1. Bubble-Sensing:Binding a
Sensing Task
to the Physical World using
mobile phones

2. Introduction
Here we present the bubble-sensing system that
support the persistent sensing of a particular location,
as required by user requests.
Conceptually, a user with a phone that has
opted into the bubble-sensing system visits a location
of interest, presses a button on his phone to affix the
sensing request to the location, and then walks away.
The sensing request persists at the location until the
timeout set by the initiator is reached.

3. Bubble Sensing
Sensing tasks are created and maintained in the
bubble-sensing system through the interaction of a
number of virtual roles.
Virtual roles-
Bubble creator
Bubble anchor
Bubble carrier
Sensing node

4. Bubble sensing

5. Bubble Creation Phase
Bubble Server
Bubble Anchor
Bubble Creator
Mobile Sensor Mobile Sensor

6. Bubble Maintenance Phase
Due to uncontrolled mobility of the creator ,the
creator may leave the bubble location while task is
still active.
So to anchor the bubble to the location of intrest we
use bubble anchors.
Two variants for bubble anchor selection:
1. Location based
2. Mobility based

7. Challenges to maintenance
y As we do not require sensing nodes to have
knowledge of their absolute location, recipients of
the task broadcast that are outside of the bubble
area defined in the broadcast may still collect and
upload data to the bubble server. This potentially
makes the effective bubble size larger than the
specified bubble size.
y The bubble drift.

8. Bubble Restoration Phase
Bubble Server
Bubble carrier
Bubble Anchor
Mobile Sensor
Mobile Sensor

9. Architecture
Programming languages
Communication
Sensor
Classifier
System integration

12. Problems
y Hold the bubble in the area of
interest.
y Recover from lost bubble.
y Exploit heterogeneous devices.

13. Privacy and security concerns
‡the sharing of device resources
with unknown third parties.
‡Individual¶s privacy concerning
their daily activities is at risk from
other users if bubble sensing
system is misused.

14. u1
Related work
‡ As the mobile phone is ubiquitous, and the
discussion of a mobile phones used as a
sensing device has some history no large-
scale mobile cell phone sensor networks
have yet been deployed in practice.
‡In the last few years, the smart phone
market has grown rapidly (e.g., Nokia N95,
Apple iPhone), cultivating ground for
research on mobile sensor networking.

15. Slide 14
u1 user, 2/19/2011

16. Conclusion
‡So mobile sensor nodes collaborate and
share sensing and communication resources
with each other in a cooperative sensing
environment.
‡So we presented an approach to support
persistent location-specific task in a wireless
sensor network composed of mobile phones.

17. References
‡A.T. Campbell, S.B. Eisenman, N.D. Lane, E. Miluzzo, R.A. Peterson,
People-centric urban sensing, in: Proc. of 2nd ACM/IEEE Int l Conf. on
Wireless Internet, WICON 06, ACM Int l Conf. Proc. Series, vol. 220, No. 18,
Boston, Aug 2 5, 2006, (Invited Paper).
‡J. Burke, D. Estrin, M. Hansen, A. Parker, N. Ramanathan, S. Reddy, M.B.
Srivastava, Participatory sensing, in: Proc. of 1st Workshop on Wireless
Sensor Web, WSW 06, Boulder, October 31, 2006.
‡T. Abdelzaher, Y. Anokwa, P. Boda, J. Burke, D. Estrin, L. Guibas, A. Kansal,
S. Madden and J. Reich, Mobiscopes for human spaces, IEEE Pervasive
Computing 6 (2) (2007)
‡S.B. Eisenman, A.T. Campbell, SkiScape sensing, in: Proc. of ACM 4th Int l
Conf. Embedded Networked Sensor Systems, SENSYS 04, 2006.

18. Thank you