• Wireless communication technology that anticipates risks of natural disasters and aging structures to prevent accidents
• Enhanced monitoring of wide, rugged natural environments with poor accessibility
• Highly reliable data collection rate of 99.999% with low maintenance costs
• Low-power multi-hop technology that can operate on battery power for over 10 years

Toshiba Corporation has developed a low-power multi-hop wireless network technology that makes it possible to monitor natural environments at risk of disaster, as well as buildings, bridges, tunnels, and other aging structures. The technology boasts a high data-collection rate of 99.999% through wireless relaying, and is not expensive to maintain as it can operate on battery power for over 10 years.

In recent years, aging public infrastructure and natural disasters have become growing problems, turning focus to sensor networks where sensors and communication devices, fitted to target objects, enable data collection and monitoring, reducing casualties due to accidents and disasters.

However, the need for these communication devices to be installed in more inaccessible, rugged natural environments has presented difficulties in installation and maintenance during operations. Monitoring a wide area has also required considerable effort.

Toshiba’s wireless communication technology addresses these problems and offers highly reliable data collection with low maintenance costs.

High reliability and data collection rate

• High data collection rate: The system is equipped with a function that enables over 99.999% of sensor data to be collected ^{(Note 1)} .
• Reliable data collection: In the event of communication failure during data transmission, the system is able to select a new communication partner with good communication status from surrounding wireless devices and retransmits the data.
• Long-distance communication: Using special low-power wireless devices that operate in the 920-MHz band enables long-distance communication exceeding 1 km in line-of- sight environments. Deployment is also easy as these wireless devices do not require a license.
• Data collection over wide areas: Relay transmission (multi-hop communication) enables data collection over wide areas, where sensor data transmitted by a wireless device is received and then retransmitted by surrounding wireless devices.

High energy efficiency with reduced power consumption

• Reduced power consumption: Wireless devices sleep when communication is not needed. This sleep occurs when communication timings are synchronized and time-division communication ^{(Note 2)} is implemented.
• High energy efficiency: Long periods of sleep even during multi-hop communication are enabled through a mechanism which autonomously determines the sleep timing for the wireless devices. The sleep timing is based on the number of wireless relay hops needed for data collection and a self-assigned device number.

Easy installation and low maintenance costs

• Easy installation: The wireless devices are easy to install as they are battery powered and do not need communication or power lines.
• Low maintenance: Computer simulation and results from field communication trials using prototype devices over a 16-day period have shown that maintenance for battery replacement is not needed for periods exceeding 10 years in all communication devices ^{(Note 3)} .

Toshiba is now proceeding with demonstration experiments by installing its low- power multi-hop wireless network technology in various natural environments and buildings.

Countries around the world today continue to face complex problems and challenges including extreme weather conditions, natural disasters and aging social infrastructure. In the Asia Pacific region, where countries are continuing to develop and urbanize, more advanced infrastructure is needed to support increasingly sophisticated technologies. According to the Asia Development Bank, infrastructure investment needs over the next decade for Asia is estimated at $8 trillion.

Toshiba is committed to addressing these issues and contributing to the infrastructure of the Asia Pacific region by developing innovative information technologies that convert data from substantial products into customer value. By using various kinds of technologies and sensors to monitor the natural environment and aging infrastructure, Toshiba aims to contribute to safe, secure and resilient societies.

(Note 1)
This value was estimated by a computer simulation in which 100 wireless devices were operated in a wireless environment designated by Toshiba, and is not guaranteed for operation in all environments.

(Note 2)
Time-division communication refers to a communication method in which the period of sensor data collection is finely divided into multiple narrow time intervals and the communication devices send the sensor data by using any of these time intervals.

(Note 3)
This value was estimated by numerical simulation assuming a CR-V3 battery and sensor data transmission at 30- min intervals.