INVITED
PAPERS
Opportunistic
Pervasive Computing
with Domain-oriented Virtual
Machines
J. Domaszewicz, M. Rój, A. Pruszkowski
Institute of Telecommunications,
Warsaw University of Technology
Nowowiejska 15/19,
00-665 Warsaw, Poland
meag@tele.pw.edu.pl
Abstract
The paper targets heterogeneous sensor-actuator
networks, in which nodes differ as to resources
(sensors and actuators) they are equipped with. Each
node contributes its specific sensors and actuators to
be used by applications. The key assumption of
“opportunistic pervasive computing” is that the actual
mix of nodes (and that of available resources) is not
known in advance to the programmer. An opportunistic
pervasive computing application is supposed to take
the best advantage of whatever sensors and actuators
happen to be available in the network. The paper
presents a technique that can be used in middleware
layers supporting such applications. The technique
uses virtual machines to orderly expose sensor and
actuator resources of a node to the programmer. The
virtual machines are domain-oriented, node specific,
and able to work with the resources at multiple levels
of abstraction. They can be implemented on severely
constrained nodes (e.g., of the TinyOS class).
Robustness in SOC design
Klaus
Waldschmidt, Markus Damm
Johann
Wolfgang Goethe-Universität
Frankfurt am Main, Germany
Technische Informatik
{waldsch/damm}@ti.cs.uni-frankfurt.de
Abstract:
Embedded
systems, ubiquitous computing and networked architec-tures are
getting more and more important within our society. System parts
are often completely implemented as integrated circuits (SoC =
System on chip). Consequently, their complexity and
heterogeneity have grown dramati-cally in the recent past.
Moreover, embedded systems are used in environ-ments where
parameters are subject to continuous changes. Hence, they have
to respond to environmental requirements and changes of their
own system parameters in a robust manner. To gain this
robustness and to cope with the design methodology, formal
measures and metrics are of great importance.
Such measures need
to be combined with the still increasing requirement for
computing performance. The implementation of robust features
requires adap-tivity by reconfiguration and parallelism. We will
call the corresponding sys-tems adaptive computing systems (ACS).
The ACS class offers the opportunity to adapt the whole
architecture or parts of the architecture to the changing needs
of applications or changing environments.
The paper
addresses some of these aspects and presents some ideas for mod-elling
and designing adaptive computing systems (ACS). Especially
measures, metrics and taxonomies for reliability, adaptivity and
robustness are analysed and discussed.
Robust behaviour
of electronic systems will contribute to significantly higher
trust of the society in modern technology. Therefore it is of
very high eco-nomical relevance for industry and commerce.
Improving Delivery Ratio and Power Efficiency in Unicast
Geographic Routing with a Realistic Physical Layer for Wireless
Sensor Networks
Juan A. Sanchez, Pedro M. Ruiz
DIIC, University of Murcia,
{jlaguna,pedrom}@dif.um.es
Abstract
In the last few
years, the amount of work in the field of routing algorithms for
WSN has increased significantly. The special characteristics of
WSN make a challenge for researchers to design efficient routing
protocols. Nevertheless, most of the work done left out of scope
an inherent aspect to WSN such as the radio transmission errors.
The well-known unit disk graph model has been widely used as a
basis for several routing protocol. However as recent
experimental research has revealed, real links behave completely
different to that model. In this paper we evaluate the problems
that arise when considering that messages can be lost and
propose a new geographic routing protocol which takes into
account the probability of error transmission to achieve a high
delivery ratio while reducing the energy consumed to the minimum
possible. We present the results of the extensive simulation
made using our protocol and compare it against a centralised
version and two others previous work. Our protocol, being
totally distributed and using only local information,
outperforms the previous work and achieves almost the same
results as the centralised version.
Lifetime Analysis in Heterogeneous Sensor Networks
Falko Dressler and Isabel
Dietrich
Autonomic Networking Group, Dept.
of Computer Science 7
University of Erlangen-Nuremberg,
Germany
{dressler,isabel.dietrich}@informatik.uni-erlangen.de
Abstract
Wireless sensor networks (WSN) are composed of battery-driven
communication entities performing multiple, usually different
tasks. In order to complete a given task, all sensor nodes,
which are deployed in an ad-hoc fashion, have to collaborate by
exchanging and forwarding measurement data. We define the
behavior of the overall sensor network based on the parameters
lifetime and functional density. The functional density
describes the distribution of all necessary tasks in a given
geographical area. The lifetime is primarily given by the time
each task is successfully performed by at least one node, i.e.
the functional density of all necessary tasks. Nodes can become
unavailable due to insufficient remaining energy. We assume that
sensor nodes can be reconfigured or reprogrammed by a mobile
robot system. There are various reasons for considering robots
for this reconfiguration, e.g. reliability, security, and
deployment issues. In this paper, we evaluate the advantages of
exploiting reconfiguration and reprogramming schemes WSN using
mobile robots. The primary objective is to increase the lifetime
of the overall network. This goal is achieved by optimizing the
functional density of heterogeneous tasks. Based on a developed
simulation model, we discuss the advantages and performance
characteristics.
