RF and Cell Sizing Test Methods

Previously I wrote about some RF properties and postulated a theory on wave propagation and effective distances for different channels. In this post I'll write up a test method I plan on using for validation. The end goal will be to develop a map of effective RF propagation distances at various transmit powers in free space. This won't be 100% effective in indoor environments, as lower frequencies propagate better through objects than higher frequencies.

My goal is to come up with an idea for future cell sizing and channel planning to prepare for the future of APs with dual band 5/6GHz radios. This may require additional study on the concept of Adjacent Channel Interference, to validate the usefulness of such an implementation. Although it'd be great to do a full lift and shift to 6GHz airspace to take advantage of the clean spectrum, it's not practical to replace all your clients.

I found this post referencing power level assignments in Cisco controllers. This leads me to believe that each step down is a -3dbm change on the AP. So, based on your regulatory domain your effective cell size could be affected by constraints (either positively or negatively) based on the maximum transmit power settings. If you're pushing more power, there may be a chance you can achieve higher MCS rates at a distance, but this will also affect conditions such as ACI and CC in your deployment and may not be recommended.

Below is a shot of the template I will use to record testing data to compare my findings. If you find that I have omitted something, or should include something please let me know by posting a comment! I plan on building as complete a table as is reasonable, keeping in mind that I don't currently have plans (for lack of a reason) to get a measurement on 2.4GHz cells larger than the maximum 5GHz cell. If you work for Aruba, Ruckus, Mist, Extreme etc and would like me to test your devices for inclusion, please submit a request to admin@wifiroundup.com. Currently I am only planning on testing OFDM rates at 20MHz.