ECEN4533 Data Communications
Lecture #6          23 January 2012
Dr. George Scheets

ECEN4533 Data Communications
Lecture #7          25 January 2012
Dr. George Scheets
www.okstate.edu/elec-engr/scheets/ecen4533

ECEN4533 Data Communications
Lecture #8          27 January 2012
Dr. George Scheets

RedNeckNet VoIP

Grading

Multiplexing

FDM

TDM

TDMA/
FDMA

StatMux

CDM

CDMA: 3D View

Direct Sequence Spread Spectrum

Slide 14

Wireless

Slide 16

Receiver Bit Detection

Receiver Bit Detection

Detection (OSI Level 1)

Someone else talking?

Someone else
 talking?

Someone else
 talking?

Two signals active?

Two signals active.

Our Traffic is Still Recovered

Switching: How Long will a
user get to use a channel?

TDM & Circuit Switching

StatMux & Packet Switching

TDM or StatMux & Cell Switching

Slide 30

Repeater or Hub

Black Box Performance...

Black Box Performance...

WAN Switch
LAN Switched Hub or Bridge

Black Box Performance...

Black Box Performance...

Internet Router

OSU Campus Network (> 2001)

Binary ASK

Binary FSK

Binary PSK

Binary PSK

POTS Connectivity (1920)

POTS Connectivity (1970)

POTS Connectivity (1990)

POTS at the CO Switch

Nyquist's Sampling Theorem

Video undersampling

PC Dial-Up Modems & POTS

Sources of POTS delay

Example) Coding a
Microphone Output

A/D Convertor

A/D Convertor. 1 bit/sample.

A/D Convertor. 1 bit/sample.

A/D Convertor. 1 bit/sample.

A/D Convertor. 2 bits/sample

A/D Convertor. 2 bits/sample.

Circuit Switched Voice (POTS)

1/8th Second of Voice

1/8th Second of Voice

1/8th Second of Voice

Sampling & Quantizing Examples

SONET Hierarchy

T Carrier & SONET

Leased Line Networks

ISO OSI Seven Layer Model
Leased Line (Circuit Switched, TDM)
 Organized around Frames:1/8000th second entity

Leased Line Packet Format

Leased Line Backbone

Carrier Leased Line Network

Circuit Switched connections waste bandwidth for bursty traffic.

Carrier Leased Line Network

Slide 72