Wireless Community Mesh Networks Hype or the Next Big Frontier

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Wireless Community Mesh Networks - Hype or the
Next Big Frontier?

• Ed Knightly
• Rice University
• http//www.ece.rice.edu/knightly

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Mesh Networks Why do we need them?

• Residences and small business access the Internet
  via slow and expensive wires

• Download speeds are in the 100s of kb/sec range.
  Average maximum comScore2003
• Cable 708 kb/sec, DSL 467 kb/sec
• The fiber glut has not reached the last mile
• 8,000 to 52,800 per fiber mile
• Estimated 100 billion for US fiber-to-the-home
• Copper T1 600 to 1500/month, DS3 5k to 30k

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Mesh Networking Case Studies

• Technology For All Houston, Texas (non-profit)
• Mesh network for low income residences,
  libraries, and small businesses

• Fastline Internet Vivian, Louisiana
• Bypassed by cable and DSL
• Mesh network with tiered pricing for bandwidths
  of 64 kb/s to 1 Mb/sec (10/mo to 60/mo)
• Research Testbeds (IITK, Microsoft, MIT, Rice, )
• And many more

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Report Card
A connectivity, deployability, economics
C performance
I service model, security, protocols,

• We can do better!
• 100 Mb/sec to leapfrog wireline technologies and
  enable new applications
• Thesis
• Ditch everything we think we know about ad hoc
  networks
• Clean-slate design

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Why Clean Slate Design?

• Deep understanding of mobile ad hoc networks

1000m x 1000m Random node placement Random
traffic matrix Random waypoint mobility
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Why Clean Slate Design?

• Critical differences mesh vs. ad hoc networks
• Mesh APs are non-mobile powered infrastructure
• Their placement is planned vs. random
• Traffic matrices are not uniform random
• Per-user, per-time performance critical
• A starved user or poor route could last
  indefinitely
• Architecture, service model, ownership model,
  security,
• WLAN, like mesh is infrastructure. Critical
  differences
• Mesh APs are not wired, are outdoors,

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Why Clean Slate Design?
Scenario Changed Fundamentally
Architecture, Protocols, PHY Change
Fundamentally
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Research Challenges

• Physical layer
• Achieve 100s of Mb/s among TAPs (MIMO!)
• Media access
• Target multi-hop and exploit PHY capabilities
• Fairness and traffic control
• With TCP/WiFi, nodes farther away from wires get
  much less bandwidth and can starve
• Prototypes, Testbeds, and Measurement Studies
• Platforms for experimentation and proof-of-concept

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Rice TAP (Transit Access Point) Platform

• 400 Mb/sec via 4x4 MIMO custom design
• Non line of sight
• Single 2.5 GHz WiFi channel and 20 bits/sec/Hz
  efficiency
• Custom MAC design and FPGA implementation

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Summary

• Where are we?
• DSL and Cable plodding along at 100s of kb/sec
• Mesh networks undercutting prices and serving
  under-served areas
• Where should we go?
• High speed 100 Mb/sec
• How to get there from here?
• Research!
• Shameless plug
• Rice TAPs project http//taps.rice.edu
• 100x100 project http//100x100network.org