Chapter 3 - Troubleshooting
Situation C: The modem always returns «No carrier» when trying to issue a communication
Solutions for “no carrier” message
If the modem |
| Then ask … |
| Action |
returns … |
|
|
|
|
no carrier(esp. for |
| Is the selected |
| Type AT+CEER to view the extended error code |
data communi- |
| bearer type |
| (see “Extended Error Report (+CEER) in the AT |
cation) |
| supported by the |
| Command guide). |
|
| called party? |
| Be sure that the selected bearer type is supported |
|
|
|
| |
|
| Is the selected |
| by the called party. |
|
| bearer type |
| Be sure that the selected bearer type is supported |
|
| supported by the |
| |
|
|
| by the network. | |
|
| network? |
| |
|
|
|
| |
|
|
|
| If no success, try bearer selection type: |
|
|
|
| AT+CBST=0,0,3 |
|
|
|
| |
If the modem |
| Then ask … | Action | |
returns |
|
|
|
|
|
|
|
|
|
no carrier |
|
|
| Be sure that the semicolon character (“;”) is typed |
(esp. for voice |
|
| immediately after the phone number in the AT | |
|
| command; e.g., ATD######; | ||
|
|
|
| type AT+CBST=0,0,3 |
|
|
|
|
|
|
| Is the received |
| See “Signal Strength Verification”. |
|
| signal strong |
|
|
|
| enough? |
|
|
|
| Is the antenna |
| See “Antenna/RF Specifications”. |
|
| properly |
|
|
|
| connected? |
|
|
19 |