A major challenge in wireless sensor networks research is energy efficiency. In the intermittent receiver-driven data transmission (IRDT) protocol, which aims at saving energy, communication between two nodes commences when multiple receiver nodes transmit their own IDs and the sender nodes receive them. This protocol can be used to construct a mesh network which is robust against node failure and wireless channel fluctuations. In our work, we improve this protocol by implementing a collision avoidance method for control packets. First, we refer to the probability of control packet collision as a function of the intermittent interval. We then introduce procedures to determine the interval which decreases or minimizes this probability. Afterwards, we include a data aggregation mechanism into IRDT to reduce data transmission frequency and the occurrence of control packet collisions. Through computer simulation, we show that IRDT can offer greater reduction of the average energy consumption compared with RI-MAC and X-MAC, especially at small loads, and we also demonstrate that IRDT with collision avoidance for control packets can attain higher performance than the original IRDT. This method ensures a packet collection ratio of more than 99% and an average energy consumption 38% lower than that of EA-ALPL and 90% lower than that of the original IRDT.

Improving the scalability and robustness of wireless sensor networks is an important task, and much research on self-organization has been conducted toward this end. However, desired behavior is not yet guaranteed in much larger networks based on pure self-organization. In this article, we propose a controlled potential-based routing protocol implementing a novel controlled self-organization scheme that also allows for external control. The scheme obtains close-to-optimal network behavior by this external control which controls a part of nodes in the network. We show that global traffic flow can be controlled through simulation experiments with a multi-sink sensor network. For example, traffic loads can be equalized among heterogeneously distributed sink nodes, and load balancing among the relay nodes based on remaining energy can bring an approximate four times extension of network lifetime. The proposed method is furthermore robust to message loss and resilient to failure of the sink node.

This paper proposes a power‐efficient access method by polling for wireless mesh networks, which is robust to channel variation due to movement in the surrounding communication environment. In the proposed method, all intermittent nodes periodically repeat ID transmission and a succeeding short period of the receiving state. A node having a packet to transmit goes into a continuous receiving state. Right after receiving an ID transmission from an arbitrary node, it transmits the packet to the node of the preceding ID transmission. In the conventional access method for wireless mesh network, a transmitting node specifies a receiving node well ahead of transmission, leading to a possible change in the wireless link quality at the time of packet transmission from the time of receiving node determination. The proposed access method is robust to wireless channel variation, in the sense that a transmitting node chooses a receiving node just before transmitting the packet. Simulation results show its robustness to wireless channel variations. In the proposed access method, an entire network consumes about one‐sixth the power of a network using the conventional method. © 2011 Wiley Periodicals, Inc. Electron Comm Jpn, 94(4): 20–27, 2011; Published online in Wiley Online Library (http://wileyonlinelibrary.com). DOI 10.1002/ecj.10309

An intermittent transmission control in the MAC layer protocol is very important for managing the energy consumption of wireless sensor networks. This research focuses on an intermittent receiver-driven data transmission (IRDT) protocol in which communication starts when multiple receiver nodes transmit their own IDs intermittently and a sender node receives them. This method aims at prolonging network life time under the conditions that data-generating frequency is comparatively small. In this paper, we clarify the performance characteristics of this method by comparing it with the low power listing (LPL) method, which is a sender-driven protocol. By simulation, we show that IRDT can result in a higher reduction of energy consumption than LPL, especially at small loads. We also propose an improved IRDT scheme. While all nodes have equal and constant intermittent intervals in the original IRDT, the improved IRDT changes each node's intermittent intervals adaptively. This achieves more than 98% packet collection ratio and 50% lower power consumption than adaptive LPL, which also sets the intermittent interval adaptively.

No abstract