Researchers make backscatter breakthrough for IoT sensors

Researchers make backscatter breakthrough for IoT sensors

Researchers make backscatter breakthrough for IoT sensors
The University of Washington team has deployed and tested its technology on this epidermal patch. (Credit: University of Washington)

University of Washington researchers have developed a way to use backscatter techniques to send IoT sensor data over distances using almost zero power. 

Researchers at the University of Washington have developed IoT devices that run on almost zero power and can transmit data across distances of up to 2.8 kilometres. The breakthrough could enable large arrays of interconnected devices, the say.

The scientists presented their findings at Ubicomp 2017 last week and demonstrated how sensors could be equipped with a built-in modulation technique called a long-range backscatter system, which uses reflected radio signals to transmit data at extremely low power and low cost.

Read more: Researchers create energy-efficient power converter for IoT

A range of deployments

In tests, the team achieved coverage throughout a 4,800-square-foot house, an office area covering 41 rooms and a one-acre vegetable farm. This new technique is called chirp spread spectrum. It spread reflected signals across multiple frequencies to enable sensitivities and decode backscattered signals across greater distances, even in ‘noisy’ conditions.

“Until now, devices that can communicate over long distances have consumed a lot of power. The trade-off in a low-power device that consumes microwatts of power is that its communication range is short,” explained Shyam Gollakota, lead faculty and associate professor in the Paul G. Allen School of Computer Science & Engineering at University of Washington.

“Now we’ve shown that we can offer both, which will be pretty game-changing for a lot of different industries and applications.”

Read more: Cranfield University teams up with Spirent on connected car tech

Cost and coverage

The sensors use 1,000 times less power than existing technologies capable of transmitting data over similar distances, which could pave the way for putting connectivity into many objects. They are also very cheap, costing up to 20 cents each. This could allow a farmer to cover an entire field to establish how to economically plant seeds or water. The sensors could also be used to monitor pollution or traffic in smart cities.

“People have been talking about embedding connectivity into everyday objects such as laundry detergent, paper towels and coffee cups for years, but the problem is the cost and power consumption to achieve this,” said Vamsi Talla, CTO of Jeeva Wireless, a spin-off company founded by the UW team of computer scientists and electrical engineers to commercialize the research.

The research team expects to begin selling the technology within the next six months.