Certain aspects of the present disclosure provide techniques and apparatus for managing transmit power in a television white space (TVWS) network. One example method generally includes transmitting a sequence of request-to-send (RTS) messages at different transmit power levels to an apparatus and determining if a clear-to-send (CTS) message was received in response to at least one of the RTS messages corresponding to a particular one of the transmit power levels. Another example method generally includes receiving, at a first apparatus from a second apparatus, a packet that cannot be decoded by the first apparatus; determining at least one of a time or a duration corresponding to the packet; transmitting a query with an indication of the at least one of the time or the duration; and receiving a message from the second apparatus in response to the query, the message identifying the second apparatus as a source of the packet.