Using Telephone and Cable Networks for Data Transmission Semester: 131 Course: CSET 221 Computer...
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Transcript of Using Telephone and Cable Networks for Data Transmission Semester: 131 Course: CSET 221 Computer...
Using Telephone and Using Telephone and Cable Networks for Data Cable Networks for Data
TransmissionTransmission
Semester: 131Semester: 131
Course: CSET 221 Computer NetworkingCourse: CSET 221 Computer Networking
Instructor: Farhan KhanInstructor: Farhan Khan
Computer Science & Engineering Technology UnitComputer Science & Engineering Technology Unit
Hafr Al-Batin Community CollegeHafr Al-Batin Community College
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OutlineOutline Telephone linesTelephone lines Dial-up modemsDial-up modems Digital Subscriber Line (DSL)Digital Subscriber Line (DSL) Cable TV networksCable TV networks
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Telephone LinesTelephone Lines Traditional telephone lines can carry Traditional telephone lines can carry
frequencies between 300 and 3300 frequencies between 300 and 3300 HzHz Giving them a bandwidth of 3000 HzGiving them a bandwidth of 3000 Hz
All this range is used for transmitting All this range is used for transmitting voicevoice A great deal of interference and A great deal of interference and
distortion can be accepted without loss distortion can be accepted without loss of intelligibilityof intelligibility
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Telephone Line Telephone Line BandwidthBandwidth
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Dial-Up ModemsDial-Up Modems
Modemstands for modulator/demodulator.
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56K Modems56K Modems
9.9.77
After traditional modems reached their peak After traditional modems reached their peak data rate, telephone companies developed data rate, telephone companies developed another technology, DSL, to provide higher-another technology, DSL, to provide higher-speed access to the Internet. speed access to the Internet. Digital Digital subscriber linesubscriber line ( (DSLDSL) technology is one of ) technology is one of the most promising for supporting high-the most promising for supporting high-speed digital communication over the speed digital communication over the existing local loops. existing local loops. ADSLADSL LiteHDSLSDSLVDSL
Topics discussed in this section:Topics discussed in this section:
Digital Subscriber Line Digital Subscriber Line (DSL)(DSL)
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Digital Subscriber Line Digital Subscriber Line (DSL)(DSL) Provides higher-speed access to the Provides higher-speed access to the
InternetInternet Supports high-speed digital Supports high-speed digital
communication over the existing local communication over the existing local loopsloops
The existing local loops can handle The existing local loops can handle bandwidths up to 1.1 MHzbandwidths up to 1.1 MHz
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ADSLADSL ADSLADSL – Asymmetric Digital – Asymmetric Digital
Subscriber LineSubscriber Line Downstream bit rate > upstream bit rateDownstream bit rate > upstream bit rate Designed for residential usersDesigned for residential users Unsuitable for businessesUnsuitable for businesses
ADSL operates on existing local loopsADSL operates on existing local loops Local loops can handle up to 1.1 MHz of Local loops can handle up to 1.1 MHz of
bandwidthbandwidth The distance limit is ~18,000 feetThe distance limit is ~18,000 feet The system uses a data rate based on The system uses a data rate based on
the condition of the local loop linethe condition of the local loop line
ADSL is an asymmetric communication technology designed for residential users; it is not suitable
for businesses.
The existing local loops can handle bandwidths up to 1.1 MHz
ADSL is an adaptive technology. The system uses a data ratebased on the condition of
the local loop line.
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Bandwidth Division in Bandwidth Division in ADSLADSL
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Discrete Multi-Tone Discrete Multi-Tone ModulationModulation Or Or DMTDMT
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Allocation and modulation of each channel are determined adaptively
4Khz
Bandwidth DivisionBandwidth Division
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VoiceVoice – Channel 0 – Channel 0 IdleIdle – Channels 1-5 – Channels 1-5 UpstreamUpstream – Channels 6-30 – Channels 6-30
24 data channels, 1 control channel24 data channels, 1 control channel 1.44 Mbps (max) upstream bit rate1.44 Mbps (max) upstream bit rate Actual bit rate: 64 Kbps to 1 MbpsActual bit rate: 64 Kbps to 1 Mbps
DownstreamDownstream – Channels 31-255 – Channels 31-255 224 data channels, 1 control channel224 data channels, 1 control channel 13.4 Mbps (max) downstream bit rate13.4 Mbps (max) downstream bit rate Actual bit rate: 500 Kbps to 8 MbpsActual bit rate: 500 Kbps to 8 Mbps
Bandwidth DivisionBandwidth Division
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ADSL Customer ADSL Customer ResidenceResidence
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DSL Access MultiplexerDSL Access Multiplexer Or Or DSLAMDSLAM
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Other DSL TechnologiesOther DSL Technologies HDSL – High-bit-rate DSLHDSL – High-bit-rate DSL SDSL – Symmetric DSLSDSL – Symmetric DSL VDSL – Very-high-bit-rate DSLVDSL – Very-high-bit-rate DSL ADSL2ADSL2 ADSL2+ADSL2+
See alsoSee also http://en.wikipedia.org/wiki/http://en.wikipedia.org/wiki/
Digital_subscriber_lineDigital_subscriber_line
Source: AWARE. ADSL2 and ADSL2+ The new ADSL standard.
9.9.2020
Table 9.1 Summary of DSL technologies
9.9.2121
The The cable TV networkcable TV network started as a video started as a video service provider, but it has moved to the service provider, but it has moved to the business of Internet access. In this section, business of Internet access. In this section, we discuss cable TV networks; in next we discuss cable TV networks; in next Section we discuss how this network can be Section we discuss how this network can be used to provide high-speed access to the used to provide high-speed access to the Internet.Internet.
Traditional Cable NetworksHybrid Fiber-Coaxial (HFC) Network
Topics discussed in this section:Topics discussed in this section:
Cable TV NetworksCable TV Networks
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Cable TV NetworksCable TV Networks Started as a video service provider, Started as a video service provider,
then moved to the business of then moved to the business of Internet accessInternet access
Communication is simplex
Communication in the traditional cable TV network is unidirectional.
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Hybrid Fiber-Coaxial Hybrid Fiber-Coaxial NetworkNetwork Or Or HFCHFC Bidirectional communication is Bidirectional communication is
achievedachieved
Communication in an HFC cable TV network can be bidirectional.
Cable companies are now competing Cable companies are now competing with telephone companies for the with telephone companies for the residential customer who wants high-residential customer who wants high-speed data transfer. In this section, we speed data transfer. In this section, we briefly discuss this technology.briefly discuss this technology.
Bandwidth CM and CMTS
Topics discussed in this section:Topics discussed in this section:
Cable TV for Data Cable TV for Data TransferTransfer
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Division of Coaxial Cable Band by Division of Coaxial Cable Band by CATVCATV
Downstream Video Band can accommodate Downstream Video Band can accommodate more than 80 channels. more than 80 channels. Each TV channel occupies 6 MHzEach TV channel occupies 6 MHzTheoretical downstream data rate is 30 MbpsTheoretical downstream data rate is 30 MbpsTheoretical upstream data rate is 12 MbpsTheoretical upstream data rate is 12 Mbps
9.9.2828
Downstream data are modulated using the QAM modulation technique.
The theoretical downstream data rateis 30 Mbps.
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Upstream data are modulated using the QPSK modulation technique.
Note
The theoretical upstream data rate is 12 Mbps.
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Cable Modem (CM)Cable Modem (CM)
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Cable Modem Transmission Cable Modem Transmission SystemSystem Or Or CMTSCMTS
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SummarySummary Telephone linesTelephone lines Dial-up modemsDial-up modems Digital Subscriber Line (DSL)Digital Subscriber Line (DSL) Cable TV networksCable TV networks