Hi,

I’ve purchased an R11e-5HacD miniPCI-express card (Winbox reports this as an 'AR9888' device), and I have some questions regarding the supported MCSs that Winbox (and WebFig) is reporting:

1) For HT mode (802.11n), Winbox shows that the device supports MCS0 through MCS 23. For MCS16 through MCS23, 3 spatial streams are required, but the R11e-5HacD only has 2 Tx/Rx chains. How can the device support MCS16 through MCS23 with only 2 spatial streams?

2) For VHT mode (802.11ac), Winbox shows that you can set the supported MCS for 3 spatial streams (options are 'MCS 0-7', 'MCS 0-8', 'MCS 0-9', or 'none') . Again, I would expect that Winbox would show only 2 spatial streams, since the device only has 2 Tx/Rx chains.

Can someone clarify? I'm using the OS v6.29.1 in case that matters.

Thanks,
Steve

At the moment RouterOS is reporting wrong interface-type value. To know which chipset wireless interface has, you must visit our RouterBoard.com product page.

http://routerboard.com/R11e-5HacD

As you mentioned - 2 chain wireless card can't use 3 SS. Winbox just showing all available options, you can set them but it will use only 2 SS rates.