[HamWAN PSDR] Signal Strength Needed for Internet Connection.

[Nigel Vander Houwen]

David,

Looking at your linked page, the '/interface wireless monitor 0’ command results are the most telling.
> [admin at WA9ONY-LARCH] > /interface wireless monitor 0
>                   status: connected-to-ess
>                  channel: 5880/5/an
>        wireless-protocol: nv2
>                  tx-rate: 1.8Mbps-5MHz/1S/SGI
>                  rx-rate: 1.6Mbps-5MHz/1S
>                     ssid: HamWAN
>                    bssid: 64:D1:54:6A:64:26
>               radio-name: S3.Larch/K7WAN
>          signal-strength: -81dBm
>      signal-strength-ch0: -105dBm
>      signal-strength-ch1: -81dBm
>       tx-signal-strength: -84dBm
>   tx-signal-strength-ch0: -90dBm
>   tx-signal-strength-ch1: -86dBm
>              noise-floor: -105dBm
>          signal-to-noise: 24dB
>                   tx-ccq: 9%
>                   rx-ccq: 6%
Here you’re seeing a reported “signal strength” of -81, but bear in mind that it’s a bit misleading because this is a two way connection, it’s important to also look at how the cell site is hearing you, the “tx-signal-strength” figures, and what your ccq’s are.

We usually see -90 being the threshold of being able to see anything at all. -80 or below being pretty marginal signals. Below -70 is getting into better territory. Above -70 is where we would expect the best performance.

With regards to the ccq figures, consider those a “success rate”, in the above data, only 9% of your transmitted frames are making it to the cell site successfully, and even worse you’re only getting 6% on RX. Trying to push internet (or much of anything at all), through that much loss is definitely problematic.

In this case, your signals are pretty weak to begin with, and that is shown in the ccq’s, it’s also possible to have good signal strengths and still get bad ccq figures if there’s lots of noise/interference/etc that interferes with proper frame decoding.

Also, you should make sure both chains are enabled on your radio. ‘/interface wireless set 0 tx-chains=0,1 rx-chains=0,1’ They may be already, but it’s always good to check since sometimes the stock config doesn’t have them enabled.

Nigel

> On Nov 6, 2018, at 10:42, David Haworth via PSDR <psdr at hamwan.org> wrote:
> 
> What signal strength is needed for Internet connection with Larch Mountain cell site?
> 
> During my experiments on doing a site survey of HamWAN Larch Mountain cell site at 71.9 miles I received the signal in the -80s but I could not connect to the Internet.
> For details of the routerOS terminal log of 71.9 miles connection see.
> http://www.stargazing.net/david/sdr/HamWAN.html#P2b <http://www.stargazing.net/david/sdr/HamWAN.html#P2b>
> 
> Best distance for Internet connect at 0.99 Mbps download and
> 1.67 Mbps upload is 43 miles with a signal in -74.
> http://www.stargazing.net/david/sdr/HamWAN.html#P2a <http://www.stargazing.net/david/sdr/HamWAN.html#P2a>
> 
> My site survey map is at
> http://www.stargazing.net/david/sdr/HamWAN.html#P2 <http://www.stargazing.net/david/sdr/HamWAN.html#P2>
> 
> 
> 73 David WA9ONY
> _______________________________________________
> PSDR mailing list
> PSDR at hamwan.org
> http://mail.hamwan.net/mailman/listinfo/psdr

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.hamwan.net/pipermail/psdr/attachments/20181106/cc401e04/attachment.html>