Method for identifying pre-candidate cells for a mobile unit operating with a switched beam antenna in a wireless communication system, and corresponding system

A wireless communication system comprising:

• an active set of cells;
• a non-active set of cells;
• and
• a wireless transmit/receive unit (WTRU) comprising
• a switched beam antenna for generating antenna beams including a plurality of directional beams and an omni-directional beam, an antenna beam being selected for exchanging data with one or more cells in the active set of cells,
• a transceiver connected to said switched beam antenna for receiving signals from cells-not in the active set of cells using the selected antenna beam,
• a measuring unit connected to said transceiver for measuring the received signals from each cell not in the active set of cells for the selected antenna beam, and
• a controller for comparing the measured signals to an add pre-candidate set threshold, and adding the corresponding cells to a pre-candidate set of cells based upon the comparison, and ranking the cells in the pre-candidate set of cells based upon a level of their measured signals,
• said transceiver also receiving signals from N of the top-ranked cells in the pre-candidate set of cells using the omni-directional beam and the selected antenna beam, with N being greater than or equal to 1,
• said measuring unit also measuring the received signals from each of the N cells for the omni-directional beam and the selected antenna beam, and
• said controller also comparing the measured signals to an add candidate set threshold, and moving the corresponding cells from the pre-candidate set of cells to the candidate set of cells based upon the comparison to the add candidate set threshold, and sending a measurement report to the network.