Wireless networks - Lecture 45: Review of Lectures 26-44

Wireless Networks

Lecture 45
Review of Lectures 26-44
Dr. Ghalib A. Shah

1


Last Lecture
 4G Overview
► Heterogeneous Wireless networks
► Evolution
► Issues in 4G

 Mobility Management
 Handoffs
► Types, VHO process, VHO Issues
► Standards

 QoS Considerations
2


26 - Outlines
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Overview of IEEE 802.11
IEEE 802.11 Protocols
Architecture
Services
MAC Protocols
► DCF
► PCF

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Overview, IEEE 802.11 Committee
 Committee formed in 1990
► Wide attendance

 Multiple Physical Layers
► Frequency Hopping Spread Spectrum
► Direct Sequence Spread Spectrum
► Infrared

 2.4GHz Industrial, Scientific & Medical shared
unlicensed band
► 2.4 to 2.4835GHz with FCC transmitted power limits

 2Mb/s & 1Mb/s data transfer
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27 - Outlines
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Problems with DCF
Virtual Carrier Sensing
RTC/CTS Protocol
Inter-frame Spacing
PCF
Fragmentation / Reassembly
MAC Frame Format
Frame Types
Physical Media in Original IEEE 802.11
5


28 - Outlines
 Introduction
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What is Ad hoc networks?

Characteristic
Ad hoc vs. cellular networks
Application
Challenges

 Routing Protocol
► Expected Properties of Ad-hoc Routing Protocols
► A taxonomy for routing protocols in Mobile ad
► Some common protocols (DSDV, AODV, DSR, ZRP,
TORA)
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29 - Outlines
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Types of Attack
Goals of 802.11 Security
WEP Protocol
WEP Authentication
Security flaws in original 802.11

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How 802.1x Address Security Issues of 802.11

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EAP Framework
User Identification & Strong authentication
Dynamic key derivation
Mutual authentication
Per-packet authentication
Dictionary attack precautions

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IEEE 802.1X Terminology

Supplicant

Authentication 
Server

Authenticator
Uncontrolled port

Controlled port

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30 - Outlines
Limitations of QoS in IEEE 802.11
Overview of 802.11e
EDCF
HCF
QoS is realized by introducing traffic categories
(TCs)
 Each instance is parameterized with TC
specific parameters
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► AIFS, CWmin, CWmax, Persistence factor (PF)
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Example
Network B

Foreign Agent

Home
network A
Internet
Home Agent

Network C

Mobile Node

Corresp.
Node C
slide by Konidala M. Divyan [3]


31 - Outlines
 Introduction to WMN
 Characteristics
 WMN vs MANET
► Backbone, dedicated routing, mobility, multiple radios

 Architecture
 Applications
 Critical factors influencing performance
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Radio techniques
Scalability
QoS
Security

Ease of Use
Mesh connectivity
12


32 - Outlines
 MAC Layer
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Scalability
Multi-Channel
Some Ideas
Research Issues

 Network Layer
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Routing
Wish List
Route Optimization Criteria
Routing fairness
Routing – Cross-layer design

 QoS Support at each layer
 WMN Standards
13


33 - Outlines
 TCP Variants
► Slow start
► Fast Retransmit/Recovery (TCP Reno)

 Issues in Heterogeneous Wireless Networks
 TCP Schemes for Wireless
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Pure Link-level Approaches
Soft-state Transport Layer Caching Approaches
Soft-state Cross Layer Signalling Approaches
Hard-state Transport Layer Approaches
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34 - Outline
 Introduction to WSN
 Applications of WSN
 Factors Influencing Performance of WSN
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Power consumption
Fault tolerance
Scalability
Topology

 Architecture and Communication Protocols
 Challenges in WSNs.

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35 - Outlines
 Attributes of MAC Protocol
 Energy Efficiency in MAC
 Proposed Routing Protocol
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S-MAC
T-MAC
DS-MAC
Traffic Adaptive MAC
DMAC

Contention-Free MAC
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36 - Outlines
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Routing Challenges and Design Issues
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Deployment
Routing method
Heterogeneity
Fault tolerance
Power
Mobility etc

Routing Protocols
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SPIN
Directed Diffusion
ACQUIRE
LEACH
TEEN/APTEEN
GAF
GEAR
SPEED
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37 - Outlines
 Transport Protocols for WSN
 TCP/UDP for WSN
 Protocols
► PSFQ
► ESRT
► CODA

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Security Threats in WSN
TinySec

Motivations of Link Layer security
TinySec Design goals
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38 - Outlines
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Security primitives in TinySec
Encryption Schemes
Keying mechanism
WMSN
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Architecture
Applications
Advantages
Design Considerations
Protocols

 WSAN
► Motivation
► WSN vs WSAN

► Architecture
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39 - Outlines
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Bluetooth introduction
Technical features
Access technique
Bluetooth topology/scenario
Specifications
Core Protocols
Link connections

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40 - Outlines
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IP Over Bluetooth
Bluetooth Security
WPAN Standards
IEEE 802.15.3 Overview
802.15.3
► Topology
► Coordination
•
•
•

►
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Starting a Piconet
Handing over control of piconet
Creating child piconet

Medium Access (Super-frame)
Channel Time Management
Power management
MAC Frame format
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41 - Outlines
 IEEE 802.15.4

► Basics, Type of Devices
► Phy Layer
► Channel Access Mechanisms
• Slotted/Unslotted CSMA/CA

► Super-frame Structure

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42 - Outlines
 WiMAX Basics
 802.16 Evolution

23


43 - Outlines
 Reference Model
 Burst profiles
 Classes of Uplink service

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44 - Outline
 4G Overview
 Mobility Management
 Handoffs

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