[Ns-developers] EDCA and WifiRemoteStation

[Mirko Banchi]

Mathieu Lacage ha scritto:
> On Sun, 2009-05-24 at 20:09 +0200, Mirko Banchi wrote:
>> Mathieu Lacage ha scritto:
>>> On Wed, 2009-05-20 at 17:39 +0200, Ramon Bauza wrote:
>>>> Hello,
>>>>
>>>> I would like to tell you something I have observed regarding the EDCA
>>>> mechanism and the WifiRemoteStation. I have realized that different packets
>>>> addressed to the same peer station contending for the medium at the same
>>>> time but enqueued in different AC queues share the same WifiRemoteStation.
>>>> This means that these packets share also the same m_slrc and m_ssrc
>>>> variables. Therefore, when an ACK is not received for a transmitted packet,
>>>> the common m_slrc variable would be incremented causing a reduction of the
>>>> transmission opportunities for the rest of the packets (destinated for the
>>>> same station but enqued in different AC queues).  Am I right about my
>>>> observation? If am not wrong, m_slrc and m_ssrc variables should be
>>> I think that you are right.
>>>
>>>> considered per packet and not per peer station.
>>> Well, they are both per packet and per peer station. I don't have any
>>> bright idea on how to fix this problem for now.
>>>
>>> regards,
>>> Mathieu
>>>
>>>
>> I agree. Maybe we could add a parameter to
>> WifiRemoteStation::ReportDataFailed in order to specify the access class
>> which the m_currentPacket belongs.
> 
> that sounds like a good idea. Will it work with HCCA ?
> 

HCCA uses a different range of values for TIDs: allowed values are 8-15.
We would map those TIDs to different access classes so it should work.

Mirko

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Mirko Banchi

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