En nog steeds wacht ik op onderbouwing van jouw kant
Overigens van hyperwrt:
Why 42mW Xmit Power and not 84mW?
- It's more than enough for most people, it's even the double of that used in the original v2.02.7 firmware from Linksys.
- It's safe to use without extra cooling.
- It's legal to use in most countries.
- Any value above 56mW will make the signal dirty, which results in packet loss and interference on the other channels.
Natuurlijk niet een heel erg goede bron zonder meetdata etc maar never the less een indicatie.
The ETSI in Europe has set standard 54g power to max out at 100mW on most european wireless devices. Going higher than this in enclosed spaces can affect your health
Overigens is het wel goed om aan te geven wat de 100% setting is bij jullie. Bij de meeste firmwares lijkt 100% namelijk iets te zijn van 83mW. Bij bv Tomator is dit 251 mW! Ik heb het bij mijn relaas over 100% power NIET over 83mW. Wel belangrijk om dat aan te geven (en dat had ik eerder moeten doen).
Welke firmware gebruik je RutgerM?
En wat betreft de metingen:
WRT54G op 50mW:
Redelijk net signaal, weinig noise.
WRT54G op 250mW (100%):
Weg redelijk net signaal, noise neemt de overhand, band wordt breder en overstraling van noise op andere channels.
Is dit wat je wilde zien? Nou graag metingen vanuit jouw kant waaruit blijkt dat het geen effect heeft
Deze min of meer grappige uitleg kwam ik nog tegen:
Increasing transmit power does little or no good. This is 2-way, not broadcast AM radio.
Think of it this way, you are talking with someone in a crowded room. You move a bit further away and can no longer talk. If you whip out a BULLHORN AND BLAST THEM, well sure they can hear you, but you still cannot hear them. Not only is it rude to the other people in the room, but it's ineffective since you are not having a functional conversation.
Chasing transmit-power increase only on the AP side is ineffective when the client doesn't have enough power.
Ter referentie omdat dit soort vragen erg vaak worden gesteld hier op GoT:
I'm always curious about the theory behind such transmit power boosts. If this only boosts the one-way power with which the router emits signals, how does it improve overall connection strengths since the wireless NIC's signal may still be too weak to come back to the router. Does increasing transmit power somehow improve the router's ability to "hear" signals sent by wireless NICs as well?
You pretty much have the right idea. If, and only if, the transmit path from the AP to the Client is has too weak a signal, will increasing transmit power from the AP help.
In practice that does happen though. But it is not likely to be seen as improved range, so much as just fewer problems at the maximum range. In most cases, for example if the connection is getting 54Mb rates, it simply isn't going to do anything.
Note that 3 dB is twice the power. It usually takes about 6 dB to double the range. Since increasing the AP's transmit power does not help the AP receive any better, there is a very practical limit to any benefits. A 3 dB increase (56 mW) probably does provide a measurable increase in fade margin, and if you often work at fringe ranges it might be worth doing. 6 dB (112 mW) is almost certainly not significant over just 3 dB.
En:
There is little good reason for increasing transmit power as most home AP's have weak client laptops which cannot similarly boost transmit power. Increasing transmit power on the AP makes ZERO sense except it gets you more bars in some client signal-measuring utility. Big deal! The AP still cannot hear your 32 mW laptop at great distance, and WiFi needing to be 2-way you are not communicating, you are just blasting interference out into the neighborhood. Instead of a good reason TO do it, I usually mention the first reason NOT TO DO IT.
For most people wanting better signal, I tell them PUT A BETTER ANTENNA ON THE UNIT! A high-gain antenna increases your receive and transmit gain at the same time. You can get double or more the REAL range improvement just by plugging in a new antenna.
Increasing transmit power makes sense to me in only one application, with point-to-point bridge units equipped with directional antenna.
En als laatste duidelijke quote:
My question is : What is the best value for transmitter power to have best signal?
It depends on too many things to actually be able to pin it down exactly. But there are some fairly easy guidelines which we could talk about.
First, understand that there are two radio transmitters involved. Lets generalize and say that one is an AP and one is a Client, even though they might be called different things if we use other configurations.
If you increase the transmit power of your AP, and do not also increase the transmit power of your Client, if all things are equal, at some distance between the AP and the Client the signal strength received by the AP will not be sufficient. The signal strength received by the Client is just fine, but your connection drops anyway. No increase in AP power output is going to keep it from dropping the connection at that distance.
If all things actually were equal the two signals would drop out at just about the same distance. But of course all things are never equal! Hence, sometimes it happens that the AP is still receiving a good signal, but the Client is not, and the connection is dropped. In that one single case it is true that if you increase the power output from the AP you will see a benefit!
So the question is actually, how often is that likely to happen, and at what power levels does it happen?
In fact it is common for path fades etc to result in a 3 dB difference in signals. But the difference is very rarely ever larger than 6 dB, simply because most changes will affect both the transmit and the receive path equally.
Given the above it is probably useful to increase the power output from your AP by 3 dB over what it takes to normally have equal signals at the Client and the AP. It is less useful but still perhaps on rare occasions worth having a 6 dB increase power in power from the AP. (Note that increasing power also increases interference to others, so your rare benefit should be balanced against the potential for not so rare interference...)
Now, if we assume (and this may not be correct at all!) that the default AP power is just about right, then twice the power (3 dB) is good, and four times the power (6 dB) is probably not really of any value.
The typical AP defaults to 28 milliWatts output, and it might very well provide noticable results to set it to 56 mW. If you insist on getting every last ounce of benefit, go for 112 mW. More than that is just massaging your ego and annoying the neighbors.
Personally, I can't see setting it higher than maybe 84 mW, which is about 4.8 dB.
offtopic:
Quotes komen uit diverse threads en diverse topics op diverse fora en websites. Ik heb niet alle threads helemaal door kunnen lezen wegens de overweldigende hoeveelheid aan informatie. Bovenstaande quotes geven echter het leeuwendeel van de threads weer.
En nu mijn eigen situatie: ik boost het signaal zelf WEL een klein beetje omdat mijn laptop kaart dit hogere vermogen ook aan kan wat nu resulteert in WEL een verbetering van het bereik. De meeste PCMCIA en mini-PCI kaarten komen echter niet van hun default zendvermogen af waardoor bovenstaande gequote verhalen voor de meeste mensen opgaan.
Come again
[
Voor 169% gewijzigd door
Bor op 22-05-2007 09:13
]
/u/24937/crop65fe1ebc2efd0_cropped.png?f=community)
.
/u/433/crop6746d51e1326a_cropped.png?f=community)
:strip_exif()/u/49483/mandarin_sm.gif?f=community)
:strip_icc():strip_exif()/u/21673/crop65674aee06c6d_cropped.jpg?f=community)
:strip_icc():strip_exif()/u/5169/sbod.jpg?f=community)
Dit topic is gesloten.