Real time data streaming in sensor networks: Integrating SAL with the RBNB data turbine

Developing a large sensor-based observation system faces two serious challenges: 1) incompatible sensor technologies from different manufacturers; and 2) complexity of the data streaming process. Sensor Abstraction Layer (SAL) is a middle-ware integration platform which enables a single interface to view and control heterogeneous sensors regardless of the technologies involved. Although SAL addresses the software compatibility issue of sensors from different manufacturers, it provides limited support for real-time visualisation of the sensed data. Real-time data streaming is extremely useful for scientific modelling and presenting study results for which the sensor network has been designed to investigate. This limitation of SAL can be improved through using existing purpose-built technologies such as the Ring Buffer Network Bus Data Turbine. The Data Turbine is an open-source data management system which provides services for data stream management, routing, monitoring and visualisation. This paper introduces SAL-T (Transmission) which integrates SAL with the Data Turbine. SAL-T is an extra software layer that facilitates the management of the sensed data from SAL into the Data Turbine. Performance tests have been conducted using SAL-T in a simulated data streaming environment indicative of a wireless sensor network. The tests showed that SAL-T dramatically reduced network traffic and improved transmission times.