Post on 28-Dec-2015
Wireless Mesh
The Premise
Case for Wireless Mesh• High-speed wireless packet data access across a
wider coverage area – Cellular systems don't provide the bandwidth available in
WLANs. – Isolated hotspot 802.11 deployments don't provide
ubiquitous access or mobility– Emergence of small-form factor terminals with 802.11
• Minimizes cost of capital, installation and commissioning – Utilizes low-cost 802.11 technology. – Uses wireless links for backhaul to eliminate costs
associates with installation of wired interconnect. – Auto-configuration algorithms in Wireless Access Point
eliminate costs associated with engineering and organization of the wireless backhaul network.
Wireless Mesh (Cont’d)
• Minimizes cost of operations – Uses wireless links for backhaul to eliminate costs
associated with ongoing leasing of facilities. – Auto-configuration, self-organizing and self-healing
are intrinsic to the Wireless Mesh Network solution – Centralized OAM&P minimizes staffing requirements.
• Highly flexible in terms of capacity, coverage and availability – Increasing capacity, coverage and/or availability
simply means deploying more Wireless Access Points.
– Wireless Access Points maybe deployed indoors or outdoors
Community Applications
• Shared Broadband Internet Access• Ubiquitous Access (roaming solved: one “true”
network)• Neighborhood Gaming• Medical & emergency response• Neighborhood watchdog (e.g. video
surveillance)• Shared Community Resource
– Media repository – Distributed backup
Challenges
• Range and Capacity– Inexpensive electronically targettable directional antenna
or MIMO for range enhancement– Multiple frequency meshes– Multi-radio hardware for capacity enhancement via greater
spectrum utilization– New data channel MAC with Interference management or
higher throughput
• Multi-hop Routing– L2.5 on-demand source routing with link quality based
routes selection– Route selection with multiple radios (multiple channels)
Challenges (cont’d)
• Security, Privacy– Guard against malicious users (and freeloaders)– EAP-TLS between MeshBoxes, PEAPv2 or EAP-TLS
between clients and MeshBoxes– Priority based admission control
Self Management & Self Healing– Minimal human intervention - avoid network operator – Watchdog mechanism with data cleaning and liar
detection
Challenges (cont’d)
• Smart Spectrum Utilization • Analytical Tools• Ease of use (Plug and play,
HCI)• Digital Rights Management (DRM)
Mesh Routing Functionality
Data Channel RadioMiniport Driver
Control Channel Radio
Miniport driver
Mesh Routing Functionality
Mesh Management Module
TCP / IP
Mesh Connectivity Layer(MCL)
Multi-hop Routing/Bridging Radio Selection Metric
Topology Control
Link Monitor Module
Mesh Box Configuration
SECURITY
Diagnostics Kernel Module
Diagnostics Client and Server DLLs
Mesh Capacity
• Connectivity Graph– Models node connectivity– Incorporates capacity of each link
• Conflict Graph – Captures interference among links
• Tool– Solves MAXFLOW problem on the connectivity graph
with constraints drawn from the conflict graph
• “What-if” Analysis– Scenario based numbers instead of asymptotic bounds– Allows evaluation of different wireless technologies