Using Wi-Fi To Count People Through Walls

Whether you’re trying to figure out how many students are attending your lectures or how many evil aliens have taken your Space Force brethren hostage, Wi-Fi can now be used to count them all. The system, created by researchers at UC Santa Barbara, uses a single Wi-Fi router outside of the room to measure attenuation and signal drops. From the release: “The transmitter sends a wireless signal whose received signal strength (RSSI) is measured by the receiver. Using only such received signal power measurements, the receiver estimates how many people are inside the room — an estimate that closely matches the actual number. It is noteworthy that the researchers do not do any prior measurements or calibration in the area of interest; their approach has only a very short calibration phase that need not be done in the same area.” This means that you could simply walk up to a wall and press a button to count, with a high degree of accuracy, how many people are walking around. The system can measure up to 20 people in its current form.

MIT’s AI Can Track Humans Through Walls With Just a Wifi Signal

Researchers at the Massachusetts Institute of Technology have developed a new piece of software that uses wifi signals to monitor the movements, breathing, and heartbeats of humans on the other side of walls. While the researchers say this new tech could be used in areas like remote healthcare, it could in theory be used in more dystopian applications.

“We actually are tracking 14 different joints on the body […] the head, the neck, the shoulders, the elbows, the wrists, the hips, the knees, and the feet,” Dina Katabi, an electrical engineering and computer science teacher at MIT, said. “So you can get the full stick-figure that is dynamically moving with the individuals that are obstructed from you — and that’s something new that was not possible before.” The technology works a little bit like radar, but to teach their neural network how to interpret these granular bits of human activity, the team at MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) had to create two separate A.I.s: a student and a teacher.

The team developed one A.I. program that monitored human movements with a camera, on one side of a wall, and fed that information to their wifi X-ray A.I., called RF-Pose, as it struggled to make sense of the radio waves passing through that wall on the other side. The research builds off of a longstanding project at CSAIL lead by Katabi, which hopes to use this wifi tracking to help passively monitor the elderly and automate any emergency alerts to EMTs and medical professionals if they were to fall or suffer some other injury.

Massachusetts Institute of Technology behind the innovation has previously received funding from the Pentagon’s Defense Advanced Research Projects Agency (DARPA). Another also presented work at a security research symposium curated by a c-suite member of In-Q-Tel, the CIA’s high-tech venture capital firm.

‘Living laboratories’: the Dutch cities amassing data on oblivious residents

Stratumseind in Eindhoven is one of the busiest nightlife streets in the Netherlands. On a Saturday night, bars are packed, music blares through the street, laughter and drunken shouting bounces off the walls. As the night progresses, the ground becomes littered with empty shot bottles, energy drink cans, cigarette butts and broken glass.

It’s no surprise that the place is also known for its frequent fights. To change that image, Stratumseind has become one of the “smartest” streets in the Netherlands. Lamp-posts have been fitted with wifi-trackers, cameras and 64 microphones that can detect aggressive behaviour and alert police officers to altercations. There has been a failed experiment to change light intensity to alter the mood. The next plan, starting this spring, is to diffuse the smell of oranges to calm people down. The aim? To make Stratumseind a safer place.

We get that comment a lot – ‘Big brother is watching you’. I prefer to say, ‘Big brother is helping you’

All the while, data is being collected and stored. “Visitors do not realise they are entering a living laboratory,” says Maša Galic, a researcher on privacy in the public space for the Tilburg Institute of Law, Technology and Society. Since the data on Stratumseind is used to profile, nudge or actively target people, this “smart city” experiment is subject to privacy law. According to the Dutch Personal Data Protection Act, people should be notified in advance of data collection and the purpose should be specified – but in Stratumseind, as in many other “smart cities”, this is not the case.

Peter van de Crommert is involved at Stratumseind as project manager with the Dutch Institute for Technology, Safety and Security. He says visitors do not have to worry about their privacy: the data is about crowds, not individuals. “We often get that comment – ‘Big brother is watching you’ – but I prefer to say, ‘Big brother is helping you’. We want safe nightlife, but not a soldier on every street corner.”

When we think of smart cities, we usually think of big projects: Songdo in South Korea, the IBM control centre in Rio de Janeiro or the hundreds of new smart cities in India. More recent developments include Toronto, where Google will build an entirely new smart neighbourhood, and Arizona, where Bill Gates plans to build his own smart city. But the reality of the smart city is that it has stretched into the everyday fabric of urban life – particularly so in the Netherlands.

In the eastern city of Enschede, city traffic sensors pick up your phone’s wifi signal even if you are not connected to the wifi network. The trackers register your MAC address, the unique network card number in a smartphone. The city council wants to know how often people visit Enschede, and what their routes and preferred spots are. Dave Borghuis, an Enschede resident, was not impressed and filed an official complaint. “I don’t think it’s okay for the municipality to track its citizens in this way,” he said. “If you walk around the city, you have to be able to imagine yourself unwatched.”

Enschede is enthusiastic about the advantages of the smart city. The municipality says it is saving €36m in infrastructure investments by launching a smart traffic app that rewards people for good behaviour like cycling, walking and using public transport. (Ironically, one of the rewards is a free day of private parking.) Only those who mine the small print will discover that the app creates “personal mobility profiles”, and that the collected personal data belongs to the company Mobidot.
‘Targeted supervision’ in Utrecht

Companies are getting away with it in part because it involves new applications of data. In Silicon Valley, they call it “permissionless innovation”, they believe technological progress should not be stifled by public regulations. For the same reason, they can be secretive about what data is collected in a public space and what it is used for. Often the cities themselves don’t know.

Utrecht keeps track of the number of boys and girls hanging in the streets, their age and whether they are acquaintances

Utrecht has become a tangle of individual pilots and projects, with no central overview of how many cameras and sensors exist, nor what they do. In 2014, the city invested €80m in data-driven management that launched in 80 projects. Utrecht now has a burglary predictor, a social media monitoring room, and smart bins and smart streetlights with sensors (although the city couldn’t say where these are located). It has scanner cars that dispense parking tickets, with an added bonus of detecting residents with a municipal tax debt according to the privacy regulation of the scanner cars. But when I asked the city to respond to a series of questions on just 22 of the smart projects, it could only answer for five of them, referring me to private companies for the rest of the answers.

The city also keeps track of the number of young people hanging out in the streets, their age group, whether they know each other, the atmosphere and whether or not they cause a nuisance. Special enforcement officers keep track of this information through mobile devices. It calls this process “targeted and innovative supervision”. Other council documents mention the prediction of school drop-outs, the prediction of poverty and the monitoring of “the health of certain groups” with the aim of “intervening faster”.

Like many cities, Utrecht argues that it acts in accordance with privacy laws because it anonymises or pseudonymises data (assigning it a number instead of a name or address). But pseudonymised personal data is still personal data. “The process is not irreversible if the source file is stored,” says Mireille Hildebrandt, professor of ICT and Law at Radboud University. “Moreover, if you build personal profiles and act on them, it is still a violation of privacy and such profiling can – unintentionally – lead to discrimination.” She points to Utrecht’s plan to register the race and health data of prostitutes, which came in for heavy criticism from the Dutch Data Protection Authority.

Another unanswered question regards who owns data that is collected in a public space. Arjen Hof is director of Civity, a company that builds data platforms for governments. “Public authorities are increasingly outsourcing tasks to private companies. Think of waste removal or street lighting,” he says. “But they do not realise that at the same time a lot of data is collected, and do not always make agreements about the ownership of data.”
‘A smart city is a privatised city’

Hof gives the example of CityTec, a company that manages 2,000 car parks, 30,000 traffic lights and 500,000 lamp-posts across the Netherlands. It refused to share with municipalities the data it was collecting through its lamp-post sensors. “Their argument was that, although the municipality is legally owner of the lamp-posts, CityTec is the economic owner and, for competitive reasons, did not want to make the data available,” Hof says. This was three years ago, but for a lot of companies it remains standard practice. Companies dictate the terms, and cities say they can’t share the contracts because it contains “competition-sensitive information”.

When I interviewed the technology writer Evgeny Morozov in October, he warned of cities becoming too dependent on private companies. “The culmination of the smart city is a privatised city,” he said. “A city in which you have to pay for previously free services.”

Morozov’s fear about public subsidies being used for private innovation is well illustrated in Assen, a city of 70,000 people in the north of the country. Assen built a fibre-optic network for super-fast internet in 2011, to which it connected 200 sensors that measure, among other things, the flow of cars. There was an experiment to steer people around traffic jams, even though traffic in the city is relatively light. The city also connected its traffic lights, parking garages and parking signs to this grid. The cost of €46m was split between Brussels, the national government, the province and the municipality. Companies such as the car navigation firm TomTom have used the sensor network to test new services.

The project, called Sensor City, filed for bankruptcy a year ago. Now the publicly funded fibre-optic network, sensors and all, will be sold to a still-unidentified private company. The municipality will have to strike a deal with the new owner about the use of its public traffic lights and parking signs.