Page 285 Test Your understanding ·8b 6-16
6-16 • Page 285 • Test Your understanding • 8 b
I Figure 6-7: Local Loop Technologies echnology Use Status 1-Pair Voice-Grade Residences Already installed UTP 2-Pair Data-Grade Businesses for Must be pulled to the UTP LoWest-speed customer premises access lines (this is expensive) Optical Fiber Businesses for Must be pulled to the higher-speed customer premises access lines (this is expensive Residential 1-pair voice-grade UTP is already installed This makes it inexpensive to use Business 2-pair data-grade UTP and fiber for leased lines must be installed; this is expensive 6-17
6-17 Figure 6-7: Local Loop Technologies Technology Use Status 1-Pair Voice-Grade UTP Residences Already installed 2-Pair Data-Grade UTP Businesses for Lowest-speed access lines Must be pulled to the customer premises (this is expensive) Optical Fiber Businesses for higher-speed access lines Must be pulled to the customer premises (this is expensive) Residential 1-pair voice-grade UTP is already installed. This makes it inexpensive to use Business 2-pair data-grade UTP and fiber for leased lines must be installed; this is expensive
Page 286 Test Your understanding °9a,b,c 6-18
6-18 • Page 286 • Test Your understanding • 9 a,b,c
Figure 6-8: Analog Telephone Transmission Analog (Analogous) Electrical Signal Sound Wave Analog signals rise and fall in intensity with the human voice No resistance to errors as there is in digital transmission Initially, the entire Pstn was analog 6-19
6-19 Figure 6-8: Analog Telephone Transmission Sound Wave Analog (Analogous) Electrical Signal Analog signals rise and fall in intensity with the human voice. No resistance to errors as there is in digital transmission. Initially, the entire PSTN was analog
Figure 6-9: The PSTN: Mostly Digital with Analog Local loops Today's Telephone Network: Predominantly Digital Local Local Loop Loo p (Analog) Switch Digital) Rq( Digital) Residential Switch Trunk line Switch PBX Tel telephone Digital) Digital) Digital Digital) (Analog) Today, everything is digital except for the local loop access line and residential telephones The actual local loop line can carry either analog or digital signals but the equipment at both ends is analog 20
6-20 Figure 6-9: The PSTN: Mostly Digital with Analog Local Loops Trunk Line (Digital) Local Loop (Analog) Local Loop (Digital) PBX (Digital) Residential Telephone (Analog) Today's Telephone Network: Predominantly Digital Switch (Digital) Switch (Digital) Switch (Digital) Today, everything is digital except for the local loop access line and residential telephones. The actual local loop line can carry either analog or digital signals, but the equipment at both ends is analog