1. Using Telephone and Cable Networks for Data Transmission
Semester: 131
Course: CSET 221 Computer Networking
Instructor: Farhan Khan
Computer Science & Engineering Technology Unit
Hafr Al-Batin Community College

2. Outline Telephone lines Dial-up modems Digital Subscriber Line (DSL)
Cable TV networks

3. Telephone Lines
Traditional telephone lines can carry frequencies between 300 and 3300 Hz
Giving them a bandwidth of 3000 Hz
All this range is used for transmitting voice
A great deal of interference and distortion can be accepted without loss of intelligibility

4. Telephone Line Bandwidth

5. stands for modulator/demodulator.
Dial-Up Modems
Modem
stands for modulator/demodulator.

6. 56K Modems

7. Topics discussed in this section:
Digital Subscriber Line (DSL)
After traditional modems reached their peak data rate, telephone companies developed another technology, DSL, to provide higher-speed access to the Internet. Digital subscriber line (DSL) technology is one of the most promising for supporting high-speed digital communication over the existing local loops.
Topics discussed in this section:
ADSL
ADSL Lite
HDSL
SDSL VDSL

8. Digital Subscriber Line (DSL)
Provides higher-speed access to the Internet
Supports high-speed digital communication over the existing local loops
The existing local loops can handle bandwidths up to 1.1 MHz

9. ADSL ADSL – Asymmetric Digital Subscriber Line
Downstream bit rate > upstream bit rate
Designed for residential users
Unsuitable for businesses
ADSL operates on existing local loops
Local loops can handle up to 1.1 MHz of bandwidth
The distance limit is ~18,000 feet
The system uses a data rate based on the condition of the local loop line

10. ADSL is an asymmetric communication technology designed for residential users; it is not suitable for businesses.

11. The existing local loops can handle bandwidths up to 1.1 MHz

12. ADSL is an adaptive technology. The system uses a data rate
based on the condition of the local loop line.

13. Bandwidth Division in ADSL

14. Discrete Multi-Tone Modulation
Or DMT

15. Bandwidth Division 4Khz
Allocation and modulation of each channel are determined adaptively

16. Bandwidth Division Voice – Channel 0 Idle – Channels 1-5
Upstream – Channels 6-30
24 data channels, 1 control channel
1.44 Mbps (max) upstream bit rate
Actual bit rate: 64 Kbps to 1 Mbps
Downstream – Channels
224 data channels, 1 control channel
13.4 Mbps (max) downstream bit rate
Actual bit rate: 500 Kbps to 8 Mbps

17. ADSL Customer Residence

18. DSL Access Multiplexer
Or DSLAM

19. Other DSL Technologies
HDSL – High-bit-rate DSL
SDSL – Symmetric DSL
VDSL – Very-high-bit-rate DSL
ADSL2
ADSL2+
See also
Source: AWARE. ADSL2 and ADSL2+ The new ADSL standard.

20. Table 9.1 Summary of DSL technologies

21. Topics discussed in this section:
Cable TV Networks
The cable TV network started as a video service provider, but it has moved to the business of Internet access. In this section, we discuss cable TV networks; in next Section we discuss how this network can be used to provide high-speed access to the Internet.
Topics discussed in this section:
Traditional Cable Networks
Hybrid Fiber-Coaxial (HFC) Network

22. Cable TV Networks
Started as a video service provider, then moved to the business of Internet access
Communication is simplex

23. Communication in the traditional cable TV network is unidirectional.

24. Hybrid Fiber-Coaxial Network
Or HFC
Bidirectional communication is achieved

25. Communication in an HFC cable TV network can be bidirectional.

26. Topics discussed in this section:
Cable TV for Data Transfer
Cable companies are now competing with telephone companies for the residential customer who wants high-speed data transfer. In this section, we briefly discuss this technology.
Topics discussed in this section:
Bandwidth CM and CMTS

27. Division of Coaxial Cable Band by CATV
Downstream Video Band can accommodate more than 80 channels.
Each TV channel occupies 6 MHz
Theoretical downstream data rate is 30 Mbps
Theoretical upstream data rate is 12 Mbps

28. Downstream data are modulated using the QAM modulation technique.

29. The theoretical downstream data rate is 30 Mbps.

30. Upstream data are modulated using the QPSK modulation technique.
Note
Upstream data are modulated using the QPSK modulation technique.

31. The theoretical upstream data rate is 12 Mbps.

32. Cable Modem (CM)

33. Cable Modem Transmission System
Or CMTS

34. Summary Telephone lines Dial-up modems Digital Subscriber Line (DSL)
Cable TV networks