# How to measure the SINR for channel bonding?

I use to have a set up of a WiFi environment where I assume all devices operating over the same wireless channel, i.e., a single 20 MHz channel. A device would treat the transmission of all neighboring devices as interference. Therefore, the SINR for a transmission can be simply calculated, which allows me to get the data rate through a lookup table.

Recently, I want to expand my problem with the feature of channel bonding where adjacent channels can be combined to form a wider channel, i.e., two 20 MHz channels can be merged as a 40 MHz channel to double the channel capacity. I want to keep using the SINR to calculate the data rate but got a problem. As I am assuming different devices may operate over different channels, when a device bonds two channels, the amount/level of interference on each channel may be different. So what is the correct way to calculate the data rate under this circumstance? Do I calculate the SINR separately to get the data rate on each 20 MHz channel and add them up to get the data rate for the whole bonded channel? Or I should average the interference over the whole bonded channel and then get the SINR?

I have not found any reference related to this problem yet and would be appreciated if anyone can provide any help.

Thanks!

– Zac67
Oct 7, 2022 at 16:26
• Did any answer help you? If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you can post and accept your own answer. Nov 19, 2022 at 23:09

Recently, I want to expand my problem with the feature of channel bonding where adjacent channels can be combined to form a wider channel, i.e., two 20 MHz channels can be merged as a 40 MHz channel to double the channel capacity.

Indeed, you can see such a 40 MHz channel as two 20 MHz channel, the "upper channel" and the "lower channel". As the same modulation is used on both channels, to find out the maximum data rate you can use you would use the lowest SINR of the two channel SINR. Indeed, the channel with the worst SINR will dictate what is the best modulation you can use.

• Thanks so much for your help. Just one more thing, do we have a reference for this yet?
– Ewan
Feb 10, 2022 at 11:25
• You can check that only one modulation is used over the 40 MHz (or larger) channels in the 2020 standard, e.g. Table 19-31 (MCS parameters for optional 40 MHz), Table 19-32 (MCS parameters for optional 40 MHz, NSS = 2, NES = 1, EQM), Table 19-33 (MCS parameters for optional 40 MHz, NSS = 3, EQM )… For the rest of my answer, no, I don't have any reference.
– user71928
Feb 10, 2022 at 12:14
• Thanks! I'll check the standard paper. Really appreciated for your help!
– Ewan
Feb 12, 2022 at 13:40