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Questions about communication link and speed
?
Why was Internet access slower from SAC than from ERC? Packets from both reach the Internet in two “hops.” Where must the bottleneck be?
WelchHall
ERCSAC
WelchHall
ERCSAC100 mb/s 1 gb/s
1 gb/s
How does my link differ from those between the buildings on our campus and between the campus and the Internet?
15-20 mb/sMy house
Why is it even slower from my home?
S/R S/RCopper vs. fiber optic cable
Questions CPU, memory and network utilization
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http://bit.ly/14xEeUs
Watch a little and vary image quality.
Which looks better?
Which requires a faster communication link? Why?
Which requires a faster CPU? Why?
What is this?
Which image is made of more dots?
Which image has smaller dots?
Baseline – only the operating system is running
Viewing low resolution video
Why did memory utilization increase when the video was playing?Why did CPU load increase when the video was playing?
10110
11101
101001101010010101010010101101110101001010101010100101010101010100101010010101010100100101010101001010101
Buffer bits in memory for smooth audio and video output
StorageOutput
Memory
What else is in memory while the video is playing?
10011
101001101010010101010010101101110101001010101010100101010101010100101010010101010100100101010101001010101
Memory
Operating system
Video player program
Viewing high resolution
Why did memory utilization increase when the resolution increased?Why did CPU load increase when the resolution increased?
Increased quality from 144p to 1080p
Network utilization
Why did network utilization increase when the resolution increased?Why does network utilization vary rather than remain constant?
Questions about embedded computers
?
Some input/output devices people use
What about input/output devices computers use?
What are its input/output devices for interaction with people?
There a computer embedded in your microwave oven
What are its input/output devices for interaction with devices?
KeypadDisplayBuzzer
Switch to start cooking unitSwitch to turn light on/offSwitch to start rotationInternal timerCooking power level adjustmentTemperature sensor
Does the oven have memory?Is there a program in its memory? What does it do?
Simplified microwave oven program
When the user hits start1. Read the cooking time2. Start the oven3. Start the dish rotating4. Turn the light on5. When the cooking time has elapsed
1. Stop the oven2. Stop the rotating dish3. Turn the light off4. Sound the buzzer5. Stop
Do you ever change the program in your microwave oven? Maybe use it as a word processor or play games on it?
No
It comes from the factory with the cooking control program in memory.
Since you never change the program, it is in a special kind of memory called read-only memory
Since you never change the program, the oven does not need a storage device.
Questions about the Internet of smart things
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This is a “dumb” TV set and it is not connected to the Internet
Can I connect it to the Internet and make it “smart?”
Connect your TV to the Internet of things
How does the Chromecast connect to the Internet and your tablet, phone or PC?
What would be the communication path for streaming video from your tablet, phone or PC to the TV set?
What is the data path for a video being streamed from the Internet?
Why is local streaming more demanding on the local device?
Streaming from the Internet:
Streaming from the local phone, tablet or PC:
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