[HL6528] Multiple PDP Context Switch

Hello everyone,

I need a dual SIM GSM/GPRS module for my application and I was thinking of the HL6528 module.
Since I need both the SIM to be registered on the network and use the GPRS data transmission on different APNs, I was wondering if the dual sim / dual standby implementation would be able to satisfy my requirements.
As far as I have read from the user guides, in order to poll the tcp buffer the active SIM has to be enabled by AT commands.

The ideal workflow would be:

  • GPRS Attach + PDP context activation on SIM 1;
  • switch to SIM2;
  • GPRS Attach + PDP context activation on SIM 2;
    (in an endless loop):
  • switch to SIM1
  • check if SIM1 has GPRS data incoming -> answer back
  • switch to SIM2
  • check if SIM2 has GPRS data incoming -> answer back

Sorry if the question may sound trivial, but I have never used GSM/GPRS modules before.

yes, this is the sequence to be followed.

You can refer http://source.sierrawireless.com/resources/airprime/application_notes_and_code_samples/airprime_hl6528x_dual_sim_dual_standby_application_note/


Hi alex,

I see. So the module will handle the double settings by itself, right?
Of course I will have to handle connection losses due to lengthy requests/call, but what knowing that I can have two GPRS connections and two different IPs is what I needed.

Thanks for your help.