Ambient Backscatter: Wireless Communication of the Future

There is a fairly new way for wireless devices to communicate and compete with each other without power, batteries, or human interaction. It is known as ambient backscatter, and it was developed in 2013 by engineers at the University of Washington. The technology involves wireless communication using ambient energy that is harvested from Wi-Fi, television, cellular, and radiofrequency emissions. Ambient backscatter could be the future of telecommunications between devices and everyday objects, making it useful in an array of tasks from finding lost keys to monitoring the condition of buildings and bridges.

Ambient backscatter works by utilizing surrounding television, radio, and cellular transmissions. Essentially, two devices reflect existing signals to communicate with each other. This communication resembles a Morse code between devices that have no batteries. They absorb or reflect signals from a nearby television or cellular tower. The wireless signals are repurposed into a communication medium of sorts using no power and no human contact. Antennas on other devices can detect the reflected signal after it has been coded. The other device can then respond accordingly. Ambient backscatter uses existing signals that are all around instead of generating new signals, and the devices reflect or absorb these waves to exchange information.

The research for ambient backscatter was funded by the University of Washington through a Google Faculty Research Award and by the National Science Foundation’s Research Center for Sensorimotor Neural Engineering at the University of Washington. In August of 2013, the team of engineers at the University of Washington published their results at the Association for Computing Machinery's Special Interest Group on Data Communication 2013 conference in Hong Kong, and their research won an award at the conference. According to Joshua Smith, a University of Washington associate professor of computer science and electrical engineering, the powerless devices “form a network out of thin air” (Ma, 2013, para. 6).

The University of Washington engineers demonstrated this innovative powerless communication by building credit card-sized prototype devices with antennas built into the circuit boards. When a user swiped the touch sensor with their finger, they initiated communication with the device. When the other device confirmed the reception, an LED light blinked. All of this was possible without any power or batteries.

The researchers also demonstrated that an offline payment application was possible without the use of a computer or phone. A battery-powered payment terminal read and displayed the monetary value of a device before and after transferring funds. The transfer was successful using only ambient RF power.

They tested groups of the device in different settings in Seattle, Washington. The locations included a street corner, a parking garage, and inside an apartment. They were all within six and a half miles away from a television tower. Their study found the following:

The devices — even the ones farthest from a TV tower — were able to communicate with each other. The receiving devices picked up a signal from their transmitting counterparts at a rate of 1 kilobit per second when up to 2.5 feet apart outdoors and 1.5 feet apart indoors. This is enough to send such information as a sensor reading, text message or contact information. (“Ambient Backscatter,” 2013, para. 8)

As of yet, companies have not taken advantage of ambient backscatter. However, this is quite certain to change. It is a fairly new technological advancement, and researchers are currently working on ways to advance the range and capacity of the ambient backscatter communication network (“Ambient Backscatter,” 2013). Once the technology has been tweaked and perfected, ambient backscatter could prove to be an extremely useful way to communicate without the use of power or batteries of any kind. This new technology could “allow us to envisage a completely connected wireless world and brings the Internet of Things a step closer to reality” (Meyer, 2013, para. 1).

These days, more and more businesses are relying on sensors and connected devices for all kinds of management uses. It is a challenge to keep all devices powered at all times at a reasonable cost. Resorting to wires requires installation woes, and batteries will always need to be recharged and eventually replaced. This is why an ambient backscatter is a feasible option in powering devices for all kinds of businesses from security and construction companies to banks, hospitals, and the housing industry. Devices would essentially be able to run without any human help.

There are many ways in which ambient backscatter can be useful to businesses of all kinds. The fact that devices will be able to interact with users and communicate with other devices using no batteries or power will save companies money in energy costs in the long run. According to Ostaffe, “the obvious appeal of harvesting ambient RF energy is that it is essentially ‘free’ energy” (2013, para. 2).

Ambient backscatter can lend a very useful hand in the infrastructure of buildings.The sensors could be built and placed put inside nearly any structure, whether it is made out of wood, concrete, or metal. The structure could then communicate if there is damage within. Sensors could be put in a bridge, and they could monitor the condition of the infrastructure. If any cracks form, they could send an alert. This will make repairs in any structure easier to fix when problems are apparent early on. Ambient backscatter could result in buildings, bridges, and homes lasting longer than ever.

Ambient backscatter will be extremely beneficial not only for businesses and healthcare but also in many applications that are a part of everyday life. A completely wireless world means that homes could essentially run themselves. From wireless security to temperature control, houses could require less energy and manpower to maintain and repair. Ambient backscatter could make home monitoring completely wireless and self-sufficient.

The ambient backscatter technology would be beneficial for devices that are used daily as well. For instance, smartphones and other phones could still be used, regardless of the battery dies. Phones could be configured so that when the battery dies, the phone would still be able to send text messages using power from ambient RF sources. The technology could be used as a viable backup power source for phones and other devices.

The backscatter-assisted wireless management may make it possible to connect all objects and places to one another. This would result in better resource management at a minimized cost. For example, a smart home would be capable of measuring the condition of the infrastructure as well as the temperature and other factors. The information would then be fed to the homeowner in real-time. “Everyday objects could also be enabled with battery-free tags to communicate with each other. For example, a couch could use ambient backscatter to let the user know where his keys were left” (Farrell, 2013, para. 9).

There is a possibility that medicine could also benefit from this technology. Smart patches have recently been developed by researchers at the University of Tokyo, but the team was lacking a way to get continuous power without using wires inside of the body. Now, ambient backscatter may make it possible for wire-free smart patches (Meyer, para. 3).

This exciting new technology does not come without possible disadvantages. It may be too soon to tell, but this advanced technology could be a blessing to some, yet for others it could mean a huge financial loss for companies and individuals in certain fields. Ambient backscatter could result in less necessary manpower, which would mean a decreased number of available jobs. While it is extremely useful, this technology may cause a huge loss in employment, especially in building infrastructure businesses. There could also be job losses in home security, construction, highway maintenance, and countless other fields that require humans to monitor conditions and changes. Plus, it is possible that there would no longer be a need for battery or wire companies to be in existence. These are grim possibilities, but it is necessary to factor them into the future of ambient backscatter technology.

It is clear that ambient backscatter is a welcome technological advancement in spite of any disadvantages that come along with it. Simply put, anything that relies on batteries could be built with this new technology. With the use of ambient backscatter, a completely wireless world is possible in business, home maintenance, and leisure activities. The applications would be endless.

References

ARRL. (n.d.). "Ambient Backscatter" Could Power Devices in the Future. Retrieved from http://www.arrl.org/news/ambient-backscatter-could-power-devices-in-the-future

Farrell, N. (2013, August 15). Ambient backscatter threatens end of batteries. TechEye. Retrieved from http://news.techeye.net/science/ambient-backscatter-threatens-end-of-batteries

Ma, M. (n.d.). Wireless devices go battery-free with new communication technique. Wireless devices go battery-free with new communication technique. Retrieved from http://phys.org/news/2013-08-wireless-devices-battery-free-technique.html

Meyer, T. (2013, September 17). Battery-free connected objects using 'ambient backscatter'. L'Atelier: Disruptive innovation. Retrieved from http://www.atelier.net/en/trends/articles/battery-free-connected-objects-using-ambient-backscatter_423954

Ostaffe, H. (n.d.). RF-based wireless charging and energy harvesting. RF-based Wireless Charging and Energy Harvesting. Retrieved from http://www.mouser.com/applications/rf_energy_harvesting/