SSB

SSB (single sideband) is a mode where the carrier and one sideband of the AM mode has been suppressed. Whether using USB (upper sideband) or LSB  (lower sideband) more of the transmitter’s signal is focused in the sideband used as compared to AM. As a result the signal travels farther and is easier to copy under many unfavourable conditions. SSB is the phone mode of choice for Amateurs on the HF bands.