Packet Reordering on Gateway as a Representative of Data Processing Techniques

Wireless Sensor Networks (WSN) are becoming an important tool for data acquisition in environmental monitoring. Their advantages are cheap deployment, long system life time and little maintenance during operation. In many applications the WSN use a multi-hop communication protocol to transmit their data to the sink node. The arriving data is of poor quality su↵ering from duplicates, packet loss, device reboots and unsynchronized time stamps caused by local clock drifts. Some of these problems have not been solved by appropriate system designs yet. Therefore, it is necessary to correct these communication artefacts and enhance data quality in a post sequent step. Several algorithms to cope with these challenges and aim higher data accuracy already exist. In this work a model-based approach for the reconstruction of the temporal packet order in a multi-hopWSN is discussed. Furthermore, the challenges for WSN in harsh environments are presented by the PermaSense project, which observes permafrost changes in the alpine region. The multihop communication protocol Dozer is described in more detail to highlight the reasons for packet loss and duplicate generation.