We have several devices using GPRS to send back small data packets (80 bytes) every 10 minutes to a CGI web server. Generally they work well, but we regularly get disconnected, with no data transmitted. Looking at the debug info it fails to establish the GPRS bearer. Once this happens, it very rarely reconnects without removing the SIM from the modem, inserting in a phone, then replacing. This isn’t easy, as the devices are mounting in buoys in a harbour 180 miles away…
We’ve tried various suppliers, all having the same problem, but currently are using Vodafone mobile broadband SIMs. After discussion with vodafone engineers, we’ve found that once we lose our GPRS bearing, having the SIM banned from the network and then un-banned brings it back to life - this is done at the network end.
Is there something we could be doing wrong that’s kicking us off the GPRS network, or any way of ‘virtually’ banning and unbanning from the modem end so we can re-establish our GPRS bearer?
The devices are only on for a minute at a time - just long enough to gather and transmit the information. Is there a minimum time period allowed before the network start to have issues?
Maybe we’re missing a command when we establish connection and this is causing a problem?
Any help or suggestions would be very much appreciated.