Download presentation
Presentation is loading. Please wait.
Published byHomer Fowler Modified over 9 years ago
1
Communication Systems I
2
How can information flow from point A to point B?
3
Morse Code Can you spell your name? See http://morsecode.scphillips.com/jtranslator.html for a live demohttp://morsecode.scphillips.com/jtranslator.html
4
Semaphores
5
http://www.globalsecurity.org Semaphore as a Signaling Tool
7
Semaphore as a Communication Tool http://www.wikipedia.org
8
ROGER
9
Nuclear Disarmamenthttp://www.viewimages.com Semaphore in Pop Culture
10
Fountain of Bits
11
Analog Signal Encoding
12
Modem Maximum Data Rate Modem 56Kbps
13
ADSL Maximum Rate? ADSL
14
Why is ADSL much faster? 256 Channels of 4 kHz each
15
How fast is ADSL? ADSL = 256 x 4 kHz x 8 bits = 8 Mbps ADSL2= 12 Mbps ADSL2+= 25 Mbps *ADSL2+ expands channel frequency from 1.1 to 2.2 MHz
16
Serial vs Parallel Transmission Image © Quatec
17
Example of Serial Comm? Example of Parallel Comm?
18
Which Mode is More Common? Cost. Less cables. Smaller size. Simplicity. Keeping bits aligned in a high- speed parallel line requires more complex electronics. Serial Why?
19
The Need for Speed USB 1.0 (12 Mbps) USB 2.0 (480 Mbps) USB 3.0 (4.8 Gbps) Firewire 400 (400 Mbps) Firewire 800 (800 Mbps) SATA (1.5/3.0 Gbps) RS-232 (115.2 Kbps)
20
Synchronous vs Asynchronous A B A B Synchronous uses a clock line Asynchronous relies on a common clock on each side
21
RS-232 (Serial Communication) Baud Rate Data bits Start bit / Stop bits Parity
22
RS-232 Pulses Letter “V” ASCII = 86 (0101 0110 2 ) 9600 bps, 8-N-1 Layout: Start Bit, Data Bits, Parity, Stop Bits * Note: Rs-232 logic pulses are inverted
23
RS-232 Pulses Letter “Y” ASCII = 89 (0101 1001 2 ) 9600 bps, 8-Odd-1 Layout: Start Bit, Data Bits, Parity, Stop Bits * Note: Rs-232 logic pulses are inverted
24
How about ASCII 0? Layout: Start Bit, Data Bits, Parity, Stop Bits The data transmission is unbalanced. Can cause transmission errors. 9600 bps, 8-N-1
25
Manchester Encoding (IEEE 802.3) Bit 1 = Low to High Bit 0 = High to Low
26
Example Image: Wikipedia
27
Data = 0 Manchester Code
28
Encode the following transmissions using the Manchester standard Letter “V” ASCII = 86 (0101 0110 2 ) Letter “Y” ASCII = 89 (0101 1001 2 )
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.