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Topic II: Wireless Sensor Network Having Environment Adaptability

On the basis of robust WSN construction technology already held by us called the Diehard Sensor Network [10][11], in which a neighboring sensor node automatically assumes the function of a failed sensor node, we will develop the following new technologies to create a function which adapts to its environment.

(a) Scenario compiler:

Technology that can be used to construct a “scenario description” and transmit it to each sensor node via wireless communication. A “scenario description” includes “roles” that each sensor node should play, along with each role’s trigger condition and the sensor node’s operation sequence. By changing the scenario description, the behavior of sensor nodes can be customized even after installation. The trigger conditions can be described as rules only by using “if…then…else” syntax in its format; but for operation sequences, the dependency among these rules and needs of the roles must also be included. The scenario compiler refers to a “task library” to generate specific tasks to be incorporated into each sensor node. The “task library” consists of the roles the sensor nodes are able to perform (e.g. functions such as sensing, data transmission, data relay, and data collection). Tasks are downloaded to sensor nodes via wireless communication (Over-the-Air Programming: OTAP). We have already developed an OTAP method [12].

(b) Sensor node capable of changing its role dynamically:

This sensor node has a mechanism to dynamically start a “role” in response to meeting a trigger condition according to environmental changes and/or user requests. Since it is difficult to incorporate this capability into any existing commercial sensor node, we will create an original prototype to achieve this concept. During prototype development, consideration will be given to radio wave propagation characteristics and durability in order to realize a design that incorporates mechanisms to suit the condition of the sensor nodes being directly placed into a disaster site.

[10] T. Miyazaki, “Dynamic Function Alternation to Realize Robust Wireless Sensor Network,” International Journal of Handheld Computing Research (IJHCR), Vol. 3, No. 3, pp.17-34, 2012.
[11] T. Miyazaki, D. Shitara, Y. Endo, Y. Tanno, H. Igari, and R. Kawano, “Die-hard Sensor Network: Robust Wireless Sensor Network Dedicated to Disaster Monitoring,” Proc. ACM The 5th International Conference on Ubiquitous Information Management and Communication (ICUIMC2011), 11.2 (10 pages) in CDROM, Seoul, Feb. 2011.
[12] H. Igari, and T. Miyazaki, “複数の無線センサノードへのプログラムを効率的に転送するOver-the-Air Programming手法の提案,” IPSJ 73rd National Convention, 1V-2, March 2011. (In Japanese)