Aspects of the disclosure provide a method for observed time difference of arrival (OTDOA) positioning. The method can include receiving from a serving cell of a first network assistance data for measuring time difference of arrival of positioning reference signals (PRSs) received from a plurality of neighboring cells of a second network, receiving from the serving cell a gap pattern for decoding a master information block (MIB) of a first neighboring cell of the plurality of neighboring cells, or a system frame number (SFN) offset of the first neighboring cell, and determining an SFN timing of the first neighboring cell based on the gap pattern for decoding the MIB of the first neighboring cell or the SFN offset of the first neighboring cell.