SARA-R4/N4 series - AT Commands Manual
UBX-17003787 - R09
7 Network service
Page 43 of 307
Parameter
Type
Description
•
255: not known or not detectable
<rsrp>
Number
Reference Signal Received Power (RSRP):
•
0: -141 dBm or less
•
1..96: from -140 dBm to -45 dBm with 1 dBm steps
•
97: -44 dBm or greater
•
255: not known or not detectable
7.4 Operator selCOPS
+COPS
SARA-R404M SARA-R410M-01B SARA-R410M-02B SARA-R410M-52B SARA-R412M
Modules
SARA-N4
Syntax
PIN required
Settings saved Can be aborted
Response time Error reference
Attributes
partial
No
Yes
7.4.1 Description
Forces an attempt to select and register with the GSM/LTE network operator, that can be chosen in the list of
network operators returned by the test command, that triggers a PLMN scan on all supported bands. Through
<mode> parameter the network selection can automatically be performed or forced by this command: the
access technology is indicated in <AcT> parameter (where supported).
In manual PLMN selection mode, if the optional <AcT> parameter is not specified, the modules will select
the default access technology with the following priority order: LTE and GSM (not supported technologies
will be ignored).
u-blox cellular modules are certified according to all the capabilities and options stated in the Protocol
Implementation Conformance Statement document (PICS) of the module. The PICS, according to 3GPP
TS 51.010-2 [
], 3GPP TS 34.121-2 [
], 3GPP TS 36.521-2 [
] and 3GPP TS 36.523-2 [
], is a statement
of the implemented and supported capabilities and options of a device. If the user changes the command
settings during the certification process, the PICS of the application device integrating a u-blox cellular
module must be changed accordingly.
To be able to exploit all command functionalities, the SIM card verification is required. The command is
accessible also without an inserted SIM. In this case the command AT+COPS=0 always returns an error result
code because the network registration cannot be performed without the SIM, while the configuration (i.e.
automatic registration) is correctly set. The set value can be checked with the command AT+COPS? or by
verifying the active profile with
command if supported (parameter <format> is then also visible).
The set command handling depends on the <mode> parameter value:
•
<mode>=0 and <mode>=1
: the AT command setting is immediately stored in the current activated profile.
If the MT is set in automatic selection mode (<mode>= 0), only the mode will be saved. If the MT is set in
manual mode (<mode>= 1), also the format (<format>) and operator (<oper>) will be stored in the profile.
•
<mode>=4
: the module starts a manual selection of the specified operator; if this operation is not
successful, the module will start an automatic network selection and will remain in automatic mode.
If the set command with <mode>=0 is issued, a further set command with <mode>=0 is managed as a user
reselection (see the 3GPP TS 23.122 [
]), i.e. the module triggers a search for the HPLMN or a higher order
PLMN. This is useful when roaming in areas where the HPLMN or a higher order PLMN is available. If no HPLMN
or higher order PLMN is found, the module remains in the state it was in prior to the search (e.g. camped and/
or registered on the PLMN before the search).
The PLMN search cannot be performed in RRC connected state when the RAT is 3G or 4G, hence no PLMN list
will be returned at the end of the PLMN scan attempt.
The manual PLMN selection can fail due to the MNO control on the network selection procedure via EF
CSP
setting; for further details see
The user should not enter colliding requests (e.g. AT+COPS=0 and AT+COPS=2) on different
communication ports, because this might cause interoperability issues in case overlapping registration
and deregistration requests are not handled by the network, and could result in an unpredictable
registration state. Similarly, when notified of a GPRS mobile terminated detach event (e.g. via +CGEV