The document discusses ad hoc social media and proposes developing ad hoc communication APIs and trustful UI guidelines. It explores existing work on ad hoc infrastructure like publish-subscribe systems. Different publish-subscribe models are described that incorporate context awareness. Implementation strategies for publish-subscribe systems like unicast, multicast, and broadcast are outlined. The challenges of message overhead with broadcast are discussed. Finally, it raises questions around integrating trust and privacy in context-aware middleware APIs and expressing data aggregation in communication APIs.

1. Ad hoc social media
Adrian Holzer

2. Currently cloud based social media

3. Cloud brings privacy concerns

4. Wearables will increase the amount of data

6. Cloud brings connectivity concerns

7. Increase in the number of NGOs

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Is there a way to replace this dark cloud?

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Ad hoc social media should be explored

10. But today there are almost no ad hoc social media apps

11. Why?

12. There is a lack of development support

13. We want to address this by providing server-less communication APIs and trustful UI guidelines
API
UI

14. API
Today we’ll look at existing work on ad hoc infrastructure

15. Publish subscribe can be a good start

16. Anonymous messaging

17. Asynchronous messaging

18. Subscribers
C
Publisher
C
C
A
B
C
CD
Match!
Basic publish / subscribe

19. Different publish / subscribe flavors exist with some context awareness

20. CP CS
Pubs are restricted to a defined Space
Publication Space
Match when:
S in the Publication space
STEAM

21. CP CS
Content Match
Location Match

22. CP CS
Pubs and Subs are restricted to a defined Space
Publication Space Subscription Space
LPSS
Match when:
P in Sub Space and S in Pub Space

23. CS
Content Match
Location Match
CP

24. CP CS
Context of
Relevance
Context of
Interest
Subscription
Space
Publication
Space
CPS
Match when:
P in Sub Space and S in Pub Space
and both contexts overlap

25. CS
Content Match
Context Overlap
CP
Pub Space Match
Sub Space Match

26. CP DPSS CS
Sub Scope
Pub
Scope
Dynamic Content Dynamic Filters
Match when:
P in Sub Scope and S in Pub Scope
Each time filter or message changes

27. CSCP
Content Match
Pub Space Match
Sub Space Match

28. [10] Yann Busnel, Nuno Cruz, Denis Gillet, Adrian Holzer, Hugo Miranda. “Reinventing Mobile Community
Computing and Communication”. In the proceedings of IEEE IUCC'13. July 2013.
[9] Adrian Holzer, François Vessaz, Benoît Garbinato. “ Middleware for Location Privacy: an Overview”. In the
proceedings of ACM Research in Applied Computation Symposium (RACS’12). October 2012.
[8] Adrian Holzer, Lukasz Ziarek, K.R. Jayaram, Patrick Eugster, “Abstracting Context in Event-based Software”.
In Transactions on Aspect-oriented Software Development (TAOSD). 9: 123-167. 2012.
[7] Patrick Eugster, Benoît Garbinato, Adrian Holzer. “Pervaho: a specialized Middleware for Mobile Context-
aware Applications”. In Electronic Commerce Research Journal, 2009. Springer.
[6] Adrian Holzer, Lukasz Ziarek, KR Jayaram, Patrick Eugster . “Putting Events in Context”. In the proceedings of
the International Conference on Aspect-Oriented Software Development (AOSD’11). March 2011, pp.241-252.
[5] Adrian Holzer, Saida Maaroufi, Samuel Pierre. “DYMES: a Dynamic Messaging Service for VANETs”. In the
proceedings of the 6th IEEE International Conference on Wireless and Mobile Communications (WiMob’10).
October 2010, pp.513-520.
[4] Patrick Eugster, Benoît Garbinato, Adrian Holzer. “Middleware Support for Context-aware Applications”.
Chapter 14 of Middleware for Network Eccentric and Mobile Applications, 2009. pp. 305-322. Springer.
[3] Patrick Eugster, Benoît Garbinato, Adrian Holzer. “Design and Implementation of the Pervaho Middleware for
Mobile Context-aware Applications”. In proceedings of the 3rd IEEE International Montreal Conference on e-
Technologies (MCETECH'08), 2008
[2] Patrick Eugster, Benoît Garbinato, Adrian Holzer. “Pervaho: A Development and Test Platform for Mobile Ad
hoc Applications”. In proceedings of the 3rd ACM Annual International Conference on Mobile and Ubiquitous
Systems: Networks and Services (Mobiquitous'06), 2006.
[1] Patrick Eugster, Benoît Garbinato, Adrian Holzer. “Location-based Publish/Subscribe”. In proceedings of the
4th IEEE International Symposium on Network Computing and Applications (NCA'05), 07-2005.
middleware references

29. How are publish / subscribe systems implemented?

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Unicast Multicast
Anycast Broadcast
They typically rely on some low level messaging protocols

31. Rule #1
All neighbors
hear a
transmission
Devices must communicate directly
Rule #2
Retransmissions
necessary to
reach further
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✉️✉️ ✉️ ✉️
📱✉️

32. Existing algorithms

33. an
analogy...
Broadcast

34. spread some gossip

35. To everyone

36. Only voice communication is allowed

37. Flooding
repeat a rumor once

38. C CC C
C
CC C

39. Message
overload
Beware of broadcast storm

40. Can we do
better?

41. Retransmit the message if
no one did it before
Listen for retransmissions
Wait when a message is
received before retransmitting

42. CBS
Wait a random time

43. C
CC
C
C
C
C
C12 3
2
21 2
1
1- 1-

52. PAMPA
Wait time proportional to sender proximity

53. C
C
C C
CC
C
3
2 2 1
-
-
2
1 1

62. !
[9] Adrian Holzer, Patrick Eugster, Benoît Garbinato. “Evaluating Implemetation Strategies for Location-based
Multicast Addressing”. In IEEE Transactions on Mobile Computing (TMC). 12(5), 2013.
[8] Adrian Holzer, Patrick Eugster, Benoît Garbinato, “ALPS - Adaptive Location-based Publish/Subscribe”. In
Computer Networks (COMNET) 56(12): 2949-2962. 2012.
[7] François Vessaz, Benoît Garbinato, Arielle Moro, Adrian Holzer. “Developing, Deploying and Evaluating
Protocols with ManetLab”. In the proceedings of NETYS'13. May 2013.
[6] Behnaz Bostanipour, Benoît Garbinato, Adrian Holzer, “Spotcast – A Communication Abstraction for
Proximity-Based Mobile Applications”. In proceedings of the 11th IEEE International Symposium on Network
Computing and Applications (NCA’12), 2012.
[5] Benoît Garbinato, Adrian Holzer, François Vessaz. “Context-aware Broadcasting Approaches in Mobile Ad
hoc Networks”. In Computer Networks (COMNET). Volume 54, Issue 7, May 2010, pp. 1210-1228. Elsevier.
[4] Adrian Holzer, Saida Maaroufi, Samuel Pierre. “BROADTRIP: Broadcast for Transit in Platoons”. In the
proceedings of the 7th IEEE International Conference on Wireless and Mobile Communications (WiMob’11).
October 2011.
[3] Adrian Holzer, François Vessaz, Samuel Pierre, Benoît Garbinato. “ PLAN-B: Proximity-based Lightweight
Adaptive Network Broadcasting”. In the proceedings of the 9th IEEE Symposium on Network Computing and
Applications (NCA’11) August 2011.
[2] Benoît Garbinato, Adrian Holzer, François Vessaz. “Six-Shot Multicast: A Location-Aware Strategy for
Efficient Message Routing in MANETs”. In the proceedings of the 9th IEEE Symposium on Network Computing
and Applications (NCA’10) July 2010 pp.1-9. [Best Student Paper Award].
[1] Benoît Garbinato, Adrian Holzer, François Vessaz. “Six-shot Broadcast: a context-aware algorithm for
efficient message diffusion in MANETs”. In proceedings of the 10th LNCS International Symposium on
Distributed Objects, Middleware, Applications (DOA'08). Springer, pp. pp. 625-638, 2008.
protocol references

63. How can trust and privacy
components can be integrated in the
design of context-aware middleware
APIs?
What is the adequate way to express
data / peer aggregation in a high
level communication API ?

64. What implementation strategies
should be followed to provide
privacy by design for such
middleware?

65. UI
Today we’ll look at existing work on ad hoc infrastructure