In a first antenna mode in a multi-antenna port radio access node, a set of logical antenna ports and its associated resource elements are mapped to a first set of physical antenna ports. Each physical antenna port comprises at least one power amplifier. Switching from first antenna mode to a second antenna mode is initiated upon receipt of information triggering antenna mode switching at a first point of time. During a time interval from the first point of time to a second point of time, the logical antenna ports are re-mapped to a second set of physical antenna ports. At the second point of time, at the end of the time interval, the antenna mode is switched to a second antenna mode by changing supply of power to each physical antenna port represented in the first set of physical antenna ports but not in the second set of antenna ports.