ECEN4533 Data Communications
Lecture #8          2 February 2009
Dr. George Scheets

ECEN4533 Data Communications
Lecture #10          6 February 2009
Dr. George Scheets

Internet Router

OSU Campus Network (> 2001)

Binary ASK

Binary FSK

Binary PSK

POTS Connectivity (1920)

POTS Connectivity (1970)

POTS Connectivity (1990)

Sources of POTS delay

POTS at the CO Switch

PC Dial-Up Modems & POTS

Nyquist's Sampling Theorem

Video undersampling

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

IEEE 802.3 Ethernet

ISO OSI Seven Layer Model
Ethernet (Packet Switched, StatMux)

802.3 Ethernet Packet Format

Duplex: We're not talking apartments

Slide 41