In one embodiment, a sender in a frequency hopping wireless network classifies a message as a large message to be fragmented into a plurality of packets for transmission to a receiver, and in response, indicates to the receiver that the message is a large message to request use of an orthogonal frequency hopping sequence between the sender and receiver for the duration of the large message transmission, the orthogonal frequency hopping sequence orthogonal to a shared frequency hopping sequence of the wireless network. Thereafter, the sender transmits the large message to the receiver on the orthogonal frequency hopping sequence, and returns to the shared frequency hopping sequence upon completion. In another embodiment, the receiver receives the indication that a message is a large message (requesting use of the orthogonal frequency hopping sequence). If the receiver can comply, the large message is received on the orthogonal frequency hopping sequence.