cs412 introduction to computer networking & telecommunication
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CS412 Introduction to Computer Networking & Telecommunication. DSL, Cable, and Mobile Telephone System. Topics. Digital Subscriber Line Cable Mobile Telephone System. Digital Subscriber Lines. Bandwidth versus distanced over category 3 UTP for DSL. Digital Subscriber Lines. - PowerPoint PPT PresentationTRANSCRIPT
Chi-Cheng Lin, Winona State University
CS412 Introduction to Computer Networking &
Telecommunication
DSL, Cable, and Mobile Telephone System
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Topics
Digital Subscriber Line
Cable
Mobile Telephone System
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Digital Subscriber Lines
Bandwidth versus distanced over category 3 UTP for DSL.
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Digital Subscriber Lines
Operation of ADSL using discrete multitone modulation.
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Figure 9.1 DMT
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Figure 9.2 Bandwidth division
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Digital Subscriber Lines
A typical ADSL equipment configuration.
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Figure 9.3 ADSL modem
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Figure 9.4 DSLAM
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Wireless Local Loops
Architecture of an LMDS system.
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Cable Television
Community Antenna Television Internet over Cable Spectrum Allocation Cable Modems ADSL versus Cable
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Community Antenna Television
An early cable television system.
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Internet over Cable
Cable television
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Compared to Telephone System
The fixed telephone system.
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Spectrum Allocation
Frequency allocation in a typical cable TV system used for Internet access
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Cable Modems
Typical details of the upstream and downstream channels in North America.
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Figure 9.8 Cable modem
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Figure 9.9 CMTS
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ADSL versus Cable
Discussions …
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Mobile Telephone System
First-Generation Mobile PhonesAnalog Voice
Second-Generation Mobile PhonesDigital Voice
Third-Generation Mobile PhonesDigital Voice and Data
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Advanced Mobile Phone System
Area is divided into cells with an antenna control by a cell office in each cell
Cell offices communicate with MTSO Transmission frequencies cannot be
the same in adjacent cells Cell size is not fixed
Smaller cells used in higher populated area
Figure 7-36
WCB/McGraw-Hill The McGraw-Hill Companies, Inc., 1998
Cellular System
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Advanced Mobile Phone System
(a) Frequencies are not reused in adjacent cells.(b) To add more users, smaller cells can be used.
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Figure 17.2 Frequency reuse patterns
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Cellular Transmission
Traditionally analogFM used to minimized noise
Digital transmissionCDPD (Cellular Digital Packet Data)
Low-speed digital service over existing cellular network
Based on OSI ModelModem needed
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Cellular System Handoff
When a mobile telephone leaves a cell1. Its base station notices the signal fading out2. The base station asks all the surrounding
base stations how much power they are getting from it
3. Ownership is transferred to the neighbor base station that receives strongest power
4. The telephone is informed of its new boss5. If a call is in progress, it will be asked to
switch to a new channel
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Channels
832 full-duplex channelsEach channel consists of 2 simplex
channelsTransmission channels
(849-824)MHz/30KHz 832
Receiving channels(894-869)MHz/30KHz 832
Typically, actual number of voice channel per cell 45
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Channel Categories
The 832 channels are divided into four categoriesControl (base to mobile) to manage
the systemPaging (base to mobile) to alert users
to calls for themAccess (bidirectional) for call setup
and channel assignmentData (bidirectional) for voice, fax, or
data
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Second-Generation Mobile Phones
D-AMP
GSM
CDMA
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D-AMPS Digital Advanced Mobile Phone System
(a) A D-AMPS channel with three users.(b) A D-AMPS channel with six users.
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GSMGlobal System for Mobile
Communications GSM uses 124 frequency channels,
each of which uses an eight-slot TDM system
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GSM
A portion of the GSM framing structure.
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Third-Generation Mobile Phones:Digital Voice and Data
Basic services an IMT-2000 network should provideHigh-quality voice transmissionMessaging
Replace e-mail, fax, SMS, chat, etc.
Multimedia Music, videos, films, TV, etc.
Internet accessWeb surfing, w/multimedia
2.5G, 4G, …