Handout 1 Flashcards
act of transmitting and exchanging information between people, people and objects, and objects and objects through various media and actions
communication
has ultimate purpose of helping people communicate more efficiently and create better lives from it
communication
largest computer network in the world
internet
largest computer network in the world
internet
meaning of ARPAnet
Advanced Research Projects Agency Network
when was ARPAnet born
1989
refers to communication between terminal devices through a computer network
network communication
uses of signal
means of communication
communicated information
electronic transmitted information
this refers to a sign or indication that conveys information about something or that tells someone to do something
means of communication
refers to an event or act, which shows that something exists or that gives information about something
communicated information
refers to a detectable physical quantity or impulse (as a voltage, current, or magnetic field strength) by which messages or information can be transmitted via telegraphy, telephony, radio, radar, or television
electronic transmitted information
examples of signals
electrical signals
acoustic signals
video signals
biological signals
noise
signal that refers to voltages and currents in a circuit
electrical signals
signal that refers to audio or speech signals
acoustic signals
signal that refer to intensity variations in an image
video signals
signal that is interference/unwanted and undesired form of signal
noise
refer to disturbances in that energy to travel through a medium from one location to another
waves
refers to the horizontal distance of a wave from a point to the corresponding point on the next wave
wavelength
wavelength is measure in
meters (m)
refers to a vertical distance from a given point on the wave from the horizontal axis, it is the height above and below the x-axis
amplitude
amplitude is measured in
volts, amperes, or watts
it describes the position of the waveform relative to time zero; it relative to some fixed reference point or another sine wave.
phase
refers to the number of waves made per second or as cycles per second, it is the reciprocal of the period to complete one (1) wave cycle. The unit for frequency is in Hertz (Hz); 1 Hz means 1 cycle per second (cps).
frequency
refers to the amount of time (expressed in seconds) required to complete one (1) full cycle
period
general categories of waves
analog
digital
a wave in which both the amplitude and time continuously vary over their respective intervals that results in a wavy characteristic. Examples of this wave include the human voice and music.
analog wave
a wave with several discrete (jumpy) states, such as high or low, and on or off. It has fixed amplitude, but its pulse width and frequency can be changed. An example of this signal is the data stored in the memory of a computer in the form of Os and 1s.
digital wave