Schemes to time-align transmissions from multiple base stations to a
terminal. To achieve time-alignment, differences between the arrival
times of transmissions from the base stations, as observed at the
terminal, are determined and provided to the system and used to adjust
the timing at the base stations such that terminal-specific radio frames
arrive at the terminal within a particular time window. In one scheme, a
time difference between two base stations is partitioned into a
frame-level time difference and a chip-level time difference. Whenever
requested to perform and report time difference measurements, the
terminal measures the chip-level timing for each candidate base station
relative to a reference base station. Additionally, the terminal also
measures the frame-level timing and includes this information in the time
difference measurement only if required. Otherwise, the terminal sets the
frame-level part to a predetermined value (e.g., zero).