Techniques for managing re-contention on a shared communication medium are disclosed. In order to facilitate re-contending for access to the communication medium, an access point may adjust one or more uplink transmission parameters associated with a triggering condition for invoking a contention timer. In addition or as an alternative, the access point may mute transmission on the communication medium during one or more symbol periods designated for transmission. In addition or as an alternative, the access point may configure a timing advance to create a re-contention gap.