R7800 MU- MIMO and Samsung

[ebec]

I had to switch off MU-MIMO on the R7800 to get 2X2 AC link sped on my Samsung galaxy S7 Edge (Exynos version). The maximum link speed I get with MU-MIMO “on” is 433 Mbps.

Now I get the expected link speed 866 Mbps on 5 Ghz but only 192 Mbps on 2.4 Ghz. I don’t know what link speed I should expect on 2.4 Ghz these days but I believe the phone is (should be) capable of both MU-MIMO and 400 Mbps (40 MHz bandwidth, QAM 256)

I guess the router will not do 2x2 or 3x3 on 2.4 Ghz because I have two other routers with 2.4 Ghz (single stream) forced to channel 1 and 6. The R7800 is on Auto (Chanel 13).

Any thoughts?

 

[pege63]

Test set it on chanel 11,
Is the Samsung galaxy S7 Edge a 1x1, 2x2 or 3x3 AC, or support MU-MIMO?
Do you measures against the Internet or a client on the network?
Wath is your ISP speed?
Do you have any MU-MIMO clients?
Is the other router SET as Router or Access points?
I have MU-MIMO OFF on my R7800 i dont have any MU-MIMO clients on my network yeat

 

[thiggins]

MU-MIMO operates in 5 GHz only and downlink (router to device) only.

192 Mbps 2.4 GHz link rate is a puzzle. 2x2 QAM 256, 40 MHz B/W with SGI would be 400 Mbps. With 20 MHz B/W would be 173 Mbps.

Remember in crowded environments, router should support only 20 MHz B/W in 2.4 GHz

 

[ebec]

Test set it on chanel 11,
Is the Samsung galaxy S7 Edge a 1x1, 2x2 or 3x3 AC, or support MU-MIMO?
Do you measures against the Internet or a client on the network?
Wath is your ISP speed?
Do you have any MU-MIMO clients?
Is the other router SET as Router or Access points?
I have MU-MIMO OFF on my R7800 i dont have any MU-MIMO clients on my network yeat

Hard to find the exact specifications on these phones. This is from the specifications on Samsung.com/no Connectivity: 802.11 a/b/g/n/ac 2.4G+5GHz, VHT80 MU-MIMO. So it has to be 2x2 on 5 GHz as I get 866 Mbps link rate. Am I right then to assume that it also can do 2x2 on 2.4 GHz?

Regarding the router settings on 2.4G isn’t the 40 MHz channel-with disabled (automatically set to 20MHz) if I force Channel selection? And is it at all possible to achieve 2x2 as long as I have two other routers on 2.4 GHz nearby?

 

[ebec]

MU-MIMO operates in 5 GHz only and downlink (router to device) only.

192 Mbps 2.4 GHz link rate is a puzzle. 2x2 QAM 256, 40 MHz B/W with SGI would be 400 Mbps. With 20 MHz B/W would be 173 Mbps.

Remember in crowded environments, router should support only 20 MHz B/W in 2.4 GHz

Regarding the MU-MIMO it is strange that a device that is advertised to support this feature actually connects at half rate. What happens when I get another device with MU-MIMO? link speed of 216.5

Well no problem for now, I only have one device that suppose to do MU-MIMO

Hm… I also get 192 Mbps link rate when I set the 2.4 GHz Mode in router to “Up to 347 Mbps” instead of 800.

 

[thiggins]

Hard to find the exact specifications on these phones. This is from the specifications on Samsung.com/no Connectivity: 802.11 a/b/g/n/ac 2.4G+5GHz, VHT80 MU-MIMO. So it has to be 2x2 on 5 GHz as I get 866 Mbps link rate. Am I right then to assume that it also can do 2x2 on 2.4 GHz?

That would be a reasonable assumption.

Regarding the router settings on 2.4G isn’t the 40 MHz channel-with disabled (automatically set to 20MHz) if I force Channel selection? And is it at all possible to achieve 2x2 as long as I have two other routers on 2.4 GHz nearby?

I don't think so. I think you can disable 20/40 MHz coexistence in advanced wireless settings. But I would not advise this.

Regarding the MU-MIMO it is strange that a device that is advertised to support this feature actually connects at half rate. What happens when I get another device with MU-MIMO? link speed of 216.5

It is possible that the phone falls back to 1x1 when connected to a MU-MIMO capable router / AP. You need two MU-MIMO devices at a minimum to get benefit from MU-MIMO, so disabling MU-MIMO on the router is the right thing to do for now. Link speed does not reduce further as more MU-MIMO devices are added.

Hm… I also get 192 Mbps link rate when I set the 2.4 GHz Mode in router to “Up to 347 Mbps” instead of 800.

I don't know where that is coming from. Link rates are commonly reported incorrectly. At any rate, I wouldn't stress about it. Useable throughput is what counts.