Enge Pilots Polaris Wireless/GPS Integration
Apr 02, 2012
Source: GPS World
Polaris Wireless, a provider of software-based wireless location solutions, announced that Per K. Enge of Stanford University has joined its executive team as the chief technical advisor. In an interview with GPS World, Enge describes how combined wireless location signatures and GPS show an exciting way forward for location in dense urban environments, where the wireless solution actually improves as GPS degrades.
Polaris Wireless, a provider of software-based wireless location solutions, based in Mountain View, California, announced that Per K. Enge has joined its executive team as the chief technical advisor to the company's CEO, Manlio Allegra.
Enge is a professor of aeronautics and astronautics at Stanford University, where he directs the GPS Research Laboratory. He is also is co-author of the textbook Global Positioning System: Signals, Measurements, and Performance and has received the Kepler, Thurlow, and Burka Awards from the Institute of Navigation (ION) for his work. He received his Ph.D. from the University of Illinois in 1983, where he designed a direct-sequence multiple-access communication system that provided an orthogonal signal set to each user.
Polaris Wireless's core product is a Wireless Location Signature (WLS) for wireless network operators to identify the location of a wireless device to within 50 meters, at low cost, even in urban and indoor environments. Polaris WLS is designed to scale as an operator's network grows, providing location capabilities in 2G (GSM/CDMA), 3G (UMTS/CDMA 2000), and emerging 4G (LTE) air interfaces, as well as indoor technologies such as W-iFi, DAS, and Femtocells. Founded in 2003, Polaris also counts among its customers law enforcement/government agencies and location-based application companies.
In an interview with GPS World, Enge described how the Polaris location solution is actually enhanced by buildings, in direct opposition to the way GPS operates, and how he sees integration of the two technologies as leading the way forward for location-based services.
"A cell phone general receives signals from 3 to 10 base stations, and is required to report the signal to noise ratio of those, even beyond base station used. We backhaul that information into the Polaris server, where we do multilateration based on signal strength measurements. Imagery shows how RF signal stregnth varies in the city. Polaris uses the base station signals (similar to how Skyhook using Wifi access points), but the cell infrastructure use is better because it is always there and used by every phone, while Wifi receiver is not on all phones yet, just smartphones.
"Marriage to GPS is very cool, because the Polaris technology loves buildings, they introduce the variation, the grain in the signal-strength map. It's jagged, it's got nooks and crannies, which are well-predicted by our propagation models. So those buildings enhance our technology.
"We've got it pretty widely deployed, on 24 E911 networks, 24 wireless carriers that we have commercial relationships with in the United States, from quite big to more boutique providers. Some are smaller, regional, other larger, like Verizon though not the total network.
Michael Doherty, Polaris Wireless product marketing and communications director, added that "We also work outside the United States for location surveillance for governments who are also looking to deploy for commercial services. The solution is software-based, in the control plane of the handset, it is already within the handset, using network measurement reports (NMRs). Emergency caller location for cell phones, E911, is just the first of applications to come, it's where we cut our teeth."
Polaris Wireless has been a research partner and sponsor at the Stanford GPS Research Laboratory that Enge directs. "Now I've stepped up my relationship with them, to start talking about getting the next level of accuracy. They joined about 4 or 5 years ago, and funded the work of David De Lorenzo , a Ph.D. student who did first big set of measurements that we did on indoor navigation, on GPS penetration into buildings. On campus. We're aviation people, so this was a new area, good for us, we expanded into that area and got a lot smarter about how to navigate indoors."
De Lorenzo's 2009 Institute of Navigation International Technical Meeting paper, "Design and Performance of a Minimum-Variance Hybrid Location Algorithm Utilizing GPS and Cellular Received Signal Strength for Positioning in Dense Urban Environments," can be accessed here.
"In New York, three-quarters of cell calls get 50-meter accuracy," stated Doherty. "99 percent get 150-meter. Polaris solutions will improve that by a factor of 2. That's a forward-looking statement."
"We are entering a significant growth period for the company. From 2007-08 we saw our business start to take off, from core E911, take off in demand from overseas governments, for anti-crime, anti-terrorism. From 2007 to 2010, Polaris Wireless had an average 66 per increase per year in bookings, in contracts signed. That's a healthy indicator of future revenues
"Year over year 2010 to 2011, we saw a quadrupling of bookings, and a revenue increase of 30 percent, as we started to see those deployments taking place, and revenues coming in as a result. we expect that trajectory to continue through 2012 and 2013. Again, forward-looking statements."
"During the deep recession, when U.S. governments were cutting back, we went overseas and were able to ride that wave."
As to particulars on directions that Polaris research and development might take under his advisement, Enge volunteered "One of the really big initiatives is the inclusion of map-matching, knowing that we're probably on a street, especially if our velocity is appreciable, going beyond a snapshot solution fix, taking advantage of knowing where streets our. We have cached that as a particle-filter problem, a Kalman filter associated with a set of hypotheses. When you have a sequence of snapshots, the particle filter is a very powerful way of putting that together.
"How do we know if we're in a building? By looking at the NMRs. Now, how high are we in that builidng, so that's aided by the database.
"The big core enterprise of Polaris, stripping away PNT, the strength is the underlying [cellular network] database. Polaris is where the database meets navigation. To make E911, law enformcement, navigation, all better.
"One application I'm particularly keen on is for campuses.The risk for muggings is greatest when walking to a car in a distant parking lot. We're thinking about how we can help that student when assaulted. You can't pull out your phone and call E911 nor run to a blue tower [emergency phone]. But you might have your keys in your hand, so if we make it so you can just push a button on it, the NMR goes to an emergency center on campus, then we can be more helpful in helping that student."
Doherty inserted, "The beauty of our technology is that no one has to do anything. Our technology is capable of locating any device connected to the cellular network, as long as the device is powered on. It's a software deployment, nothing to go out and deploy equipment cell tower by cell tower. Nor can bad guys disable anything in the phone to void this service. Polaris's solution resides in the network, not in the handset. The confluence of signals in the network drives the solution. There is no chip in the handset that can be disabled or turned off. Whether GPS is enabled or not."
In a final comment on concerns for the future, Enge said, "Personal privacy devices, PPDs, the GPS jammers. I'm pretty worried about that. Unlike the Polaris technology, GPS technology can be slapped on someone's car without an organization making sure the rule of law is preserved. We're hoping to make the PW technology complementary to GPS, so that when GPS is jammed, the PW solution will still provide a location.
Doherty added, "It is complementary today. Cellular networks covers a large area. Take for example, downtown San Francisco: The wireless signature solution is absolutely the best to locate there. In wide-open country, GPS has an advantage. That complementarity is happening today.
"Having Per onboard, we're going to make that complementarity work better and better."