Reception failure indication by legacy message

摘要

A first radio device receives a first radio transmission from a second radio device. In response to reception of the first radio transmission by the first radio device being unsuccessful, the first radio device sends a second radio transmission to the second radio device. The second radio transmission comprises an indication to the second radio device that reception of the first radio transmission by the first radio device was unsuccessful. The first radio device generates the second radio transmission to be decodable by one or more other radio devices than the second radio device as comprising a positive acknowledgement message, indicating to the second radio device that reception of the first radio transmission by the first radio device was successful, as comprising a clear-to-send message to the second radio device, or as some other legacy message supported by the other radio device(s).