Radio coexistence mechanism for variable data rate radio links

A device has a radio transmitter for a first radio link such as a Bluetooth link, having a coexistence controller arranged to communicate with a co-located other radio transmitter for another radio link, to enable both radio links to use potentially conflicting transmission frequencies. A link monitor monitors the first radio link, according to an output from the coexistence controller. By making the link monitor dependent on the coexistence controller, it can distinguish between transmission losses caused by the coexistence interface, and those caused by other effects, to reduce the risk of a data rate controller unnecessarily reducing a transmission rate if transmission losses caused by the coexistence control are misinterpreted as a drop in link quality.