Mobility models for pedestrian content distribution networks
by
Vladimir Vukadinovic(KTH EE/LCN)
→
Europe/Stockholm
A5:1069 Albanova
A5:1069 Albanova
Description
Ubiquitous wireless coverage is hard, or at least uneconomical, to provide
in reality. Recently revived interest in delay and disruption tolerant
networks is based on the premise that continuous connectivity is not
universally needed and that intermittent communication is useful for
applications characterized by a low degree of interactivity, e.g.,
broadcasting, paging, messaging, and data collection. It has been suggested
that communication paradigms that rely on people moving around, carrying
mobile terminals (e.g. mobile phones, PDAs), and exchanging contents with
one another when they are within radio range could form public content
distribution systems that span large urban areas. In the envisioned network,
pedestrians carry the data onwards through their own movements and therefore
their mobility patterns affect the speed, throughput and reliability of the
data forwarding. Realistic mobility modeling is vital for the evaluation of
such networks. Mobility models traditionally used in networking community
typically assume that moving nodes do not interact. Walking behavior of a
person is however very dependent on the actions of its immediate neighbors.
For instance, a person slowing down in the front is likely to cause others
to slow down or change directions. This type of social interaction among pedestrians will affect the rate and the duration of contact opportunities.
There is apparent lack of efforts in networking community to capture such
phenomena analytically. The random waypoint and related random walk models
have been extensively studied instead. These models are not adequate to
describe the length distribution of opportunistic contacts because of their
inability to model platooning, lane formation, and other characteristics of
moving crowds. More elaborate efforts to mathematically describe pedestrian
mobility are found in the area of transportation and traffic engineering.
The social force concept by Helbing et al. has inspired a number of
relatively simple models that aim to capture interaction among pedestrians.
This talk is intended to give an overview and discuss possible application
of such models for evaluation of pedestrian content distribution networks.
