Multiple Applications in Wireless Sensor Networks
Sensors in wireless sensor networks (WSNs) are able to measure data from the physical world and generate messages for several applications, e.g. temperature and humidity for environment monitoring, video and audio records for traffic control, etc.. Meanwhile, the separation of the manager and the customers of a WSN reveals the possibility that the WSN manager may rent the WSN to several customers who require different applications running simultaneously.
Although sensors have improved functionalities, they are still powered with limited battery capabilities and required to maintain significant network lifetime. The energy resource becomes even more crucial when multiple applications are supported in the WSN.
Furthermore, in WSNs, computations (data aggregation) and communications are always paired with each other. When multiple applications are running concurrently in the WSN, different topologies and different aggregation methods need to be supported simultaneously.
To summarize, an efficient design of a WSN supporting multiple applications is a cross-layer problem since it requires joint consideration of data computation, topology control, power consumption, connectivity maintenance and quality-of-service (QoS) requirement.
In this context, we are considering the following questions:
1. The joint consideration of hybrid computations which results from different aggregation functions of applications (e.g. averaging, downloading, max/min) and communications in two-way relaying scenarios in WSNs with multiple applications
2. The investigation of a way to quantify the change of the message length due to the aggregations of different application messages
3. The investigation of the delays of different applications that are concurrently running in the WSN
4. The energy minimization problems for different communication and computation paradigms, e.g. routing-based WSN and random gossiping-based WSN
5. The efficiency to run multiple applications with different topology requirement and aggregation in WSNs
6. The trade-off between network-lifetime and QoS when multiple applications are running in the WSN.
The following methods are used in this project:
1. Cross-layer optimization and resource allocation
2. Graph theory
3. Random gossiping
4. Two-way relaying, multi-way relaying
5. Network coding and network capacity analysis