A method, performed in a first access point arranged to communicate with one or more wireless devices (10a, 10b) of a first Basic Service Set, BSS through information streams that are created using multiple co-located antennas, for evaluation of a channel estimate of a channel between the first access point and a first wireless device of the one or more wireless devices of the first BSS, the method comprising: - transmitting or receiving (S1b) a packet, to or from, the first wireless device, wherein the packet is transmitted using a precoder determined using the channel estimate; - retrieving information about possibly interfering transmissions between one or more further access points and respective one or more second wireless devices (10c, 10d) associated with respective one or more further BSSs (BSS2, BSS3) in the vicinity of the first access point, wherein the information comprises location information related to the respective possibly interfering transmissions and timing information related to the respective possibly interfering transmissions; - determining spatial separations between the transmission of the packet and the possibly interfering transmissions from the retrieved information; - evaluating the channel estimate, based on at least the determined spatial separations, to decide whether a measured interference associated with the transmission or reception of the packet is attributable to interference originating within the first BSS or whether the measured interference associated with the transmission or reception of the packet is attributable to interference originating from one or more of the one or more further BSSs (BSS2, BSS3), wherein the evaluation comprises determining whether a small spatial separation between the transmission or reception of the packet and other transmissions in a vicinity of the access point coincides with a high measured interference; - determining, based on the evaluation of the channel estimate, whether a sounding sequence is to be transmitted. - transmitting or receiving (S1b) a packet, to or from, the first wireless device, wherein the packet is transmitted using a precoder determined using the channel estimate; - retrieving information about possibly interfering transmissions between one or more further access points and respective one or more second wireless devices (10c, 10d) associated with respective one or more further BSSs (BSS2, BSS3) in the vicinity of the first access point, wherein the information comprises location information related to the respective possibly interfering transmissions and timing information related to the respective possibly interfering transmissions; - determining spatial separations between the transmission of the packet and the possibly interfering transmissions from the retrieved information; - evaluating the channel estimate, based on at least the determined spatial separations, to decide whether a measured interference associated with the transmission or reception of the packet is attributable to interference originating within the first BSS or whether the measured interference associated with the transmission or reception of the packet is attributable to interference originating from one or more of the one or more further BSSs (BSS2, BSS3), wherein the evaluation comprises determining whether a small spatial separation between the transmission or reception of the packet and other transmissions in a vicinity of the access point coincides with a high measured interference; - determining, based on the evaluation of the channel estimate, whether a sounding sequence is to be transmitted.