User guide

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