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Publicatie

Enabling interoperability between MAC-heterogeneous sensor networks

Boek - Dissertatie

Sensor networks consists of small, cheap, battery powered devices equipped with a number of sensors (temperature, noise, …) that communicate wirelessly with one another in order to provide a combined view of the area in which the sensors are deployed. Given the importance of extending the battery-lifetime as much as possible, it has long been considered standard practice to optimise or even custom-build the used communication protocols to the specific task for which the sensor network is being deployed. Because of this, there is generally no interoperability between sensor networks deployed in the same area. ​Over the last decade however, the rise of the `Internet-of-Things’ has meant that sensor networks are increasingly expected to integrate seamlessly with external networks and infrastructure. This means that today interconnectivity and interoperability are more important than ever in the design of sensor networks. ​Therefore, the goal of this thesis to enable link-level interoperability between sensor networks using heterogeneous (incompatible) MAC protocols. The strategy for doing so is to use so-called virtual gateways: regular sensor nodes that have been configured to run multiple MAC protocols at the same time. ​To determine the feasibility of this approach, it is first investigated to what extent the performance of the MAC-heterogeneous sensor networks is affected by the interference that exists between them. It is shown that, except in extreme circumstances, the effect of this interference is small enough to allow these networks to co-exist without much issue. ​Next the feasibility of running multiple MAC protocols simultaneously on low-power sensor nodes is considered. To investigate this, the software architecture needed to do so is implemented for and evaluated using the extremely resource constrained Tmote Sky sensor node platform. It is shown that the proposed architecture is flexible and extensible enough to support a wide variety of MAC protocols and that the overhead of the Tmote Sky-implementation is minimal. ​Finally, the problem of virtual gateway selection is investigated. To this, end, the IRVG algorithm (Iterative Removal of Virtual Gateways) is introduced. This algorithm selects the virtual gateways to use by first configuring all sensor nodes as a virtual gateway and then iteratively disabling those virtual gateways that are unnecessary. It is shown that IRVG is able to both minimise the performance overhead of using virtual gateways and to balance between the possibly conflicting performance requirements of the individual networks.​
Aantal pagina's: 280
Jaar van publicatie:2020
Trefwoorden:Doctoral thesis
Toegankelijkheid:Open