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Using Telephone and Cable Networks for Data Transmission Semester: 131 Course: CSET 221 Computer Networking Instructor: Farhan Khan Computer Science &

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Presentation on theme: "Using Telephone and Cable Networks for Data Transmission Semester: 131 Course: CSET 221 Computer Networking Instructor: Farhan Khan Computer Science &"— Presentation transcript:

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

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

4 4 Telephone Line Bandwidth

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

6 6 56K Modems

7 9.7 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. ADSL ADSL Lite HDSL SDSL VDSL Topics discussed in this section: Digital Subscriber Line (DSL)

8 8 Provides higher-speed access to the Internet Provides higher-speed access to the Internet Supports high-speed digital communication over the existing local loops Supports high-speed digital communication over the existing local loops The existing local loops can handle bandwidths up to 1.1 MHz The existing local loops can handle bandwidths up to 1.1 MHz

9 9 ADSL ADSL – Asymmetric Digital Subscriber Line ADSL – Asymmetric Digital Subscriber Line Downstream bit rate > upstream bit rate Downstream bit rate > upstream bit rate Designed for residential users Designed for residential users Unsuitable for businesses Unsuitable for businesses ADSL operates on existing local loops ADSL operates on existing local loops Local loops can handle up to 1.1 MHz of bandwidth Local loops can handle up to 1.1 MHz of bandwidth The distance limit is ~18,000 feet The distance limit is ~18,000 feet The system uses a data rate based on the condition of the local loop line 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 13 Bandwidth Division in ADSL

14 14 Discrete Multi-Tone Modulation Or DMT Or DMT

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

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

17 17 ADSL Customer Residence

18 18 DSL Access Multiplexer Or DSLAM Or DSLAM

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

20 9.20 Table 9.1 Summary of DSL technologies

21 9.21 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. Traditional Cable Networks Hybrid Fiber-Coaxial (HFC) Network Topics discussed in this section: Cable TV Networks

22 22 Cable TV Networks Started as a video service provider, then moved to the business of Internet access 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 24 Hybrid Fiber-Coaxial Network Or HFC Or HFC Bidirectional communication is achieved Bidirectional communication is achieved

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

26 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. Bandwidth CM and CMTS Topics discussed in this section: Cable TV for Data Transfer

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

28 9.28 Downstream data are modulated using the QAM modulation technique.

29 The theoretical downstream data rate is 30 Mbps.

30 9.30 Upstream data are modulated using the QPSK modulation technique. Note

31 The theoretical upstream data rate is 12 Mbps.

32 32 Cable Modem (CM)

33 33 Cable Modem Transmission System Or CMTS Or CMTS

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


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