A Wireless Sensor Network (WSN) consists of a large number of small, low-cost and low-power wireless sensing nodes. WSNs can gather information about the environment automatically and unattended and are suitable for many applications.
The typical characteristic of WSNs is that they are energy and bandwidth constrained. Hence, routing protocols and algorithms for WSN must aim to conserve these two scarce resources. WSNs are also highly application-specific. This mean, firstly, that there is a tight bound between the application layer and the different protocol layers. Secondly, there are some WSN target applications that require certain protocol functionality that is not mandatory for other WSNs. In other words, both the general challenges and the specific application challenges must be addressed.
This thesis aims to address routing in WSNs both from a general and an application specific perspective. Among the general energy-and bandwidth related topics the work in this thesis focuses on aggregation and routing-efficiency. Among the application-related topics the work focuses on localization and interoperability.
The main contributions are:
• A method for letting the routing protocol contribute in node localization.
• A method for increasing the energy and bandwidth utilization with passive clustering.
• A method for increasing the energy and bandwidth utilization using multiple sinks.
• A data-aggregation scheme for WSNs that interoperates with external networks via a standardized interface.
• A hybrid routing mechanism that are able to operate in high-interference scenarios.
• Lessons learned from a real-world test campaign of a surveillance WSN.