Note that like reference numerals refer to corresponding parts throughout the drawings. Moreover, multiple instances of the same part are designated by a common prefix separated from an instance number by a dash.

A radio node that dynamically adjusts a transmit time of instances of keep-alive messages to a computer is described. During operation, the radio node may provide, at a transmit time during a first time interval corresponding to a first instance of a transmit expire time, a first instance of a keep-alive message to the computer, where a given instance of the keep-alive message requests authorization to transmit in a granted portion of a spectrum. Then, the radio node may receive, at a receive time prior to the first instance of a transmit expire time, an instance of a keep-alive response from the computer, where the instance of the keep-alive response authorizes the radio node to transmit in the granted portion of the spectrum until a second (subsequent) instance of the transmit expire time has elapsed. Moreover, the radio node may determine, based at least in part on the receive time and the first instance of the transmit expire time, an updated transmit time, where the updated transmit time is temporally offset relative to a transmit time during a second time window corresponding to the second instance of the transmit expire time. Next, the radio node may provide, at the updated transmit time, which is prior to the second instance of the transmit expire time, a second instance of the keep-alive message addressed to the computer.