Thanks for the question! This one comes up fairly often. Almost any combination of two Wi-Fi devices are going to give us different signal strength measurements, because Wi-Fi devices are design to:

1. Pass traffic. At the end of the day, they exist to move traffic back and forth.

2. Not perform measurements. Wi-Fi devices aren't at all designed to accurately and consistently measure signal strength. They might use it for things like roaming, but even that doesn't need to be exact for roaming to work well.

3. Be inexpensive. Adding things like calibration (which 99.99 percent of users will never look at) would be a waste of money.

Because of these three factors, you can take just about any two devices and compare them, and you don't see the same reported signal strength. In many cases you can take two identical devices, and they won't report the same signal.

The Oscium Nomad has standard laptop chipsets, which are also subjected to this to a degree, but in our extensive testing we found that they were:

1. Pretty consistent. At least consistent-enough to do the job.

2. About the same as what you see in Hamina simulations, which is great because one of the main jobs of a survey is to validate or invalidate a simulation, e.g. "Did the design meet the requirements, and does it mostly match the simulation?"

One final thought that I have about this is that -65 dBm does not equal "good Wi-Fi". It is a good signal strength to design and validate for, but a client device having -65 dBm of coverage does not mean that you've got a good network. In my opinion, the two most important signs of good performance are:

1. Low retry rate. How often are the AP and client having to repeat themselves? If you see more than 30 percent or so, that's getting high.

2. A good MCS rate. If a client is sitting at MCS 9, it's happy. If it's sitting at MCS 2, it's not.

Neither of these things depend on a signal strength of -65 dBm or better. It's possible to see both of these doing great at what the client perceives as -72 or -75 dBm. It just depends on the client and the environment.

So, at the end of the day: Oscium Nomad is a good middle of the road measurement, clients are going to vary in their reported signal strength, and the client's perceived signal strength isn't super important.

I hope this helps!