A method and apparatus for medium access control in a wireless ad hoc network is disclosed that takes advantage of physical layer properties to jointly and collectively optimize in a distributed fashion transmission parameters such as beam-patterns and transmit powers of all active links in the network. To resolve signal transmission contention, each potential link is associated with a persistence parameter and the persistence parameter is adapted locally, with no central control, to provide medium access for transmissions. Where a node contending for a transmission slot is unable to optimize its transmission parameters due to an invalidity condition or infeasibility condition, the persistence parameter is updated, preferably so as to reduce the probability of such conditions.