Speaker
Dr
Edith Ngai
(Uppsala University)
Description
With the popularity and advancements of smart phones, mobile
users can interact with the sensing facilities and exchange
information with other wireless devices in the environment
by short range communications. Opportunistic exchange has
recently been suggested in similar contexts; yet we show
strong evidence that, in our application, opportunistic
exchange would lead to insufficient data availability and
extremely high communication overheads due to inadequate or
excessive human contacts in the environment. In this
paper, we present "OppSense", a novel design to provide
efficient opportunistic information exchange for mobile
phone users in sensing field with data repositories that
tackles the fundamental availability and overhead issues.
Our design differs from conventional opportunistic
information exchange in that it can provide mobile phone
users guaranteed opportunities for information exchange
regardless the number of users and contacts in different
environments. Through both analysis and simulations, we show
that the deployment of data repositories plays a key role in
the overall system optimization. We demonstrate that the
placement of data repositories is equivalent to a connected
K-coverage problem, and an elegant heuristic solution
considering the mobility of users exists. We evaluate our
proposed framework and algorithm with real mobile traces.
Extensive simulations demonstrate that data repositories can
effectively enhance the data availability up to 41% in low
contact environment and significantly reduce the
communication overheads to only 28% compared to
opportunistic information exchange in high contact environment.
