Re: How to debug a reluctant WISP AP association (before I blame the WISP)



So far, by googling, I've found only one radio that does this:
Alfa Network AWUS036H ($28), TX=20dBm (100mW), RX=-91dBm@xxxxxxxxxxxxx
Antenna=2dBi omni,
Power = USB, Linux drivers = yes,
Monitor mode = yes, Packet injection = yes, Promiscuous=?

The AWUS036H works fine with kismet. They have a 1 watt version.


But if I'm going to buy anything, I prefer a stronger gain such as this 1
Watt USB radio (but I don't know if it is promiscuous):
Alfa Network Tube-U(N), TX = 30dBm (1 Watt), RX = -95dBm@ 1Mbps802.11b
Antenna Connector=N-Type Male (so you can add any antenna you like
Power = USB, Linux drivers = yes,
Monitor mode = ?, Packet injection = ?, Promiscuous=?

I have the tube/u. It is less power than the AWUS036H. It works fine in Kismet.

Incidentally, Kismet is totally passive. I'd have to research packet injection, but that sounds like something active.


quality of signal is what you want rather than signal strength.

One you have comms, the firmware will yield a quality signal. I will admit I don't know how they get this figure of merrit, but it seems to be what you want to optimize.

Interesting. I was going for pure decibels. Is transmit CCQ the quality
metric I try to maximize? If not, I don't know what other 'quality'
metric to aim for that I can measure at the radio.

I'm currently using the 19dBi Laird Technologies PA24-19 from Streakwave
in San Jose, installed on the antenna mast along with the 28dBm (630mW)
Bullet M2 radio so I'm familiar with that suggested brand (and I like
them).


I can see that antenna being a bit tricky to set up due to the lobes.

In addition, if I buy the 1 Watt Alfa Network bullet USB radio, I'll need
an additional external antenna. The antenna consumes 100 Watts though, so
I'm not sure if that can be handled by the USB port (because 500mA USB x
5 volt USB is only 2.5 Watts)

My point was to hook up the wifi dongle and just monitor. That would be from your existing antenna. You might find that you are fighting with some other source.


the lobes of the 19dbI antenna are down about 12 dB.
I preferred to use the 16dbi version, while has lobes that are further
down and much more to the side.

Of the three Laird antennas on that datasheet, I agree, the lobes of the
16 dBi version are cleanest (by far)!

One potential issue with the 16 dBi antenna is that, of the three, it's
the only one that doesn't support "surface mounting". What is "surface
mounting" anyway? They all support 1" to 2" pole mounting, which I'm
familiar with. But what is surface mount anyway?

I got the impression the whole family of antennas is similar except for dimensions. Mine is pole mounted.

In the end, it cost me as much (or more) than it would have for him to do
the work - but I have a better installation - and I can control the radio
and the settings.

And you are a better person for this! There is a lot to be said for knowing exactly what you have installed and how it was set up. I can't tell you how much money I wasted on a gate control company that was reaming me for repairs on what I finally determined was a PCB with an intermittent bug. [You could push it and signals would change.] I bypassed the service company and arranged to get the board swapped. Problem solved, and the gate guy doesn't get to make a boat payment.


Do you know if you have line of sight? Are there tree in the way?

I've never visually 'seen' the WISP antenna but the WISP came to my house
and said there was line of sight and he gave me the coordinates to his
antenna (which I posted in the picture in the first post).


That kind of stuff is EXACTLY why I want to find good sniffer software
that works on the Linux laptop (along with a good external antenna& USB
radio for that laptop)!


I don't think you want to sniff your local environment. I think sniffing with the antenna is the way to go. I'm going to go back and try to find the coordinates you mentions, but it has been my experience that mountain tops are full of wifi these days. It seems some companies use wifi as a way to remotely read their instrumentation. Maybe all that wifi causes your receiver to think it has a strong signal.

Normally I just do a point to point where there is just one source at each location. Now probably a question for Jeff would be is there a way to see if one direction is working well, but not the other. Perhaps the WISP has interference from your direction, so link that is your transmitter to their receiver is poor, but you can "hear" the WISP just fine.
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