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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.
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CS412 Introduction to Computer Networking & Telecommunication DSL, Cable, and Mobile Telephone System Chi-Cheng Lin, Winona State University
Topics • Digital Subscriber Line • Cable • Mobile Telephone System
Digital Subscriber Lines • Bandwidth versus distanced over category 3 UTP for DSL.
Digital Subscriber Lines • Operation of ADSL using discretemultitonemodulation.
Digital Subscriber Lines • A typical ADSL equipment configuration.
Wireless Local Loops • Architecture of an LMDS system.
Cable Television • Community Antenna Television • Internet over Cable • Spectrum Allocation • Cable Modems • ADSL versus Cable
Community Antenna Television • An early cable television system.
Internet over Cable • Cable television
Compared to Telephone System • The fixed telephone system.
Spectrum Allocation • Frequency allocation in a typical cable TV system used for Internet access
Cable Modems • Typical details of the upstream and downstream channels in North America.
ADSL versus Cable • Discussions …
Mobile Telephone System • First-Generation Mobile Phones • Analog Voice • Second-Generation Mobile Phones • Digital Voice • Third-Generation Mobile Phones • Digital Voice and Data
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 Cellular System The McGraw-Hill Companies, Inc., 1998 WCB/McGraw-Hill
Advanced Mobile Phone System (a) Frequencies are not reused in adjacent cells. (b) To add more users, smaller cells can be used.
Cellular Transmission • Traditionally analog • FM used to minimized noise • Digital transmission • CDPD (Cellular Digital Packet Data) • Low-speed digital service over existing cellular network • Based on OSI Model • Modem needed
Cellular System • Handoff • When a mobile telephone leaves a cell 1. Its base station notices the signal fading out 2. 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 boss 5. If a call is in progress, it will be asked to switch to a new channel
Channels • 832 full-duplex channels • Each channel consists of 2 simplex channels • Transmission channels • (849-824)MHz/30KHz 832 • Receiving channels • (894-869)MHz/30KHz 832 • Typically, actual number of voice channel per cell 45
Channel Categories • The 832 channels are divided into four categories • Control (base to mobile) to manage the system • Paging (base to mobile) to alert users to calls for them • Access (bidirectional) for call setup and channel assignment • Data (bidirectional) for voice, fax, or data
Second-Generation Mobile Phones • D-AMP • GSM • CDMA
D-AMPS Digital Advanced Mobile Phone System (a) A D-AMPS channel with three users. (b) A D-AMPS channel with six users.
GSMGlobal System for Mobile Communications • GSM uses 124 frequency channels, each of which uses an eight-slot TDM system
GSM • A portion of the GSM framing structure.
Third-Generation Mobile Phones:Digital Voice and Data • Basic services an IMT-2000 network should provide • High-quality voice transmission • Messaging • Replace e-mail, fax, SMS, chat, etc. • Multimedia • Music, videos, films, TV, etc. • Internet access • Web surfing, w/multimedia • 2.5G, 4G, …