Distance detection may help secure Wi-Fi

Intel is developing a way to locate a Wi-Fi user by timing how long it takes for packets to travel to and from an access point.

Intel is developing a way to locate a Wi-Fi user by timing how long it takes for packets to travel to and from a wireless access point, which could prevent users outside a house or office from accessing a Wi-Fi network indoors.

Precision location technology is one of several key ideas for the next few years that Justin Rattner, Intel senior fellow and director of the company's Corporate Technology Group, showed off during a keynote presentation on the last day of the Fall Intel Developer Forum in San Francisco Thursday.

Knowing where a system is located also could be an invaluable aid in finding and fixing hardware problems in data centers and for informing mobile device users of places or services nearby, Rattner said. Satellite-based GPS (Global Positioning System) works well outdoors but generally not indoors, he said. Triangulation among Wi-Fi access points based on signal strength is available today indoors but is not precise enough for many uses, Rattner said. This led Intel to study other systems.

In the technology demonstrated Thursday, the access point times how long it takes a packet to travel out to the client system and come back. From the length of that round-trip time, it can extrapolate how far away the client is, Rattner said.

The technology is so precise, even up to 70 meters from the access point, that it can tell whether a client device is inside or outside a wall, Rattner said. For keeping neighbors or passers-by from intruding on a home or enterprise network, it might even be more effective than current encryption systems, he added. Another possible use of the location technology demonstrated at the show was to make a video program follow a user from room to room. For example, if a user carried a notebook PC, the program could move from a TV in the living room to a large PC monitor in an office and then come up on the notebook when the user got out of range of either stationary display, he said.

Both access points and clients would have to be modified to support the system. Intel plans to bring the technology to the IEEE 802.11 group for standardization, he said. Theoretically, the technology could be extended to other types of wireless networks, he said during a question-and-answer session after the presentation.

The coming advances Rattner demonstrated are intended to help systems take care of themselves. PCs, servers and other devices require too much hands-on tinkering, he said.

"We really need to get to a point where the systems support the users, rather than users supporting the systems," Rattner said.

Rattner also showcased a new approach in Intel's ongoing struggle to reduce power consumption. He demonstrated a 100MHz CMOS (complementary metal-oxide semiconductor) voltage regulator that he said can turn the CPU power level up and down more quickly than today's regulators. By following changes in CPU demand more closely -- responding within a fraction of a microsecond -- the CMOS voltage regulator can avoid sending power to the processor when it isn't needed, Rattner said. Intel integrated the voltage regulator and a GMCH (graphics and memory controller hub) with a Pentium M processor. That could cut notebook power consumption by 15 percent to 30 percent without affecting performance, according to Intel. Rattner said he expects to see the technology in notebooks over the next couple of years.

Going to an integrated CMOS voltage regulator could bring big benefits, said Nathan Brookwood, principal analyst with Insight64, in Saratoga, California. Current analog regulators are located across the motherboard from the CPU, so it takes a relatively long time to send messages between the two. As a result, the regulators tend to keep power levels high, not knowing whether demand is about to go up again, he said.

Other glimpses of future technologies included the following:

-- In security, Intel is developing technology that will let PCs detect network-borne worm attacks based on traffic patterns and automatically isolate themselves by shutting off all network connections. Intel has studied the traffic patterns worms create, such as the sudden opening of many new connections, and has fine-tuned the technology to have essentially no false positives, he said. The system can better deal with new worms because it doesn't rely on profiles of specific known worms, and it can spring into action in time to prevent fast-spreading attacks that human intervention isn't fast enough to stop, Rattner said.

-- Intel and Carnegie Mellon University are collaborating on the Diamond Project, developing a digital image search technology. Among other things, it would allow users to set multiple filters on the fly and use them simultaneously to narrow down searches. Rattner and a researcher looked for pictures of IDF keynotes on 85,000 digital photographs stored on a PC. They used the search system's tool for finding face-like images and then defined a blue Intel shirt in one of the pictures -- commonly worn by Intel executives -- and used that color sample in a second search filter.

-- With IBM, Intel is working on autonomic computing systems that can detect environmental conditions such as heat and humidity in a data center and automatically shut down servers that are in danger of overheating. By shutting the servers down quickly, the system prevents any data loss or damage to the server, according to the companies.

Show Comments