Re: [nwcrg] [dtn] Network Coding and SATCOM - call for review

[Marie-Jose Montpetit <[e-mail]>]

Yes this is a study done a few years ago.

Marie-José Montpetit
[e-mail]
[e-mail]

> On Nov 13, 2018, at 6:35 PM, Lloyd Wood <[e-mail]> wrote:
> 
> Likely relevant to this draft:
> 
> 
> Can network coding bridge the digital divide in the Pacific?, Spiedel et al.,
> International Symposium on Network Coding (NetCod), Sydney, June 2015.
> 
> 
> http://arxiv.org/abs/1506.01048
> http://dx.doi.org/10.1109/NETCOD.2015.7176795
> https://internetnz.nz/sites/default/files/IR201404%20-%20University%20of%20Auckland%20-%20FINAL%20REPORT%20April%202015.pdf
> https://conference.apnic.net/data/41/apricot-talk_1451964216_1456023873.pdf
> 
> My take from years of using a very large number of TCP accelerators across satellite
> links is that:
> 
> - the performance benefits from the local file/stream/chunk/'object' rapid fetch
>  from Internet side and cached delivery that they offer for the satellite link
>  will far outweigh benefits of network coding across the path and its virtual
>  'erasure channel' for responsiveness, but that's hard to see from a throughput
>  graph.
> 
> 
> - the over-satellite-link FEC feature offered is rarely that useful in practice,
>  as channel coding makes it largely redundant. If the PEP accelerator FEC becomes
> 
>  useful, the channel coding needs to be adjusted for the SNR, and that's often
> 
>  a local ACM problem, e.g. heavy rain fade at Ka-band, which the O3b example used
>  in the paper suffers from.
> 
> - there's a whole bunch of tuning of traffic for the offered satellite link
>  capacity (QoS, prioritisation, shaping, etc) brought to the table by PEPs
>  that network coding cannot consider. Sometimes this gets called 'Orchestration',
>  though that means different things to different communities.
> 
> 
> oh, draft typo: writting->writing. Haven't had the time to reread
> and think about the whole draft revision yet.
> 
> L.
> 
> Lloyd Wood [e-mail] http://about.me/lloydwood
> 
> 
> 
> ________________________________