 Keying (PSK) 12.2.4 Quadrature PSK 12.2.5 Quadrature Amplitude Modulation 12.2.6 Trellis-Coded Modulation 12.2.7 Theoretical Maximum 12.3Modulation Summary 12.4Voiceband Modem Standards 12.4.1 V.34 Modems 12.4.2 "56K" Modems 12.5Negotiation and Handshaking 12.6Modem Control and the AT Command Set 12.7Modem Jargon and Buzzwords 12.7.1 Baud vs. Bits/Second 12.7.2 Half-Duplex and Full-Duplex 12.8Factors Limiting Modem Data Rates 12.8.1 Crosstalk and NEXT 12.8.2 Harmonics 12.8.3 A/D Conversion Noise 12.8.4 Voice Compression 12.8.5 Impulse Noise: Spikes 13 BROADBAND MODEMS An in-depth overview of high-capacity or "broadband" technologies: DSL and Cable modems, and discuss the age-old question: which is faster? We'll also explore the next generations of DSL, how data over digital cellular works as well as reviewing broadband wireless. 13.1 DSL PAGE 10 TELECOM 101 REFERENCE BOOK TERACOM TRAINING INSTITUTE 13.1.1 ADSL VS. SDSL VS. XDSL 13.1.2 DSLAMs and Co-Location 13.1.3 "Always On" 13.1.4 Advantages of DSL 13.1.5 DSL Modulation Techniques 13.1.6 Loop Length Limitations 13.1.7 Next Generations of DSL 13.1.8 VDSL and OPI DSLAMs 13.2Cable Modems 13.2.1 CATV Network Architecture 13.2.2 Two-way Communications 13.2.3 Sharing the Access Circuit 13.3Which Is Faster, Cable Modem Or DSL? 13.4Data over Analog Cellular 13.5Data over Digital Cellular 13.5.1 Recap: Digital Cellular for Voice 13.5.2 Communicating Data Instead of Voice 13.5.3 Navigation Servers 13.5.4 WAP and XML 13.5.5 3G 13.6WiFi and WiMAX 14 UNDERSTANDING LANS LANs: Local Area Networks are the technology used to connect computers - and in the future telephones - inside the building. We'll complete this module with a basic, solid understanding of LANs: Ethernet and the original idea of a bus, how this changed to 100 Mb/s and now Gigabit Ethernet connected with LAN switches. You'll learn about categories of cables, hubs and switches, and as a preview of Part III, how to interconnect LANs using routers and TCP/IP. 14.1 Categories of Cables 14.1.1 TIA-568A VS. TIA-568