Re: [Make-wifi-fast] [Cerowrt-devel] [tsvwg] Comments on draft-szigeti-tsvwg-ieee-802-11e

[Jonathan Morton <chromatix99@gmail.com>]

[-- Attachment #1: Type: text/plain, Size: 868 bytes --]

The only mandatory form of aggregation in 'n' is of the one-checksum type,
even though other types are permitted.  The overhead at the data layer is
slightly less, and checksum failure handling on receive is simpler (just
throw the whole thing out and nak it), as is handling the nak at the
transmitter (just retransmit the whole aggregate at the next opportunity).
Most 'n' hardware thus caters only to this lowest common denominator.

I'm not sure whether soft-MAC type hardware (like ath9k) can also support
the more flexible type via driver support - I would hope so - but hard-MAC
hardware almost certainly can't be retrofitted in this way.

However, since 'ac' hardware is required to support individual-checksum
aggregation, a dual-band 'ac' card running on 2.4 GHz will effectively be
an 'n' card with such support, even if it's a hard-MAC.

- Jonathan Morton

[-- Attachment #2: Type: text/html, Size: 999 bytes --]