I invented a coffee machine which works using 10000 times less power: it works by deferring the actual coffee making to another machine you plug into another wall socket.
UW engineers achieve Wi-Fi at 10,000 times lower power
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Re: UW engineers achieve Wi-Fi at 10,000 times lower power
#42This seem another wifi achievement only replicable in a desert environment, during a solar maximum, on the dark side of the moon, while holding a black cat. If you are using a "wifi" antenna then that antenna is going to be picking up all sorts of little things. Normally these aren't much of an issue, but at these sensitivities suddenly that phone down the hall, the one not running at a 10e-3 power setting, is a real…
I'm not seeing anything to indicate that the passive transmitters are extra-sensitive. The whole wifi system is still running at full power and producing full-power signals; you've just shifted the power load from the remote transmitters (which are dependent on tiny batteries) to the central transmitter (which has a nice fat power main to draw from).
Re: UW engineers achieve Wi-Fi at 10,000 times lower power
#43Earlier quoted context omitted.
You won't be downloading OS images very well, but it's still a lot. That's two HD videos simultaneously, with some to spare.
5Mbps is an interesting definition of HD...
Also, not to mention, current best AC3200 wifi is rated at 1Gbps+, however, actual speeds are max 320mbps, or roughly 30% of the rated speed (for a single client right next to the antenna).
So, based on that type of math, I expect to see only 4mbps actual throughput to a single client; less if shared by multiple clients. These radios are likely not MIMO, so the antenna will have to "context switch" between multiple clients, so expect bandwidth to be significantly less in multiple device scenarios.
All that being said, I think this is fascinating, and quite perfect for the hundreds of various environmental sensors that will inevitably end up in all of our houses to help us live more automated lives. All hail our new IoT sensor streaming, data driven, fully automated smart homes...
Re: UW engineers achieve Wi-Fi at 10,000 times lower power
#44This article is a few months old. The technology is now being commercialized by the same authors, as Jeeva Wireless: http://www.jeevawireless.com/
In case someone is wondering 'Jeeva' (pronounced as Jeev) means living thing in Hindi.
To add, Jeeva means living thing in Malayalam, another language from the south India. In fact, Jeeva is a common name in Kerala and Tamil Nadu, two states from the south India.
Re: UW engineers achieve Wi-Fi at 10,000 times lower power
#45Earlier quoted context omitted.
I've looked at the paper [1], but I can't figure out how this is different from backscattered RFID with 802.11 on top. The paper says RFID requires a full-duplex radio while the WiFi chipset is orders of magnitude less expensive. Are they modulating differently or is there some RF magic? [1] http://passivewifi.cs.washington.edu/files/passive_wifi.pdf
The technology is ~50 years old, and was originally invented by the Soviets to eavesdrop on the US embassy in Moscow. https://youtu.be/mAai6dRAtFo?t=9m35s https://en.wikipedia.org/wiki/The_Thing_(listening_device) TL;DR Using a passive antenna to modulate a directed microwave emission.
When will they reevaluate those twelve wing aeroplane designs
Re: UW engineers achieve Wi-Fi at 10,000 times lower power
#46I invented a coffee machine which works using 10000 times less power: it works by deferring the actual coffee making to another machine you plug into another wall socket.
Yeah but can it fill your cup from the next room?
Re: UW engineers achieve Wi-Fi at 10,000 times lower power
#47Earlier quoted context omitted.
You won't be downloading OS images very well, but it's still a lot. That's two HD videos simultaneously, with some to spare.
I take it you've never used 802.11b. You were lucky to get a single YouTube video at 480p to load without downgrading, let alone two HD streams.
I'm (un)lucky enough that my WiFi has never been slower than my internet connection
Re: UW engineers achieve Wi-Fi at 10,000 times lower power
#48I invented a coffee machine which works using 10000 times less power: it works by deferring the actual coffee making to another machine you plug into another wall socket.
Hey I invented a one bit compressor, which consist of the file.
Re: UW engineers achieve Wi-Fi at 10,000 times lower power
#49The low-power devices don't actually generate any signal at all thus don't have to pay that expensive power cost. Instead a passive antenna is modulated to reflect or absorb ambient signal, the reflected signal conforms to traditional 802.11 packets. The ambient signals are created by a relatively high-powered device that is plugged into wall power. Here is a 2 minute video showing an early prototype of their work fr…
Is it the sort of tech used by some devices in the NSA ANT catalog? It is useful for spying because they are undetectable if they are not subjected to a carrier frequency. There was also The Thing[1]
[1]https://en.wikipedia.org/wiki/The_Thing_(listening_device)
Re: UW engineers achieve Wi-Fi at 10,000 times lower power
#50Earlier quoted context omitted.
I've looked at the paper [1], but I can't figure out how this is different from backscattered RFID with 802.11 on top. The paper says RFID requires a full-duplex radio while the WiFi chipset is orders of magnitude less expensive. Are they modulating differently or is there some RF magic? [1] http://passivewifi.cs.washington.edu/files/passive_wifi.pdf
Passive RFID is powered by the incoming radio waves that is 1000x stronger than the signal transmission energy from the RFID tag. There is no statement to the power requirement for passive WIFI from an active WIFI power source. The active WIFI transmitter may require outputting radio waves many times more powerful in order to receive a signal transmission from the passive wifi device. edit: For that reason, I'm not t…
The maximum transmitting power is regulated. In the article they state that it can use some kind of crafted wifi packet to be compatible with any existing devices.
Edit: After looking at the pater, it seems that I may have misunderstood the article, it needs a plugged RF carrier tone generator at at fixed frequency.