Discussion of IoT networks and DTNs, including some speculation on social behavior-based routing and the similarities between the IoT and the ecology of living things.

1. ALWAYS OFFLINE
Delay-tolerant Networking for the Internet of Things
Daniel Austin
GRIN Technologies, Inc.
“The Connected Life Company”
daniel.austin@grintech.net
1st Annual IoT Conference
Oct 21, 2014
V1.4

2. ABOUT GRIN TECHNOLOGIES, INC.
• Founded July 4th 2014
• “The Connected Life Company”
• Developing Systemsware at the Intersection of Big Data and the Internet of Things
• Focused on the Connected Car
• Coming in Q3 2015: The Connected Life Server ™

3. FOUR BIG IDEAS FOR TODAY’S TALK
1. No “Internet of Things”, only disjoint Networks of Things
2. Delay-Tolerant Networking as a solution for the IoT
3. Strategies for DTN and VDTN architectures
4. Social cooperation and Networks of Things

4. NETWORKS OF THINGS
“If we had computers that knew everything there was to know about things –
using data they gathered without any help from us – we would be able to track
and count everything, and greatly reduce waste, loss and cost. We would know
when things needed replacing, repairing or recalling…”
-Kevin Ashton, 1989

5. HYPE CYCLES COMPARED
Gartner 2011 Gartner 2014

6. WHY THERE WILL BE NO “INTERNET OF THINGS”
• No clients; no servers
• No network that connects them all
• No protocols that make sense
• Intermittent, Transient, Low Value, Connectionless
Many of Our Current Assumptions About the Internet Simply Don’t Apply!

7. INSTEAD, DISJOINT NETWORKS OF THINGS
• Disjoint – for Security and Privacy and Management
• Functional and Context-Specific
• Mesh-based Peering Architectures
Peer 1
Peer 2
Peer3
Peer 4
Peer 1
Peer 2
Peer3
Peer 4
Gateway Gateway
Public
Internet

8. A DAY IN THE CONNECTED LIFE
…”a system
where the
Internet is
connected to
the physical
world via
ubiquitous
sensors…”

9. By 2020 everyone, everything and
everywhere will be connected in real
time. More than 50 100 billion
connected devices will be used in the
Networked Society.
Source: http://www.ericsson.com/thinkingahead/networked_society

10. CHARACTERISTICS OF THE NETWORK OF
THINGS
• Many small messages
• Intermittent transmission
• Connectionless
• Stateless
• No guaranteed delivery
• Heterogeneous nodes
• Lazy/No Acknowledgements
• Mesh architectures based on proximity
• Mixed/variable security

11. MOBILITY + UBIQUITY REQUIRE NEW IDEAS
• TCP/IP Assumptions:
• End-to-End connection
• Short, fixed delays
• Symmetric data rates
• Low error rates
• Knowledge of network state
• Deterministic
• DTNs originated at NASA for interplanetary communications (RFC 4838 &
5050)
• Applies to all intermittently connected scenarios, including the IoT

12. WHAT PROBLEM(S) ARE WE SOLVING?
Sensor
Networks/
IoT
Mobile
Devices
Vehicle
Networks
Military/
Emergency
Space
Exotic
Cases:
Animal
Tracking
Communica
tions
Low
Population/
Infrastructure
DTN
Each of these
scenarios involves

13. HOW DTNS WORK
TCP/IP
DTN
Source; DTN SIG

14. EXISTING IMPLEMENTATIONS
• Interplanetary Internet Project (NASA)
• MIT CarTel
• Haggle (Cambridge)
• Bytewalla (Android-based DTN)
• Multiple commercial VDTN projects
• Several others, all small scale or research-oriented

15. DTN PROTOCOL ARCHITECTURES

16. STORE-CARRY-FORWARD
• Every DTN networking scheme is based on the S-C-F pattern
• Requires cooperation among nodes
• Messages are (too) often replicated
• Custody transfer required for committed transfer

17. FLOODING VS. FORWARDING
Source: Khabbaz et al.: Delay-Tolerant Networking: A Comprehensive Survey of Recent Results

18. ECOLOGY OF THE IOT
• Hypothesis: The ‘Flooding’ vs.
‘Forwarding’ strategies correspond
to the r/K reproductive strategies
used in ecological environments.
• This suggests that opportunistic (r)
‘Flooding’ strategies will work best
when the network is below its
capacity, and ‘Forwarding’ (K)
strategies will work best when the
network is near capacity.
• Is the evolution of the Internet of
Things governed by the logistic
function?

19. ROUTING STRATEGIES COMPARED
Routing Strategy Copies Replication Objective
Epidemic unlimited high Reduce delay
Direct Delivery single N/A Serial delivery
Prophet unlimited med Probabilistic
Spray-and-Wait N copies med Limited copies
MaxProp unlimited high Reduce queue time
RAPID unlimited high Reduce propagation

20. CUSTODY TRANSFER
Requirements for Custody Transfer:
1) Be closer to the bundle’s ultimate destination.
2) Certify long period bundle storage ability.
3) Certify the ability and willingness to strive for
the ultimate goal: depositing the bundle at its
ultimate destination.
4) Possess enough power to remain usefully
active over long periods.
5) Be cooperative and take advantage of every
chance to realize the ultimate goal.
Source: Khabbaz et al.: Delay-Tolerant Networking: A Comprehensive Survey of Recent Results

21. THE CAP THEOREM AND DTNS
Source: DTN SIG

22. PERFORMANCE OF DTNS
Important Factors:
• Probability of Delivery
• the ratio of messages delivered to the total
• Hopcount
• the number of individual nodes involved in the message transfer
• Dropped Messages
• the total number of messages not delivered
• Started Messages
• the total number of messages
• Latency is
• the time between sending and delivery
• Overhead ratio
• How many times each message was duplicated

23. SOCIAL COOPERATION AND DTN ROUTING
• Ad-hoc and opportunistic networks display social behavior
• Cooperation us crucial in DTNs
• Social routing for DTNs based on:
• Similarity
• Community
• Friendship
• Selfishness
• Incentives
• Social routing can reduce propagation overhead and increase delivery
probabilities
• Games such as Give2Get and Tit-for-Tat can be solved in limited cases

24. CHALLENGES AND NEXT STEPS FOR DTNS
DTNs offer a solution to a number of networking problems in pervasive
computing and the IoT…
…but still need to prove their worth and solve outstanding issues:
• Rapidly address security/sensitive information transfer
• Expand existing implementations especially for VDTNs
• Design routing based on social factors

25. KEY TAKEAWAYS
• Delay-Tolerant Networking provides a solution for transient and intermittent
networks based on the Store-Carry-Forward design pattern
• Vehicles and sensor networks are natural targets for DTNs, but challenges
remain, especially around security, receipt reliability and routing
• DTNs have a social and cooperative aspect that rewards cooperation and
fairness while discouraging selfish behavior (and may display ecological
behaviors as well).

26. is where nothing connects.

27. THANKS!
“When everyone’s life is connected, that’s when the
Singularity will happen.”
Daniel Austin
GRIN Technologies, Inc.
The Connected Life Company
daniel.austin@grintech.net
http://www.grintech.net
@daniel_b_Austin
@GRINTechInc