By Gerry Blackwell
June 25, 2007
This player in wireless sensor networks says it has the smallest sensor motes to date.
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The market for wireless sensor networks using tiny, low-powered sensor devices called motes that can measure everything from soil temperature to motion is about to take off, and Moteiv Corp., a San Francisco startup, hopes to cash in big with products it says are smaller and easier to use than the competition’s.
Moteiv’s latest, the recently-introduced Tmote Mini, is the market’s smallest yet, the company says. It fits in the MiniSD slot in a phone or PDA, or it can be incorporated in stationary network nodes. Given that a mote comprises a wireless radio, microprocessor, at least one sensor and application software, this is an astonishing achievement. The Tmote Mini comes standard with a temperature sensor, but includes hooks for connecting multiple sensors.
“The motes self-configure themselves into wireless sensor networks,” explains company co-founder and chief technology officer Joe Polastre. “Hundreds or thousands of these things can form a system.”Applications include asset tracking in industry and health care, micro-climate monitoring in agribusiness, security surveillance in the military, monitoring corrosion on airliner airframes, energy management in commercial buildings – and adding sensing capabilities to toys.
The Tmote Mini is a breakthrough on a few counts. It’s smaller than competitors’ products and smaller than Moteiv’s previous products. This makes it easier to incorporate in custom sensor nodes. It can be installed in a PDA or smartphone for mobile monitoring of wireless sensor networks (WSNs). And it’s less expensive than previous products – $30 to $50, depending on volume, compared to $80 for Moteiv’s previous, much larger mote.
The wireless technology in the Mini and Moteiv’s earlier products isn’t Wi-Fi, though. They use radios based on the IEEE 802.15.4 wireless personal area network (WPAN) standard, and comply with the ZigBee narrowband wireless protocol for home and building automation. These technologies appear to be the de facto emerging standards in the WSN industry.
Still, Polastre says there is a role for Wi-Fi to play in the mote-based WSN market. If development of lower power consumption Wi-Fi radios comes to fruition, those could be incorporated in future motes. Current Wi-Fi radios draw too much power, and wouldn’t last long enough in the field without recharging. A more likely role in the near term is Wi-Fi to backhaul traffic from sensor networks to servers where the data can be processed.
Moteiv grew out of work its trio of twenty-something co-founders – Polastre, Cory Sharp and Rob Szewczyk – did as graduate students at the University of California at Berkeley. The original blue-sky idea was “smart dust,” computing devices the size of a speck of dust – hence, “mote” – that could be embedded in paint and other liquids and sprayed into an environment or onto surfaces to create ad hoc mesh networks.
After university, the friends looked for ways to commercialize the smart dust concept. The business plan they came up with involved a compromise of sorts: build the smallest motes possible using off-the-shelf silicon – not quite dust particle size yet – and sell them into the emerging WSN market.
They launched Moteiv in 2003, with first-round funding from Onset Ventures and Claremont Creek Ventures. Last year, they brought Rick Schell on board as CEO and resident greybeard. As Polastre puts it, Schell, a veteran software developer and entrepreneur, has “basically been part of every software revolution in the past 30 years.”
The company was to some extent in stealth mode until recently, but has for a couple of years been selling an earlier “development” product, the board-level Tmote Sky. The market for this type of device has been evolving pretty much in lockstep with Moteiv’s own development, and appears ready to take off.
Polastre cites market research from an unnamed source suggesting there are already millions of WSN nodes in place worldwide, with the population expected to grow to billions by 2015.
A 2005 study from ON World, a wireless industry market researcher, claimed demand for WSN technology was already high among industrial companies, with 29% of 44 survey respondents saying they already used wireless sensor networks, and more than 40% saying they were highly likely to pilot test WSNs within 18 months. It predicted one million nodes would be deployed worldwide by the end of that year.
The ON World report noted that dozens of networks with 500-plus nodes and several with thousands had been deployed, including many in harsh industrial settings, and that hundreds of OEMs worldwide were already offering or were developing WSN solutions.
The firm’s most recent WSN market study predicts that one segment alone, sensor networks in commercial buildings for energy management, will reach $2.6 billion in revenues by 2011.
Moteiv has had some initial success in a few application areas. The most interesting is micro-climate management for high-value crops such as wine grapes, fruit trees and orchids.
In vineyards in Northern California, wine growers are installing WSNs with soil moisture sensors to tell them when the grapes need to be irrigated. In the past, they used satellite weather information, but that only provided information updated every month. And for crops such as fruit trees, it could only show moisture levels at tree-top level.
With ground-level soil moisture sensor networks, growers can tell in real time exactly how much irrigation is required and when. The sensor network can even turn on an irrigation system automatically when soil moisture reaches a certain threshold. “It not only saves water,” Polastre says, “but they get higher yields because they’re able to keep moisture at a consistent level.”
Another key application segment for Moteiv is mobile asset management in harsh environments such as rail yards, truck depots and grocery distribution centers. “They tend to lose things quite often, which is a little disturbing,” he says. “And containers move in and out.” A mobile asset tracking system would allow a worker to walk into an environment, query the network to find the lost asset, then upload its location over the cellular network.
“The traditional view in the wireless sensor network world is that you [monitor] only through a centralized server,” Polastre says. “But we figured that since the assets [you want to track] are potentially mobile, you should be able to do it while mobile as well.”
The mobility that the Tmote Mini enables would also help in setting up sensor networks, Polastre notes. Now a wine grower deploying WSN nodes wouldn’t have to go back to the central server to see if the new node was up and running properly. He could query it with a portable device on the spot.
There are many more applications for WSN motes, including a few that Moteiv would never have thought of on its own, Polastre admits.
The military, for example, is looking at using Tmote Mini-powered WSNs in isolated areas to ensure they remain secure in the absence of direct monitoring. The nodes would be equipped with motion detectors that could record the presence of people or vehicles. Personnel returning to the area with mobile devices could then query the network to find out if there had been activity in their absence.
Healthcare providers at Johns Hopkins University are exploring using ad hoc WSNs in disaster situations. Triage nurses with Tmote Mini-enabled mobile devices could attach nodes to casualties and program the nodes with their assessment. This data could then be used to generate a route map from patient to patient for a doctor following behind, carrying a similar mobile device.
Another idea is to attach a mote to a piece of equipment such as a heart monitor used in emergency situations, so medics wouldn’t have to disconnect the device – causing some trauma – as the patient moved from one environment to another: ambulance to emergency room to hospital ward and so on. The mote would help the owner find and recover the unit later.
Wireless sensor networks may not exactly be the next great frontier for Wi-Fi – or not yet, anyway – but it’s definitely an interesting new wireless market. And Moteiv is clearly a player to watch.