Using other than a wired connection to transfer signals or power. Includes optical and (ultra)sound, but most often refers to RF (Radio Frequency). Distances can be as low as centimeters (e.g. RFID); there's no upper limit.
Questions tagged [wireless]
1172 questions
47
votes
4 answers
Why don't we use wireless electricity today?
I was reading about Nikola Tesla today (via the Oatmeal) and read about the Wardenclyffe Tower which (among other things) was intended to transmit electricity wirelessly. Forgive the naivety of the question, but if technology that could transmit…
n00b
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9 answers
Why is wired Ethernet losing its speed advantage over wireless?
This has been bugging me for a while now. I did a couple wireless transmission courses back in my university days and it's a known fact that wireless transmission is hard. Partly because it's a shared channel, physical objects can be in the way, air…
Francois
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What is XBee and how is it different from Zigbee?
It's easy to get an introductory explanation of Zigbee.
Zigbee on Wikipedia
Home networking with Zigbee
Zigbee alliance
But technical information on XBee seems harder to find. It's unclear to me what its similarities and differences to Zigbee are.
Craig McQueen
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Why 2.4 GHz Band?
Bluetooth, WiFi, Zigbee, Remote Controls, Alarms, Cordless Phones etc..
Why all of these protocols, devices, etc. use 2.4 GHz band instead of 3.14 GHz. What is so special about it?
cbr
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How come radio signals don't interfere with each other all the time?
I'm a newbie on wireless technologies and I'm trying to understand how they work.
One thing I don't understand is this: How come transmissions from different devices don't interfere with each other all the time?
For example, I'm living in a dense…
Ram Rachum
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Why can't USB-C receivers be as small as their USB-A counterparts?
We're all familiar with the USB-A 2.4 GHz receivers from companies like Logitech that are absurdly small and barely protrude from the port. But when looking at available USB-C equivalents, they are quite a lot larger even after accounting for the…
Adam
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I need the most basic circuit diagram for wireless energy transfer please
I have been all over the net looking for the most basic circuit diagram or instructions to put together a small project on wireless energy transfer. If anyone knows of a good schematic that is super simple and geared towards noobs could you please…
Digital Brent
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4 answers
How can I measure the temperature wirelessly inside a piece of meat?
For a cooking experiment, I'd like to be able to measure the temperature inside a piece of meat while it's being cooked. Due to the mechanics of the cooking process, it's going to be difficult to use a wired temperature probe, so I was wondering if…
Rocketmagnet
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Why do higher frequency waves have better penetration?
In free space, lower frequency signals seems to go farther because the signal is either diffracted by the ground or reflected by the upper atmospheric layers, making it actually go farther.
In urban condition, where we need to penetrate walls, does…
pstan
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19
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9 answers
Ideal WiFi to Serial (or SPI) bridge?
What are some recommendations on an ideal WiFi to Serial bridge? My ideal qualities would be:
Simple connectivity, SPI or Serial
Reasonable fast speed, at least 1mbit/sec ideally (though probably wouldn't always need that fast)
Inexpensive, I'm…
davr
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16
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2 answers
Calculate distance from RSSI
I am working on an indoor positioning system where I need to:
Compute distance based on RSSI (I understand this won't be 100% accurate)
Then do trilateration to pinpoint the location of the wifi signal. This part might be solved via this solution:…
zengr
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Why does WiFi have a shorter range than LTE?
It seems confusing that my phone receives -87 dbm LTE signal and shows a full 4 bars with the speeds of
UPLOAD: 20Mbps
DOWNLOAD:13.6Mbps
But my WiFi is showing 1 bar at -89 dbm and I get disconnected as soon as I move slightly away, and speeds are…
ObsessionWithElectricity
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15
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2 answers
Why does the 802.11 wifi spec allow for 11 channels?
The general wisdom is that it is better to only ever use channels 1, 6, and 11 as they are the only three non-overlapping channels for 2.4ghz wifi (in the US), and two adjacent networks on the same channel would perform better than two adjacent…
AndrewH
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How can I tell if an RF transmitter is transmitting?
In my project, I use a use an RF transmitter and receiver.
One of the RF components seemed to fail because the connection between my Arduinos no longer works. I cannot determine whether the RF receiver or transmitter works.
I want to see if my RF…
slippery
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Why do we still use cable for a lot of forms of data transmission?
Like many people I'm often annoyed by ugly cable clutter, especially when it's long distance. In my opinion it would be ideal if cables could be eliminated altogether, so that you'd just have two corresponding plugs without the cable, which you…
user9878