LTE-BL/CE (LTE-M1) - Location in Frequency Domain
I understood that LTE-M1 scheduling can be a little complicated than legacy LTE because eNB has to take into consideration of repetative transmission, half duplex etc but I thought the frequency domain scheduling would not be that difficult. I just thought .. once we set a Narrowband index at the beginning of the attach all the communication would use the same Narrowband Index throughout all the transmission and reception. However, what I noticed as I dig more into LTE-M1, I learned that frequency domain scheduling is not simpler at all. In some sense, it looks more complicated than the time domain resource allocation.
So I decided to summarize how the frequency domain resource is determined for each Downlink and Uplink transmission. It can be illustrated as follows.
Most of these steps required pretty much detailed descriptions for you to get clear understanding. I put down additional links for each of these steps for your reference.
Step (B) : SIB1-BR Information Element Details
Step (D) : SIB2 Information Element Details
Step (E) : DCI Format 6-1A
Step (F) : RACH Response (RAR)
Step (G) : RACH Response (RAR)
Step (H) : DCI Format 6-1A
Step (I) : SIB2 Information Element Details
Step (J) : RRC Connection Setup
Step (K) : RRC Connection Setup
Step (L) : DCI Format 6-1A
Step (M) : RRC Connection Setup
Step (N) : RRC Connection Setup
 3GPP TS 36.211 V13.2.0 (2016-06)