A special form of ISDB-T and ISDB-TB is the 1-segment mode, which is used specially for mobile reception by means of handhelds. The narrow spectrum permits the reception of TV and audio content at low energy consumption levels.
The channel is split into 13 sub-bands (segments). The 13 segments in the OFDM spectrum can be combined to create segment groups called "layers." For a narrowband receiver that can receive programs only at a lower quality (for example, mobile terminal equipment), each layer will contain only one segment. This segment is always placed in the center of the 6 MHz channel and can easily be received as a result of its position and its width of about 429 kHz. However, it is still a complete receive signal.