An illustrative application example: cargo state monitoring

The previous chapters in this book provide the foundations and a brief description of the DEMANES tool chain. This chapter describes a real self-adaptive system developed using the DEMANES tool chain. This chapter focuses on the design and implementation stages of a real use case development. The use case under study is a subsystem, called Cargo Monitoring System (CMS) , that monitors the state of the container cargo and pushes all the data to a back office infrastructure for further processing. The containers can be on a truck, a train, or any other appropriate transportation means, or stacked in a container terminal or a cargo ship. A WSN will measure physical magnitudes (temperature, humidity and so on) inside a container and will forward data to others processing nodes in the CMS network. The CMS has to meet several self-adaptive requirements. For instance, the parameters of the CMS elements that monitor the container cargo state are reconfigured accordingly to adapt to internal or external changes (e.g. a low battery level or a container temperature out of the adequate bounds), and the CMS adapts the WSN nodes power transmission to save energy while providing an acceptable quality of service.