Multimodal wireless networks are wireless networks that offer multiple functionalities realized on the same infrastructure. In this paper, we consider a multimodal network that has two modes of operation: the communication mode, when the network is used as a traditional wireless communication network, and the surveillance mode, when the network is used as a distributed sensor network that can detect illegal intrusion by detecting changes in the propagation environment caused by the intruder. We address the problem of distributed surveillance in a network consisting of multiple nodes: we develop a multi-sensor model for the received signal parameters of interest and derive a detector capable of detecting changes in these parameters. The experimental results demonstrate that combining the information from different nodes with the appropriate fusion function results in considerably improved detection performance compared to that of single-node detectors.

The initial work on an indoor infrastructure for context dependent mobile multimedia communication is presented. The aim is to enable simultaneously research and software development at the infrastructures application and service level, system software level and finally at the basis technology level. The research is carried out in a loosely coupled community of researchers mostly specializing into work at one of the levels. The infrastructure consists initially of an IEEE 802.11b WLAN coverage of a part of the IT University indoor site, a system for indoor geographical routing planning, positioning and tracking of mobile terminals, which have a general speech recognition, synthesis interface. The aim is that the infrastructure makes available Java interface to communication and positioning, and a software repository for the support of development of location based services and the multimedia signal processing functions needed for these. The paper describes the initial experiences on the implementation and application of the infrastructure on a part of the university indoor site of approx. 1200 m/sup 2/.

The authors present a method for automatic verification of real time control programs running on LEGO(R) RCXTMbricks using the verification tool UPPAAL. The control programs, consisting of a number of tasks running concurrently, are automatically translated into the timed automata model of UPPAAL. The fixed scheduling algorithm used by the LEGO(R) RCXTMprocessor is modeled in UPPAAL, and supply of similar (sufficient) timed automata models for the environment allows analysis of the overall real time system using the tools of UPPAAL. To illustrate our techniques, we have constructed, modeled and verified a machine for sorting LEGO(R) bricks by color.