Also, we have a requirement for the antenna to be low-gain, omnidirectional because we don't know where the towers are. So most of what we transmit is lost. LW
On Sep 20, 2013, at 9:09 PM, "Chris de Morsella" <[email protected]> wrote: > T > > From: [email protected] > [mailto:[email protected]] On Behalf Of L.W. Sterritt > Sent: Friday, September 20, 2013 8:09 PM > To: [email protected] > Cc: L.W. Sterritt > Subject: Re: What gives philosophers a bad name? > > Chris, Brent and meekerdb, > While we have been considering optimizing the efficiency of circuitry and > software, we neglected that while talking on the smartphone, 1/2 of the total > power budget goes to radiation from the smartphone antenna - about 2 Watts as > I remember. That will drain a typical smartphone battery in less than 3 > hours, and there is not a lot we can do about it, except use the phone for > all of it's other functions and don't talk too much! > LWSterritt > > Good point… where is the energy usage going. A lot goes into the displays as > well and into Blue Tooth and GPS. > Wouldn’t vastly increasing the number of base stations (very small scale base > stations) and concurrently lowering the network signal strengths needed lower > the total system wide energy requirements of a cellular system; including of > course transmission strengths. > Also I am not certain that nothing can be done to improve antenna performance > itself. One way would be to accept the hit and use a lower powered lower > fidelity antenna and then improve the signal by algorithmic means achieving a > similar level of quality of service. In this instance I am suggesting that > software could be used to process a low energy, weak & noisy signal and that > the overall energy required would still be less than that required by the > better signal produced by a higher powered antenna that requires no dsp layer. > > > On Sep 20, 2013, at 5:24 PM, meekerdb <[email protected]> wrote: > > > On 9/20/2013 4:40 PM, Chris de Morsella wrote: > Current software is very energy efficient -- and on so many levels. I worked > developing code used in the Windows Smartphone and it was during that time > that I had to first think hard about the energy efficiency dimension in > computing -- as measured by useful work done per unit of energy. The > engineering management in that group was constantly harping on the need to > produce energy efficient code. > > Programmers are deeply engrained with a lot of bad habits -- and not only in > terms of producing energy efficient software. For example most developers > will instinctively grab large chunks of resources -- in order to ensure that > their processes are not starved of resources in some kind of peak scenario. > While this may be good for the application -- when measured by itself -- it > is bad for the overall footprint of the application on the device (bloat) > and for the energy requirements that that software will impose on the > hardware. Another example of a common bad practice poorly written > synchronization code (or synchronized containers). > > These bad practices (anti-patterns in the jargon) can not only have a huge > impact on performance in peak usage scenarios, but also act to increase the > energy requirements for that software to run. > > I think that -- with a lot of programming effort of course (which is why it > will never happen) that the current code base, and not only in the mobile > small device space, where it is clearly important, but in datacenter scale > applications and service (exposed) applications as well -- that the energy > efficiency of software has a huge headroom for improvement. But in order for > this to happen there has to first be a profound cultural change amongst > software developers who are being driven by speed to market, and other > draconian economic and marketing imperatives and are producing code under > these types od deadlines and constraints. > > There's a lot of bad design in consumer electronics, particularly in user > interfaces, because the pressure is to get more and newer features and apps. > Eventually (maybe already) this will slow down and designers will start to > pay more attention to refining the stuff already there. > > > > If there is a theoretical minimum that derives from the second law of > thermodynamics it must be exceedingly far below what the current practical > minimums are for actual real world computing systems. And I do not see how a > minimum can be determined without reference to the physical medium in which > the computing system being measured is implemented. > > It is determined by the temperature of the environment in which entropy must > be dumped in order to execute irreversible operations (like erasing a bit). > But you're right that current practicle minimums are very far above the > Landauer limit and so it has not effect on current design practice. The > current practice is limited by heat dissipation and battery capacity. > > > > In fact how could a switch be implemented without it being implemented in > some medium that contains the switch? > > The way to completely avoid Landauer's limit is to make all operations > reversible, never lose any information so that the whole calculation could be > reversed. Then there's no entropy dumped to the environment and Landauer's > limit doesn't apply. > > Brent > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/everything-list. > For more options, visit https://groups.google.com/groups/opt_out. > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/everything-list. > For more options, visit https://groups.google.com/groups/opt_out. > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/everything-list. > For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups "Everything List" group. 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