PDP: Picking Digital Pockets

Funded by: Academy of Finland
Principal Investigators: Prof. Dr. Jussi Kangasharju, University of Helsinki
Prof. Dr.-Ing. Jörg Ott, Aalto University
Duration of the Project: 01.09.2012 31.08.2015

Mobile devices of people form a new and unexplored data reserve. In an urban area, terabytes of data are literally walking around in the pockets of people, who may be happy to share or exchange (trade) their contents. But no means exists to take advantage of the availability of this data in the environment: to assess or categorize what is available, to map data, and facilitate the exchange of information capabilities readily available in the fixed Internet, where content is easily indexed and searched for. In the PDP project, we plan to explore mechanisms for searching and mining these kinds of data reserves. Striving for developing mechanisms for yet unparalleled ways of mobile cooperation, we will carefully consider addressing privacy and related concerns. PDP extends our on-going collaboration on floating content (FI SHOK) and will focus on gaining fundamental understanding about the nature of such mobile data reserves and how their nature affects applications designed to exploit these data reserves.

PDP is based on ad-hoc node-to-node communication which is paramount for at least two reasons:
  1. Not using a central element for sharing avoids both censorship and data gathering so that important properties such as anonymity and privacy can be retained.
  2. Ad-hoc communication allows offloading data from the wireless access links, thereby aiding in conserving scarce link capacity and supporting operation even if there is no (affordable) wireless network infrastructure available.

The scientific objectives are providing a fundamental understanding of the feasibility mining data in mobile devices and characterizing the mutual dependencies of accuracy, latency, and convergence of views as a function of content dynamics and volume, node mobility, and cost. Analytical work will yield insights into the elementary bounds when mining such distributed environment. We will devise a system architecture and a set of algorithms, validate those by means of extensive simulations, and implement those for experimental validation in realworld settings.

From a practical application perspective, the ultimate goal is to provide a basis for novel applications that exploit awareness of their (immediate) environment exploiting opportunistic communication between mobile devices. To this end, we will implement the PDP platform and a set of prototype applications for mobile users.


Figure 1: Searching content in an urban environment.


[1] S. Bayhan, E. Hyytiä, J. Kangasharju and J. Ott, Two Hops or More: On Hop-Limited Search in Opportunistic Networks, in ACM International Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems (MSWiM), 2015, Cancun, Mexico.
[2] E. Hyytiä, T. Spyropoulos and J. Ott, Offload (Only) the Right Jobs: Robust Offloading Using the Markov Decision Processes, in IEEE International Symposium on a World of Wireless, Mobile and Multimedia Networks (WoWMoM), 2015, Boston, MA, USA. (Runner-up for the best paper award) (link)
[3] S. Bayhan, E. Hyytiä, J. Kangasharju and J. Ott, Analysis of Hop Limit in Opportunistic Networks by Static and Time-Aggregated Graphs, in IEEE International Conference on Communications (ICC'15), 2015, London, UK.
[4] E. Hyytiä, S. Bayhan, J. Ott and J. Kangasharju, Searching a Needle in (Linear) Opportunistic Networks, in ACM International Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems (MSWiM), 2014, Montreal, Quebec, Canada. (link)
[5] A. Hess, E. Hyytiä and J. Ott, Efficient Neighbor Discovery in Mobile Opportunistic Networking using Mobility Awareness, in 6th International Conference on Communication Systems & Networks (COMSNETS), 2014, Bangalore, India.
[6] E. Hyytiä, R. Righter and S. Aalto, Task Assignment in a Server Farm with Switching Delays and General Energy-Aware Cost Structure, Performance Evaluation, 2014. (link)
[7] M. S. Desta, A. Keränen, Teemu Kärkkäinen, Esa Hyytiä and Jörg Ott, Evaluating (Geo) Content Sharing with the ONE Simulator, Invited demo paper, in the 14th ACM Symposium Modeling, Analysis and Simulation of Wireless and Mobile Systems (MSWiM), October 2013.
[8] S. Bayhan, E. Hyytiä, J. Kangasharju and J. Ott, Seeker-Assisted Information Search in Mobile Clouds, in The Second Mobile Cloud Computing (MCC) Workshop in SIGCOMM'13, 2013, Hong Kong, China.
[9] E. Hyytiä, Lookahead Actions in Dispatching to Parallel Queues, Performance Evaluation, 2013, Vienna, Austria, (IFIP Performance'13) (link)
[10] E. Hyytiä and S. Aalto, To Split or not to Split: Selecting the Right Server with Batch Arrivals, Operations Research Letters, vol. 41, no. 4, pp. 325-330, Elsevier, 2013 (link)
[11] E. Hyytiä and J. Ott, Criticality of Large Delay Tolerant Networks via Directed Continuum Percolation in Space-Time, in IEEE INFOCOM, 2013, Turin, Italy (link)
[12] M. S. Desta, E. Hyytiä, J. Ott and J. Kangasharju, Characterizing Content Sharing Properties for Mobile Users in Open City Squares, in 10th Annual IEEE/IFIP Conference on Wireless On-Demand Network Systems and Services (WONS), 2013, Banff, Alberta, Canada. (pdf)