What leads to ECL escalation in nRF91 NBIoT?

[jing]

My understanding is that when the module's measured RSRP is lower than that defined in the broadcasted SIB, ECL will be escalated to higher level during RACH process.

Besides RSRP, will a poor measured SINR lead to ECL escalation?

 Also, if there are consecutive RA failures during RACH process, will this lead to ECL escalation too?

 Other than the RSRP/SINR/RACH failures mentioned above, is there any other factors that will cause ECL escalation?

jing

[Øyvind]

Hello Jing, 

Here is the answer I got from our R&D team:

Different CE levels if configured by NW are in SIB2. Initial CE level is determined based on the measured RSRP and the threhold for CE levels from SIB2 parameters. In addition based on SIB2 parameters CE level may be increased if RACH attempt count is exceeded for that particular CE level. This is described in 3GPP spec 36.321 clause 5.1.1 for initial CE level selection and in clause 5.1.4 for CE level ramping incase of unsuccesfull RACH attempt.

In addition network may instruct UE to use a particular CE level directly via a PDCCH order.

Kind regards,
Øyvind