The Internet of Things concept is leaving its toddler age where essentially it was a research issue and becoming a key player in many current applications where smart cities are perhaps its greatest exponent. In such real-world scenarios, efficient large scale machine-to-machine communications is of utmost importance. However, the current 6LoWPAN standard, proposed by the IETF, has some efficiency problems which can make its application to the Internet of Things very difficult to scale up. This work transforms the existent 6LoWPAN implementation enabling a data-centric solution that will overcome the current viability issues of 6LoWPAN through the integration of an in-network data processing aggregation mechanism. The proposed data aggregation mechanism increases the sustainability and network lifetime of 6LoWPAN based sensor networks, contributing directly to the Internet of Things revolution.