Using Telephone and Using Telephone and Cable Networks for Data Cable Networks for Data

TransmissionsTransmissions

01204325: Data 01204325: Data Communication and Communication and Computer NetworksComputer Networks

Asst. Prof. Chaiporn Jaikaeo, Ph.D.Asst. Prof. Chaiporn Jaikaeo, Ph.D.chaiporn.j@ku.ac.thchaiporn.j@ku.ac.th

http://www.cpe.ku.ac.th/~cpjhttp://www.cpe.ku.ac.th/~cpjComputer Engineering DepartmentComputer Engineering Department

Kasetsart University, Bangkok, ThailandKasetsart University, Bangkok, ThailandAdapted from lecture slides by Behrouz A. Forouzan© The McGraw-Hill Companies, Inc. All rights reserved

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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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V.32 and V.32bisV.32 and V.32bis

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56K Modems56K Modems

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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 MHz.bandwidths 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

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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 VDSL – Very-high-bit-rate DSLVDSL – Very-high-bit-rate DSL SDSL – Symmetric DSLSDSL – Symmetric 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.

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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

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Hybrid Fiber-Coaxial Hybrid Fiber-Coaxial NetworkNetwork Or Or HFCHFC Bidirectional communication is Bidirectional communication is

achievedachieved

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Data Transfer over CATVData Transfer over CATV Division of coaxial cable band by Cable TVDivision of coaxial cable band by Cable TV

Theoretical downstream data rate is 30 MbpsTheoretical downstream data rate is 30 Mbps Theoretical upstream data rate is 12 MbpsTheoretical upstream data rate is 12 Mbps

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Cable ModemCable Modem

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Cable Modem Transmission Cable Modem Transmission SystemSystem Or Or CMTSCMTS

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Fiber To The Fiber To The XX Optical broadband network architecturesOptical broadband network architectures

Fiber-to-the-node

Source: Wikipedia

Fiber-to-the-curb

Fiber-to-the-building

Fiber-to-the-home