Re: use of radiotap bit 14?

Johannes Berg <[email protected]> Thu, 19 Jun 2008 20:41:17 +0200

Newsgroups	org.netbsd.radiotap
Message-ID	<[email protected]>

> > I propose to add two new presence bits, 29 and 30.
> [...]
> 
> I'm trying to capture this with examples here:
> http://www.radiotap.org/Discussion/Vendor-Extensions
> 
> Look there in a bit.

Done. While writing that, I noticed that it is not strictly required to
reserve two bits in every it_present field and added the following under
a "Discussion" headline:

There is no need to reserve two bits in every it_present bitmap if one
is willing to expend slightly more space for vendor namespaces: Say the
reset bit is 30 instead of 29 and vendor-namespace is a regular
free-running bit number (e.g. 20) that is reserved in every namespace.
Then, to switch into a vendor namespace, you first reset the radiotap
namespace to 0 using flagbit 30 and then switch to the vendor namespace
using a normal field (e.g. 20).

johannes

signature.asc (application/pgp-signature, 836 B)