Where transmission of bits across the network occurs and includes physical and electrical network characteristics
Physical Layer
If it changes during the clock cycle, then a 1 is represented (otherwise, 0 is represented)
Transition Modulation
Cables are part of __________ layer?
Physical layer
Layer 1 devices view networks from a physical topology perspective. Which is also true about layer 1?
A. Can be transmitted asynchronously only
B. Can be transmitted asynchronously and synchronously
C. Can be transmitted synchronously only
D. Can be transmitted asynchronously and synchronously
B. Can be transmitted asynchronously and synchronously
Uses start and stop bits to indicate when transmissions occur from the sender to the receiver
Asynchronous
Uses a reference clock to coordinate the transmissions by both sender and receiver
Synchronous
From the following example, what transmission type is this?
- Communication happens out of synch or out of time (example - voicemail)
Asynchronous
From the following example, what transmission type is this?
- Same place at the same time (example - talking on the phone)
Synchronous
Divides bandwidth into separate channels
Broadband
Uses all available frequencies on a medium (cable) to transmit data
Baseband
Each session takes a turn, using time slots, to share the medium between all users
Time-Division Multiplexing
What is TDM?
Time-Division Multiplexing
What is this an example of?
- Each person in a household wants to watch TV but there is only one TV. Each person gets a time slot to put on whatever show they want to watch during that time slot.
Time-Division Multiplexing
Dynamically allocates the time slots on an as-needed basis
Statistical Time-Division Multiplexing
What is StatTDM?
Statistical Time-Division Multiplexing
What is this an example of?
- As long as no-one is using TV, I can get on whenever.
Statistical Time-Division Multiplexing
Divides the medium into channels based on frequencies and each session is transmitted over a different channel
Frequency-Division Multiplexing
What is FDM?
Frequency-Division Multiplexing
Layer 1 devices are essentially repeaters, passing along whatever is received
“Dumb devices”
Which of the following is NOT a dumb device?
A. Router
B. Hubs
C. Access Points
D. Media Converters
A. Router
