[Cerowrt-devel] [bufferbloat-fcc-discuss] arstechnica confirms tp-link router lockdown

[David Lang]

On Sun, 13 Mar 2016, Adrian Chadd wrote:

> You do that in hardware. Do the Mac, phy and RF in hardware.
>
> This is what the qca hardware does.

unfortunantly, that's not what the existing chipsets do.

So unless you can create a new chipset, you can't just change what's done in 
hardware.

David Lang

> a
> On Mar 13, 2016 5:25 PM, "David Lang" <david at lang.hm> wrote:
>
>> On Sat, 12 Mar 2016, Adrian Chadd wrote:
>>
>> On 12 March 2016 at 11:14, Henning Rogge <hrogge at gmail.com> wrote:
>>>
>>>> On Sat, Mar 12, 2016 at 3:32 PM, Wayne Workman
>>>> <wayne.workman2012 at gmail.com> wrote:
>>>>
>>>>> I understand that Broadcom was paid to develop the Pi, a totally free
>>>>> board.
>>>>>
>>>>> And they already make wireless chipsets.
>>>>>
>>>>
>>>> The question is how easy would it be to build a modern 802.11ac
>>>> halfmac chip... the amount of work these chips do (especially with 3*3
>>>> or 4*4 MIMO) is not trivial.
>>>>
>>>
>>> It's not that scary - most of the latency sensitive things are:
>>>
>>> * channel change - eg background scans
>>> * calibration related things - but most slow calibration could be done
>>> via firmware commands, like the intel chips do!
>>> * transmit a-mpdu / retransmit
>>> * transmit rate control adaptation
>>> * receiving / block-ack things - which is mostly done in hardware anyway
>>> * likely some power save transition-y things too
>>>
>>
>> you are ignoring MU-MIMO, the ability to transmit different signals from
>> each antenna so that the interference patterns from the different signals
>> result in different readable data depending on where the receiver is in
>> relation to the access point is not a trivial thing.
>>
>> But it's one of the most valuable features in the spec.
>>
>> David Lang
>>
>