A method can include, in a wireless device connected to a first network and configured to transmit over a medium, while a detected packet is being received: determining if the detected packet has a network identification value, the network identification value identifying a network in which wireless devices are connected; when at least the network identification value of the detected packet matches that of the first network, setting a timer value that prevents transmissions on the medium by the wireless device during the duration of the detected packet; and when at least the network identification value of the detected packet does not match that of the first network, dropping the detected packet before it is fully received and not setting the timer value.