NB-IOT MAC Rach 过程求解惑

woshiwojia

If no RandomAccess Response is received within the RA Response window, or if none of allreceived Random Access Responses contains a Random Access Preamble identifiercorresponding to the transmitted Random Access Preamble, the Random AccessResponse reception is considered not successful and the MAC entity shall:

-     if the notification of power ramping suspension hasnot been received from lower layers:

     -          increment PREAMBLE_TRANSMISSION_COUNTER by 1;

-     if the UE is an NB-IoT UE, a BL UEor a UE in enhanced coverage:

-        ifPREAMBLE_TRANSMISSION_COUNTER = preambleTransMax-CE+ 1:

-            if the Random Access Preamble is transmitted on the SpCell:

-                   indicate a Random Access problem to upper layers;

-             if NB-IoT:

-                consider the RandomAccess procedure unsuccessfully completed;

3gpp 36.321 chapter 5.1.4

疑问： power ramping suspension什么时候物理层会发给MAC ？