Troubleshooting handover mobility on LTE Band 1

IoT Modules MC/EM Series
#1

Hello,

We have installed several EM7455 to provide in-train wifi. Each device is connected to one specific band. We noticed, through RAN counters, that the device connected to LTE2100 band (B1) is performing very poorly in terms of handover success rate (from LTE2100 to LTE2100), which is around 50%.

We are troubleshooting this issue, checking with standard phones if those handovers go through correctly, but that’s difficult to do as the LTE2100 coverage within the train is rather weak. From RAN counters though, we reckon the handover success rate is > 90% for normal users.

My question : is it possible to query the EM7455 about its HO activity (RACH attempts, specifically) ?
Is it possible to collect RRC messages and RACH information ? How could I verify that an HO is occuring , or if it was replaced by a RRC Reestablishment, as we suspect.

Thanks a lot for your help,

Best Regards

#2

You would typically need to run Qualcomm tools to capture air interface messages to confirm network/mobile interaction and behaviour. Any “current” network registration status can be polled using AT!GSTATUS command. Beyond that we would suggest contact your technical support channel who can advise you on appropriate message mask/Filter for your test case scenario to use to capture DM logs which can be passed on for analysis to confirm network/mobile interaction pertaining to the handoff behaviour you maybe seeing.