pfctl on wireless interfaces

[jdta]

I'm running tests on a few congestion control schemes which use pfctl to
activate the respective queue controller. This works fine on interfaces
with a fixed capacity as altq sets up the respective queue taking the
bandwidth into consideration. On wireless interfaces however this
capacity varies over time. an so altq's use of the declared capacity is
overly optimistic (in my case, 54Mbps). This results in pfctl not
queueing packets until this capacity has been met: the packets are
queued at the interface as pfctl has no indication of the varying signal
level.

Is there anyway of either extracting the queue level directly from the
interface card or, alternatively, forcing altq to take into
consideration the signal level at any given time? The first seems more
plausible, but I'm not really sure if the second would have other uses
(priority queueing etc).

Thanks in advance.