In wireless sensor networks, the aim of storage protocols is to efficiently replicate data across nodes and to improve data collection and querying by sinks. Among them, in-network storage protocols replicate data in a set of nodes that depends on some characteristics such as network topology and geographic location. Researchers have proposed various techniques to implement in-network storage. In this article, we summarize and highlight the key ideas of existing protocols which are further classified into three categories (reactive, unstructured proactive, and structured proactive) based on topology, load balancing, transmission strategy, and reliability. Benefits and drawbacks of each protocol are studied and compared with different requirements. Finally, future research directions are provided for efficient in-network storage in wireless sensor network.

A new area is coming with communicating materials which is able to provide diverse functionalities to users all along the product lifecycle. These materials can track their own evolution all along the product lifetime, gather helpful information and thus allow information continuum at all time and everywhere. These functionalities are fulfilled via the integration of thousands of specific electronic components into the product's material. This paper forms part of this framework in considering that thousands of micro-sensor nodes are integrated into the material. Specific wireless sensor network (WSN) storage protocols were recently proposed for communicating materials, that uniformly replicate information in the integrated nodes. To extract this information during the product lifecycle, a dedicated WSN data retrieval protocol called random walk and pull gossip data retrieval protocol (RaWPG) is presented in this paper. Unlike well-known literature protocols, RaWPG avoids request flooding because all data are uniformly replicated in WSN. With usual protocols, this may lead to high response duplication rate. RaWPG employs three mechanisms. First, the random walk is used as multihop process to forward the request to further nodes. Then, the pull gossip mechanism is added to interrogate the neighbor nodes during each hop. Finally, a mechanism called farthest neighbor selection is added. Only the farthest and most powerful neighbor is selected as next hop for improving the transmission reliability of request and response messages. The performances of the proposed protocol are evaluated based on a case study, and compared to results obtained with classic approaches issued from the literature.

The communicating material is a new paradigm of Internet of Things. It is designed to perform efficient product control and ensure an information continuum all along the product life cycle. Therefore, storage of life cycle information and data dissemination in communicating materials are very important issues. This paper provides solutions for storing data on the material by systematic dissemination through integrated ultra-small wireless sensors nodes using counter-based broadcasting scheme, hop-counter and probabilistic storage mechanisms. Different algorithms are developed for non-localized and localized dissemination. The performances of our solutions are evaluated for non-segmented and then segmented data. Comparison results between storage mechanisms via simulation using Castalia/OMNeT++ show that probabilistic algorithm provides uniform and efficient data dissemination than hop-counter one for different density level.

Wireless sensor networks have profound effects on many application fields like security management which need an immediate, fast and energy efficient route. In this paper, we define a fault-tolerant and QoS based network layer for security management of chemical products warehouse which can be classified as real-time and mission critical application. This application generate routine data packets and alert packets caused by unusual events which need a high reliability, short end to end delay and low packet loss rate constraints. After each node compute his hop count and build his neighbors table in the initialization phase, packets can be routed to the sink. We use FELGossiping protocol for routine data packets and node-disjoint multipath routing protocol for alert packets. Furthermore, we utilize the information gathering phase of FELGossiping to update the neighbors table and detect the failed nodes, and we adapt the network topology changes by rerun the initialization phase when chemical units were added or removed from the warehouse. Analysis shows that the network layer is energy efficient and can meet the QoS constraints of unusual events packets.