Agenda 1. QUIZ 2. HOMEWORK LAST CLASS 3. HOMEWORK NEXT CLASS 4. TRANSMISSION MATHEMATICS a. dBs, NYQUIST & SHANNON b. NOISE 5. DIGITAL SYSTEMS 6. ANALOG AND ANALOG TO DIGITAL CONVERSIONS 7. ISDN 8. DSL

Homework Chapter 4: 10, 11, 12, 14, 15, 16, 22, 50, 54, 63 Chapter 5: 1, 3, 6, 7, 9, 14, 17, 32

Decibells & Logarithms Converting watts to dB (or milliwatts to dBm): 10 log watts = 30 dBw Converting dB to watts (or dBm to milliwatts): 30 dBw = log -1, or log -1 (3) or 10 raised to the 3rd power = 10 3 = 1000 watts 35 dBw = = watts Note: There’s a point between the 3 & 5.

Decibells & Logarithms dBWWatts

Nyquist 1. Nyquist: The maximum practical data rate (samples) per channel. Max R = 2 H log 2 V Logarithmic function to the base 2: For each # V, log V = the exponent to which 2 must be raised to produce V. Then if V = 16, the log 2 of V = 4. If V = 2, the log 2 of V = 1. Then what is the maximum practical data rate for BPSK signal on a line with a bandwidth of 3000 Hz? What is the maximum practical data rate for a QPSK signal on a line with a bandwidth of 3000 Hz?

Shannon Shannon: The maximum theoretical data rate per channel. Max R = CBW x log 2 (1 + S/N) [CBW = H in Nyquist Theorem] Then what is the maximum practical data rate for signal with a 30 dB S/N on a line with a bandwidth of 3000 Hz?

Noise N = Noise Power = kTB, where B is bandwidth. (Used in Shannon’s Limit) N o = Noise Density = kT, where k is Boltzmann’s Constant ( dBw) (Used in Carrier to Noise ratios, i.e., C/N o ) T = SNT = System Noise Temperature (Used in radio and satellite link equations, e.g., G/T is a measure of quality in satellite link equations.)

Chapter 4 Signals

Figure 4-1 Comparison of Analog and Digital Signals

Figure 4-2 Example of Periodic Signal

Figure 4-3 Example of Aperiodic Signal Aperiodic signals are _____________? Inconsistant

Figure 4-4 A Sine Wave

Figure 4-5 Amplitude

Figure 4-6 Period and Frequency

Figure 4-7 Relationship between Different Phases

Figure 4-8 Amplitude Change Amplitude relates to ___________? S in S/N

Figure 4-10 Phase Change Phase shift relates to ______________? Phase shift keying

Figure 4-11 Time and Frequency Domains

Figure 4-12 Time and Frequency Domains for Different Signals

Figure 4-13 A Signal with a DC Component

Figure 4-14 Composite Waveform

Figure 4-15 Bandwidth

Figure 4-16 Example 4.8

Figure 4-17 Example 4.9

Figure 4-19 Bit Rate and Bit Interval

Figure 4-20 Harmonics of a Digital Signal

Figure 4-21 Exact and Significant Spectrum

Chapter 5 Encoding

Figure 5-3 Types of Digital to Digital Encoding

Figure 5-5 Types of Polar Encoding

Figure 5-6 NRZ-L and NRZ-I Encoding

Figure 5-7 RZ Encoding

Figure 5-8 Manchester and Diff. Manchester Encoding

Figure 5-9 Types of Bipolar Encoding

Figure 5-10 Bipolar AMI Encoding

Figure 5-15 Analog to Digital Conversion

Figure 5-16 PAM

Figure 5-17 Quantized PAM Signal

Figure 5-19 PCM

Figure 5-20 From Analog Signal to PCM Digital Code

Figure 5-21 Nyquist Theorem This assumes what?

Figure 5-27 FSK

Figure 5-28 Baud Rate and Bandwidth in FSK

Figure 5-29 PSK Why do you think PSK is better than FSK? Needs less power per bit

Figure 5-30 PSK Constellation

Figure PSK

Figure PSK Characteristics

Figure PSK Characteristics

Figure 5-34 Baud Rate and Bandwidth in PSK

Figure QAM and 8-QAM Constellations

Figure 5-44 Frequency Modulation

Figure 5-45 FM Bandwidth

Integrated Services Digital Network (ISDN) Standard 1. A major TELCO attempt to integrate voice and non-voice services. 2. Integrated multiple channels interleaved with time division multiplexing. A - 4 KHz analog telephone channel B - 64 Kbps digital PCM channel for voice or data C - 8 or 16 Kbps digital channel D - 16 Kbps digital channel for out of band signalling E - 64 Kbps channel for internal ISDN signalling H - 384, 1536, or 1920 Kbps digital channel Basic Rate = 2B + 1D (the nominal 128 frequently used in homes) Primary Rate = 23 B + 1D

Integrated Services Digital Network (ISDN) Standard TE 1 ISDN Terminal TE 1 ISDN Telephone Non-ISDN Terminal TA S S S R ISDN PBX NT1 ISDN Exchange T U R, S, T & U are CCITT defined reference Points TA is terminal adapter

Digital Subscriber Line (DSL) Standard Drivers: ISDN didn’t capture significant market share for TELCOs Higher speed applications require new technologies Users want to stay connected longer High cost of converting infrastructure Telephone lines weren’t designed to provide simultaneous digital and analog services Competition from satellite (e.g., DirectTV/Direct PC) & cable industry

Digital Subscriber Line (DSL) Standard Services Type DSLSpeed Asymmetric DSL1.5 to 8 Mbps to user 16 to 640 Kbps to network High-data-rate DSL1.544 Mbps to and from user Single-line DSL768 Kbps full duplex on a pair Rate-adaptive DSL1.5 to 8 Mbps to user 16 to 640 Kbps to network (can adjust speeds) Consumer DSL1 Mbps to user 16 to 128 Kbps to network (does not include splitter) ISDN DSLBasic ISDN rate Very-high-data-rate DSL13 to 52 Mbps to user 1.5 to 6 Mbps to network

DSL Rates (using 24 gauge wire) Connection Max Data Rate Distance Limit ADSL Mbps downstream K feet Up to Mbps upstream HDSL T Mbps (4 wire) 12,000 feet IDSL 144 Kbps (symmetric) 18,000 feet (36 w rptr) SDSL T Mbps (2 wire)11,000 feet VDSL Mbps downstream1-4.5 K feet Mbps upstream Up to 34 Mbps Symmetric R-ADSL Mbps downstream12-18 K feet Up to Mbps upstream

DSL Network Configuration

Asymmetric DSL Characteristics Uses frequency division multiplex occupying spectrum above voice Principal modulation scheme is Discrete multitone (DMT), a quadrature amplitude modulation coding technique developed by Bell Labs (ANSI T1.413 standard) Can be mapped into higher layer protocol mechanisms that can include IP frames or ATM cells Can interface to Simple Network Management Protocol (SNMP) for operations, administration and management 0-4 KHz 25KHz 200KHz 1.1MHz To Network To User

Cable Modem DSL Access

Serving CO Who Fixes The Network? Hub office DSLAM ADM DWDM Internet DWDM ATM Network Verizon ILECVerizon ILEC Worldcom Verizon Advanced DataVerizon Advanced Data Verizon Advanced Data AOL ADM LECNAP LEC NAP BackboneNAP NSP Application e-business Content Provider

Providers Ask Two Pivotal Questions Is the network service up and running properly? If it’s not, where’s the problem and how do we fix it? and how do we fix it?

LEC The Answer... trading partnersintegratedservice assurance Providers must tightly link their operations with their trading partners through integrated service assurance NAP NSP

Service Assurance Market Test & Measurement Operations Support Systems Service Assurance $3.5B* in 2000 $8.4B* in 2004 Growing at 25% Includes OSS software, services, and remote probes Key players: Spirent Communications, Telcordia, Lucent, Acterna (TTC/WWG), Micromuse * RHK Estimates

Service Assurance Activities Monitor SLAs Report Allocate Resources Determine SLA Violations Test Isolate Root Cause Detect Alarms/Events Detect Performance/Traffic Problems Decide Repair

Network “Communication” is Key Need to provide service information within and between networks LEC NAP NSP