Data dissemination with ring-based index for wireless sensor networks

In wireless sensor networks, sensor nodes are capable of not only measuring real world phenomena, but also storing, processing, and transferring these measurements. Many techniques have been proposed for disseminating sensing data. However, most of them are not efficient in the scenarios where a huge amount of sensing data are generated, but only a small portion of them are queried. In this paper, we first propose an index-based data dissemination scheme to address the problem. With this scheme, sensing data are collected, processed, and stored at the nodes close to the detecting nodes, and the location information of these storing nodes is pushed to some index nodes, which act as the rendezvous points for sinks and sources. To address the issues of fault tolerance and load balance, we extend the scheme with an adaptive ring-based index (ARI) technique in which the index nodes for one event type form a ring surrounding the location which is determined by the event type, and the ring can be dynamically reconfigured. Considering that frequently updating or querying index nodes may cause high overhead, we also propose a lazy index updating (LIU) mechanism and a lazy index querying (LIQ) mechanism to reduce the overhead. Analysis and simulations are conducted to evaluate the performance of the proposed scheme. The results show that the proposed scheme outperforms the external storage-based scheme, the DCS scheme, and the local storage-based schemes with flood-response style. The results also show that using ARI can tolerate clustering failures and achieve load balance and using LIU (LIQ) can further improve the system performance.