Wireless sensor networks are gaining in popularity in government and industry and are being used more and more in inventory tracking and control and industrial and building monitoring. There are, however, problems with the reliability and performance of sensor networks. Hayward, CA-based Dust Networks says it has solved many of these problem with a new mesh platform.
Rob Conant, Dust's co-founder, said that frequency hopping is the best approach for wireless networks in industrial and commercial building applications. "802.15.4 in fixed-frequency mode just isn't viable," he said. "If you rely on a single frequency and the convenience store next door turns on a WiFi access point, your system will fall apart." Dust, therefore, uses frequency hopping so that the signal is spread out over the entire band. The company says that frequency hopping is the only way to guarantee 99.9 percent system reliability. "There just too many unknowns and interferers that the system has to be able to deal with that dynamically," Connant said.
The system's reliability is further enhanced by the platform's mesh-network architecture, in which every node acts as a router, in the process providing built-in redundancy. Dust's SmartMesh-XR-based system can accommodate up to 250 nodes per manager device, and all nodes can be upgraded or reconfigured remotely with over-the-air software updates. The nodes consume only 25µA of current, and even routing nodes which carry heavy traffic from multiple of neighbors will consume less than 200 µA. The low power consumption allows devices to run for five to 10 years on batteries.