Linked IoT

Aim:

• By using Linked-Data and the web-standard semantic interoperability should be achieved

• The goal is to demonstrate how already existing standards of the Linked-Data can be used for IoT

• To reach the largest possible target audience, everything should be easily implemented (and as cheap as possible)

• Throughout a modular setting it should be possible for everybody to use their own components

• An extensive documentation should make it as easy as possible for the target audience to get started

Problem:

• Linked Data has already proven its feasibility as instrument for connection and integration of data in the web

• With Linked Data it is possible to semantically combine structured data in order to describe their relationship

• At the moment it is difficult to bundle the different ways of broadcasting of each sensor and connect them with each other

• The different sensors can be addressed only with great effort but it’s impossible at the moment to process unknown structures and types of sensor independently

• With the use of Constrained Devices their individual limitation has to be considered

Approach of solution:

• To make the modular setting possible, a library with abstract classes was built which can imported in the own project and run in Arduino

• The context which is used in the JSON-LD, is saved on the gateway

• The bridge is working as operator in order to use the consistent web-standards for the broadcast

• With a web interface the sensor’s initialisation and broadcasting-configuration is enabled

• The linking between sensor and gateway is implemented throughout a web standard

• The bandwidth of the original payload (broadcast of the sensor’s data) is reduced through the transfer of the context at the linking

• The bridge is requesting the needed context at the gateway when broadcasting the sensor-data und is publishing the sensor’s value to the topic