 repeti- tion is to transmit more energy: a repetition of 2 theoretically gives a better coverage of 3 dB, and a repetition of 10 gives 10 dB. The maximum allowed repetition depends on the mode and channel type. Mode A allows a maximum of 32 repetitions for the PDSCH and PUSCH, while Mode B allows up to 2048 repetitions for those data chan- nels. The selection between Mode A and B is controlled by eNodeB according to the UE measurements. In general, a UE is kept in Mode A unless it is experiencing very poor coverage. Other Cat-M solutions for improving coverage are frequency hopping, multi- subframe channel estimation, and dynamic frequency domain scheduling. Fre- quency hopping means that the UE can hop from one narrowband to another for frequency diversity gain. Multi-subframe channel estimation refers to the case where the UE stays in one narrowband for a fixed amount of time prior to hopping. Dynamic frequency domain scheduling means that a UE can be scheduled in any narrowband location. The instantaneous peak rate with Cat-M is 1 Mbps, while the sustained peak rate is lower. A full-duplex UE can receive in eight subframes out of 10 ms since the maximum number of HARQ processes is 8. That gives a peak rate of 800 kbps. The half-duplex UE data rate is lower because simultaneous uplink and downlink is not supported. The half-duplex peak rate in the downlink is 300 kbps. The corresponding peak rates in the uplink are 1 Mbps with full duplex and 375 kbps with half duplex. The downlink transmission timing is shown in Figure 14.5 and the peak rates in Table 14.4. Figure 14.4 Possible Cat-M locations within 10 MHz LTE carrier. 10 MHz 8 possible 50 PRBs Cat-M locations 14.4 Narrowband-loT Full duplex Control 10 ms Half duplex Control 10 ms Figure 14.5 Full-duplex and half-duplex transmissions (DCI=Downlink Control Information). Table 14.4 Cat-M peak data rates. Downlink Uplink Instantaneous peak 1 Mbps 1 Mbps Sustained peak rate with full duplex 800 kbps 1 Mbps Sustained peak rate with half duplex 300 kbps 375 kbps 3