Did they lie about the distance?

RouterOS Wireless Networking
1

I purchased a setup from a reseller that promises 500Mbps over a 2km distance. The setup is using RBSXTG-5HPacD on each side of a fjord.

It was pre-configured and I have only mounted the Base station on one side, and two klients on the other side.

The speed I get is about 110-120 Mbps, which is far off the promised 500 Mbps. When I measure the distance in google maps it’s about 1.3 km with free sight point to point over a fjord.

Is this a speed I should be happy with, or may I expect this to be improved by tuning? Appreciate any feedback since I am new to this but willing to learn.

2
  1. when you want maximum performance, make onluy a point-to-point link, not a single base with 2 clients
  2. performance of WiFi links is always way overstated, you have to divide by at least 2 to have real-life performance relative to specified speed.
    all manufactures do this. the speed in advertisements is not the link speed but the raw radio speed
3

The datarate supported by protocol is 866 Mbit, so even if you half that it should be more than 400 Mbit?

4

Only on a completely optimized point-to-point link. And even then it will depend on the type of traffic.

5

Which is the question in this topic. Is there something I can do to optimize the link to get closer to the promise of the vendor, or is 100+ Mbit the speed I need to settle with?

6

Run Spectral Scan and Snooper on both sides. Make sure you have chosen the most optimal frequency with no other devices nearby. What is the signal and noise level on both sites at the best frequency?

In wireless there are no guarantees. Even the weather will affect your result.

7

There was a thread about shooting over the bay wit special findings related to the very unusual environment by refractions and salt water vapor. Find it and read it.

8

We have a link over a salt water sea arm and the signal quality changes with the tide. No real explanation for it, other than what you could guess about reflections and path length.
(not really plausible since the wavelength of the radio is quite small compared to the water wave height)

9

Thanks for any feedback and help. I’m away from the location, but will check back this weekend.

As I got a reccomondation about point to point, is there an off the shelf component I could use to spred the wifi on the client side?

I can put a client in one house, and spread it to the other two. There is line of sight between the locations and slightly less than 90 degrees spread and 50-60 meter away, Preferable solution would be to be able to use normal indoor wifi routers at each house without external antenna. Can’t use cable between the locations.

10

btw how did you tested the speed?

11

I have tested the speed in two ways.

One is by connecting a PC to the network and using speedtest.net, achieved 100-110 Mbit. Ping 8-10ms.
The other was to use the speed test in winbox. Did send, receive and both from one client to base. Send only or receive only to base showed around 130Mbit.

Then tried the same from client to another client and got lot worse results, but learning a bit about how this thing works. The capasity is shared between all parties on the link, and not duplex.

12

The same radios give me 200-250mbps. But with -40 signal.

13

That gives me a bit of hope :slight_smile:

As I said, I’m completely new to this but a nerd and really willing to learn. What does -40 signal mean? Is that a very good signal or a very bad or neither?

Also, I just measured on a map. The distance looks to be 1.06 km, so really not far compared to they propose to use this for 2 km links.

14

It means “-40 dBm”. It is a measure of the signal’s strength. -40 is quite good, the upper limit something around -30 (above this point You start getting saturation problems on the receiver).