1. OV 2 - 1 Copyright © 2011 Element K Content LLC. All rights reserved. Network Communications Methods  Data Transmission Methods  Media Access Methods  Signaling Methods

2. OV 2 - 2 Copyright © 2011 Element K Content LLC. All rights reserved. Data Transmission Transfer of data between computers

3. OV 2 - 3 Copyright © 2011 Element K Content LLC. All rights reserved. Digital Data Transmission

4. OV 2 - 4 Copyright © 2011 Element K Content LLC. All rights reserved. Unicast Transmission Receives transmission Ignores transmission

5. OV 2 - 5 Copyright © 2011 Element K Content LLC. All rights reserved. Broadcast Transmission Sent from a source node to all nodes on a network Sent from a source node to all nodes on a network

6. OV 2 - 6 Copyright © 2011 Element K Content LLC. All rights reserved. Multicast Transmission Member of multicast group Member of multicast group Member of multicast group Member of multicast group Ignores transmission

7. OV 2 - 7 Copyright © 2011 Element K Content LLC. All rights reserved. Serial Data Transmission ReceiverSender 1 character = 8 serial bits

8. OV 2 - 8 Copyright © 2011 Element K Content LLC. All rights reserved. Parallel Data Transmission 1 character = 8 parallel bits ReceiverSender

9. OV 2 - 9 Copyright © 2011 Element K Content LLC. All rights reserved. Baseband Transmission

10. OV 2 - 10 Copyright © 2011 Element K Content LLC. All rights reserved. Broadband Transmission

11. OV 2 - 11 Copyright © 2011 Element K Content LLC. All rights reserved. Types of Media Access Contends for media access Contends for media access Central device determines media access Central device determines media access

12. OV 2 - 12 Copyright © 2011 Element K Content LLC. All rights reserved. Multiplexing Mux Combined signal

13. OV 2 - 13 Copyright © 2011 Element K Content LLC. All rights reserved. Polling Client polled for data Client polled for data

14. OV 2 - 14 Copyright © 2011 Element K Content LLC. All rights reserved. CSMA/CD 3. Transmit 4. Collision 5. Wait 1. Data to transmit 2. Check network

15. OV 2 - 15 Copyright © 2011 Element K Content LLC. All rights reserved. CSMA/CA 1. Data to transmit 2. Check network 3. Jam signal 4. Wait 5. Transmit 6. Monitor for jam signal

16. OV 2 - 16 Copyright © 2011 Element K Content LLC. All rights reserved. Contention Domains

17. OV 2 - 17 Copyright © 2011 Element K Content LLC. All rights reserved. Analog Signals  Carries information as continuous waves of electromagnetic or optical energy.  The intensity of analog signals is measured in volts.  Oscillates between maximum and minimum values over time and can take any value between those limits.  The size, shape, and other characteristics of the waveform describe the analog signal and the information it carries.

18. OV 2 - 18 Copyright © 2011 Element K Content LLC. All rights reserved. Analog Signal Characteristics Cycle Phase Amplitude Crest One-second frequency Wavelength Trough

19. OV 2 - 19 Copyright © 2011 Element K Content LLC. All rights reserved. Digital Signals + 0 - Zero at the ground or zero voltage state Zero at the ground or zero voltage state One at a positive voltage

20. OV 2 - 20 Copyright © 2011 Element K Content LLC. All rights reserved. Analog Signal Modulation and Demodulation Modulated signal Modulated signal Data Carrier

21. OV 2 - 21 Copyright © 2011 Element K Content LLC. All rights reserved. Digital Signal Modulation and Demodulation 00 11 00 111 Low frequency represents 0 Low frequency represents 0 High frequency represents 1 High frequency represents 1

22. OV 2 - 22 Copyright © 2011 Element K Content LLC. All rights reserved. Digital Signal Reference Methods 0011 0011 0011 Referenced to ground Output Single-ended Differential + - 0 1 0

23. OV 2 - 23 Copyright © 2011 Element K Content LLC. All rights reserved. Reflective Questions 1. What are the factors to consider when you need to use unicast, broadcast, or multicast transmissions in your networking environment? 2. In your opinion, what is the importance of knowing different signal types?