Developing and Deploying Multi-hop Wireless Networks for a Low-Income Communities

1. 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)

2. Outline • 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

3. 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

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

5. Pecan 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

6. TFA Melcher Library Map: Pecan Park Business District

7. Outline • Background • Societal Objectives • Community Benefits • TFA-Wireless Business Model • Lessons Learned: Community Outreach • Technical and Economic Objectives • Network Architecture • Future Work

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

9. TFA-Wireless Business Model

10. Lessons 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

11. Outline • Background • Technical and Economic Objectives • Network Architecture • Future Work

12. Economics: 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

13. Outline • Background • Technical and Economic Objectives • Network Architecture • Hardware Platform • Performance Targets • Network Topology • Future Work

14. Hardware: 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)

15. Performance 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

16. Network Topology • Hexagonal Packing • 250 meter range • Need for Directional Antennae

17. Outline • Background • Technical and Economic Objectives • Network Architecture • Future Work • Extensibility • Research Challenges • Measurement Study

18. Future: Extensibility • 802.11g Cards • Other CTCs and Neighborhoods • Increasing Customer Base • Maintain Sense of Community Involvement

19. Future: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

20. Future: 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

21. Questions?