Transcript Slide 1

Connection characteristics
Skills: none
IT concepts: wired and wireless connections,
connection technologies, connection length
and speed, units of measure for amount of
data and connection speed
This work is licensed under a Creative Commons Attribution-NoncommercialShare Alike 3.0 License.
Where does this topic fit?
• Internet concepts
– Applications
– Technology (communication)
– Implications
• Internet skills
– Application development
– Content creation
Connection characteristics
Computer 1
Computer 2
Is the connection wired or wireless?
What technology does the connection use?
How long is the connection?
How fast is the connection?
Wireless connection technologies
Terrestrial radio
Satellite radio
Wired connection technologies
Copper, twisted pair
(electronic)
Copper, coaxial cable
(electronic)
Fiber (optical)
Only use wireless connections when a
wired connection is not practical.
Connection length
Connection speed
How fast can it transmit data?
Computer 1
Computer 2
Some units of measure
Time
minutes
Distance
inches
Weight
pounds
Amount of data bits
Can you think of others?
What is a bit?
A bit is a binary digit, it may take on one of
two values, 0 or 1:
0
1
All data types – numbers, images, audio,
video, images, etc. are encoded as bits!
Larger units of amount of data
Bit
Kilobit
Megabit
Gigabit
Terabit
Petabit
a single 0 or 1
1,000 bits
1,000,000 bits
1,000,000,000 bits
1,000,000,000,000 bits
1,000,000,000,000,000 bits
(These are approximate. A kilobit is actually 1,024 bits, a
megabit 1,024*1,024 bits, etc., but this is close enough for
most discussions).
One more -- what is a byte?
8 bits, for example:
0 0 0 0 0 0 0 0
1 1 1 1 1 1 1 1
0 1 1 0 0 0 1 0
Connection speed
How fast can it transmit data?
001110101010101010
Computer 1
Computer 2
How many bits can be sent from one computer
to the next in a given amount of time?
Units of measure for a rate
(velocity)
Time
hours
Distance
miles
Velocity
miles/hour
miles/hour = “miles per hour”
the distance traveled in one hour
Distance/time
Can you think of others?
Units of measure for a rate
(data transmission speed)
Time
seconds
Amount of data
bits
Transmission rate
bits/second
bits/second = “bits per second”
the number of bits transmitted in one second
amount of data/time
Can you think of others?
A few questions
We discussed four characteristics of a communication link. Without
looking back, do you recall what they were?
What is a unit of measure for:
Weight
Length
Rate at which you run
Amount of data
Rate of data transmission
What are two other units of measure for each of the above?
The general form of a unit of measure for velocity is distance/time.
What is the general form of a unit of measure for data transmission
speed?
How many bits in a megabyte?
How long would it take to transmit a 100 megabit file
over a 100 megabit/second communication link?
How long would it take to transmit a 100 megabit file
over a 10 megabit/second communication link?
How long would it take to transmit a 100 megabit file
over a one gigabit/second communication link?
How long would it take to transmit a 100 megabyte
file over a 100 megabit/second communication link?
How long would it take to transmit a 100 megabit file over
a 100 megabyte/second communication link?
This is a 2.03 megabyte image
How many megabits is that?
How long would it take to download this image over a
1 megabit per second connection?
How long would it take over a 1 gigabit per second
connection?
Connection characteristics
Skills: none
IT concepts: wired and wireless connections,
connection technologies, connection length
and speed, units of measure for amount of
data and connection speed
This work is licensed under a Creative Commons Attribution-NoncommercialShare Alike 3.0 License.