Allocation schemes are provided for one or more portions of time during a data transmission time interval for contention by personal coordination points, access points and client devices to perform transmit sector sweep operations. In addition, a personal coordination point determines whether the set of channels universally agreed to be free by nearby synchronization access points is empty and selects any channel in the frequency band to initiate a Basic Service Set or continue operation of an existing Basic Service Set if it is determined that no channel in the frequency band is free among the channels that are universally agreed to be free.