Unwanted Wireshark Optimizing Received 802.11 Channel for Frames

Question

I am trying to run an experiment which involves monitoring 3 wireless channels simultaneously in Wireshark which would allow me to see a single frame captured 3 times on each channel.

To do this, I have 3 Wifi adapters configured on channels 1, 6, and 11 and have selected them in Wireshark to have their traffic captured.

However, instead of seeing 3 of each frame in the captured traffic (one for each channel), I see only one, which I assume means that Wireshark has chosen the one with the strongest signal strength or some other criteria. I am wondering if there is a setting in the application that would allow me to disable this feature or if there is an issue with how I have setup the experiment.

Edit: I see that it would not make sense for the frame to be picked up on the three channels (1, 6, 11) since their bands to not overlap.

Answer 1

Each frame is only transmitted once and you can capture it only on the transmitted channel, once. Only if there are multiple copies of an original frame (e.g. broadcast/multicast across multiple channels or bridged between channels) should you be able to capture (mostly) identical frames multiple times.

Basically, each channel represents a layer-1 segment of its own - wireless device can only transmit to each other when they're on the same channel. Think of a shared wire like with 10BASE5 or 10BASE2 - different channel, different wire.

With a multi-radio access point or multiple WAPs bridged together it is possible that a frame is bridged between channels (or even bands) but that depends on the setup that you haven't told us anything about.

Wireshark doesn't suppress/filter multiple identical (or mostly identical) frames.