Re: [Bloat] DSLReports Speed Test has latency measurement built-in

[Sebastian Moeller <moeller0@gmx.de>]

Hi Toke,


On May 6, 2015, at 22:43 , Toke Høiland-Jørgensen <toke@toke.dk> wrote:

> Jonathan Morton <chromatix99@gmail.com> writes:
> 
>> Compare these totals to twice the ITU benchmark figures, rate
>> accordingly, and plot on a map.
> 
> A nice way of visualising this can be 'radius of reach within n
> milliseconds'. Or, 'number of people reachable within n ms'. This paper
> uses that (or something very similar) to visualise the benefits of
> speed-of-light internet:
> http://web.engr.illinois.edu/~singla2/papers/hotnets14.pdf
> 
> That same paper uses 30 ms as an 'instant response' number, btw, citing
> this: http://plato.stanford.edu/entries/consciousness-temporal/empirical-findings.html

	This number does not mean what the authors of that paper think it does (assuming that my interpretation is correct)… they at least should have read their reference 7 in full. Yes 30ms will count as instantaneous, but it s far from the upper threshold.
To illustrate, the reference basically shows that if two successive events are spaced further than 30 ms apart they will be (most likely) interpreted as two distinct events instead of one event with a temporal extent. To relate to networks, if one would send successive frames of video without buffering these 30ms would be the time permissible for transmission and presentation of successive frames without people perceiving glitches or a slide show (you would think, but motion perception would still be of odd movement). 
	BUT if we think about the related phenomenon of flicker-fusion frequency it becomes clear that this might well depend on the actual stimuli and the surround luminosity. I think no one is proposing to under buffer so severely that gaps >= 30ms occur, so this number seems not too relevant in my eyes. 
	I think the more relevant question is what delay between an action and the response will people tolerate and find acceptable. I guess I should do a little literature research.

Best Regards
	Sebastian

> 
> -Toke
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