SARA-R42 - Application note
UBX-20050829 - R02
PSM, eDRX and deep-sleep mode
Page 28 of 58
C1-Public
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All other values are to be interpreted as multiples of 1 minute.
Example: "
000
00100" = 4
x 2 s
= 8 s
8.1.3
PSM and roaming
When the module is registered on a roaming network (not a home network), and the default
“Automatic network selection” mode is enabled by the
+COPS
AT command, then the module will
periodically search for a HPMLN (Home Public Land Mobile Network). HPLMN searches cause the
module to exit PSM and delay PSM entry until the search is completed. If the device is roaming in
“Manual network selection” mode
, there are no HPLMN searches to impact the PSM feature.
8.1.4
Example of usage of PSM
Persistent settings
Command
Response
Description
AT+CFUN=0
OK
De-register the module.
AT+CEDRXS=0,4
OK
Disable eDRX in E-UTRAN (WB-S1 mode).
AT+UPSMR=1
OK
Enable the +UUPSMR diagnostic URC.
AT+CSCON=1
OK
CSCON diagnostic URC.
AT+CPSMS=1,,,"00111000"
,"00001010"
OK
Enable PSM deep-sleep mode and set the desired timer values
(T3412(ext)=24 hours and T3324=20 s in the example).
AT+CFUN=15
OK
Reboot the module to apply the configuration.
AT+UPSMVER?
+UPSMVER:4,3,3,4,0
OK
Make sure the +UPSMVER AT command is set to its default
value where PSM with context retention feature is enabled,
otherwise enable it and start from the beginning.
AT+CPSMS?
+CPSMS:1,,,"00111000","
00001010"
OK
Check the +CPSMS AT command settings.
AT+CLCK="SC",2
+CLCK: 0
OK
Make sure SIM PIN check is disabled, otherwise disable it and
start from the beginning.
Volatile settings
Command
Response
Description
AT+CEREG=4
OK
Enable the +CEREG URC with extended syntax to report
negotiated PSM timer values. If issued in full functionality, the
current status shall be queried via the +CEREG read command.
PSM in normal mode
Command
Response
Description
+CSCON: 1
During LTE attach, the module is in RRC connected state.
+CEREG: 1,"1","0","1",7,
,,"00001010","00111001"
During successful LTE attach PSM negotiation is performed.
The
+CEREG
URC reports the PSM timer values assigned by the
network, if any (T3324=20 s and T3412(ext)=25 hours in this
case).
AT+CEREG?
+CEREG: 4,1,"1","0","1",
7,,,"00001010","00111001
"
OK
Same information will be returned by querying the +CEREG AT
command.
AT+UCPSMS?
+UCPSMS: 1,,,"00111001"
,"00001010",1
OK
The network assigned PSM settings are returned also by the
proprUCPSMS AT command, which provides the
information whether PSM has been granted or not
(
+UCPSMS:0)
and the granted PSM timer values in case it has
been granted.
