A cell transmits synchronization signal blocks (SSB) to a user equipment (UE) for the UE to synchronize with the cell. The cell configures a discovery reference signal (DRS) window for synchronization signal block (SSB) transmission to a user equipment (UE), determines that a channel in an unlicensed spectrum is not occupied and transmits multiple SSBs to the UE in response to determining that the channel in the unlicensed spectrum is not occupied.