The CATER Initiative
Cost-Effective Appropriate Technologies for
Emerging Regions
Lakshminarayanan Subramanian
Courant Institute of Mathematical Sciences
New York University
A joint effort with researchers from Courant
Institute, NYU School of Medicine, NYU Wagner School of
Public Policy
The CATER Lab
Mission:
Develop low-cost and appropriate Information and
Communication Technologies (ICT) for improving essential
services in developing regions around the world
Focus Application Areas
• Communications
• Healthcare
• Micro-finance
• Education
The CATER team
Technology
NYU:
• Lakshmi Subramanian
• Jinyang Li
• Yann Lecun
External collaborators:
• Eric Brewer(Berkeley)
• Tapan Parikh(Berkeley)
Healthcare and Medical
Education
• Mary Ann Hopkins
• Brian Levine
Micro-finance
• Jonathan Morduch
• Tapan Parikh
Developmental Economics
• Yaw Nyarko
Why ICTD Research?

Development Theories

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
Sachs: Give Aid
Easterly: $50 trillion – nothing much to show
Prahlad: Bottom of the pyramid
Empower Rural Markets (Amartya Sen)
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3-4 billion people with per-capita < US$2,000/year
Could swell to 6-8 billion over the next 25 years
Most live in rural villages or urban slums and shanty
towns—movement towards urbanization
Hard to reach, disorganized, and local markets
4
ICT: A Big Missing Piece

Communications

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Awareness, access to external world, phone calls
Healthcare

“Where there is No Doctor?”: Rural healthcare system

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Finance
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Microfinance audit, insurance schemes
Education
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Telemedicine/consultation
Continuing Medical Education for Health-workers
Low-cost diagnostic tools
Educational modules, distance learning
Others

Agriculture, Commerce, Supply chain and E-governance
5
Network connectivity is key!
Traditional wire-line connectivity solutions are
not economically viable!
 Potential options


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Develop new low-cost connectivity solution!
Leverage existing low-bandwidth wireless solutions

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Cellular, Satellite, CDMA450, WiMax
Intermittent links are a fact of life

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Budget constrained links
SMS
Power outages
Physical transportation links
6
Connectivity options
Type of Network Connectivity
High b/w
(5-10 Mbps)
WiLDNet
Telemedicine,
Distance
Learning,
Education,
Video
Low b/w
Intermittent
Intermittent
(10-80 Kbps)
Low b/w
High delay
GPRS, Satellite, Usage constraint
Bus,
CDMA, WiMax
SMS
Postal network
Teleconsultation,
IP Telephony,
Web and
Cellphone based
services
Cell-phone
Services for
Finance
Supply Chain
Health care
Rural Cafes
Rural ATMs
Bulk content
7
Distribution
Focus Areas

High bandwidth low-cost connectivity

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Extending the Web to Rural Areas
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WiRE architecute: An alternative to Cellular
WiLDNet: Wifi-based Long Distance Networks
Multi-Radio Mesh networks
Rural Café: Web Access over Intermittent Networks
SMS Find: SMS Search
Contextual Search Portals
Intermittent Mobile Applications



Cell phone based Medical Records
SmartTrack: Drug Tracking System
ATMosphere: Intermittent Rural ATMs
Need for Economic viability

Challenges
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
Satellite

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$15K installation + $3K per month /Mbps
Cellular/ WiMax

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Low user densities
Low purchasing power
High Opex. 5-25 cents/min
Wireline solutions

Non starter
9
Need a new connectivity solution
Operational Expenditure is very high for Cellular/WiMax
Fiber/WiMax is the least economically viable
10
WiRE Architecture
11
Architectural components
Point-to-point WiLDNet links
 Point-to-multipoint distribution links
 Multi-radio mesh links
 A large local cache at each node
 Mobile devices as end-points


Why? – 40% rural users own a cellphone in Africa!!!
12
Challenges

Physical layer
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MAC layer
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Naming, Addressing, QoS, routing
Robustness

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Unified MAC
Network layer
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Steerable antennas, better radios, 802.11n?
Power, maintenance
Application layer

Security, End-to-end performance
13
Overall vision

WiRE architecture – a replacement to the
cellular architecture
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Significantly lower cost
Much higher bandwidth
Focused coverage
Significantly lower power
Intermittent operations
Economically viable!
14
WiFi-based Long Distance Networks


WiLD links use standard 802.11
radios
Longer range up to 150km

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Directional antennas (24dBi)
Line of Sight (LOS)
Why choose WiFi:

Low cost of $500/node
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Volume manufacturing
No spectrum costs
Customizable using open-source
drivers
Good datarates
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11Mbps (11b), 54Mbps (11g)
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AirJaldi Network
•
•
•
•
•
•
Tibetan Community
WiLD links + APs
Links 10 – 40 Kms
Achieve 4 – 5 Mbps
VoIP + Internet
10,000 users
Routers used: (a) Linksys
WRT54GL, (b) PC Engines Wrap
Boards,
Costs: (a) $50, (b) $140
16
Aravind Eye Hospital Network
•
•
•
•
•
•
•
South India
Tele-ophthalmology
All WiLD links
Links 1 – 15 Kms long
Achieve 4 – 5 Mbps
Video-conferencing
3000 consultations/month
Routers used: PC Engines Wrap
boards, 266 Mhz CPU, 512 MB
Cost: $140
17
New World Record – 382
Kms
Pico El Aguila, Venezuela
Elev: 4200 meters
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Overall Impact
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Both networks financially sustainable
50000 patients/year being scaled to 500000
patients/year
Over 3000 thousand patients have recovered sight
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Multi-radio Mesh Networks
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Goal: Can we improve wireless throughput
using multi-radio mesh networks?
Challenges:

Radio separation constraints

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Solving routing and channel assignment together

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Nodes are very small
Intra-path interference
Channel losses and highly fluctuating link behavior
Distributed operation
Our multi-radio node
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Small nodes
Highly varying link qualities
Key Idea
Our Indoor Testbed

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NSC Geode Processors, 128MB RAM, 1GB Flash
Implemented on the Click Modular Router
Patched Madwifi 0.9.3.3
Focus Areas

High bandwidth low-cost connectivity




Extending the Web to Rural Areas




WiRE architecute: An alternative to Cellular
WiLDNet: Wifi-based Long Distance Networks
Multi-Radio Mesh networks
Rural Café: Web Access over Intermittent Networks
SMS Find: SMS Search
Contextual Search Portals
Intermittent Mobile Applications



Cell phone based Medical Records
SmartTrack: Drug Tracking System
ATMosphere: Intermittent Rural ATMs
Rural Cafes

We Search over intermittent links?
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A typical search today involves 4-8 queries!
Can we do web search in one round?
An Intermittent proxy based solution
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Change the query interface
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Specify all that you know about what you are searching for
Intermittent proxy issues multiple queries,
prefetches and bundles response pages
Local proxy enables search within retrieved bundle
Under deployment in Amrita University, India
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RuralCafe Basic Idea
Local Area Network
Internet
Intermittent
Link
Local Proxy
Clients
Remote
Proxy
Web Servers
RuralCafe Search Interface
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SMSFind
SMS based Contextual Web Search
 Google SMS ,Yahoo Onesearch restricted to
fixed contexts
 SMSFind features
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140 byte useful information extraction engine
Contextual extractors
Works for arbitrary contexts
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Contextual Search Portals

How do we setup malaria.google.com?
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Uses of Contextual Portals
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A portal to search all information about malaria!
Offline web search
Packing the Relevant Web in a Hard Disk
Health portals
Rethinking page-rank within a context?
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Focus Areas

High bandwidth low-cost connectivity




Extending the Web to Rural Areas




WiRE architecute: An alternative to Cellular
WiLDNet: Wifi-based Long Distance Networks
Multi-Radio Mesh networks
Rural Café: Web Access over Intermittent Networks
SMS Find: SMS Search
Contextual Search Portals
Intermittent Mobile Applications



Cell phone based Medical Records
SmartTrack: Drug Tracking System
ATMosphere: Intermittent Rural ATMs
Cellphone explosion!
50-80% coverage in many parts of Africa
 100 million subscribers in India, 200 million in
China and growing at 20%
 Grameen Phone model


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Use a SIM and not a cellphone!
Calling rates are still incredibly high in Africa!
31
Lightweight Mobile Databases
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Need for Tele-consultation
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Where there is No Doctor?
Health-workers in the field use cell-phones to enter health
records
Need a distributed database synchronization/search mechanism
which works over SMS-links
Lightweight Cell-phone based medical record system
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Example: CD4 History DB for AIDS patients
Constrained Databases (fields+queries)
Semantic Compression of DB records
Records are SMS-updatable
Privacy + Security Challenges
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SmartTrack

Two big problems with ARV Therapy Programs
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Drug theft and counterfeit drugs
Patient adherence
SmartTrack
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Use Cell phones to track flow of drugs
Tag medication bottles with Smart Tags
Patients report consumption using SMS
User Interface Challenges
 User Studies + Initial testing in Ghana, South
Africa

33
Cell-phone based Microfinance
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Pitfalls of Existing Microfinance Models
 High transaction costs
 Corruption
The Branchless Banking Model
 Use programmable cell-phones to authenticate
transactions
 Outsource loan recollection to shop-keepers
 Provide SIM cards to shopkeepers and loan-takers
 Secure repayment receipts using SMS
Benefits: Reduce transaction costs and corruption
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ATMosphere
Rural ATMs over mobile SMS
 ATMosphere
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Offline authentication
Redistribution of balances
Cash availability
Minimal risk of cheating/overdraft
Results from Uganda model
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99% cash availability
Usage costs of 18 cents/user/year
Up to 10% cash availability in offline mode
35
Questions?
Thank you!
Distance to Clinic
37
Literacy
38
Need translators
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Age distribution
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Challenges
Prohibitive cost of smartphones
 Limited data communication infrastructure
 Cost of communication
 Language
 Illiteracy

Motivation
 Maintaining
accountability in the
supply chain
 Tracking patient
adherence and
symptoms
Cellphones as a
healthcare platform
Deployment
43
Results
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Elimination of intra-path interference leads to
multi-hop throughputs comparable with singlehop throughputs
Having multiple gateways greatly improves
spatial frequency reuse, leading to high overall
throughput
Load and short-time-scale link variance is very
important to consider when evaluating a link
Routes and channels are stable, under ROMA