Presentation of Daniel Patrick Iland, Don Voita and Elizabeth Belding on the topic "Delay Tolerant Disaster Communication with the One Laptop Per Child XO" at ISCRAM2013

1. Delay Tolerant Disaster
Communication with the
One Laptop Per Child XO
Daniel Iland, Don Voita, and Elizabeth Belding
University of California, Santa Barbara
Department of Computer Science
{iland, don, ebelding}@cs.ucsb.edu

2. What happens to network
connectivity during a crisis?

3. http://latimesblogs.latimes.com/world_now/2012/03/strong-earthquake-hits-mexico.html

5. What happened to network
connectivity during Sandy?
Hurricane
Sandy's
Landfall

6. Loss of Power == Loss of Connectivity

7. Source: USA Today

8. Cellular and Wi-Fi networks typically provide
blanket Internet connectivity
o (almost) always on Internet
o available (almost) everywhere
In a disaster, users can only take advantage of
connectivity islands
o A functional Wi-Fi or cellular base station
o Preparedness: Locations with backup power and
networking options
 Satellite, packet radio, white space connections, etc.
How is Internet connectivity
different in a crisis?

9. UCSB's blanket connectivity:
10+ cellular towers, 360+ Wi-Fi APs

10. UCSB's connectivity islands
(without power or fiber)

11. The Problem
How can we enable communication in
a disaster area when network infrastructure
is limited, unreliable or unavailable?

12. How can a few locations with
Internet access impact a large area?

13. Our Solution
Delay-Tolerant, peer-to-peer applications
spread information using Wi-Fi

14. Goals for Connectivity in a Crisis
•Maximize information spread through the
networks of mobile devices in a disaster area
•Take advantage of infrastructure
oBut do not rely on it
•Be available before, during, and after a crisis
o'Viral installation' from user to user
•Minimal configuration and interaction required

15. What did we build?
•An Activity for One Laptop Per Child laptops
oUsers can share messages without infrastructure
oEach device uploads messages automatically if
Internet access is available
•An Ushahidi Plugin
oDrop-in plugin that extends Ushahidi API to handle
submissions from OLPCs and generate cures

16. The One Laptop Per Child Project
•2.5 million OLPC XOs in the field worldwide
•Open source platform with existing mesh and ad-hoc
network capabilities
•Solar and manual charging available

17. One Laptop Per Child XO Laptops
communicate without infrastructure

18. Our example use case: Ushahidi

19. Ushahidi reports from Haiti

21. Disaster victims may have difficulty
using Ushahidi after a disaster
• Submitting to Ushahidi requires Internet or cellular
connectivity
• An Ushahidi instance may not exist before the crisis
• Users will not have the URL, the SMS number, etc.
• Configuration information is required
• Texting +44 762 480 2524 is non-obvious
• 'Shortcode' may not yet be available
• User interaction is required
• Each message must be submitted individually

22. Morrow, Nathan, et al. "Independent evaluation of the Ushahidi Haiti project."Development Information Systems International 8 (2011).

23. Goals for this work
•Enable users of One Laptop Per Child laptops to
easily share messages with each other
•Enable OLPCs to automatically upload messages to
Ushahidi
•Use cures generated by the Ushahidi server to
maximize network efficiency and provide delivery
confirmation.
1. Vahdat, A., & Becker, D. (2000). Epidemic routing for partially connected ad hoc networks (p. 18)

24. Simple Delay-Tolerant Routing
•Epidemic Routing1
oTransmit to any device that comes into range
o"Store and Forward" approach
oProvides maximum delivery probability
•Epidemic Routing with cure generated on delivery.
oMarks message as received (with time of receipt)
oCures cascade through the network opportunistically
 Just like messages
oPrevent unnecessary duplication and retransmission
1. Vahdat, A., & Becker, D. (2000). Epidemic routing for partially connected ad hoc networks (p. 18)

25. What happens when an Internet
connection is found?
1. Upload all uncured messages to Ushahidi
2. Download and stores new cures
3. Download and store new messages
4. Redistribute new messages and cures throughout the
area, using Wi-Fi
Satellite
Internet
ConnectionWi-Fi Wi-Fi
Physical
Movement

26. How do OLPCs
exchange information?

36. Evaluation and Future Work
• Analysis of OLPC ad-hoc networking
• Future focus on Android devices and
wireless routers
• Other Delay-Tolerant applications
o Twitter
o Facebook
o Google Person Finder
o etc.

37. XMPP/Clique overhead that maintains connections between
OLPCs dominates the network!
OLPC ad-hoc networking: high overhead
500 Messages
PercentageofPacketsorBytes

38. Target Platform: Android Devices
• 750 million+ Android devices in use worldwide
o 250 million activated from September 2012-March 2013
• 4+ projects that enable ad-hoc or mesh
o Serval
o Commotion
o SPAN
o Android IBSS

39. Two Internet connections support
40,000+ message authors

40. Two Internet connections support
40,000+ message recipients

41. Questions?
Daniel Iland
University of California, Santa Barbara
iland@cs.ucsb.edu

45. What causes a battery to drain
quickly?
Carroll, Aaron, and Gernot Heiser. "An analysis of
power consumption in a smartphone." Proceedings of
the 2010 USENIX conference on USENIX annual
technical conference. 2010.

47. One Laptop Per Child XO Laptop
Power Consumption
An OLPC distributing messages An OLPC receiving and forwarding
messages