W10L1 Communicating in Binary Flashcards
Physical Layer
Deals with bits Defines what a 1 and 0 represent Defines what cables look like Best effort Point to point or multiport Forward error correction
Data Link
Frames - message construction from 1 and 0
Delimiting messages - start and stop sequence
Error detection (and sometimes correction)
Flow control - how fast something should go
Addressing
Dial up modems, ethernet
Simplex
Broadcast media
Stations can only transmit in one direction only send/receive
Half-Duplex
coax, wifi
Stations can transmit and receive on the same medium, but can’t do both at the same time
Full-Duplex
switched, ethernet
Station can transmit and receive on the same medium at the same time
What is an issue between independent clocks?
They can drift with time
Data is usually sent in?
8 bit bytes
How can we send more bits at once?
Send different voltages
Voltage translates to
Binary translates to
What is Idle state?
Sending 1 continuously
Start message
Send a 0 bit
Stop message
Send a 1 bit
Serial Protocol
Keeps the clock in line through making adherence to rules about sending data. When end bit then start bit are seen the clocks realign
Noise Immunity
Easily distinguish 0s and 1s
Timing Immunity
Look at the middle of each interval rather than at the start of each bit. So timer restarts on each character
