WOLF (Weak-signal Operation on Low Frequency) is a proposed new signal format and protocol designed specifically for the LF bands. It can be used for beacons and for two way communication.

Unlike existing formats, which are optimized for a particular S/N (and corresponding speed), WOLF can operate over a wide range of signal levels. For example, a WOLF beacon transmits a 15-character message repeatedly.

If the received signal would be adequate for conventional CW, copy will be displayed in 24 seconds. At a level barely enough for 0.4 WPM QRSS, copy will appear within two minutes. Even if the signal is another 10 dB weaker, the message can still be received. It will take from 20 minutes to several hours, depending on the stability of the Tx and Rx. Of course, it is also necessary that the propagation path remain open over the required interval.