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They talk about the technique in the article: > The Wi-Fi radio runs on extremely low power by transmitting data via a technique called backscattering. It take
by txcwpalpha 7y ago
They talk about the technique in the article:
> The Wi-Fi radio runs on extremely low power by transmitting data via a technique called backscattering. It takes incoming Wi-Fi signals from a nearby device (like a smartphone) or Wi-Fi access point, modifies the signals and encodes its own data onto them, and then reflects the new signals onto a different Wi-Fi channel to another device or access point.
It sounds like the device doesn’t actually transmit its own signals, which I believe is what typically requires the most power.
However, I get the feeling from this press release that while the WiFi chip uses less power, this does nothing to reduce the power requirements of the processing chip that is actually using the WiFi chip to communicate. In the article they use a camera as an example in the diagram. Even though the WiFi component might require less juice, you’re still going to need a hefty power supply to power the camera.
- chubs 7y agoAh thanks, that explains it. So i assume it won't work unless something else is also transmitting?
- Polylactic_acid 7y agoI'm struggling to find a single use case where this would work. You need 2 wifi APs, regular wifi usage and a device where such aggressive power saving is more important than working reliably.
- dev_tty01 7y agoActually, just 1 AP. It can backscatter signals to the AP from other wifi devices such as phones. Regular wifi usage is not a constraint in most applications.
- Polylactic_acid 7y agoDoesn't it say that it has to change to a different wifi channel?
- airstrike 7y agoAutomated factories
- generatorguy 7y agoIf you have a factory you run wires to the things that are important for your factory to run.
- airstrike 7y agoCollecting data from those processes is arguably easier done with Wi-Fi
- generatorguy 7y agoEasier but factories are unfriedly to WiFi with all the giant metal structures, high,medium,low voltage power cables, emi noise from motors and VFDs, etc. WiFi is more difficult to troubleshoot whereas Pretty much anybody can use a cat5 cable tester. And there are already cable trays and raceways going to all of the different equipment because it uses electricity. So in the industrial processes I’ve been involved in radio was only used outdoors and when communications cable would have had to have been strung up on poles. Reliability and ease of troubleshooting are characteristics industry values more than labor saved running cat5, in my experience.
- wtallis 7y agoIt sounds like this technique won't work for realtime communication, but that doesn't rule out much of the IoT use cases. As for the 2 APs requirement: when's the last time you've been in range of just one AP, with the 2.4GHz band otherwise quiet?
- joshspankit 7y agoI don’t see anything that says you have to control both APs. Almost everyone in populated areas lives within range of a few neighbour APs.
- reportgunner 7y agoMarketing is the use case. Uses New ultra green eco friendly low power wifi technology that is micro sized. Your internet will be FASTER! BUY NOW
- roywiggins 7y agoCameras are not entirely out of the question: https://www.futurity.org/streaming-hd-video-wireless-camera-1736022/ https://www.futurity.org/streaming-hd-video-wireless-camera-...
- simpsond 7y agoThat is true, but, there are applications where the majority of the power budget goes to the radio, such as a wireless sensor. I worked with battery powered wifi sensors in the past, and very infrequent transmissions (15 minutes) still accounted for 90+% of the power budget. Average current for a 2-3 second transmission was something like 60-80 mA, with a huge in-rush current on boot. I see this and think it's probably too good to be true in practice for something like that.
- lmilcin 7y agoStill, the problem with IoT devices is distributing the power to them. It is cheap to have some central device in your home that can have relatively powerful transmitter and sensitive receiver if you can drop a bunch of backscattering devices powered off battery.