acrylic wifi home shows no signal to noise on channel

ACRYLIC WIFI HOME SHOWS NO SIGNAL TO NOISE ON CHANNEL DRIVERS

How accurate are your measurement devices actually? Making an accurate system to measure power at these frequencies is not easy. High Res Wifi Signal Mapping by user CNLohr on youtube This video pretty much discribes what I am trying to say here: This could result in there actually being a significant difference in signal strength, even though they are measured in very close proximity. You say that you measured in the same place, but how much difference is there? Even a few tens of centimeters could have a large impact because of the complex behavior of reflections you get with WiFi indoors. This could (and likely is) another source of error: there might be losses between the antenna and the actual power measurement, causing one to read lower power levels than the other.Ģ) Signal strength is different depending on location The manufacturer might have compensated for this, but you don't know.

This could add a few more dB loss, resulting in a weaker received signal.ī) Due to the receiver itself: Do you know where the power of the receiver is measured? Is it right at the antenna? Or perhaps after a first filter to isolate the wifi channel? Depending on how much there is between the antenna and the point of measurement, you will find that you might get different results. A small antenna in a dongle is likely to be less efficient since it has to work in a smaller space and on a PCB, versus the 'dedicated' antennas often found in laptops. Some antennas do a better job of 'absorbing' the electro-magnetic wave and turning it into an electrical signal. In addition, not all antennas are equally efficient. If the different devices were not oriented the same way you will get different results - even if they were exactly identical in every other way. As a result, you should find that the received power goes up and down depending on the orientation.

To test this, what you can do is repeat the measurements with just one of the devices, but every time you do, rotate the device a little - both horizontally and vertically. You can't know how every antenna was 'oriented' and this could make a big impact. What this means is that every antenna is more sensitive in certain directions than it is in others. Antennas are all directional - it can be proven that a truly omnidirectional antenna is impossible. In other words, can I assume that the signal to noise ratio for both adapters will be the comparable, if only dominating noise from group (2) is considered?įirst I would just like to clarify few things that could influence this and I think you are misunderstanding a few concepts.Ī) Due to the antenna: Just because your two antennas are in exactly the same location, does not mean they will receive the same amount of power. Thereby I assume that the internal noise (Group 3) for both WiFi radios is below -90dBm and not a factor for the measured noise value, which would be dominated by noise from group (2). From what I have seen in my experience, I expect them to be typically below -90dBm.Īm I right to assume that group (2) noise will also show up with different levels on my two Wifi radios, since also the actual WiFi signal strength is different.Īssuming there is a babymonitor (from group 2) producing heavy noise on a 2.4GHz WiFi channel which shows up as noise around -60dBm on my internal adapter, could I then expect that this will cause a noise level of around -75dBm to -80dBm on my nano USB WiFi adapter, if also all WiFi signals (group 1) measured on the two WiFi radios typically differ by about 15 to 20 dBm. I assume that noise from group (3) will be independent for both WiFi adapters, as they will use different components and different layouts. Internal noise produced by the electronics inside the WiFi radio (operation amplifiers, thermal resistor noise, etc.microwaves, baby monitors, Bluetooth, etc.) Outside noise that is also received via radio waves (for the 2.4GHz band e.g.The signal itself, which is received via radio waves.Naively, I would put the received signals on the WiFi radio into three groups: Specifically, how the measured noise on the WiFi radio is related to things like the antenna size/layout. However, now I would be interested what to expect for the measured noise in that situation.

ACRYLIC WIFI HOME SHOWS NO SIGNAL TO NOISE ON CHANNEL DRIVERS

Unfortunately the drivers for both cards did not provide any noise measurements. I assume that this is mostly due to confined space on the nano USB wifi adaptor compared to the internal Wi-Fi card, mainly limiting the antenna size, etc. I saw that the signal strength measured on the nano usb wifi adapter was lower by 15 to 20 dBm as compared to the internal WiFi card, although measured almost at the exact same location. I was checking the signal strength of wifi access points on my laptop in parallel with the internal Wi-Fi card and a nano usb wifi adapter connected to the same laptop.

Acrylic wifi home shows no signal to noise on channel