58 digital cellular system (DCS), 380 DSLAMs (Digital Subscriber Line Access Multi- digital, conversion of analog cable TV to, 192 plexers), 13, 195, 202 digital divide, 297-298 edge routers handling aggregated traffic from, other factors beside Internet access, 297 digital loop carriers (DLCs), 200 electrical requirements, 206 electrical requirments for, 206 using small DSLAMs and mini-RAMs for TV digital mobile services, 308 and higher speed Internet access, 195 digital service unit (DSU), 243, 250 DSL (Digital Subscriber Line), 134, 189, 195, 257 digital signal levels, 258 copper wiring connectind to fiber on PON, 197 Digital Signal Processors. See DSPs in Germany, 415 digital signals, 17 mobile broadband taking place of, 217 conversion of RF from cable TV networks to, mobile services replacing DSL, 307 standards, 259 leaking into adjacent spectrum, 320 using DLC to improve speeds, 200 versus analog signals, 46-49 using for Internet access, 239-242 digital signal zero (DS-0), 247 advances in DSL technology, 241 Index using for Internet access using DPI to manage networks, 13 advances in DSL technology (Contd.) 8x8, Inc., 93 as backup option for business customers, Elastic Compute Cloud (EC2), 31 electrical properties, copper cabling, 39 worldwide DSL subscriptions for 2008-09, electrical requirements for towers, residential service, DLCs, and DSLAMs, 206 DSL modems electrical signals new, use for triple-play services, 242 changing light pulses into, 44 DSPs (Digital Signal Processors), 75, 99 electricity in digital wireless handsets, 321 ensuring adequate, lower-cost power, 64 on media gateways, 79 Wi-Fi network electrical requirements, 369 DSU (digital service unit), 243, 250 electronic commerce. See e-commerce DWDM (Dense Wavelength-Division Multiplex- e-mail, 53 archiving services, 32 DWDM multiplexers with ROADM cards, 179 governments using DPI to monitor and censor fiber-optic cable with DWDMs attached, 6 messages, 10 on OTN equipment, 175 servers located centrally at headquarters, 248 dynamic spectrum ac