To carry more information bits, the enhanced NB IoT WUS in Alt.1 can be extended to the multi-stages sequences based power saving signal as shown in Figure 10. To avoide ambiguity of different stages sequence caused by overlaping of WUS, the stage indication information should be transmitted along with the base sequence, e.g., as the cover code. Furthermore, the orthognality of base sequencess is not essential for multistage sequences if sequence mulptiplexing capacity is not required to be very large at a time.