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;...
Wireless Networks Lecture 45 Review of Lectures 26-44 Dr Ghalib A Shah Last Lecture 4G Overview ► Heterogeneous Wireless networks ► Evolution ► Issues in 4G Mobility Management Handoffs ► Types, VHO process, VHO Issues ► Standards QoS Considerations 26 - Outlines Overview of IEEE 802.11 IEEE 802.11 Protocols Architecture Services MAC Protocols ► DCF ► PCF 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 27 - Outlines 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 28 - Outlines Introduction ► ► ► ► ► 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) 29 - Outlines Types of Attack Goals of 802.11 Security WEP Protocol WEP Authentication Security flaws in original 802.11 How 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 IEEE 802.1X Terminology Supplicant Authentication Server Authenticator Uncontrolled port Controlled port 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 ► AIFS, CWmin, CWmax, Persistence factor (PF) 10 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 ► ► ► ► ► ► Radio techniques Scalability QoS Security Ease of Use Mesh connectivity 12 32 - Outlines MAC Layer ► ► ► ► Scalability Multi-Channel Some Ideas Research Issues Network Layer ► ► ► ► ► 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 ► ► ► ► Pure Link-level Approaches Soft-state Transport Layer Caching Approaches Soft-state Cross Layer Signalling Approaches Hard-state Transport Layer Approaches 14 34 - Outline Introduction to WSN Applications of WSN Factors Influencing Performance of WSN ► ► ► ► Power consumption Fault tolerance Scalability Topology Architecture and Communication Protocols Challenges in WSNs 15 35 - Outlines Attributes of MAC Protocol Energy Efficiency in MAC Proposed Routing Protocol ► ► ► ► ► ► S-MAC T-MAC DS-MAC Traffic Adaptive MAC DMAC Contention-Free MAC 16 36 - Outlines Routing Challenges and Design Issues ► ► ► ► ► ► Deployment Routing method Heterogeneity Fault tolerance Power Mobility etc Routing Protocols ► ► ► ► ► ► ► ► SPIN Directed Diffusion ACQUIRE LEACH TEEN/APTEEN GAF GEAR SPEED 17 37 - Outlines Transport Protocols for WSN TCP/UDP for WSN Protocols ► PSFQ ► ESRT ► CODA Security Threats in WSN TinySec Motivations of Link Layer security TinySec Design goals 18 38 - Outlines Security primitives in TinySec Encryption Schemes Keying mechanism WMSN ► ► ► ► ► Architecture Applications Advantages Design Considerations Protocols WSAN ► Motivation ► WSN vs WSAN ► Architecture 19 39 - Outlines Bluetooth introduction Technical features Access technique Bluetooth topology/scenario Specifications Core Protocols Link connections 20 40 - Outlines IP Over Bluetooth Bluetooth Security WPAN Standards IEEE 802.15.3 Overview 802.15.3 ► Topology ► Coordination • • • ► ► ► ► Starting a Piconet Handing over control of piconet Creating child piconet Medium Access (Super-frame) Channel Time Management Power management MAC Frame format 21 41 - Outlines IEEE 802.15.4 ► Basics, Type of Devices ► Phy Layer ► Channel Access Mechanisms • Slotted/Unslotted CSMA/CA ► Super-frame Structure 22 42 - Outlines WiMAX Basics 802.16 Evolution 23 43 - Outlines Reference Model Burst profiles Classes of Uplink service 24 44 - Outline 4G Overview Mobility Management Handoffs 25 ... Schemes for Wireless ► ► ► ► Pure Link-level Approaches Soft-state Transport Layer Caching Approaches Soft-state Cross Layer Signalling Approaches Hard-state Transport Layer Approaches 14 34 - Outline... Outlines Attributes of MAC Protocol Energy Efficiency in MAC Proposed Routing Protocol ► ► ► ► ► ► S-MAC T-MAC DS-MAC Traffic Adaptive MAC DMAC Contention-Free MAC 16 36 - Outlines Routing... Slotted/Unslotted CSMA/CA ► Super-frame Structure 22 42 - Outlines WiMAX Basics 802.16 Evolution 23 43 - Outlines Reference Model Burst profiles Classes of Uplink service 24 44 - Outline 4G Overview