1. EEL 4598/5718: Computer Communications
Wireless Information Networking Group (WING)
EEL 4598/5718: Computer Communications
Review 1

2. Layer Design Architecture
Wireless Information Networking Group (WING)
Layer Design Architecture
Seven Layer Reference Model
Their main functionalities
Mapping functionalities to corresponding layers
TCP/IP layering

3. Data Transmissions Signals and information representation
Wireless Information Networking Group (WING)
Data Transmissions
Signals and information representation
Time/frequency domain representations and their relationship
Data rate and bandwidth
Channel impairments
Channel capacity

4. Wireless Information Networking Group (WING)
Signal Coding Schemes
Line coding: NRZ-L, NRZI, bipolar-AMI, pseduoternary, Manchester and differential Manchester
Mapping from bit stream to waveform and vice versa
Digital modulation schemes (ASK, FSK, PSK)
Basic idea
A/D and D/A conversion (codec)
PCM and delta modulation (idea)

5. Performance Limits Nyquist capacity
Wireless Information Networking Group (WING)
Performance Limits
Nyquist capacity
Shannon capacity theorem: Given any two of C, SNR and W, the third quantity can be found
C=Blog2(1+SNR)
SNR=S/N: it is the ratio of signal power to the noise power in the given band with bandwidth B
SNR must be in decimal representation, not dB representation

6. Multiplexing and Switching
Wireless Information Networking Group (WING)
Multiplexing and Switching
Basic concepts on multiplexing and switching
Know the advantages and disadvantages of various switching technologies
Circuit switching (CS)
Virtual circuit switching (VCS)
Packet switching (PS)
Rough evaluation on CS, PS, and VCS

7. Data Link Control (DLC)
Wireless Information Networking Group (WING)
Data Link Control (DLC)
Error detection and correction
CRC code generation and redundancy check
Sliding window control mechanism
ARQ protocols and channel/link efficiency
Stop and Wait Protocol and its evaluation procedure
GBN (basic idea and operations)
Selective Repeat (basic idea and operations)
HDLC
Basic operational modes and examples
Bit stuffing and de-stuffing

8. Wireless Information Networking Group (WING)
First test
Consists of
A problem of multiple conceptual questions, testing fundamental concepts
2 or 3 individual problems testing specific topics
Lecture notes and homeworks are the base for the test
Simple calculator is allowed
One 8.5X11 crib sheet is allowed
2 hours