Computer Hope
Internet & Networking => Networking => Topic started by: John1397 on March 26, 2019, 05:00:35 AM
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"The 802.11 standard provides several distinct radio frequency ranges for use in Wi-FI communications: 900 MHz 2.4 GHz, 3.6 GHz, 4.9 GHz, 5 GHz, 5.9 GHz and 60 GHz bands and most WiFi router list two frequencies, usually 2.4 GHz and 5 GHz" this being said can one pickup Wi-Fi from 20 miles away maybe only in the low frequency's?
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While WiFi can work over long distances like that, it's not the sort of thing where you'd just be able to pull out a laptop/phone and connect to an access point 20 miles away. These long distance links use high power radios on each end where the radios have line of sight to each other. In a deployment you would usually have a pair of these high power point-to-point radios on top of the buildings to link the two sites together and then within each site you'd have the radio connected to a conventional access point/router that you'd connect your devices to.
This is the sort of equipment you would be dealing with over those distances, it's technically still WiFi but very different hardware from what you'd use to provide a signal within a single building- https://www.ui.com/airmax/powerbeam-ac-gen2/ (https://www.ui.com/airmax/powerbeam-ac-gen2/)
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"The 802.11 standard provides .... can one pickup Wi-Fi from 20 miles away maybe only in the low frequency's?
Short answer: No. And No even if.
Long answer: All the frequencies are above the HF and VHF bands. Over the horizon propagation is only on HF. For VHF there are some locations that have longer range under special conditions. Any Satellite communication is not part of the 802.11 stuff.
Read this:
https://en.wikipedia.org/wiki/Line-of-sight_propagation
If you really need long range communication, you must get a license from the FCC. It should be obvious why that is needed. :-*
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I was just comparing to TV uhf which is under 900 mhz depending on channel and I can pick up signal from 80 miles away I know the higher the frequency the less in distance signal travels. I would think watts of power would be a factor also as if wifi was broadcasting at 2g at 10000 watt you could pickup signal
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TV stations often put their transmitting equipment on a mountain top. This fact alone gives it over
four five orders of magnitude advantage,or even more.
Also, TV stations are allowed to have effective power levels of over 100,000 watts.
And TV stations are subject to intense regulation by the government.
If you have a need for long range private data from a remote mobile device, there are companies that provide such services, for a price.
Do you have a special need that can not be done over the internet? 8)
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I found this video very informative: https://www.youtube.com/watch?v=Tdv_uwz3tf4&t=742s
Also these are pretty rad:
https://www.amazon.com/dp/B00DCNRTAG/ref=sspa_dk_detail_2?psc=1&pd_rd_i=B00DCNRTAG&pd_rd_w=cDzzS&pf_rd_p=733540df-430d-45cd-9525-21bc15b0e6cc&pd_rd_wg=8YjFc&pf_rd_r=4H55Y25KJ9FAKRTAP9MZ&pd_rd_r=8f138e60-51b3-11e9-8012-738d1edf946a
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The difference between WiFi and TV is that TV signals only need to travel in one direction - from the mast to the receiver. With WiFi the client device has to be able to transmit back to the access point. There is a practical limit to how much transmission power you can have in something like a laptop or phone.
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Fact: The FCC has cracked-down on individuals who think they can circumvent the law.
When anyone has any 802.11 device he/she is required to comply with the law even if he/she does not like it or it restricts some kind of fun.
The law is extended also to companies that make equipment that can break the law.
FCC Imposes $240,000 Fine on Wireless Equipment Provider For Violating Marketing and Authorization Rules (https://commlawgroup.com/2014/735-fcc-imposes-fine-wireless-equipment-provider-violating-marketing/)
On August 26, 2014, the Federal Communications Commission’s (“FCC”) Enforcement Bureau (“Bureau”) released an Order containing a Consent Decree with international equipment importer ASUSTeK Computer Inc. (“ASUSTeK”), wherein ASUSTeK was ordered to pay a $240,000 fine for violating the FCC’s rules and a provision of the Communications Act of 1934 (“Act”) governing the authorization and marketing of radio frequency (“RF”) equipment. See In the Matter Of ASUSTeK Computer Inc., File Nos. EB-SED-14-00013341, EB-SED-13-00008785, Order, DA 14-1044.
This Order and Consent Decree is another prime example of the extremely stringent Bureau enforcement policies as forecasted by our firm in a previous Client Advisory and Memorandum.
Notice the above names a major maker of computer stuff. So, just because you can buy it, do not assume it is legal. :o
The above is from a reliable source of legal information.
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This antenna would do about as good a job as any thing could not sure how one would hook coaxial to phone though would need adapter I assume . It is to bad TV uhf antenna not the same as already have one of those bars are longer.
TP513 Yagi WiFi Antenna 2.4GHz 17dBi
TP513 Wireless Yagi is ideally suited for directional and multi point 2.4 MHz band applications.
This 17dBi 2.4Ghz Outdoor Yagi Antenna offers 24° Vertical and 25° Horizontal Beamwidth. 35 Inch long WiFi Antenna comes with an N-Female pigtail connector and N-Female industry standard connector.
The Yagi antenna operates without the need for a grounding in most cases. However, you can ground antenna via the outer conductor of the connector and the cable, or through the mounting hardware. We do, however, recommend you install a lightning surge protector between the Yagi and a device to prevent a lightning strike to the antenna from damaging your device and equipment.
Wireless Yagi Antenna TP513 in most cases can not be attached directly to the device (wifi router, signal booster, etc.) without some type of cable converter/adapter. This Antenna has N-Female connector so it will need the cable/converter from N-Female type to [your device connector type], usually some pigtail coax RP-SMA cable connector. Also, you can put amp of some kind or signal booster between device and antenna.
The antenna does not come with mast pole mount; it comes with two U-bolts which can be used with the attached plate for pole mounting. It allows horizontal or vertical polarization.
The Panel antenna is used to direct the WiFi beam. It will increase the signal/reception in the direction it is pointing.
Product description
2400-2483 MHz H-POL or V-POL, 2.4GHz yagi antenna 17dBi outdoor, angle 20, N female
Electrical Data:
Frequency: 2400-2483 MHz
Gain: 17 dBi
VSWR:18 dB
Max Input Power: 100 W
Lightning Protection: DC Ground
Mechanical Data:
Connector: N Female
Dimensions: 35.04in
Weight: 1.01 lb
Cable Length: 9.45in
Antenna Material: Aluminum Alloy
Mast Size: Ø40-Ø50mm (not included)
Rated Wind Velocity: 210km/h
Operating temperature: -40~+65C
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Is this for non-licensed low-power use?
You might want to consider another band.
Do not assume the antenna is compliant with legal limits. It depends on a number of factors. If you have not already investigated, check out the rules in your region.
Do yu want links about this?
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If you were using WiFi across a Newtonian vacuum in theoretical perfect alignment between transmitter and receiver then all frequencies could travel an infinite distance without loss.
Unfortunately pesky quantum physics says that particles pop in and out of existence in space-time all the time and therefore a perfect vacuum is impossible. Boo quantum physics.
Also the ping or delay will be dependent on the distance given by C*m, so as long as you don't mind when the data starts arriving the distance doesn't matter, that is until you factor in the expansion of space-time. As we all know, expansion is accelerating uniformally across the universe from the repulsive gravity of dark energy, so the later you leave it to set up your WiFi system the higher the ping you'll have.
If you wait any more than 16 billion years then if the transmitter and receiver are placed any further than a million light-years away from each other then the expansion will be so great that the distance (and therefore ping) will increase faster than than light can travel and so the signal will never arrive, in fact it will only ever get further and further away at a faster and faster rate.
Eventually, and now this part is purely theoretical, after all the black holes have evaporated and all that remains are photons and gravitons, distance will have lost all meaning (as it is relative) and the scale of the universe will have effectively been reset, causing a new Aeon or "big bang" and so you will be able to start again with your WiFi system with much more reasonable ping.
Hope this helps.
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The speed of light is about 300, 000 kilometers per second.
Lower frequencies permit better penetration of small obstacles.
Higher frequencies permit smaller antennas.
Radiant emery dissipates with the inverses of the spare of distance.
Lon-range microwave communication is regulated by the FCC with a few exceptions.
the 802.11 WI-Fi was intended for NEAR range communication without a license.
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then all frequencies could travel an infinite distance without loss.
Don't they have the inverse-square law in your universe?
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Nothing better than elementary errors in "look how smart I am" tangential diatribes.
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Don't they have the inverse-square law in your universe?
"in theoretical perfect alignment between transmitter and receiver"
So yeah, as you point out it's practically impossible, but I wasn't claiming that it was possible. :P
This really boils down to whether space is continuous or granular in nature. It's more a question of the rate of "dilution", if space is continuous, which quantum physics states it is not, then an impossibly tight beam could travel forever. This however is just as impossible as absolute zero temperature is for example and the whole thing is in practicality absolutely ridiculous.
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That all means "if something which isn't true, was true, then something that was impossible would be possible", padded out with a lot of physics-sounding woo-woo.
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That all means "if something which isn't true, was true, then something that was impossible would be possible", padded out with a lot of physics-sounding woo-woo.
And yet if Einstein hadn't thought about what would happen if you could catch up to a beam of light (which is impossible) then we wouldn't have General Relativity theory.
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The original past said:
"The 802.11 standard provides several distinct radio frequency ranges for use in Wi-FI communications: 900 MHz 2.4 GHz, 3.6 GHz, 4.9 GHz, 5 GHz, 5.9 GHz and 60 GHz bands and most WiFi router list two frequencies, usually 2.4 GHz and 5 GHz" this being said can one pickup Wi-Fi from 20 miles away maybe only in the low frequency's?
It was never intended for 802.11 devices be use for a distance of miles.The intent was to provide a reliable and easy way to send high speed data over a distance under about 100 meters, or about 300 feet.
Some recent changes in the rules will allow longer range,but with some limitations. These changes are to other commercial or unlicensed services
Reference:
https://transition.fcc.gov/Daily_Releases/Daily_Business/2018/db0322/DOC-349845A1.pdf (https://transition.fcc.gov/Daily_Releases/Daily_Business/2018/db0322/DOC-349845A1.pdf)
Short answer: Never20 miles! :o
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And yet if Einstein hadn't thought about what would happen if you could catch up to a beam of light (which is impossible) then we wouldn't have General Relativity theory.
How do I delete somebody else's account?