3. Combined with a sensor network in an attraction system

Tell us about the attraction system you concerned with.

FujiokaHitachi worked on the construction of an interactive attraction system for an event, and μWirelessWeb was one of the technologies used. We developed a dedicated protocol that is based on the IEEE 802.15.4 wireless communication specifications, which feature low power consumption. We used that protocol to implement sensor nodes with the μWirelessWeb technology and to construct a sensor network from the sensor nodes and a wireless base station. The sensor node is a compact terminal that has a sensor function. In this system, the terminal had the form of a ball that was carried around by the attraction participants as they walked. The terminal was also programmed with action functions so that an LED in the terminal would blink or the ball would vibrate according to the actions of the user that were detected by an acceleration sensor action when a participant came near the base station of the sensor network.

Why is it based on IEEE 802.15.4?

FujiokaWe based it on IEEE 802.15.4 because power consumption is a problem. The wireless communication function and the LED blinking or vibration action require the sensor node to have a built-in power supply. For one thing, the sensor node itself must be small enough and light enough that anyone can easily carry it around. IEEE 802.15.4 is a very compact wireless communication standard, so using it as a base allows us to make the program small enough that it can be implemented together with the sensor function and action function on a one-chip microprocessor. Having done that, we just have to find the best match between the sensor node size and weight and the microcomputer and battery to be used.

Was it successful?

FujiokaMaking direct contact with over a hundred thousand customers is an event of this scale and being able to directly see their reactions to the system that we ourselves developed gave us a great feeling of satisfaction. The actual market for the attraction system is probably not large, but the technology can be applied to the distribution of goods and various other services that can use this kind of sensor network. In order to accumulate the know-how about these application, we found great value in the fact that we ourselves built this system up from beginning to end.

Figure 3: An attraction system using IEEE 802.15.4 wireless communication protocol