Wireless networks - Lecture 45: Review of Lectures 26-44. The main topics covered in this chapter include: overview of IEEE 802.11; problems with DCF, virtual carrier sensing, RTC/CTS protocol; Ad-hoc networks; expected properties of Ad-hoc routing protocols; limitations of QoS in IEEE 802.11;...
Trang 1Wireless Networks
Lecture 45Review of Lectures 26-44
Dr Ghalib A Shah
Trang 4Overview, 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
Trang 6► Expected Properties of Ad-hoc Routing Protocols
► A taxonomy for routing protocols in Mobile ad
► Some common protocols (DSDV, AODV, DSR, ZRP,
TORA)
Trang 8How 802.1x Address Security Issues of 802.11
EAP Framework
User Identification & Strong authentication
Dynamic key derivation
Mutual authentication
Per-packet authentication
Dictionary attack precautions
Trang 9IEEE 802.1X Terminology
Controlled port Uncontrolled port Supplicant Authenticator Authentication Server
Trang 11slide by Konidala M Divyan [3]
Example
Internet Home Agent
Mobile Node
Trang 13► Routing – Cross-layer design
QoS Support at each layer
WMN Standards
Trang 1433 - Outlines
TCP Variants
► Slow start
► Fast Retransmit/Recovery (TCP Reno)
Issues in Heterogeneous Wireless Networks
TCP Schemes for Wireless
► Pure Link-level Approaches
► Soft-state Transport Layer Caching Approaches
► Soft-state Cross Layer Signalling Approaches
► Hard-state Transport Layer Approaches
Trang 1635 - Outlines
Attributes of MAC Protocol
Energy Efficiency in MAC
Proposed Routing Protocol
Trang 18 Motivations of Link Layer security
TinySec Design goals
Trang 21• Handing over control of piconet
• Creating child piconet
► Medium Access (Super-frame)
► Channel Time Management
► Power management
► MAC Frame format
Trang 2342 - Outlines
WiMAX Basics
802.16 Evolution