If you want to put a sensor in exactly the right spot, whether or not there is line power available, then the ability to run on batteries or harvested/scavenged power can be critically important and make (or break) the ROI of the application.  Wireless data transmission consumes power: if a node is continuously transmitting it is consuming maximum power and requires either frequent battery replacement or a wired connection to a power source (in which case it is not a truly wireless network).

All of Dust Networks' products use time synchronization to reduce power consumption to an absolute minimum. In these systems, all of the nodes share a common sense of time. They transmit, listen or sleep at specified times called timeslots. Timeslots are measured in milliseconds, and in typical applications this leads to a duty cycle of less than 1 percent for all nodes in the network, including those relaying messages for neighboring nodes. Thus these systems are capable of ultra-low-power operation, with typical battery lifespans of 7 to 10 years, or more.

The result is a solution that  can easily be used in battery-powered and energy-scavenging applications that demand proven performance and scalability while drawing very little power. Based on Dust Networks' breakthrough IEEE 802.15.4-compliant low power hardware, all motes can function as both routers and end-nodes, enabling a full mesh topology that provides more redundant routes and higher performance. Additionally, the intelligence embedded in each device allows for careful monitoring of charge consumed during operation, reporting the remaining battery life to the control system or gateway, which in turn can dynamically re-route network traffic to other nodes to balance the network load and provide for deterministic battery life.

If an application has line-power readily available to some or all nodes, the network should be smart enough to adapt its topology to use the line-powered nodes in an intelligent way. Additionally, the network should be flexible enough to allow the application to programmatically take advantage of the availability of line-powered nodes to optionally increase sampling rates and/or decrease latency.