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 log10 1000 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 = 103 = 1000 watts

35 dBw = 103.5 = 3162.3 watts

Note: There’s a point between the 3 & 5.

Decibells & Logarithms

dBW Watts -3 .5 0 1 3 2 6 4 9 8 10 10 20 100 30 1000 40 10000

Nyquist1. Nyquist: The maximum practical data rate (samples) per channel.

Max R = 2 H log2 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 log2 of V = 4. If V = 2, the log2 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 log2 (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)

No = Noise Density = kT, where k is Boltzmann’s Constant (-228.6 dBw)

(Used in Carrier to Noise ratios, i.e., C/No)

T = SNT = System Noise Temperature(Used in radio and satellite linkequations, 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 5-8Manchester 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 5-31

4-PSK

Figure 5-32

4-PSK Characteristics

Figure 5-338-PSK Characteristics

Figure 5-34

Baud Rate and Bandwidth in PSK

Figure 5-35

4-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 channelB - 64 Kbps digital PCM channel for voice or dataC - 8 or 16 Kbps digital channelD - 16 Kbps digital channel for out of band signallingE - 64 Kbps channel for internal ISDN signallingH - 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 ISDNExchange

T U

R, S, T & U are CCITT defined reference PointsTA 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 DSL SpeedAsymmetric DSL 1.5 to 8 Mbps to user

16 to 640 Kbps to networkHigh-data-rate DSL 1.544 Mbps to and from userSingle-line DSL 768 Kbps full duplex on a pairRate-adaptive DSL 1.5 to 8 Mbps to user

16 to 640 Kbps to network(can adjust speeds)

Consumer DSL 1 Mbps to user16 to 128 Kbps to network(does not include splitter)

ISDN DSL Basic ISDN rateVery-high-data-rate DSL 13 to 52 Mbps to user

1.5 to 6 Mbps to network

DSL Rates (using 24 gauge wire)

Connection Max Data Rate Distance LimitADSL 1.5-8 Mbps downstream 12-18 K feet

Up to 1.544 Mbps upstream

HDSL T1 - 1.544 Mbps (4 wire) 12,000 feet

IDSL 144 Kbps (symmetric) 18,000 feet (36 w rptr)

SDSL T1 - 1.544 Mbps (2 wire) 11,000 feet

VDSL 13-52 Mbps downstream 1-4.5 K feet 1.5-2.3 Mbps upstream Up to 34 Mbps Symmetric

R-ADSL 1.5-8 Mbps downstream 12-18 K feet Up to 1.544 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

ATMNetwork

VerizonILEC Verizon ILEC

Worldcom

VerizonAdvanced

Data Verizon Advanced Data

VerizonAdvanced

Data

AOL

AOL

ADM

ADM

ADM

LEC NAP LEC NAP

BackboneNAPNSPApplicatione-business

Content Provider

Providers Ask Two Pivotal Questions

Is the network service up Is the network service up

and running properly?and running properly?

If it’s not, where’s the If it’s not, where’s the problemproblem

and how do we fix itand how do we fix it??

LEC

The Answer...

Providers must tightly link their operations with their trading trading partnerspartners through integratedintegrated service assurance service assurance

NAP

NSP

Service Assurance Market

Test & Measurement

Test & Measurement

OperationsSupportSystems

OperationsSupportSystems

Service AssuranceService AssuranceService AssuranceService 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 SLAsMonitor SLAs

ReportReport

Allocate ResourcesAllocate Resources

Determine SLA ViolationsDetermine SLA Violations

TestTest

Isolate Root CauseIsolate Root Cause

Detect Alarms/EventsDetect Alarms/Events

Detect Performance/Traffic ProblemsDetect Performance/Traffic Problems

Decide RepairDecide Repair

Network “Communication” is Key

Need to provide service information within and between networks

LEC

NAP

NSP