Specifications

Chapter 8 – Network Service Commands
Multi-Tech Systems, Inc. AT Commands for EDGE Modems (S000371B) 96
8.4 AT+CREG Network Registration
Description: The AT+CREG command serves to verify the network registration status of the ME. For this
purpose two types of URCs are available.
The AT+CREG read command returns the URC presentation mode <n> and an integer <stat>
that shows the registration status of the ME. The location information elements <lac> and <ci>
are returned only when <n>=2 and ME is registered to the network.
Test Command Syntax: AT+CREG=?
Response(s): +CREG: (list of supported<n>s)
OK
Read Command Synatx: AT+CREG?
Response(s): +CREG: <n>, <stat>[, <lac>, <ci>]
OK
ERROR
+CME ERROR: <err>
Write Command Syntax: AT+CREG=[<n>]
Response(s): OK
ERROR
+CME ERROR: <err>
Unsolicited Result Codes:
URC 1
If <n>=1 and there is a change in the ME network registration status:
+CREG: <stat>
URC 2
If <n>=2 and there is a change in the ME network registration status or a change of the network cell:
+CREG: <stat>[, <lac>, <ci>]
Parameter Descriptions:
<n>
0 Disable +CREG URC. Default.
1 Enable URC +CREG:<stat> to report status of network registration
2 Enable URC +CREG:<stat>[,<lac>,<ci>] to report status of network registration including location
information. Optional parameters <lac> and <ci> will not display during calls or if these values
have not changed since last AT+CREG read command or since last indication by +CREG URC.
<stat>
0 Not registered. ME is currently not searching for new operator.
Normally, status 0 occurs temporarily between two network search phases (Status 2). However,
if it persists, one of the following reasons may apply:
• Automatic network selection is active, but probably there is:
∗ No SIM card available
∗ No PIN entered
∗ No valid Home PLMN entry found on the SIM
• Manual network selection is active, and the selected network is available, but login fails due
to one of the following reasons:
∗ #11 ... PLMN not allowed
∗ #12 ... Location area not allowed
∗ #13 ... Roaming not allowed in this location area
In either case, user intervention is required. Yet, emergency calls can be made if any network is
available.
1 Registered to home network
2 Not registered, but ME is currently searching for a new operator.
The ME searches for an available network. Failure to log in until after more than a minute may be
due to one of the following causes:
• No network available or insufficient Rx level.
• The ME has no access rights to the networks available.
• Networks from the SIM list of allowed networks are around, but login fails due to one of the
following reasons:
∗ #11 ... PLMN not allowed
∗ #12 ... Location area not allowed
∗ #13 ... Roaming not allowed in this location area
After this, the search will be resumed (if automatic network search is enabled).
• The Home PLMN or an allowed PLMN is available, but login is rejected by the cell (reasons:
Access Class or LAC).
If at least one network is available, emergency calls can be made.