75/25 downlink/uplink with 50/50 MIR?

If most customers want 75/25 download/upload on, say, a 2M package so I set the AP that way, but then someone wants 50/50, can I still create a MIR for them for that, or would I just have to bump them up to 8/2M and limit their SU in some other way maybe at the local router to make it psuedo/synchronous?

When you say "75/25 download/upload" are you talking about the download/upload ratio in the schedular section on the AP? If this is the case, all this means is that you're telling the AP to use 75% of the airtime for download data slots and 25% for upload data slots. Let's say you have 100mbps of capacity at the AP... that capacity would be split into a maximum download of 75mbps and a maximum upload of 25mbps. This 100mbps total would be split between all the clients connected to the AP using the aforemention ratio. This means that a single client should have no problem being set to an MIR of  8mbps download and 2mbps upload. Another example using this same scenario, you could have a client that has an MIR of 1mbps download, and 20mbps upload. As long as your MIR's don't exceed the estimated capacity ceilings of the download/upload ratios you've chosen, you're fine. Oversubscription ratios... now that's a story for another day...


Okay, but if I have low signal strength at the SU, and my speed only tests at, say, 5M down/up on a 50/50 AP schedule, if I switch the AP to 75.25, would that mean I could then never get upload to 5M, and it would just be 1.25?

Wow, I've edited this post like 3 times now trying to wrap my head around what I think you're asking...

If there's enough bandwidth available at the AP, then you would see 5mbps download and 5mbps upload even if you change the schedular to a 75/25 ratio. If there's not enough bandwidth at the AP, then yes, you would see your upload decrease by changing the schedular to a 75/25 ratio. The decrease will be 5mbps or less depending on bandwidth availability.

Thanks for the patience, I appreciate it. Yes, the AP has the capacity, I'm just trying to understand how the client relates a 50/50 request to an AP that's set to provide 75/25 bandwidth so synchronous customers would still work though most customers would prefer the 75/25 plan.

I am trying to understand the scheduler, i.e. originally I thought if a radio spends half it's time on tx and half on rx anyway, the only way to get 75/25 would be to not use half the capacity of one of the those cycles that's not being used, but I now *think* I understand it doesn't work like that? Sorry if that still sounds muddy, but maybe if someone could explain how it really works a little more clearly if I'm way off?

I've confirmed with some of my friends at Cambium and they've confirmed that the examples I've given you are an accurate representation of how the schedular ratios work.

To get a better idea of what sort of speeds you can expect under various conditions and schedular ratios, why don't you check out Cambium's LinkPlanner or the CapacityPlanner spreadsheet?

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