OLPC hardware: what if there was an SDR modem / chipset?

Luke Kenneth Casson Leighton lkcl at lkcl.net
Tue Jan 26 09:13:03 EST 2010

On Tue, Jan 26, 2010 at 1:29 PM, John Watlington <wad at laptop.org> wrote:
> On Jan 26, 2010, at 6:46 PM, Luke Kenneth Casson Leighton wrote:
>> (and i also specifically mentioned the gnu-radio project resources as
>> being one option.  there are a _lot_ of people who would be
>> _extremely_ happy to not have to spend $750 on a USRP in order to do
>> free software development gnu-radio.)
> That's nice, but OLPC does not exist to provide development
> platforms for hackers.  We exist to provide high quality laptops
> at cost to kids in the developing world.

 ... and would part of reducing the cost of that high quality laptop
involve, say, replacing a proprietary licensed firmware blob with a
zero-cost free software-only firmware blob?   but this part is
speculation - let's leave the "free software" option out of the
equation for now (particularly in light of the requirement for
world-wide re-certification of said free software firmware blob).

>>> Re certifications, on both XO-1 and XO-1.5 we
>>> use slightly non-standard modules (on XO-1 to
>>> support 802.11s, on XO-1.5 to reduce power
>>> consumption by 50%) and have paid the full
>>> certification costs.   They run about 100K$ for
>>> starters, with each additional country adding
>>> around 5K$.
>>  ok.   interesting to know.  ridiculously high, but important to know.
>>  and, given that they _are_ non-standard, such that the full
>> certification costs would have to be paid, that means that you're "in
>> the game" already for paying such up-front certification costs if
>> there was a ready-made off-the-shelf SDR modem kicking around.
> High, but not ridiculously, given the cost of the equipment and staff
> required for certification.    However, you are missing a crucial point
> about SDR.
> See http://lwn.net/Articles/240840/
> in particular, the comment at http://lwn.net/Articles/240921/

 interesting.  something has to give, there.  or, particularly
irritatingly, i have to help create a "locked" solution.  i wonder if
the OLPC potential would help break down the door?

 another thing for me to investigate.  rather important one, so thank
you for bringing it to my attention.

> (pulling in Luke's comments from a previous email:)
>>  ... did you have to sign an NDA in order to get the firmware, and can
>> the 88W8686 be reprogrammed by anyone?  if i want to write my own
>> peer-to-peer 802.11 algorithms, doing an implementation e.g. of the
>> Babel routing algorithm to run actually on the WIFI chip itself, can i
>> do so, right now, _without_ being forced to sign a Marvell NDA?
> As the previous links point out, getting certified for sale and meeting
> your desires are mutually exclusive at the current time.


>>  * what's the current price;
>>  * what's the current power budget (given that 802.11 is 100mW max or
>> 400mW max in Hong Kong)
> I can't release the current price, but it is lower than $9.

 ok.  good enough.

> The current 8686 SD WLAN module pulls about 400 mW
> (peak, total on all supplies) when operating.   The power numbers
> you are quoting are RF output power --- I am talking about
> how much power must be supplied to the module for operation.

 yep.  i understand.

>> *  the USRP from ettus research ($750 and made of discrete components)
>> *  the lyrtech SDR developer kit (again, discrete components)
> These are not consumer products certified for sale, they are
> development boards.

 that's correct.  i did say you wouldn't be happy with the answer :)
the two chips i've found: they're it.  they're the options, found
after about two months of research.

>   If I can't certify it for sale in every
> country in the world, I can't use it in an XO.   Read the above links,

 willdo.  thank you.


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