Ambient backscatter[1] uses existing radio frequency signals, such as radio, television and mobile telephony, to transmit data without a battery or power grid connection. Each such device uses an antenna to pick up an existing signal and convert it into tens to hundreds of microwatts of electricity.[2] It uses that power to modify and reflect the signal with encoded data. Antennas on other devices, in turn, detect that signal and can respond accordingly.
Initial implementations can communicate over several feet of distance, even if the transmission towers are up to 10.5 kilometres (6.5 mi) away. Transmission rates were 1k bits per second between devices situated 0.45 metres (1 ft 6 in) apart inside and 0.75 metres (2 ft 6 in) apart outside, sufficient to handle text messages or other small data sets. Circuit sizes can be as small as 1 sq. mm.[2] Later implementation uses Wi-Fi,[3] Bluetooth,[4] FM radio[5] and LoRa transmissions.[6][7] There exists technology to extend backscatter communication range up-to 3.4 kilometers while consuming 70 μW power at the backscatter tag.[8]
This approach would let mobile and other devices communicate without being turned on.[9] It would also allow unpowered sensors to communicate, allowing them to function in places where external power cannot be conveniently supplied.[10]
In 2021, researchers integrated RF backscatter with Li-Fi to achieve greater range via PassiveLiFi.[11]
^https://dl.acm.org/doi/10.1145/2486001.2486015
^ ab"Battery-free short-range wireless communication between devices". KurzweilAI. Retrieved 2013-08-15.
^Ensworth, Joshua F.; Reynolds, Matthew S. (September 2017). "BLE-Backscatter: Ultralow-Power IoT Nodes Compatible With Bluetooth 4.0 Low Energy (BLE) Smartphones and Tablets". IEEE Transactions on Microwave Theory and Techniques. 65 (9): 3360–3368. Bibcode:2017ITMTT..65.3360E. doi:10.1109/TMTT.2017.2687866. ISSN 0018-9480. S2CID 44760506.
^Peng, Yao; Shangguan, Longfei; Hu, Yue; Qian, Yujie; Lin, Xianshang; Chen, Xiaojiang; Fang, Dingyi; Jamieson, Kyle (2018-08-07). "PLoRa". Proceedings of the 2018 Conference of the ACM Special Interest Group on Data Communication. SIGCOMM '18. Budapest, Hungary: Association for Computing Machinery. pp. 147–160. doi:10.1145/3230543.3230567. ISBN 978-1-4503-5567-4.
^Varshney, Ambuj; Pérez-Penichet, Carlos; Rohner, Christian; Voigt, Thiemo (2017-11-06). "LoRea". Proceedings of the 15th ACM Conference on Embedded Network Sensor Systems. SenSys '17. New York, NY, USA: Association for Computing Machinery. pp. 1–2. doi:10.1145/3131672.3136996. ISBN 978-1-4503-5459-2. S2CID 3938018.
^Georgia Institute of Technology. "Backscatter breakthrough runs near-zero-power IoT communicators at 5G speeds everywhere". techxplore.com. Retrieved 2021-06-27.
^"Ambient backscatter tech allows devices to communicate, sans batteries". Gizmag.com. 15 August 2013. Retrieved 2013-08-15.
^"IoT Devices Will No Longer Need to Rely on Batteries to Operate". Hackster.io. Retrieved 2021-11-27.
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passive sensor to detect and measure the radiation that is reflected or backscattered from the target. LIDAR is often used to acquire information about the...
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rediscovered by Gernsheim, presents a negative or positive image dependent upon ambient reflection in the 20.3 × 16.5 centimetre pewter plate. By viewing the plate...
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the vents more difficult to identify from CTD measurements or optical backscatter methods. Lost City and other hydrothermal vent systems support vastly...
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