Which Cisco technology improves the signal quality for clients at the edge of a cell by optimizing beamforming?

CleanAir is Cisco's spectrum intelligence technology that detects, classifies, and mitigates non-802.11 RF interference sources using dedicated spectrum sensors - it has no beamforming function.

ClientLink is a Cisco proprietary technology that applies transmit beamforming by adjusting the phase and amplitude of signals across multiple antenna elements to steer the RF beam toward a specific client device. This improves RSSI and SNR for edge clients without requiring the client device itself to support any special beamforming protocol, making it universally applicable to legacy clients.

FastLane is a Cisco QoS feature that prioritizes Wi-Fi traffic for Apple iOS devices by leveraging 802.11r and 802.11k capabilities, unrelated to beamforming or signal strength optimization.

FlexConnect is a deployment mode that allows branch-office APs to locally switch client traffic when the WAN link to the controller is unavailable, with no relation to beamforming or signal quality.