Wireless bridge, only 15 meters but bad signal -90

RouterOS Wireless Networking
1

Hi all,

I am using two Grooves and able to setup a wireless bridge (bridge, station), using nv2 protocol.

When testing within the same room I am able to get a strong link in the same room and transfer at 65Mbps between two computers.

I then mounted the Grooves to the windows with double sided gorilla tape to bridge across a court yard (15 meters, red line and rectangle indicates other Groove). This is through glass windows, but the signal is really bad (-90db) and the majority of the time too weak to form a bridge.

This is using 2GHz antennas, nv2 protocol, and various frequency bands, the power is set to default at 27dB and antenna gain is set at 0.

This is strange as my apartment 10 stories up I can get signal from the ground floor with a rb2011 and this is passing out through my window, so I know mikrotik is very strong.

What could be going on here, and any adjustments i could do to make this work? Directional antennas? Or is the window somehow blocking the signal and making it impossible?
bad signal.jpg

2

Hello,

if at all possible, you could try the units just outside of the windows and note the change in signal.

The windows could be coated in a metallic film which could have an effect on signal penetration.

Out of interest, I assume the groove unit is set at 2GHz and not 5GHz, :sunglasses:

If you had a 5GHz antenna, it would be interesting to see the difference.

Just a thought, have you tried rotating the omnis by 90deg? I know omnis are supposed to be omnis but why not try anyway.

Cheers.

3

Low E windows are really good at blocking wireless.

4

Would it help by going 5GHz or setting up directional antennas?

5

Did you made the test and measurements with the same devices, in the same distance but without the glass blocking the way?

6

Yes, they work really well. I have other Mikrotiks inside the building and they provide WiFi through walls similar distance so for sure open air line of sight is still powerful.

Unfortunately in this instance it has to be through the windows as can’t mount kit outside (landlord may complain plus may get stollen!).

I’m 99.99% sure its something to do with the windows

7

Line of sight without obstructions I have to reduce the tx power to get a signal of around 60, transfer runs at around 65Mbps from laptop to laptop with test http transfer, i know the link is good as the groove shows WiFi plus all bars for signal.

Through windows the WiFi link goes on very occasionally as is one signal bar. Checking on winbox shows no link, when scanning signal comes up -90 or so

8

Seems to me that your windows are made of Pilkington K glass.

This type of glass has 50dB of attenuation for 2.4Ghz signal.

From this article:
hxxp://www.powerwatch.org.uk/library/downloads/windows_pilkington-20100520.pdf

Alasdair and Jean Philips
Microwaves, windows and Pilkington-K glass

Normal single or double-glazing glass offers little resistance to the passage of microwaves into
your rooms - almost all pass straight thorough.
Pilkington-K is a specially treated thermal insulation glass, coated with a thin metallic layer,
which includes indium and tin oxides, and this does offer a reasonable level of protection,
stopping over 99% of microwaves in the frequency range 300 to 3000 MHz (this range contains all
current mobile phone mast bands).