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List of WiLink8 supported 802.11 MCS, channel width and Guard Interval

FS
Prodigy 120 points

Hello,

If possible I would like to know the list of all 802.11 data rates and modes supported by WiLink8.

For instance: does it support all MCS from MCS0 to MCS7? If yes, does it support  20Mhz and/or 40Mhz channels? Using 800ns and/or 400ns Guard Intervals?

Same question for MCS8 to MCS15.

Thank you very much in advance for your reply. 

 

 

 

 

 

 

  • 0
    TI__Genius 12935 points

    Hi FS,

    WL8 fully supports MCS0~7, and only 20Mhz bandwidth for MCS8~15.

  • 0 in reply to Victor_Lin
    Prodigy 120 points

    Hi Victor,

    Thank you very much for your prompt reply.

    2 additionnal questions if you don't mind:

    1) For MCS 8 to 15 with 20Mhz channel width: is 400ns Short Guard Interval supported? For all MCS 8~15? Or only for a subset?

    2) The WiLink8 use SDIO. As far as I know, SDIO Mbps limit is 104Mbps. Data rates for  MCS 6 and 7 with 40Mhz are larger than 104Mpbs (ranging from 121.5Mbps to up to 150Mbps).  Given this, I assume that WiLink 8 is able to receive burst of data at, for instance, 150Mbps (MCS 7, 40Mhz, 400ns SGI) but that it cannot sustain longer constant 150Mbps throughput.

    Am I correct?

    Thank you very much in advance for these additional details.

  • 0 in reply to FS
    Expert 1585 points

    Hi FS,

    About #2: There is a different between the capability of a host "polling" messages very fast and between ability of capturing packets over the air.
    The WiLink have a packet ram that stores the packets and waits for the host to poll them

    Once this pool is full, the STA won't send ACK to the peer, slowing the link speed (retries), until there will be room

  • 0 in reply to Elad Raz92038
    Prodigy 120 points

    Hello Elad,

    Thank you for your explanation.

    Is it possible to know the size of this WiLink internal packet ram?

    Thank you in advance.

  • 0 in reply to FS
    TI__Genius 12935 points

    Hi FS,

    1. Yes, short guard interval (400ns) is supported for MCS8~15
    2. I'm not certain about this issue, but the experimented data rate at 40Mhz SISO for both bands can continuously be above 110Mbps when tested inside a chamber

    Update: I just checked the data rate for SDIO. The max data rate is actually 200Mbps, so this shouldn't be the bottleneck. (source: http://en.wikipedia.org/wiki/MultiMediaCard#Table)

  • 0 in reply to Victor_Lin
    Prodigy 120 points

    Hi Victor,

    Thank you for your reply and update.

    Regarding 2: yes in fact I made a gross mistake: the highest SDIO limit is 104MBytes/s (not bits) and it's when the clock frequency is 200Mhz. 

    Assuming that WiLink8 clock freq is 50Mhz, the theoretical limit is indeed 200Mbits/s . There is thus room for even the MCS 7 higher rate of 150Mbits /s.

    This is also probably the reason why you said 40Mhz channel is not supported in 2x2MIMO: the higher rates would exceed 200Mbits/s.

    Sorry for my mistkae, and thanks again.