Sector sweeps are described for establishing two-way data communications with directional antennas. Some examples receive a sequence of base station transmit sector sweep signals from a base station (BS) at the UE, each signal being transmitted to a different transmit sector from a multiple antenna array of the BS, select a best transmitted signal at the UE from among the received signals, send a sequence of UE transmit sector sweep signals to the base station from the UE, each signal being transmitted to a different transmit sector from a multiple antenna array of the UE, send an identification of the selected best base station transmit sector sweep signal to the base station, receive an identification of a selected best UE transmit sector sweep signal from the base station, and send data to the BS using the identified best UE transmit sector.