10,000 times lower power, but achieving speeds up to 11Mbps Being named passive wifi. Quite neat and could be useful for IoT considering also approx 100 ft distance
100' is a very low distance for real IoT applications I've run across
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
#32Earlier 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...
Naturally it depends on compression, bandwidth variability, etc. It's what Netflix recommends, and they have zero incentive to lowball that.
https://help.netflix.com/en/node/306
The biggest issue is that people think they're getting 20mbps but they're lucky if they get 8. And that not a technology problem.
Re: UW engineers achieve Wi-Fi at 10,000 times lower power
#33This is great research! 10,000 times lower power is only for the "passive wifi" devices, but these passive wifi devices require a "heavy-lifting and power-consuming plugged-in device" nearby. Assuming that device consumes no more than a traditional wifi device, then the overall system would consume: [usual consumption of 1 wifi device] + [# of passive devices] * [usual consumption] / 10000 So, if we want to calculate…
I am just wondering if the plugged in part needs to transmit at full power all the time. This could seriously increase the overall energy consumption.
Plus, I have a hard time deciding what it would transmit at full power all the time...
Re: UW engineers achieve Wi-Fi at 10,000 times lower power
#34Interesting idea. Things like this generally need a bigger antenna, since they're getting power from it. It probably means the base station has to run at high power most of the time, rather than throttling down for short range transmissions. If it went all the way to full wireless power, like some RFID tags, it would be more useful.
High data rate capability probably doesn't matter. Anything that's receiving or sending a substantial amount of data is probably using more power doing something with it than sending it.
Re: UW engineers achieve Wi-Fi at 10,000 times lower power
#35old news. I guess I remember this news in February here at HN
Re: UW engineers achieve Wi-Fi at 10,000 times lower power
#36Re: UW engineers achieve Wi-Fi at 10,000 times lower power
#37The 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…
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 that excited about this, and this is likely why it wasn't pursued earlier due to the power requirements of active passive signalling. If it pollutes the EM spectrum with powerful radio waves that are magnitudes more powerful than what we're outputting today, then I hope it gets abandoned. If it's the same power consideration, then it's worth pursuing imo.
Re: UW engineers achieve Wi-Fi at 10,000 times lower power
#38This 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.
Jeeva is a telugu[1] word, which is actually pronounced 'jee-vaa' athough Jeev does mean a living thing in Hindi. It's easily to get confused with less popular Indian languages as being Hindi words because it's more popular, although they're similar because they're all derived from Sanskrit.
Re: UW engineers achieve Wi-Fi at 10,000 times lower power
#39It would be great if this could be used in (new) mobile phones and tablets in a low power mode when you don't need high data rates.
Re: UW engineers achieve Wi-Fi at 10,000 times lower power
#40This is great research! 10,000 times lower power is only for the "passive wifi" devices, but these passive wifi devices require a "heavy-lifting and power-consuming plugged-in device" nearby. Assuming that device consumes no more than a traditional wifi device, then the overall system would consume: [usual consumption of 1 wifi device] + [# of passive devices] * [usual consumption] / 10000 So, if we want to calculate…
I am just wondering if the plugged in part needs to transmit at full power all the time. This could seriously increase the overall energy consumption. Plus, I have a hard time deciding what it would transmit at full power all the time...
I'm not an RF expert, but it sounds like it would be transmitting an empty carrier wave, not a real signal. Think of it as a big light source and the passive transmitters as mirrors used to flash signals back and forth with reflected light.
(Of course you'd also need a traditional wifi router for everything to connect through, and you might as well build that router into the same shell as the emitter thing, so it gets confusing. But the basic carrier wave wouldn't necessarily carry a signal.)