A network node device of a communication network comprises physical (PHY) layer circuity configured to transmit and receive data packets via a communication network; and processing circuitry connected to the PHY layer circuitry. The processing circuitry is configured to encode a data packet for sending according to a first communication protocol for sending to a second network node during a specified communication time slot, initiate resending of the data packet when the second network node does not respond during a specified acknowledge time slot, and encode the data packet according to a second communication protocol for sending to the second network node for a last retry attempt of a finite number of retry attempts, wherein the time to send the data packet formatted in the second communication protocol extends into the specified acknowledge time slot.