def send_cts(self, cts, rts):
"""Additional processing for outgoing CTS.
:param cts: Outgoing CTS packet.
:param rts: Received RTS packet.
This method uses the 'phy-sinr' annotation to apply the rate adaptation
algorithm used by `RBAR`.
"""
DCF.send_cts(self, cts, rts)
errmsg = "[RBAR]: Invalid RTS! No RAI found in send_cts()!"
assert rts.haslayer(RAI), errmsg
errmsg = "[RBAR]: Invalid CTS! No RAI found in send_cts()!"
assert cts.haslayer(RAI), errmsg
errmsg = "[RBAR]: Cannot find 'phy-sinr' annotation in send_cts()!"
assert rts.hasanno('phy-sinr'), errmsg
# extract info from RTS+RAI
sinr = rts.getanno('phy-sinr')
newrate = self.calcrate(sinr)
cts[RAI].rate = newrate
cts[RAI].length = rts[RAI].length
