From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path:
On Wed, Apr 12, 2017 at 10:33 AM, Toke H=C3=B8iland-J=C3=B8rg= ensen <toke@toke.dk> wrote:
> Matias Richart <mrichart@fi= ng.edu.uy> writes:
>
>> Hi to all! I occasionally follow the wifi-fast list and I have jus= t
>> found this initiative.
>> I've been working with ns3 rate control for several years and = I would
>> also like to contribute if there is an ns3 approach.
>
> Awesome! Welcome :)
Hi Pasquale and Matias, it's great to see some new names on the = list! :)
One thought: Since we're doing simulation, would it be poss= ible to
>>> And is there a concept "retry chains" for the rate s= election
>>> algorithm (where a sequence of rates to try are picked at once= when a
>>> decision is made)?
>>
>> It exists an implementation of Minstrel and Minstrel HT, which use= s
>> the concept of retry chains, but this is implemented in the same >> algorithm, not as part of the MAC layer.
>>
>> In summary, we can simulate the retry chain behavior. Currently, t= here
>> are functional implementations of Minstrel and Minstrel HT which I=
>> think work well.
>
> Right, excellent. The retry chain and the inability to re-calculate al= l
> probabilities for every packet are some pretty hard constraints on rea= l
> hardware, so having simulation work in a similar way is most likely
> quite central for carrying over the simulation results to a Linux
> implementation.
>
>>>I think the two main things we are trying to figure out are the=
>>>correlations between different rates. Which involves answering<= br> >>>questions like:
>>>
>>>1. What correlations exist between the success probabilities of= sending
>>>=C2=A0 =C2=A0at different rates. I.e., can we always assume tha= t if a
>>> transmission
>>>=C2=A0 =C2=A0fails at a low rate (more robust encoding), it wou= ld also have
>>>=C2=A0 =C2=A0failed at a higher rate (or conversely, if it succ= eeds at a high
>>>=C2=A0 =C2=A0rate, it would also have succeeded at the lower ra= te). Does this
>>> hold
>>>=C2=A0 =C2=A0within the same MIMO configuration? What about bet= ween different
>>> MIMO
>>>=C2=A0 =C2=A0configurations?
>>
>> In my opinion, this is quite easy to implement. I'm thinking o= n an
>> experiment with an static deployment and testing all possible rate= s.
>
> Yes, that was my thought as well, and I figure this is easier to do in=
> simulation.
compute the packet success probability of every rate, for every
packet? I mean so that we get to know the "counterfactual": "= ;Our
algorithm chose MCS-13, which according to simulation had a success
probability of 0.5 for this specific transmission, but according to
the simulation MCS-15 had a success probability of 0.7 *for this same
transmission*"? Then we could calculate correlations and regret and
similar very easily...
/Bj=C3=B6rn