Wireless Sensor Networks

Fraunhofer Institute for Integrated Circuits

Technical Details

Extremely energy-saving Wireless Sensor Networks - a Technical Challenge

Netzschema 

Each application has differing requirements concerning energy consumption, system lifespan and quality of service of the communication (latency, scalability, data throughput, topology). The functions and features of a wireless sensor network depend largely on the software it is based on. Only optimized communication protocols can therefore provide a suitable solution. The software developed by Fraunhofer IIS provides a comprehensive basis for implementation of s-net® wireless sensor networks.

s-net® Sensor Nodes

The sensor nodes in a s-net® sensor network take on various roles:

  • Gateway nodes are responsible for the connection of the sensor network with a back-end system, e.g. an IP network
  • Intermediate nodes are responsible for forwarding the data to the destination for providing information as a stationary basis (so-called anchor nodes), e.g. for localization
  • End nodes are responsible for sensory acquisition, data processing or application logic

s-net® Sensor Network

Communication in a s-net® sensor network takes place on three logical levels. On the application level, the application components on the nodes communicate with the corresponding components in the back-end system. On the so-called middleware level, fundamental services or complex processes between nodes provide the application components with their functionalities. If required, the middleware components communicate directly with one another. The transfer of messages via the sensor network is controlled by the communication protocol.

s-net® System Environment

The s-net® system environment on the sensor nodes is made up of the s-net® operating system KOM-OS, monitoring mechanisms hardware drivers, the s-net® communication protocol, the application and a middleware. The sensor nodes have a host controller interface (HCI) for connection to the outside world.

s-net® Application Integration

Project-specific applications can be integrated into the s-net® system environment via three different interfaces:

  • The application can be derived from a system template which is then saved within the system. The KOM-OS operating system provides all required functions in order to define and integrate an application component.
  • For data communication with other sensor nodes, services or the back-end system, an application can use the serviceoriented messaging exchange system of the s-net® service manager.
  • For local hardware drivers and comparable applications, special interfaces are used for programming the basic function or control components.