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Transcript of Shivkumar Kalyanaraman Rensselaer Polytechnic Institute 1 A Geography-Aware Community Wireless...
Shivkumar KalyanaramanRensselaer Polytechnic Institute
1
A Geography-Aware Community Wireless Testbed
Bow-Nan Cheng, Max KleinShivkumar Kalyanaraman
Email: [email protected]
: “shiv rpi”
RPI, Troy, NY
Funding: NSF-ITR 0313095, Intel
Shivkumar KalyanaramanRensselaer Polytechnic Institute
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Outline
Wireless Ad-hoc Mesh Networks: Challenges Physical Layer: A “street-level” network Network Layer: Addressing Framework and Auto-
configuration Microcosm Test Bed Lab Future Work
Shivkumar KalyanaramanRensselaer Polytechnic Institute
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Community Wireless: What’s New?
Lots of work in ad-hoc networks coming to fruition Startup companies in the mesh networks space:
Tropic networks, Mesh networks etc
What’s different in CWNs? Why a testbed? Unmanaged, but operational network Ad-hoc, but operational Fixed (I.e. not mobile) Medium scale Supports organic growth and evolution Supports legacy internet traffic
Shivkumar KalyanaramanRensselaer Polytechnic Institute
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Community Wireless Networks: Challenges ? Why a Testbed?
Auto-configuration and auto-management: Only lightweight “governance” allowed Beyond addressing: routing, naming, other protocols
Higher quality than ad-hoc networks to support legacy applications (links, end-to-end transport)
Capacity maximization (c.f. Gupta/Kumar results) => routing choices, traffic engineering
Cheap, simple, standards-based components. New community apps (eg: p2p video, games).
Several nitty-gritty issues leading to new protocol design challenges… best researched in a testbed…
Shivkumar KalyanaramanRensselaer Polytechnic Institute
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Broadband exists. Why CWN? Ans: Multiplicity.
Cable modem and DSL and CWN and … Commodity => cheap to get multiple access facilities …
EthernetWiFi (802.11b)802.11a
USB/802.11a/b
Firewire/802.11a/b
Phone modem
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Physical Layer: Street-level vs Rooftop Leverage directionality and quasi-LOS
of streets => better quality links Omni-directional vs.
Directional Antennas
Eg:
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Antennas: Pringles cans disappoint
Cheap… But low gain:
6.01425 dBi
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COTS Directional Antennas
2.4 GHz 12 dBi Radome Enclosed YagiSuperior performance Light weight All weather operation 45° beam-width Can be installed for either vertical or horizontal Polarization. Includes tilt and swivel mast mount
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Network Layer: Addressing Goals:
IP-based architecture Support for geographic routing
Why? Medium-scale, Organic Growth, Location-services
Support for local traffic engineeringWhy? Dirn antennas, capacity maximization.
Support for distributed auto-configuration
Proposed Addressing Framework: Geographic Distributed Addressing (GDA)
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Geographic Distributed
Addressing (GDA)
Idea: Hash GPS -> IP address
Shivkumar KalyanaramanRensselaer Polytechnic Institute
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Shivkumar KalyanaramanRensselaer Polytechnic Institute
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Why GPS-to-IP?
GPS-to-IP => Medium-scale, Server-less auto-configuration,
With routable addresses…
IP address has dual semantics: geographic and topological Long-range geographic routing/TE Short-range: (k-hop) topological RF-aware QoS routing … using the same IP/geographic address…
Location information also leveraged to auto-configure other L2/L3 protocols: Eg: cluster/area boundaries for routing, support location-based CWN
services
Shivkumar KalyanaramanRensselaer Polytechnic Institute
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Future: Geographic Source Routing
Source Routing
i.e. flex, large header
Greedy Routing
i.e. no header or state, but no flex
Trajectory-Based Routing
A
Q(t)
B
Trajectory defined as aparametric curveTBR route
Shortest-Pathroute
Gives us abilityto pick randomlyfrom a large number ofphysical routes
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Deployment Plan
Microcosm lab: internal prototyping, tests Logistics for long-term deployment around RPI
campus (eg: dealing with landlords etc) RPI-CIO providing access points at borders of campus
to help connect the CWN to RPI’s internal network
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Microcosm Test Lab
Variable attenuators, and directional antennas allow flexibilityin testing
We also intend to use public facilities like Utah’s Emulab Wireless
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Testbed Hardware… contd
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Testbed: Software
Fixed Nodes:- RedHat Linux Kernel 2.4.20-30.9- Click Modular Router: CVS March 5
Autoconfigured Nodes:- Redhat Linux 9: 2.4.20/21 Kernel- Click Modular Router: CVS March 5- HostAP 0.2 Driver + Utilities for
Firmware flashing- GPSD 1.10- DHCP Server + preconfigured NAT
w/ iptables ipmasq- Customized GSP Autoconf Scripts- Webserver + SSH in the future
-Intel Stargate/east platform will be considered as well
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Future Work GeoNet Framework to verify intersection between Geography
and Topological routing K-hop RF Awareness, QoS routing Distributed Geographic Traffic Engineering
Test Bed Improvements GPS Simulation Lab Reflectivity
Transport and application-layer activities kicked off Key: survival & quality under heavy erasure conditions. Collaboration ongoing with Intel and AT&T Research
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Vision #1: Multipath P2P Video/Data Over CWNs
“Fast” path
I
“Slow” path
P Traffic engineering &Transport level upgrades
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Vision #2: free-space-optical CWN
Ongoing NSF-STI project…
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Thanks!
: “shiv rpi”
Student Heroes: Bow-Nan Cheng: [email protected]
Max Klein: [email protected]