PH8 network selection with roamed network | Telit Cinterion IoT Developer Community
November 25, 2016 - 9:21am, 2143 views
I have many devices with PH8 FW 03.320.
All are suffering from network selection issue with roamed networks.Everything is okay when I'm using regular SIM cards from homeland operators.
But when I'm using SIM cards from roamers operators, the PH8 is always changing from one roamed network to another one (about every minute), doing +CREG 5 (PLMN A), +CREG 2, +CREG 5 (PLMN B), +CREG 2, +CREG 5 (PLMN C), +CREG 2, +CREG 5 (PLMN A) ... and so on.
It is not possible to attach a roamed network and stay on it.
Added Note: Requesting AT+CREG? makes the modem attach correctly for about 10 to 20 minutes, but switches networks again after that.
Could you write some more about the problem?
Is it the same with more than one foreign SIM card and more than one module?
Have you tested in one place only? How about the signal quality are there any problems?
The network selection behaviour could depend on the local conditions like poor signal or the roaming operator or the preferred operator lists configuration (AT+CPOL and AT+CPLS commands).
It seems that this was due to an incomming AT+COPS=0 whereas the ****m is already in COPS+0 ****.
This causes the re-selection.
If already attached and in **** COPS=0, a new AT+COPS=0 shouldn't lead to a "re-selection". Maybe a rescan, but it shouldn't leave an attached network. This seems to happen only if currently attached network is a roamed network.
I asked the company designing that device to remove the additionals COPS=0.
So this was the source of the problem. According to the AT commands specification the AT+COPS write command forces an attempt to select and register to a network operator. In case of home network it will always register to the same network but in case of roaming it can register to different networks.