Leon Evers

SensorScheme: Supply chain management automation using Wireless Sensor Networks

The supply chain management business can benefit greatly from automation, as recent developments with RFID technology shows. The use of Wireless Sensor Network technology promises to bring the next leap in efficiency and quality of service. However, current WSN system software does not yet provide the required functionality, flexibility and safety. This paper discusses a scenario showing how WSN technology can benefit supply chain management, and presents SensorScheme, a platform for realizing the scenario. SensorScheme is a general purpose WSN platform, providing a safe execution environment for dynamically loaded programs. It uses high level programming primitives like marshalled communication, automatic memory management, and multiprocessing facilities. SensorScheme makes efficient use of the little available memory present in WSN nodes, to allow larger and more complex programs than the state of the art. We present a SensorScheme implementation and provide experimental results to show its compactness, speed of operation and energy efficiency.

A Distributed Precision Based Localization Algorithm for Ad-Hoc Networks

In this paper we introduce a new distributed algorithm for location discovery. It can be used in wireless ad-hoc sensor networks that are equipped with means of measuring the distances between the nodes (like the intensity of the received signal strength). The algorithm takes the reliability of measurements into account during calculation of the nodes positions. Simulation results are presented, showing the algorithms performance in relation to its accuracy, communication and calculation costs. The simulation results of our approach yield 2 to 4 times better results in position accuracy than other systems described previously. This level of performance can be reached using only few broadcast messages with small and constant size, for each node in the network.

Supply Chain Management Automation using Wireless Sensor Networks

Supply chain management is an application area where wireless sensor networks can play an important role in improving process efficiency. This demonstration shows an implementation of a supply chain management monitoring application using standard WSN nodes. It makes use of an interpreted runtime system called SensorScheme to allow efficient reprogramming and safe execution of monitoring applications running on these nodes. The demo shows all aspects of programming nodes, monitoring and fault detection, and shows the use of the SensorScheme tool set to achieve this functionality.

On the design of an energy-efficient low-latency integrated protocol for distributed mobile sensor networks

Self organizing, wireless sensors networks are an emergent and challenging technology that is attracting large attention in the sensing and monitoring community. Impressive progress has been done in recent years even if we need to assume that an optimal protocol for every kind of sensor network applications can not exist. As a result it is necessary to optimize the protocol for certain scenarios. In many applications for instance latency is a crucial factor in addition to energy consumption. MERLIN performs its best in such WSNs where there is the need to reduce the latency while ensuring that energy consumption is kept to a minimum. By means of that, the low latency characteristic of MERLIN can be used as a trade off to extend node lifetimes. The performance in terms of energy consumption and latency is optimized by acting on the slot length. MERLIN is designed specifically to integrate routing, MAC and localization protocols together. Furthermore it can support data queries which is a typical application for WSNs. The MERLIN protocol eliminates the necessity to have any explicit handshake mechanism among nodes. Furthermore, the reliability is improved using multiple path message propagation in combination with an overhearing mechanism. The protocol divides the network into subsets where nodes are grouped in time zones. As a result MERLIN also shows a good scalability by utilizing an appropriate scheduling mechanism in combination with a contention period.

Partially evaluated sensor networks: automatic specialization for heterogeneous wireless sensor & actuator networks

Wireless sensor and actuator networks consist of a large number of disparate computing devices that together aim to perform a common tasks. Management of large networks may become difficult, when the individual task of each of the devices is different from others, and memory restrictions prevent the devices from all carrying the same network-wide program. This paper presents a technique to specialize a single generic network-wide program into node-specific variants that are small enough to store in each devices memory and efficiently send across the network. We describe the details of our partial evaluation-based specializer and demonstrate that it achieves its goal of producing small device-specific programs, thereby making it a practical tool.