Developing and Deploying Multi-hop Wireless

Networks for a Low-Income Communities

Developing and Deploying Multi-hop Wireless

Networks for a Low-Income Communities

Authors: Joseph Camp (Rice U.) Edward Knightly (Rice U.)Will Reed (Technology For All)

Authors: Joseph Camp (Rice U.) Edward Knightly (Rice U.)Will Reed (Technology For All)

OutlineOutline

• Background– Technology For All (TFA)– Rice Transit Access Points (TAPs)

Project– Neighborhood Demographics– Map: Pecan Park

• Societal Objectives• Technical and Economic Objectives• Network Architecture• Future Work

• Background– Technology For All (TFA)– Rice Transit Access Points (TAPs)

Project– Neighborhood Demographics– Map: Pecan Park

• Societal Objectives• Technical and Economic Objectives• Network Architecture• Future Work

Technology For All (TFA)Technology For All (TFA)MISSION: To empower low-income and

under-resourced communities through the tools of technology

• TFA-Wireless created to deploy a wireless cloud around neighborhood

• TFA-Wireless using sustainable business model to provide broadband Internet access to local residents and businesses

• TFA-Wireless – one example of TFA’s social enterprise strategy to achieve its mission

MISSION: To empower low-income and under-resourced communities through the tools of technology

• TFA-Wireless created to deploy a wireless cloud around neighborhood

• TFA-Wireless using sustainable business model to provide broadband Internet access to local residents and businesses

• TFA-Wireless – one example of TFA’s social enterprise strategy to achieve its mission

Rice TAPs ProjectRice TAPs Project

• NSF Funded Project (5 years, $7.5M)• In Connection with 100x100 Project• Real-world motivation

• NSF Funded Project (5 years, $7.5M)• In Connection with 100x100 Project• Real-world motivation

Pecan Park DemographicsPecan Park Demographics

• Per-capita Income one-third of national average

• 36.7 percent of children (under 18) live below poverty line

• 71 percent of families with children under 5 live below poverty line

• 64.2 percent of adults (over 25) are without high school diploma or GED

• 4.2 square kilometers in area

• Per-capita Income one-third of national average

• 36.7 percent of children (under 18) live below poverty line

• 71 percent of families with children under 5 live below poverty line

• 64.2 percent of adults (over 25) are without high school diploma or GED

• 4.2 square kilometers in area

Map: Pecan ParkMap: Pecan Park

TFAMelcher Library

Business

District

OutlineOutline

• Background• Societal Objectives

– Community Benefits– TFA-Wireless Business Model– Lessons Learned: Community Outreach

• Technical and Economic Objectives• Network Architecture• Future Work

• Background• Societal Objectives

– Community Benefits– TFA-Wireless Business Model– Lessons Learned: Community Outreach

• Technical and Economic Objectives• Network Architecture• Future Work

Societal ObjectivesSocietal Objectives

• Affordable Internet access• Online education opportunities • Work-at-home opportunities• Health education and information• Economic Development• Sustainable Business Model

• Affordable Internet access• Online education opportunities • Work-at-home opportunities• Health education and information• Economic Development• Sustainable Business Model

TFA-Wireless Business ModelTFA-Wireless Business Model

Lessons Learned: Community OutreachLessons Learned: Community Outreach• Early adopters at all socio-economic

levels• Higher community interest when

members of the community involved

• Low-income community wants a high quality affordable product

• More community broadband in neighborhood than expected

• Early adopters at all socio-economic levels

• Higher community interest when members of the community involved

• Low-income community wants a high quality affordable product

• More community broadband in neighborhood than expected

OutlineOutline

• Background• Technical and Economic

Objectives• Network Architecture• Future Work

• Background• Technical and Economic

Objectives• Network Architecture• Future Work

Economics: Case for MeshEconomics: Case for Mesh

• Fiber as high as $200,000 per linear mile

• DSL and CATV infeasible• $1K/month for 1.5 Mbps• $5K to $30K/month for 45 Mbps • Economies of scale: Affordable IEEE

802.11 Hardware• Aggregate all traffic to a single wire

• Fiber as high as $200,000 per linear mile

• DSL and CATV infeasible• $1K/month for 1.5 Mbps• $5K to $30K/month for 45 Mbps • Economies of scale: Affordable IEEE

802.11 Hardware• Aggregate all traffic to a single wire

OutlineOutline

• Background• Technical and Economic Objectives• Network Architecture

– Hardware Platform– Performance Targets– Network Topology

• Future Work

• Background• Technical and Economic Objectives• Network Architecture

– Hardware Platform– Performance Targets– Network Topology

• Future Work

Hardware: VIA mini-ITXHardware: VIA mini-ITX

• VIA C3 1Ghz• SMC 200 mW 802.11b• 5 GB Hard Drives• 32 MB Flash to run

Linux OS• LocustWorld Mesh SW• 15 dBi Omni-

directional Antenna (8 deg. Beam)

• VIA C3 1Ghz• SMC 200 mW 802.11b• 5 GB Hard Drives• 32 MB Flash to run

Linux OS• LocustWorld Mesh SW• 15 dBi Omni-

directional Antenna (8 deg. Beam)

Performance TargetsPerformance Targets

• Four Hop Limitation– Inefficiency in forwarding single

active flows over multiple hops– Unfairness of 802.11 when multiple

flows active from multiple hops

• 1 Mbps Commercial Connection– 3 Mbps backbone

• Four Hop Limitation– Inefficiency in forwarding single

active flows over multiple hops– Unfairness of 802.11 when multiple

flows active from multiple hops

• 1 Mbps Commercial Connection– 3 Mbps backbone

Network TopologyNetwork Topology

• Hexagonal Packing

• 250 meter range

• Need for Directional Antennae

• Hexagonal Packing

• 250 meter range

• Need for Directional Antennae

OutlineOutline

• Background• Technical and Economic Objectives• Network Architecture• Future Work

– Extensibility– Research Challenges– Measurement Study

• Background• Technical and Economic Objectives• Network Architecture• Future Work

– Extensibility– Research Challenges– Measurement Study

Future: ExtensibilityFuture: Extensibility

• 802.11g Cards• Other CTCs and

Neighborhoods• Increasing

Customer Base• Maintain Sense of

Community Involvement

• 802.11g Cards• Other CTCs and

Neighborhoods• Increasing

Customer Base• Maintain Sense of

Community Involvement

Future:Research ChallengesFuture:Research Challenges• Off-the-Shelf means fixed Media Access

Control (MAC) and Physical (PHY) Layers• Rate Limiting on Nodes• TCP over wireless• Synergizes well with TAPs Project

– 400 Mbps Multi-Input Multi-Output (MIMO) Physical Layer

– Custom Hardware using Field-Programmable Gate Arrays (FPGAs)

– Fairness in Multi-hop Wireless

• Off-the-Shelf means fixed Media Access Control (MAC) and Physical (PHY) Layers

• Rate Limiting on Nodes• TCP over wireless• Synergizes well with TAPs Project

– 400 Mbps Multi-Input Multi-Output (MIMO) Physical Layer

– Custom Hardware using Field-Programmable Gate Arrays (FPGAs)

– Fairness in Multi-hop Wireless

Future: Measurement StudyFuture: Measurement Study• SNMP and tcpdump for network

monitoring• Network Planning

– Link Level Measurements• Mesh node to client• Mesh node to mesh node

– Multi-hop Measurements– Placement Schemes

• SNMP and tcpdump for network monitoring

• Network Planning– Link Level Measurements

• Mesh node to client• Mesh node to mesh node

– Multi-hop Measurements– Placement Schemes

Questions?Questions?