Thank you very much John for the explanation and all the help. :) G'day. On Tue, Jul 10, 2012 at 9:33 AM, John Watlington <[email protected]> wrote:
> > NANDBlaster uses a fixed transmit speed (modulation). > If the signal budget for a laptop isn't sufficient to support > that speed, it will fail to receive many packets. > > When using normal WiFi, the transmit speed (modulation) > is decreased until reliable communication can be obtained --- > therefore a laptop with decreased signal budget (e.g. bad antenna) > may still work, although with degraded performance. > > Regards, > John > > On Jul 9, 2012, at 11:10 PM, James Cameron wrote: > > > That the antenna change did not work shows the problem is in the > > wireless card. > > > > You asked why not use the same mechanism as Sugar? > > > > Consider the transmitter performance. > > > > Your network used by Sugar probably has an access point with higher > > transmit power and better antenna than the laptop being used as > > NANDblaster sender. > > > > So it is perhaps the combination of small damage to one laptop and > > large damage to another laptop, that causes NANDblaster to fail. But > > the combination of good access point and large damage causes Sugar > > networking to be successful. > > > > See http://wiki.laptop.org/go/Antenna_testing#Link_Budget for a > > calculation of wireless success, to see what variables are important. > > > > Does Sugar in ad-hoc wireless mode work between the two laptops? Or > > Sugar in mesh wireless mode with no other laptops nearby? > > > > If so, that's very interesting. > > > > Open Firmware and Linux use different commands sent to the wireless card. > > > > I've checked, and we are using the same wireless firmware 5.110.22.p23 > > in both Open Firmware and Linux (build 883). > > > > Daniel, do you know of any commands that the Linux kernel may have > > sent to the card that may improve signal, even by accident? > > > > On Mon, Jul 09, 2012 at 04:06:16PM +0545, Roshan Karki wrote: > >> I tried with antenna change but as you told, didn't work. So I think > this is > >> the dead end. Thank you for your help. But one question I wonder is in > Sugar I > >> can use very poor network very well. Why not use the same mechanism in > OFW as > >> well? > >> > >> On Fri, Jul 6, 2012 at 10:41 AM, James Cameron <[email protected]> > wrote: > >> > >> G'day, > >> > >> Thanks for the photographs. There's nothing wrong that I can see > >> either. > >> > >> Repair may attempt antenna change, but it is unlikely to be fixed > with > >> only antenna change. > >> > >> Perhaps the radio module has been damaged. On XO-1 the module is > >> soldered down and is impractical to replace. In later models > (XO-1.5, > >> XO-1.75) the module is in a socket. > >> > >> -- > >> James Cameron > >> http://quozl.linux.org.au/ > >> > >> > > > > -- > > James Cameron > > http://quozl.linux.org.au/ > > _______________________________________________ > > Devel mailing list > > [email protected] > > http://lists.laptop.org/listinfo/devel > >
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