Hi Everyone,
Sorry if this is the wrong place to post it. I'm working on the implementation of a MAC+PHY layer protocol which requires me to be able to change the timing of RTS/CTS and ACK packets(for example delay the DATA packet by 1 slot time instead of SIFS after a CTS is received).
I tried this with the madwifi driver but found out it is not possible to dictate the transmission of control packets from the driver.
From my understanding, these packets are transmitted by the firmware/hardware (I'm not sure which).
Is there a way to do this in using openwrt or by modifying it?

thanks in advance for any help.

You are talking in MAC/PHY level of access....
With openwrt or any other firmware, you wont
be able to do it because not a single chip manufacturer
give access to that info unless you sign a NDA..

Openwrt has some functions to play with ACK, but
(they are there) not working .......

Atheros released only binary file of the MAC/PHY
driver to open source community.....

Thanks Nathan! Will see what I can do with openhal..

can MAC layer be modified by modifying the source code of OpenWRT

On Broadcom-based devices most of the MAC layer is handled by the firmware which is loaded on the wireless card during boot. You can try a 2.6 kernel, the b43 driver and the open source BCM firmware, you should be able to do it.
You can find the open firmware and documentation about it at http://www.ing.unibs.it/openfwwf/