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Re: 2.0 and Radio Impacts/battery efficiency

From: Zhong Yu <zhong.j.yu@gmail.com>
Date: Thu, 12 Apr 2012 10:23:42 -0500
Message-ID: <CACuKZqGA9Tyv_zhO2HhyLNvqvzNCrTyZYy+b_Tt616F7eLbT1w@mail.gmail.com>
To: Salvatore Loreto <salvatore.loreto@ericsson.com>
Cc: HTTP Working Group <ietf-http-wg@w3.org>
I don't get it. Cerntainly a new connection requires an extra round
trip which drains extra power, but only for the duration of the round
trip. Why is it "extremely expensive"?

The article says

    "Every time you create a new network connection, the radio
transitions to the full power state."

which I don't think implies that,

    "If you reuse a network connection, the radio does NOT necessarily
transition to the full power state."

To compress all network activities(including FIN-FIN) into a shorter
time span, the article event suggests that

    "so it's also good practice to close your connections when they
aren't in use"


On Thu, Apr 12, 2012 at 3:52 AM, Salvatore Loreto
<salvatore.loreto@ericsson.com> wrote:
> Hi there,
>
> here a good read about "Optimizing Downloads for Efficient Network Access"
> http://developer.android.com/training/efficient-downloads/efficient-network-access.html
>
> the major points are
>
> 1) reducing the number of connections is a MUST as each new network
> connection is extremely expensive
> from a Radio/Battery prospective
>
> It is also worth to add that the server-initiated closing of  idle
> connection is also something to avoid.
> So if the client keeps the connection open longer, then the specification
> has to mandate servers to keep
> the connection open for very long.
>
>
> 2) the ping frequency is also very important:
> "An app that pings the server every 20 seconds, just to acknowledge that the
> app is running and visible to the user, will keep the radio powered on
> indefinitely"
>
>
> 3) also Prefetching data need some consideration from the radio prospective
> as Prefetching data (on a wireless connection)
>  may cost money but for sure has a cost from a battery prospective
>
>
> cheers
> Sal
>
> --
> Salvatore Loreto, PhD
> www.sloreto.com
Received on Thursday, 12 April 2012 15:24:17 GMT

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