***Archived: This is a past project, it is not on offer at the moment!***
Project Description:
Due to the rapid developments in semiconductor technology, on-die computing capacity becomes exponentially smaller and cheaper. Researchers can use semiconductor manufacturing techniques to build not only small and low-power processing elements, but also low-power radio interfaces and tiny sensors for various physical parameters. In this context, microelectronic technology has been exploited to build low-cost and low-power miniaturized devices, called “sensor nodes”, that can be deployed in a target area to sense physical phenomena (such as temperature or pressure changes, movements of objects), process and communicate the results and coordinate actions with other nodes. These capabilities must be combined with a system software technology that drives and coordinates node activities and implements networking support. This results in a network of wireless-connected sensors (wireless sensor network – WSN) collaborating together to capture information about the environment in which they are deployed. However, one of the major challenges in these WSNs is the energy efficiency of wireless communication, since the power consumption levels of receiving or transmitting data are the highest among all the components of the node.
The purpose of this project is to develop an energy conserving communication protocol targeting various layers of the network stack at the Operating System (OS) level, especially at the Medium Access Control (MAC) layer and later on if it is feasible at the network (i.e. routing) layer. The primary goal of the work is to achieve the ultra-low power requirements of the overall system. Then, the secondary goal is to improve the scalability of the whole internal framework of the OS. This work will be carried out using the Holst-IMECNL (The Netherlands) ultra-compact sensor modules, called Sensor Cubes. From the hardware viewpoint, each Sensor Cube has a size of 14x14x18mm³, includes a Texas Instruments MSP430 microcontroller and the whole system works using a 2-cell NiMH battery to provide a nominal voltage of 2.4V. Also, the layer responsible for the wireless communication consists of a single-chip short-range 2.4GHz transceiver (Nordic nRF2401, 18nJ/bit) and a custom coplanar integrated folded dipole antenna. From the software viewpoint, the platform includes a complete porting of Tiny OS and the necessary toolchain for the MSP430. Also, it is available as starting point in this work a code example used for the current sensor module stack implementation, an USB stick radio interface to work as a master in the star-topology, and various sampling and data processing applications, i.e. electromyographic (EMG), Electroencephalogram (EEG) and electrocardiogram (ECG) sampling and data processing, and simple temperature, light, etc. measurements for environment self-managed mechanisms.
Tasks :
The tasks expected by the student developing this project are very briefly described in the following:
- Study of the Tiny OS software toolflow.
- Study of Sensor Cubes hardware and their testing with several available applications (EMG, EEG, ECG, etc.).
- Study of the Tossim sensor networks simulator where a ported version of Tiny OS is present.
- Modification of the Tossim framework to model the physical transmission level of the Sensor Cubes.
- Porting of several existing MAC layers to the Tossim simulator using the Sensor Cubes physical layer added.
- Validation of the observed effects in the Tossim simulator with different MAC layers in the available Sensor Cubes hardware.
Requirements:
This project involves knowledge of various aspects of digital system designs. Its requirements are enumerated below:
- Knowledge of operating systems.
- Advanced programming knowledge of C code.
This project was supervised by Andrea Acquaviva and David Atienza.
***Archived: This is a past project, it is not on offer at the moment!***