A first access node obtains (601) an identity of a plurality of MRSs associated with the first access node, determines (602) an identity of a second mobility beam associated with a second access node, which second mobility beam is a neighbour mobility beam to a first mobility beam associated with the first access node, wherein the identity of the second mobility beam is determined based on a neighbour relation between the second mobility beam and the first mobility beam, and controls the transmission of MRSs by transmitting (605), to the second access node, a request to transmit a reference signal for mobility comprised in the plurality of MRSs, on the second mobility beam, and wherein the request comprises: a respective identity of one or more MRSs comprised in the plurality of MRSs, which respective identity is based on the identity of the plurality of MRSs, and the identity of the second mobility beam.