In one embodiment, a transmitter in a communication network receives an indication of active transmission times of a receiver to which the transmitter attempts to reach with first transmissions, the active transmission times indicating respective times of second transmissions initiated by the receiver. Based on determining when the first transmissions occur, the transmitter may then compute a link reliability metric for a link from the transmitter to the receiver by excluding one or more of the first transmissions from the indicated active transmission times of the second transmissions. In one embodiment, the active transmission times are in the past and the reliability metric excludes any first transmissions in the past during those times, while in another embodiment the active transmission times are scheduled in the future and the reliability metric does not include any first transmissions since the first transmissions may be scheduled to avoid the active transmission times.