Developing and Testing of Software for Wireless Sensor Networks - Networked Embedded Systems - page 278

Script manager
(e.g., state tracking, create
new scripts)

Admission and policing
of resource usage

Resource handling

Radio/networking CPU and time service Sensing

FIGURE . SensorWare runtime environment.

Injection of scripts by users

Message exchanging

Applications
and
services

Applications
and
services

Scripts Scripts

Code
migration

SensorWare SensorWare

RTOS RTOS

Hardware abstraction Hardware abstraction

Hardware Hardware

Sensor node 1 Sensor node 2

FIGURE . Sensor node architecture.

within the network and the script code migrates between different nodes. SensorWare ensures that
no script is loaded twice onto a node during the migration process.

12.3.5 MiLAN
MiLAN is a middleware concept introduced by Mark Perillo and Wendi B. Heinzelman from the
University of Rochester [,]. he main idea is to exploit the redundancy of information provided by
sensor nodes. he performance of a cooperative algorithm in a distributed sensor network application
depends on the number of involved nodes. Because of the inherent redundancy of a sensor network
where several sensor nodes provide similar or even equal information, evaluating all possible sensor
nodes leads to high energy and network costs. herefore, a sensor network application has to choose
an appropriate set of sensor nodes to fulfill application demands.
Each application should have the ability to adopt its behavior in respect to the available set of
components and bandwidth within the network. This can be achieved by a parameterized sensor