Technarch Posted February 12, 2006 Report Share Posted February 12, 2006 I'm not a fan of wireless, but I see as they come from the store the power only goes up to 17 or 21 db or something, but the 3rd party firmwares they've been modified to allow you to go up to 251 maximum.I'm wondering is there a reason why the 'retail' limit is 20ish?Because this morning the router was getting disconnected a bunch, and I looked at what was in the area and there are 2 new routers on the same channel and both had full bars of strength and I think they are right next door.And I have a feeling the chinese university students next door who have a coffee can tip on their car exhaust probably installed the 3rd party firmware and boosted the power to maximum or something because 'moer is bettar rice rice'. Link to comment Share on other sites More sharing options...
Animorc Posted February 12, 2006 Report Share Posted February 12, 2006 I don't know the US laws, but boosting a wireless transmitter up to 251 dBi is (most certainy) impossible.As for the laws here in Sweden, I think any antenna above 24.5 dBi is considered illegal. Link to comment Share on other sites More sharing options...
Inf Posted February 12, 2006 Report Share Posted February 12, 2006 21 dB compared to what ? Or is it dBm ? If its dBm, while 21dBm is approx 200mW (kinda high, yet still normal), while 251dBm would 12589254117941714 MEGAWATT. The question here isnt if it is possible or not, if it was possible, would it fry an entire earth population or just a part of it Animorc: dBi is a unit used for antenna gain (dB isotropic, the gain relative to an ideal isotrpoic antenna), not power. So the regulation you mentioned is kinda unrelated.Technarch: Anyway, why dont you just switch the channel to another one ? Link to comment Share on other sites More sharing options...
Technarch Posted February 12, 2006 Author Report Share Posted February 12, 2006 Sorry for getting my units wrong. And I did try different channels but they're all so close to each other that it makes no difference. I really hate wireless but it's the roommate's gear so I have no choice.Anyways I did check netstumbler, and the power levels are not too great next door, it's just really close, maybe even on the other side of this wall. (Townhouse.) Sigh. Link to comment Share on other sites More sharing options...
Animorc Posted February 12, 2006 Report Share Posted February 12, 2006 Inf: Thanks for the clarification. I'm aware of the difference between dBi and dBm, but I just picked the guess seeming most logical to me. Link to comment Share on other sites More sharing options...
Inf Posted February 13, 2006 Report Share Posted February 13, 2006 Technarch, i would first talk to your neighbours and make sure you select the different channels for your networks first, so they do not interfere with each other (and no, it doesnt matter that the channels are close, those are still different channels). If this really wont do any difference, i'd try looking for other sources of interference. Think about everything else that works on similar frequencies, such as 2.4GHz cordless phones, bluetooth devices in an immidiate proximity, operating microwave ovens (especially older or poor quality ones that could be more 'leaky') etc Link to comment Share on other sites More sharing options...
Firon Posted February 13, 2006 Report Share Posted February 13, 2006 I cranked up the power on mine, but you can't really go past 84mW on these things, just doesn't have enough cooling. It's better to have antenna gain than it is amplifier gain anyway, so raising it up to 251mW is just silly. Link to comment Share on other sites More sharing options...
Falcon4 Posted February 13, 2006 Report Share Posted February 13, 2006 It seems like saying "dBi isn't related to power" is kinda like saying "watts are not related to amps". Why do techno-nerds get this all fucked up? Watts and amps are both means to measure amounts of power (as, e.g. 120 watts = 1.6 amps @ 120vac or something) so I'm pretty much guessing dBi is just another one of these mix-ups?And why do I not have that setting on my router? edit: Or is it dBi vs dBm that has me mixed up? Why can't we just all call it dB? Link to comment Share on other sites More sharing options...
Firon Posted February 13, 2006 Report Share Posted February 13, 2006 dBi/dBd is antenna gain, dBm is amplifier power, though isotropic antennas don't really exist Link to comment Share on other sites More sharing options...
Inf Posted February 13, 2006 Report Share Posted February 13, 2006 It seems like saying "dBi isn't related to power" is kinda like ...dBi related to power in one aspect only, the more dBi - the higher the gain, hence you get more power if all other condition are the same, but thats it. Watts and amps are both means to measure amounts of powerWatts are units of power, yet ampers are NOT. Current of 1A at 10V would give you 10W, yet the same current of 1A at 1000V would give you 1kW, how the hell can you call Ampers 'units of power' ?!?!?!Or is it dBi vs dBm that has me mixed up? Why can't we just all call it dB? dB - generic unit, more like a multiplier, saying 3dB is more or less like saying multiplied by 2dBi - dB isotropic, used to specify antenna gain relative to an ideal isotropic antennadBm - dB milliwatt, units of power, relative to 1 milliwattWhy do techno-nerds get this all fucked up?:mad: STFU & go fuck yourself, IMHO u r the one 'fucked up' here. :mad:EDIT: or may be i am, indeed, fucked up. after all, responding to such a stupid post kinda means something like that Link to comment Share on other sites More sharing options...
RoyalShrubber Posted February 14, 2006 Report Share Posted February 14, 2006 Yeah, it isn't so easy, cuz there aren't only some constants connecting units, it is somehow exponentially connected (I don't remember how, I know we've learned those decibels - exam still waiting. ). So is there any smartass, who would write down equations? Link to comment Share on other sites More sharing options...
Firon Posted February 14, 2006 Report Share Posted February 14, 2006 decibels are logarithmic.Anyway, it's better to get dBi (antenna gain) than dBm (amplifier power), because raising the amplifier power doesn't help at all if the other end isn't equally strong. Higher antenna gain, on the other hand, will. I recommend you raise the power to a decent amount (no more than 84mW), then make a parabolic reflector to boost the antenna gain. And make sure the antennas are in a good position, as well as the router, and make sure you've selected the correct antenna for TX and RX. http://www.freeantennas.com/projects/template/ Link to comment Share on other sites More sharing options...
The Mighty Buzzard Posted February 15, 2006 Report Share Posted February 15, 2006 You could always just go over and kick the crap out of your neighbors. Sure, it may not fix anything but it'll make you feel better and you won't have to worry about signal problems since you'll be in jail. Link to comment Share on other sites More sharing options...
Inf Posted February 15, 2006 Report Share Posted February 15, 2006 ... write down equations?Gain_In_dB = 10*log10(Linear_Gain)Linear_Gain = 10^(Gain_In_dB/10)It's as simple as that. Note that this is correct for power gain only, for voltage or current gain it is 20log instead of 10 (and .../20 instead of .../10).Some dB based units:dBm - dB relative to milliwattsdBW - dB relative to wattsdBi - dB relative to isotropic antenna gaindBd - dB relative to dipole antenna gain (dBd = dBi - 2.15)Now, lets return to the original topic.YES, it is illegal to crank up the power on your wireless over a particular maximum, but that maximum differs from country to country. Link to comment Share on other sites More sharing options...
Firon Posted February 15, 2006 Report Share Posted February 15, 2006 most APs can't reach that illegal amount, at least not without modification (or really really good antennas) Link to comment Share on other sites More sharing options...
Inf Posted February 15, 2006 Report Share Posted February 15, 2006 Agreed. Link to comment Share on other sites More sharing options...
chaosblade Posted February 16, 2006 Report Share Posted February 16, 2006 /Me looks at inf and blinks in confusion*shrugs* Link to comment Share on other sites More sharing options...
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