1. Network Communications Chapter 7 Modems, DSL, Cable Modems and ISDN

2. Public Switched Telephone Network (PSTN) Figure 7.1 Signal PSTN Public Switch Telephone Network

3. Telephone Carrier Signal (Sine Wave) Voltage 180270 0 90 360 Degree Figure 7.2

4. Amplitude Shift Keying (ASK) Figure 7.3

5. Frequency Shift Keying (FSK) Figure 7.4

6. 90 Degree Phase Shift Figure 7.5 1 Cycle Original Signal A sine wave 90 degree phase shift A cosine wave 1 cycle

7. Phase Shifting the Carrier Figure 7.6 Note: Error in text a. 90 degree shiftb. 180 degree shiftc. 270 degree shift

8. Constellation Diagrams Figure 7.7 QPSK Figure 7.8 8-PSK 000 010 110 001 011 101 111 0000 00145 01090 011135 100180 101225 110270 111315 Bits Phase Shift 000 01 10 90 11 180 270 Bits Phase Shift

9. 8 – QAM Modulation Figure 7.9Figure 7.10

10. 56 Kb/sec Modem Connection Figure 7.11

11. ADSL Modem Asymmetric Digital Subscriber Line Figure 7.12Figure 7.13

12. ADSL Modem Architecture Figure 7.14 ADSL Modem POTS Mbps kbps Filter POTS Line Exchange Switch POTS Filter ADSL Modem Mbps Kbps Customer End POTs filters do not operate on the DSL signal!

13. Cable TV Distribution Figure 7.15

14. Hybrid Fiber Coax (HFC) Figure 7.16

15. A Cable Modem Connection Figure 7.17

16. Sharing a Cable/DSL Modem Figure 7.18 Should be a Router and a Hub / Switch

17. ISDN Basic Rate 2B + D: 144 Kb/sec Figure 7.19

18. Using the Basic Rate Interface 2 wires Figure 7.20

19. ISDN Primary Rate 23B + D (T1) Figure 7.21 64 Figure 7.22

20. ISDN PRI Application Figure 7.23