitization.
Pulse Amplitude Modulation (PAM)
Tracking an analog waveform and converting it to pulses that represent the wave's height above or below a threshold; part of pulse code modulation.
Quantization Levels
The divisions of the y-axis that are used in pulse code modulation.
Quantization Error
The error that is introduced during digitization. Also known as quantization noise.
Quantization Noise
The noise that occurs during digitization.
Sampling Rate
The rate at which an analog input is sampled in order to convert it to a digital stream of 1's and 0's.
Delta Modulation
A method of converting analog data to a digital signal in which the incoming analog signal is tracked and a binary 1 or 0 is transmitted when the analog signal rises or falls.
Slope Overload Noise
The noise that results during analog-to-digital conversion when the analog waveform rises or drops too quickly and the hardware tracking it is not able to keep up with the change.
Data Code
The set of all textual character or symbols and their corresponding binary patterns.
Nyquist's Theorem
A theorem that states that the data transfer rate of a signal is a function of the frequency of the signal and the number of signal levels.
Shannon's Theorem
A theorem that demonstrates that the data rate of a signal is proportional to the frequency of the signal and its power level, and inversely proportional to the singal's noise level.
Extended Binary Coded Decimal Interchange Code (EBCDIC)
An 8-bit code allowing 256 possible combinations of textual symbols (2 to the 8th power = 256).
American Standard Code for Information Interchange (ASCII)
A 7-bit code that is used to represent all the printable characters on a keyboard plus many non-printable control characters.
unicode
127 characters