IOT sensors use the publish/subscribe model for communication to benefit from its
decoupled nature with respect to space, time, and synchronization. Because of the
heterogeneity of communicating parties, semantic decoupling is added as a fourth
di
mension. The added semantic decoupling complicates the matching process and reduces
its efficiency. The proposed algorithm clusters subscriptions and events according to topic
and performs the matching process within these clusters, which increases the throughput
by reducing the matching time . Moreover, the accuracy of matching is improved when
subscriptions must be fully approximated . This work shows the benefit of clustering, as
well as the improvement in the matching accuracy and efficiency achieved using this
approach.