Has anyone seen any throughout tables like the one below for the ePMP4500 and ePMP4600?
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I don’t believe they’ve released any yet because they’re still optimizing TDD mode, and eventually WLR mode is going away… so any tables they released today would quickly be outdated.
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There is a throughput calculator.
https://www.cambiumnetworks.com/epmpcapacityplanner/index.html
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Thanks @alex_torres . Do you know if there is any documentation to help explain exactly how the calculator works?
Not that I’ve seen. However, I did enter in the distance from some test SMs we have up, and it’s pretty close!
for two spatial streams, easy calculation for total bandwidth available for “ratio split” is : multiply channel width in MegaHertz by QAM exponent and you will get real TCP/IP throughput in megabits per second.
64QAM = 64 is 2 to the power of 6 (2^6) so the QAM exponent is 6. If you have 40MHz channel, then your throughput will be 40 x 6 = 240Mbit/s. You will be working with 240Mbit/s grand total, divided between download and upload channel. If you decide to go with 75/25, your download will be 75% of 240Mbit = 180Mbit. Upload will be 25% of 240Mbit = 60Mbit.
Check the table above : 178Mbit reported at 40MHz and MCS15 (=64QAM = 2^6 modulation). Calculation estimate I described gives you 180Mbit.
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80MHz channel, 1024QAM (1024 = 2^10 so the exponent is 10. Calc : 80MHz x 10 = 800Mbit/s real throughput shared between download and upload according to chosen ratio (50/50 = 400Mbit download & 400Mbit upload).
10Mhz channel, 256QAM (256 = 2^8 so the exponent is 8). Calc : 10Mhz x 8 = 80Mbit/s throughput shared according to chosen ratio.
20Mhz channel, 512QAM (512 = 2^9 so the exponent is 9). Calc : 20x9 = 180Mbit/s total shared according to ratio.
40Mhz channel, 16QAM (16 = 2^4 so the exponent is 4). 40Mhz x 4 = 160Mbit total, shared… you know how.
It’s rough calculation but works in reality and is valid for all radios and all manufacturers with 2 spatial streams = MCS9 and above.
Single spatial stream is half of the throughput, so if you are working with MCS7 and below, simply divide the result by two.
Jeeeez, sounds much more complicated than it really is. For two spatial streams (MCS9+) :
16QAM = 2^4 (exponent is 4). Multiply any channel width by 4 to calculate total (DL+UL combined)
32QAM = 2^5 (exponent is 5). Multiply any channel width by 5 to calculate total (DL+UL combined)
64QAM = 2^6 (exponent is 6). Multiply any channel width by 6 to calculate total (DL+UL combined)
128QAM = 2^7 (exponent is 7). Multiply any channel width by 7 to calculate total (DL+UL combined)
256QAM = 2^8 (exponent is 8). Multiply any channel width by 8 to calculate total (DL+UL combined)
512QAM = 2^9 (exponent is 9). Multiply any channel width by 9 to calculate total (DL+UL combined)
1024QAM = 2^10 (exponent is 10). Multiply any channel width by 10 to calculate total (DL+UL combined)
That easy.
PS : I hope it’s really called exponent in english. I’m not native speaker, math wasn’t my favorite subject and it’s 2:24am here as I type it now, so I’m exhausted/lazy/everything to verify.
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Yes it is called exponent, but is also commonly called “the power of” and example would be: 64 is the product of 2 to the power of 6 or the product of 2 to the power of 6 is 64. Both are correct but used when it makes gramatical sense.
Your correct on your math but Cambium reserves some bandwidth for link overhead such as scheduling and control words.
Cheers!
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