Redwood City, Calif. In a handful of high-level programs, the Defense Advanced Research Projects Agency is pushing beyond Ethernet and Internet Protocol to hammer home the message that peer-to-peer networks intrinsically more efficient than end-to-end topologies are the future, and the future is now.
Darpa is pushing toward a world of ultralow-cost, low-power, ad hoc mesh networks. The programs are part of a broad military drive toward ubiquitous computing based on next-generation networks, including RFID and wireless sensor nets.
At the Wireless Ventures conference here last week, Preston Marshall, a program manager in Darpa's Advanced Technology Office, moved the spotlight away from the rise of today's 802.11 networks in the business world, saying in keynote that an improvement of five orders of magnitude is needed. "We get trapped by the vision of Internet Protocol like its some sort of theocracy when in fact there are much better models," he said.
Marshall's contrarian note resonated amid predictions like the one by a venture capitalist that Wi-Fi nets will ultimately surpass even cellular as both race toward the consumer broadband era.
But such networks are grossly inefficient for sending small amounts of data that will be the hallmark of future machine-to-machine networks of embedded devices, Marshall said. An 802.11b network could take as many as 12,480 bits and 57 acknowledgments to send an 80-bit data packet, a 0.65 percent efficiency rating.
"This is five orders of magnitude from what we can do. This is like selling cars that get 10 inches per gallon," Marshall said. "We need to think as a community how we can get that efficiency up."
Darpa's vision is to create a new kind of peer-to-peer network for "edge-driven computing." Unlike Ethernet, that network will not depend on packets or predefined client/server topologies with guaranteed end-to-end connections. Instead, it will forward data one hop at a time over a distributed network of autonomous nodes using new and more reliable and efficient schemes.
Darpa is doing its part in at least four major programs now under way. One program is developing so-called connectionless networks using new physical layer chips and protocols that could reduce the energy requirements for communications three-hundredfold. The program includes experiments using silicon-on-sapphire technology to reduce energy requirements in oscillators and mixers.
Another program aims to create systems that automatically scan the airwaves in real-time for available spectrum in which it can set up and tear down ad hoc networks in hundreds or even tens of milliseconds. The project includes development of a machine-readable policy language as the basis for its software.
"This opens up hundreds of megahertz of new spectrum without new licensing," said Marshall, adding that the Darpa program is working in conjunction with the Federal Communications Commission's efforts in so-called cognitive radio (see www.eet.com/showArticle.jhtml?articleID=18700443).
A parallel project is exploring delay-tolerant networks based on work at NASA. In this scheme individual nodes collaborate to form complex relationships forwarding data reliably but without knowledge of the overall topology of the network.
Separately, Darpa is also sponsoring one project in wireless networking that generates RF signals with lasers and another that will experiment with using radio isotopes to create ultralong lasting batteries (see accompanying story below).
The programs all stem from a broadly held belief among military researchers that the future of networking lies in ubiquitous ad hoc mesh networks. "We want to put robots and sensors on the battlefield and not have to drive all the data back
to the Pentagon," Marshall said. "The Department of Defense is committed to this even though we are not sure it will all work yet," he added.
Tags and sensors
Indeed, the military is one of the key backers of emerging RFID and wireless sensor nets. The Pentagon is ordering its estimated 40,000 suppliers to begin using RFID tags on containers and palettes, said Vic Verma, chief executive of Savi Technology (Sunnyvale, Calif.), which sells RFID networking gear. Verma showed a video at the conference examining the British military's adoption of RFID technology that it is promoting to other NATO military.
The Yankee Group estimates such supplier mandates from the DOD and retail giant Wal-Mart could generate anywhere from $515 million to $3.8 billion in spending on RFID technology.
The military is also key in kick-starting an emerging class of wireless sensor networks, said Charlie Chi, a senior research analyst for On World Inc. (San Diego) that follows the nascent market.
Passive RFID tags contain fixed data messages scanned by reader systems and are typically used to track shipments of goods. By contrast, sensor nets typically have on-board processing, memory and battery capabilities and actively create their own ad hoc mesh networks to monitor machines or environments.
"Initially, the military and homeland defense are providing some traction here. We don't see a ramp up [for sensor networks] in commercial applications until about 2006 providing the Zigbee networking standard is ratified this year," Chi said, referring to the low-cost wireless protocol.
Startups such as Crossbow Technology, Dust Inc. and Millennial Net presented at the conference, claiming they are seeing movement in commercial pilot projects and deployments this year.
"It's a target-rich environment," said Tod Riedel, senior vice president for business development at Millennial Net. "We are doing a project for a 2,000-space parking garage, effectively creating a network of parking spaces," he said.
Commercial deployments are beginning now that individual nodes have come down to prices of about $65 each, said Mike Horton, chief executive of Crossbow. The startup said its year-over-year sales of sensor nets tripled in the first quarter, though it did not break out specific figures. However, Horton said per-node costs must fall below $10 to enable volume deployments, something that may not happen until 2007.
Venture capitalists expressed some skepticism about both RFID and sensor net startups. Both areas have been emerging markets for several years and have seen their share of startups that went bust, they said. However, Millennial Net was still voted as one of the top 10 startups of the conference.
"They are the only sensor network company I have seen that is radio-agnostic rather than trying to build their own radios," said Laura Druyan, general partner of Allegis Capital. "But this market is still really early."