Modem is no longer reachable from the Internet

IoT Modules General wireless topics
1

We observe that after some time (~2 days) the Q2698 modems are not reachable by their ip address.

When we connect via serial line our application is running and reports:

SIM card full init. Sim registered, home network, IP Status connected.

When i issue at!gstatus it responds with:

at!gstatus?

!GSTATUS: 
Current Time:  257573		Temperature: 49
Bootup Time:   130918		Mode:        ONLINE         
System mode:   WCDMA      	PS state:    Attached     
WCDMA band:    WCDMA 2100 	GSM band:    GSM900     
WCDMA channel: 10588		GSM channel: 57
GMM (PS) state:REGISTERED     	NORMAL SERVICE 
MM (CS) state: IDLE           	NORMAL SERVICE 
WCDMA L1 State:L1M_DCH        	RRC State:   CELL_DCH       
RX level (dBm):-96
OK

Why would it connect to GSM ?

I issued to following commands, then the sim state changed to not registered ME currently searching. However it is not recovering the connection.

at!gstatus for the second time

at!gstatus?
at!gstatus?

!GSTATUS: 
Current Time:  260871		Temperature: 50
Bootup Time:   130918		Mode:        ONLINE         
System mode:   WCDMA      	PS state:    Attached     
WCDMA band:    WCDMA 2100 	GSM band:    GSM900     
WCDMA channel: 10588		GSM channel: 57
GMM (PS) state:REGISTERED     	NORMAL SERVICE 
MM (CS) state: IDLE           	NORMAL SERVICE 
WCDMA L1 State:L1M_DCH        	RRC State:   CELL_DCH       
RX level (dBm):-95

What i can see from this is, that the modem is no longer registered and the error +CEER: Error 235 means: PDP unsuccessful activation causes NWK reject.

What does that mean?

I think it means:

The modem got rejected after 2 days because it was supposed to do something or react to something from the network, but did not.

PDP = Packet data protocol
NWK = Network

What can i do to ensure my modems do not get kicked out of the network?

Is this the networks fault?

Our electrical engineer is threatening to cut the power to the boards when they missbehave.

Our code works as follows:

Modulestart:
adl_simSubscribe(sim_Handler, _setup.PinCode);

on ADL_SIM_EVENT_FULL_INIT
wip_bearerOpen(&wipGprsHandle, "GPRS", ipgprs_Bearer_Handler, 0);

then the module is ready for IP communicaton.

The ipgprs_Bearer_Handler

on Error:
wip_bearerStop(wipGprsHandle);
on WIP_BEV_STOPPED:
wip_bearerStart(wipGprsHandle);

“Developer Studio\0” “2.3.1.201305211544-R11859\0”
“Open AT Application Framework package\0” “2.52.0.A1.201307221109\0”
“Open AT OS Package\0” “6.52.0.A1.201306271522\0”
“Firmware Package\0” “7.52.0.A1.201307191706\0”
“Internet Library Package\0” “5.56.0.A1.201307011505\0”
“Location Library Package\0” “1.4.6.201305151408\0”
“\0”;
[/quote]

2

Hiya,

I’ve had similar problems on the Q2686 when they repeatedly move in and out of poor reception areas.

Try not just doing a bearer stop, but completely stopping the WIP stack as well. Then do a complete stack restart (i.e. check for sim, wait for creg etc).

I’ve also had some limited success forcing a disconnect from the network (+COPS), then reconnecting and restarting the stack.

Sadly, the only foolproof way I’ve found to clean up after the disconnect is to reset the modem (at+cfun=1).

ciao, Dave