This disclosure provides methods, devices and systems for synchronizing an end of an exchange of frames during a transmission opportunity (TXOP) with a target synchronization time using a synchronization short inter-frame space (SynSIFS) before a transmission by a wireless communication device that controls the medium. The wireless communication device obtains control of the medium for the TXOP by completing a CCA procedure. An exchange of frames during the TXOP includes transmissions from the wireless communication device and responses from other devices while the wireless communication device controls the medium. A duration of the SynSIFS may be adjustable at a microsecond granularity. Accordingly, the wireless communication device may select a duration of the SynSIFS that allows alignment of the end of the exchange with the target synchronization time. The wireless communication device also may adjust a number of symbols in the transmission from the wireless communication device.