ADG 1

Fall 2013 Review

A slide to a chapter summary of the material covered

(based on the 8/e book)

ADG 2

C1. Data Communications and Networking Overview

• The 3 (or 5) entity general communication model• Actual data communications is more complicated

– Transmission system utilization, interface, signal generation, synchronization, exchange management, error detection and correction, flow control, addressing, routing, recovery, message formatting, security, network management

• Networking – LANs– MANs– WANs

• circuit switching, • packet switching

– frame relay, cell relay

ADG 3

C2. Protocol Architecture• A simple (quite general) protocol architecture

– Protocols: syntax, timing, semantics• Layering combats complexity• Open System Interconnection (OSI)

– 7 layers– Standardisation framework– Service Primitives, and Parameters

• The TCP/IP protocol architecture– 5 layers– The “industry” standard

ADG 4

C3. Data transmission• Terminology

– Frequency, spectrum, bandwidth etc• Any signal can be expressed as an infinite number of sine

waves (frequency components).– Remember it is only the odd ones (1, 3, 5, 7….)

• Relationship between data rate and bandwidth– The higher the data rate the higher the required bandwidth– The higher the bandwidth the greater data rate can be achieved

• Transmission impairments (attenuation, delay distortion, noise)

• Channel capacity (Nyquist, Shannon)

ADG 5

C4. Transmission Media

• Guided media (description, characteristics, categories) (3)

• Wireless transmission technologies (3)– Dish antenna, Antenna gain

• Wireless propagation (3)• Wireless (line-of-sight) impairments (4)

ADG 6

C5. Signal Encoding Techniques

• Digital & Analogue Data – to Digital & Analogue Signals

• D-dataA-signal(3)• D-dataD-signal(3, 6, scrambling)• A-dataD-signal(2)• A-dataA-signal(3)

ADG 7

C6. Digital Data Communication Techniques

• Transmission approaches – Synchronous– Asynchronous

• Errors, types• Error detection• Error correction

ADG 8

C7. Data Link Control Protocols

• Flow control (SAW, SW)• Error control (ARQ and its mechanisms)• HDLC protocol

– Basics (types of stations, configuration and modes)

– Frame types and structure– Operation

ADG 9

C8. Multiplexing

• Utilising a single line to relay multiple connections

• Frequency Division• Time Division• Statistical Time Division (relies on non frequent

use)• ADSL

– Separates the 1MHz in 3 regions– FDM within upload and download

ADG 10

C14. Cellular Wireless Networks

• Not covered fully (first 14 slides) • Cellular network organisation

– Cells– Frequency reuse– Increasing the capacity

• Operation of a cellular systems– Base station– Cells– MTSO

ADG 11

C17. Wireless Networks

• Single and multi cell LANs• Applications (nomadic, adhoc, cross

building, lan extension)• Technologies

– IR, Spread spectrum, Narrow band microwave

ADG 12

C15. LAN Overview• LAN applications (high speed, backbone, storage area

networks, personal, backend)• Topologies (ring, star, bus, tree)• IEEE 802 reference model

– LLC and MAC• Medium Access Control

– Central vs distributed– Synchronous vs asynchronous

• Asynchronous– Round robin, reservation, contention

• Bridges (only basic functionality)

ADG 13

Finally (the exam)

• 40 Multiple choice questions– I might increase the number, I’ll let you know on my website

• Wednesday 15/01/2014• This room (216)• Between 09:00 and 11:30• Bring (Yourself (on time))

– Your stationary– A watch (silent mobiles are allowed)– A dictionary (if you need one)– A bottle of water or drink (only if it has a cap, no open glasses and

such)