SIM900 cannot detect/connect to carrier/network

[M84AB1]

Hi guys,

I have now been trying for more than a week to get this GPRS Shield v1.0 module working but without luck. As the heading suggests the module is simply not able to see/detect my carrier. Carrier of question here is TPG (Optus network) in Australia, but my sim900 based module is not able to see any carrier other than VicTrack (50516). I will give you a run down of AT commands so am hoping that someone can point me in the right direction.

SIM Status

AT+CPIN?

+CPIN: READY

OK

Signal Strength (marginal)

AT+CSQ

+CSQ: 10,0

OK

Registration Status (not registered but is searching, UTRAN used as access technology)

AT+CREG?

+CREG: 2,2

OK

Mobile Operating Band (I have tried all of the available operating bands but only EGSM_DCS_MODE and DCS_MODE,ALL_BAND see to work)

AT+CBAND?

+CBAND: DCS_MODE,ALL_BAND

OK

Available carriers(no matter what I try this is the only carrier I see. I have gone through every available band by using AT+CBAND="" command and my module does not appear to see any other carrier, why is this!?!)

AT+cops=?

+COPS: (3,"","","50516"),,(0,1,4),(0,1,2)

OK

If anyone knows why my module only sees this one carrier and only accepts two bands (EGSM & DCS) please let me know. Maybe I am missing some additional config. Having said that the SIM card works as that is the card I use in day to day phone.

 

[ARQuattr]

Have you set the access point name, using AT+CSTT ?

 

[M84AB1]

Hi ARQuattr,

thanks for the response. No I have not set the APN, as a matter of fact I have not even used that AT command yet. Am currently at work and will check it out when I get home. Having said that, I thought APN was relevant to tcp/ip data?

Maybe I am not aware of it, but how does it relate to SMS and standard calling using this GPRS Shield module?