MindMap Gallery Computer network physical layer mind map
Mind map of the physical layer of computer networks. The physical layer mainly solves how to transmit data bit streams on transmission media connecting various computers. The main task is to determine the characteristics (defining standards) related to the transmission media interface.
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This is a mind map about bacteria, and its main contents include: overview, morphology, types, structure, reproduction, distribution, application, and expansion. The summary is comprehensive and meticulous, suitable as review materials.
This is a mind map about plant asexual reproduction, and its main contents include: concept, spore reproduction, vegetative reproduction, tissue culture, and buds. The summary is comprehensive and meticulous, suitable as review materials.
This is a mind map about the reproductive development of animals, and its main contents include: insects, frogs, birds, sexual reproduction, and asexual reproduction. The summary is comprehensive and meticulous, suitable as review materials.
physical layer
Basic concepts of the physical layer
Solve the problem
Mainly solves how to transmit data bit streams on transmission media connected to various computers
main mission
Determine characteristics related to transport media interfaces (define standards)
Physical layer interface characteristics
Mechanical properties
Electrical characteristics
Features
process characteristics
Media and equipment required for the physical layer
Oriented transmission media
twisted pair
Shielded twisted pair
Unshielded twisted pair
coaxial cable
optical fiber
single mode fiber
multimode optical fiber
unguided transmission media
radio waves
infrared
visible light
microwave
Satellite Communications
Terrestrial microwave relay communication
physical device layer
Repeater
hub
communication
the term
Code element, rate, baud, bandwidth, data
signal, channel, source, sink
three communication methods
simplex communication
half duplex communication
Full duplex communication
Two transmission methods
serial transmission
Parallel transfer
Two communication sequences
synchronous transmission
asynchronous transfer
Coding and modulation
Signal
Digital signal
analog signal
coding
Digital data encoded into digital signal Encoding analog signals into digital signals
return to zero encoding
non-return-to-zero encoding
Reverse does not return to zero
Manchester encoding
Differential Manchester encoding
modulation
basic modulation
AM
FM
Phase Modulation PM
Mixed modulation
Channel limit capacity
Factors affecting signal distortion
code element transmission rate
Signal transmission distance
noise disturbance
Transmission media quality
two theorems
Nye's criterion
Shannon's theorem
Channel multiplexing technology
frequency division multiplexing
time division multiplexing
Wavelength division multiplexing
code division multiplexing
Data exchange method
circuit switching
message exchange
packet switching
store and forward switching