5 ms·
14 dBm EIRP = 25 milliwatts, typical legal max for wifi, and the -5 dBm/MHz EIRP power spectral density says that 25 mW must be spread over an 80 MHz channel.
by hnuser123456 2y ago
14 dBm EIRP = 25 milliwatts, typical legal max for wifi, and the -5 dBm/MHz EIRP power spectral density says that 25 mW must be spread over an 80 MHz channel.
- JoshTriplett 2y ago> 25 milliwatts, typical legal max for wifi AFAIK wifi can use more power than that, at least in the US: 100mW, possibly 200mW, not sure what the hard limit is (or how much that must be spread).
- olyjohn 2y agoI'm pretty sure you can run 1 watt on WiFi.
- deleted 2y ago[deleted]
- jdietrich 2y ago1 watt conducted power, 4 watts EIRP. For most of the world, the ETSI limit is 100mW EIRP. https://www.ecfr.gov/current/title-47/chapter-I/subchapter-A/part-15/subpart-C/subject-group-ECFR2f2e5828339709e/section-15.247 https://www.ecfr.gov/current/title-47/chapter-I/subchapter-A...
- throw10920 2y ago1 watt? With beamforming to increase the energy density you could run a tiny microcontroller off of that.
- rocqua 2y agoThis is about radiated power in any direction not exceeding what you would get with an omnidirectional 1W antenna. So beamforming under these rules lets you use less input power for the same directional power. But it doesn't let you bundle all your power into a single direction.
- brookst 2y agoWhich is probably good, as 100mw focused in a very tight beam could cause considerable mischief.
- GeorgeTirebiter 2y agoYes. Beamforming for the receiver, tho, is highly beneficial. MIMO does that for you. The previous poster is correct, the EIRP must not increase when antenna gain does; you have to turn down the wick on the TX.
- koolala 2y ago600 watt is a microwave oven.
- zamadatix 2y agoA microwave may generate waves with many hundreds of Watts but the FCC limits the allowed leakage to ~the same effectively radiated power as they do Wi-Fi in the 2.4 GHz band.
- dylan604 2y agothe only real limit is until you start interfering with other people to the point they notice and complain. it's not like the FCC has vans roving the streets looking for unlicensed TV usage like the BBC but for wifi.
- ajsnigrutin 2y agoThere's a LOT of testing done, before you can sell a device, including TX power measurement. And yes, they have vans roving the streets looking for illegal transmissions.
- hnuser123456 2y agoTo be fair, there are a lot of people in the FPV drone community using 600mW+ 5ghz transmitters for analog video without HAM licenses, and I don't think I've ever heard of anyone getting in trouble for it. But that's typically in unpopulated areas.
- withinboredom 2y agoAlso, they are gone before anyone can triangulate them.
- BubbleRings 2y agoHa. My friend and I had the FCC van roving our neighborhood looking for us once, back in the late 70s. A guy with a CB base station dropped a dime on us, cause we were playing with our 0.1 watt walkie talkies near his house. The guy that sold us the handhelds said “what channel crystal do you want, how about 9?” and we said sure; we didn’t know that 9 is the emergency CB channel and the law prevents its use for, for example, playing hide and seek as a 13 year old.
- dylan604 2y agoOf all of those hypothetical "if you could go back in time" situations, I'd want to go back and rat that guy out for selling kids that crystal. Just the other day in another thread there was the conversation about mischievous people doing things, and that pretty much sounds like what that guy was doing. He got the best of both worlds knowing he was going to cause some chaos but none of the repercussions of it.