Physical Uplink Control Channel (PUCCH) PUCCH for Cat-M only occupies 2 PRBs. Physical Uplink Shared Channel (PUSCH) Used for Cat-M data transmission with appropriate bandwidth. However, it is still possible to allocate the MPDCCH and PDSCH in the same subframe but to different UEs. In this case, two PRBs are allocated for the MPDCCH, and the remaining four RBs are allocated for the PDSCH. The possible locations of Cat-M within the 10 MHz LTE carrier are illustrated in Figure 14.4. There are a total of eight possible locations, each of which has six PRBs, called narrowband (NB) locations. The first and the last resource blocks cannot be used by Cat-M allocations. A Cat-M UE is instructed as to which NB location is to be used in the SIB. The information indicates the index of the narrowband MPDCCH location. A similar structure is also defined for the other LTE bandwidths: 20 MHz LTE has correspondingly 16 NB locations, and 5 MHz has 4 locations. Cat-M includes two modes of coverage enhancements: Mode A. A small amount of repetition or no repetition, full mobility support, and VoLTE support. Operation in coverage enhancement Mode A would have an equiva- lent coverage as that of a Category 1 UE. The difference in coverage between LTE-M and a Category 1 UE lies in the fact that LTE-M uses only 1 Rx, 6 PRB narrow- band transmission, and reduced uplink transmit power. The reduced uplink power in LTE-M is compensated by utilizing repetition coding. 14 Internet of Things Optimization Mode B. This mode uses large repetitions and has limited mobility support. There are up to 15 dB coverage enhancements. The transmission power for both the Physical Uplink Control Channel (PUCCH) and Physical Uplink Shared Channel (PUSCH) is set to be MAX. Since the power does not change (i.e. no power control is performed) DCI formats 6-0B and 6-1B do not carry a transmission power control field. This mode is designed to be used in very poor propagation conditions. Repetition is the main solution for coverage enhancements. The target of the