EM7455 SMS over IMS

in technical specifications says:
• Mobile-originated and mobile-terminated SMS over IMS for LTE
• Mobile-originated and mobile-terminated SMS over SGs for LTE

however there is no documented AT command to enable/disable IMS.

Sierra, any comments?


So the firmware is capable of doing this but it is all wrapped up in operator configuration. The unit was developed when IMS’s were not common. To get it to work (assuming IMS is enabled on the unit which is a factory setting) you need to set a CID (at+cgdcont) to the IMS’s APN, typically this is ‘ims’ and then point the firmware at it, example below

at$qcpdpimscfge=2,1,0,0 //Set the IMS stack to use CID 2

I have tested this in the WP76, not an MC, hopefully it will work.



at$qcpdpimscfge works and IMS set to CID
however “IMS reg state: No Srv


Current Time: 880 Temperature: 24
Reset Counter: 5 Mode: ONLINE
System mode: LTE PS state: Attached
LTE band: B20 LTE bw: 10 MHz
LTE Rx chan: 6300 LTE Tx chan: 24300
EMM state: Registered Normal Service
RRC state: RRC Connected
IMS reg state: No Srv

PCC RxM RSSI: -71 RSRP (dBm): -105
PCC RxD RSSI: -98 RSRP (dBm): -140
Tx Power: – TAC: 020B (523)
RSRQ (dB): -15.6 Cell ID: 013F2D08 (20917512)
SINR (dB): -3.6


What network is this? Do they definitely have an IMS and you have the right APN? Last Q why do you explicitly want to send SMS through the IMS? It can go via other channels (which the unit will probably choose anyway). After that there effectively no use for it with regards the MC as it is a data only product.