ETSI domain and high gain directional antenna's with 036H power control. Is there any point ?!?

Discussion in 'Antennas' started by kevsamiga, 11 Nov 2013.

  1. kevsamiga

    kevsamiga Well-Known Member
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    I live in an ETSI domain (UK) in possession of an Alfa 036H adapter (with the TX power control drivers), and a 16dbi YAGI, and 14dbi panel for usage, along with 5dbi, ALFA 7dbi panel and Alfa 9dbi Omni.

    At the present time from reading, I'm struggling to comprehend the point of the ALFA's TX power control under ETSI, or even the use of higher gain antenna's in the ETSI region (which even if you forcibly changed region, would be rectified by the connected to AP even if changed to say FCC) under Windows.

    Now where it gets confusing is where the ETSI rules state :

    "Under the ETSI regulations, the power output and EIRP regulations are much different from what they are in the North American regulatory domain. The ETSI regulations specify maximum EIRP as +20 dBm.

    Because this includes antenna gain, this limits the antennas that can be used with a transmitter. To use a larger antenna, the transmitter power must be reduced, so the overall gain of the transmitter plus the antenna gain (less any losses in coax) are equal to or less than +20 dBm EIRP."

    Now under the understanding that setting 20% TX using the power control drivers on the ALFA 036H equates to 20dbm with 100% being 30dbm, and access to several high gain antenna's ranging all the way from 4dbi to 16dbi, what is actually going on here ?

    Does the ALFA 036H unit in fact limit the TX power output compared to whatever antenna is installed in the ETSI domain to remain under the ETSI regulatory EIRP limits ?

    If so...., and this is the case...what *exactly* is the point of using higher gain antenna's, or even adjusting the 036H's power control if you are located in the ETSI region if your total EIRP is always going to be less than or equal to +20dbm no matter what antenna you use, or whatever ALFA 036H power control setting.

    Therefore I'm struggling to comprehend that you should achieve any less transmit distance using a simple 5dbi Omni, compared to using a 16dbi YAGI since the EIRP cannot exceed +20dbm anyway regardless of antenna.

    Although FCC allows 6 dB of antenna gain for a 1-W transmitter, ETSI allows 20 dBm including the antenna gain, meaning the transmit power before the antenna must be no more than 20 dBm minus the antenna gain.

    Since higher gain antenna's also work bi-directionally in gain, you may then say that you may now be able to receive a signal you could not before with a lower gain antenna, but since the transmitting end is also limited by ETSI +20dbm total output no matter what antenna is installed, you also have the same problem of not being able to hear.

    So in conclusion, does this all actually mean that the use of high gain WIFI antenna's in European ETSI regions is actually totally pointless on one or both ends beyond a certain point in distance regardless of antenna ?!?

    Please share your thoughts... :)
     
    #1 kevsamiga, 11 Nov 2013
    Last edited: 11 Nov 2013
  2. mon0

    mon0 Well-Known Member
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    Well this real question is do you want to go above the EIRP limits? If so there are ways to increase the TX power of the card above the BO reg trick that everyone does.

    If you take a look at some FCC legislature directional antennas are allowed to have a higher dbi without having to lower TX power (unless they amended that from the last time I checked).

    I guess you really need to start with answering that question for yourself before we can take this any further.
     
  3. kevsamiga

    kevsamiga Well-Known Member
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    I may or may not want to smash the EIRP limits, but I would rather know how it all actually works to find out what antenna you have attached to how it decides to set the output power under the ETSI domain where antenna gain *is* factored into the output limits according to these regulation rules.

    My confusion is that the FCC domain does not include the antenna gain factored in in relation to output power, and gain is therefore irrelevant in relation to allowed TX power under FCC. Fine in that case if your in the US, larger antenna's of the bigger and better variety work better and are going to give you more range in the US. However in Europe, this doesn't appear to operate quite the same, as output power and antenna gain are both taken into account.

    The ETSI domain if examined doesn't behave the same where my query lies where you are allowed a paltry 100mw and no more severely handicapping your range on both ends of the link, so my point is are devices, as complied with by sellers, not just by buyers, scaling back the TX power automatically *in order to comply with regulations* when consecutively higher gain antenna's are attached in the European domain as antenna gain *is* taken into account in the amount of TX power allowed or used. I can seem to find no answer to it, but it appears that adding successively larger and more directional antenna's offer no tangible benefit under this domain.

    Therefore using a 16dbi antenna in the ETSI domain (changing to BO which would be corrected upon connection to a connected to AP despite the BO or BZ trick) would provide you with an automated paltry scaled back 4dbm of output power in combination with your huge 16dbi paperweight to still stay under the 20dbm 100mw EIRP limits imposed in Europe, or the device/s would therefore be exceeding this regulation if it behaved like the US and didn't bother to take antenna gain into account ?

    Sure there are always shady devices such as linear amps to cheat your way around these things, (it's not illegal to sell them, but illegal to use them or so I was told) but smuggling them into Europe past customs from out of the orient is another matter, along with the incompatible power supplies to contend with that blow up.

    As it stands, if this is the case of auto scale back to never output more than 20dbm regardless of antenna attached, then these restrictions seem poor, and expensive antenna's trying to extend range under this domain is ultimately a pointless exercise all my assumptions being correct.

    Meaning you would get the same range with an Omni as a 24dbi grid because you are not allowed to exceed 100mw/20dbm of EIRP regardless of size of antenna gain you decide to attach. It doesn't appear up to the user to decide what the EIRP limit is like in the US, in Europe it appears enforced because antenna gain is factored into output power unlike the US.

    Or am I missing something ?
     
    #3 kevsamiga, 15 Nov 2013
    Last edited: 15 Nov 2013
  4. rioboy

    rioboy Well-Known Member

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    we need an RF Engineer to advise us here.

    I had similar thoughts but the routers also need tweaks not only the connecting Alfa?

    You cant amplify a weak transmission emanating from a router just by having a high gain receiving Alfa.

    Can you??

    By changing the regions in the Alfa setup I dont think provides any power tweaks other than communication on other channels that are not authorised in some countrys than in others.

    No way to try the BO trick in windows :-(
     
  5. kevsamiga

    kevsamiga Well-Known Member
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    I don't know whether connecting to the net through a bolivian proxy would work quite the same under Windows. :)

    It's the AP that says "wait a minute your not in Bolivia, your in the UK". And then sends out frames to dumb down your power accordingly.

    You would have to set the target router to another country, and then some actually support the setting, some don't and will have no effect even if changed from off of Europe setting.
    (Unless you flash a North American US eeprom, was going to try this on my old netgear D834G but never got around to it)

    I think a "burner", although highly illegal in the UK, is the only way to bypass all this region lockout, and locked AP crap, since all these fancy antenna's seem to make
    no difference because of the handicapped power fed into them.
     
  6. rioboy

    rioboy Well-Known Member

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    The old consumer watch dog programme should be resurrected and take on the case of misleading antenna sales..LOL

    I was also tinkering on the idea of re flashing a netgear and play around with WRT or similar but my netgear is not supported and was looking for a used alternative guinea pig

    Oh and GCHQ ears would start twitching with a burned router
     
  7. kevsamiga

    kevsamiga Well-Known Member
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    I suppose it all depends where you are really...

    If your in a City with high AP density, then using a burner is a big no-no as it would instantaneously piss off everyone around you and someone would soon be making a phone call about your newly aquired toy (even if it a) makes it past customs that is, and b) you can figure out what all the incompatible plugs and voltages are, then convert them) and then there is the fact they can no longer connect wirelessly thanks to you, because you would have a wifi jammer in effect....spewing hundreds of strong beacons a minute, and bleeding over all the channels with it's increased power and spectral density from anywhere up to 8 watts which is more than enough microwave juice to get you over town, and probably into the next one.

    And then there's the risk of your prized adapter going pop if the output power to the linear is too high above 12db, because they won't take fed high input loads already to achieve their dastardly deeds.

    However in a village or rural areas the 100mw provided is complete and utter stingy and feeble in this scenario where you are highly unlikely to annoy anyone. In the US they even allow you higher power if you go directional point to point. They didn't even bother to cover that kind of setup under ETSI at all. Your range and the antenna's you can use with ETSI to get any benefits of substance therefore is severely crippled. Higher gain matters, but only for bumping up the receive, and as we all know everyone else isn't illegal so they can't transmit far either.

    You can't amplify a signal if a signal just isn't there, and even when you do your amplifying noise and your SNR ratio goes down...

    In other words buying any "powerful wysiwyg" device under this domain is a total farce because it's all the same 20dbi limited crap (17 taking into account 3db cable loss which is already factored in so when you show 20 your actually 17), and limiting to what you can achieve in any distance compared to the US. After wasting time buying bigger and badder antenna's I realised one thing....my connections were becoming worse not better. A stronger signal doesn't necessarily mean it's a good quality signal.

    Besides, I think GCHQ has got other matters to attend to far too busy covering the NSA's ass of late thanks to Mr. E. Snowden.

    I guess if you see any low flying aircraft performing barrel rolls, then it's perhaps time to unplug the damn thing right ?

    So ETSI might be crippled for transmit, but the gain of an antenna is reciprocal and benefits transmit *and* receive, so in effect, yes you can amplify a "weak" router signal, just not increase your transmit power any more than what it already is under this domain, so in effect it's all pull and no push. Same goes for t'other end with ETSI.

    Having high power adapters here are a complete waste o' money. Well they're not but they're only going to get you out so far as opposed to the ten a penny el cheapo dongles.

    Certainly not Km or miles, and not down the street half the time depending on atmospheric conditions, or even a metal van parking his ass infront of your signal. :)
     
    #7 kevsamiga, 31 Jan 2014
    Last edited: 31 Jan 2014

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