home/Research Interests/Floating Content

Floating Content

(Joint work with Prof. J. Ott, Prof. J. Kangasharju, Dr. P. Lassila and Prof. J. Virtamo)

Floating Content, proposed by Kangasharju et al. in [6], is a best effort, geographically limited information dissemination scheme using principles of opportunistic networking. In Floating Content, a message (a text message, an image, etc.) deemed to be of interest to other people at a certain area is tagged with geographical coordinates of that area. This area is referred to as the anchor-zone of the message. A message is disseminated in opportunistic manner whenever two nodes meet within the anchor-zone. Outside the anchor-zone, nodes are free to delete it. The unique characteristics are that the scheme does not rely on any infrastructure (cf. privacy aspects), a message can only be created and distributed locally, and it cannot be deleted afterwards. Instead, a message remains available within the anchor-zone until it expires, assuming there is a sufficient number of nodes in the anchor-zone constantly to ensure that the message does not disappear accidentally. However, due to stochastic fluctuations, there is a finite probability that the message gets deleted before the expiration time.

Our Work

The research question we have studied is under what circumstances a message remains available. This involves.
  • Mobility modeling: the mobility pattern and the (mean) density of the mobile users moving through the vicinity of interest (anchor-zone) are the key parameters
  • Stochastic analysis, e.g., what is the spatial density of the information carrying nodes
  • Analysis of continuum percolation models
  • Analysis of contact durations, which must be sufficiently long to enable transmissions
  • Scheduling and priorization of the transmissions
A complete system involves many parameters and must be evaluated by simulations, while the fundamental properties can be studied analytically (by means of stochastic processes, transport theory and fluid approximations).
   Floating Content scheme
Figure: Floating Content, a localized opportunistic information dissemination scheme.


[1]  A. Hess, E. Hyytiä and J. Ott, Efficient Neighbor Discovery in Mobile Opportunistic Networking using Mobility Awareness, 6th International Conference on Communication Systems & Networks (COMSNETS), January 2014, Bangalore, India. (NEW)
[2]  S. Bayhan, E. Hyytiä, J. Kangasharju and J. Ott, Seeker-Assisted Information Search in Mobile Clouds, The second mobile cloud computing (MCC) workshop, SIGCOMM'13, August 2013.
[3]  E. Hyytiä and J. Ott, Criticality of Large Delay Tolerant Networks via Directed Continuum Percolation in Space-Time, IEEE INFOCOM Mini-Conference, 2013, Turin, Italy. (pdf)
[4]  J. Virtamo, E. Hyytiä and P. Lassila, Criticality Condition for Information Floating with Random Walk Nodes, Performance Evaluation, vol. 70, no. 2, pp. 114-123, 2013. (pdf)
[5]  M. S. Desta, E. Hyytiä, J. Ott and J. Kangasharju, Characterizing Content Sharing Properties for Mobile Users in Open City Squares, 10th Annual IEEE/IFIP Conference on Wireless On-Demand Network Systems and Services (WONS), Banff, Canada. March 2013.
[6]  E. Hyytiä, J. Virtamo, P. Lassila and J. Ott, Continuum percolation threshold for permeable aligned cylinders and opportunistic networking, IEEE Communications Letters, 16(7), pp. 1064-1067, 2012. (pdf)
[7] E. Hyytiä, P. Lassila, J. Ott and J. Kangasharju, Floating information with stationary nodes, in the Eighth Workshop on Spatial Stochastic Models for Wireless Networks (SpaSWin), May, 2012, Paderborn, Germany. Held in conjunction with WiOpt 2012. (pdf)
[8] E. Hyytiä, J. Virtamo, P. Lassila, J. Kangasharju and J. Ott, When Does Content Float? Characterizing Availability of Anchored Information in Opportunistic Content Sharing, in IEEE INFOCOM, pp. 3123-3131, 2011, Shanghai, China. (pdf)
[9] J. Ott, E. Hyytiä, P. Lassila, T. Vaegs and J. Kangasharju, Floating Content: Information Sharing in Urban Areas, in IEEE PerCom, 2011, Seattle, USA. (pdf)
[10] J. Ott, E. Hyytiä, P. Lassila, J. Kangasharju and S. Santra, Floating Content: Information Sharing in Urban Areas, Pervasive and Mobile Computing, 7(6), pp. 671-689, Elsevier, 2011. (pdf)
[11]  J. Kangasharju, J. Ott, and O. Karkulahti, Floating content: Information availability in urban environments, in IEEE PerCom Workshops, April 2010. (pdf)

See the floating content in action (a simple java applet).