Dual SIM

Some Series 40 devices with Java Runtime 1.0.0 for Series 40 or newer support dual-SIM functionality. Dual-SIM devices have two SIM card slots: SIM1 for the default SIM under the battery and SIM2 for the swappable SIM. Users can use the dual-SIM functionality to:

Switch between multiple SIMs to take advantage of different service offers
Use multiple SIMs to ensure network coverage in areas without fully developed coverage
Switch off their employer-provided SIM while not at work

Note: If the swappable SIM is swapped while a MIDlet is running, the MIDlet is exited. If the MIDlet is backgroundable, it is sent to the background instead.

Note: This feature is not supported in Nokia SDK for Java.

SIM selection prompts

In a MIDlet, the user is prompted to select which SIM to use once per session for each type of communication request (call operation, network access, messaging). The prompt is shown at the first request to use a particular type of communication. There are typically one or two SIM selection prompts per session.

If a device has only one SIM inserted (SIM1), the device functions as a single-SIM device and SIM selection prompts are not shown.

Prompting for SIM selection depends on the Preferred SIM value in the SIM Manager. Some devices may have separate Preferred SIM selections for different types of communication, for example, for SMS and MMS. Preferred SIM can have the following values:

**Table:** Possible values for Preferred SIM
Value	Description
Ask every time	The user is prompted every time the device is used for outgoing communication. This is the default value.
SIM1	SIM1 is set as the preferred SIM.
SIM2	SIM2 is set as the preferred SIM.

Figure: Preferred SIM selection

Figure: SIM selection for making a call

System properties

Dual-SIM devices support the following additional system properties:

com.nokia.multisim.cellid.sim1 and com.nokia.multisim.cellid.sim2
com.nokia.multisim.lac.sim1 and com.nokia.multisim.lac.sim2
com.nokia.multisim.mnc.sim1 and com.nokia.multisim.mnc.sim2
com.nokia.multisim.networkavailability.sim1 and com.nokia.multisim.networkavailability.sim2
com.nokia.multisim.networkid.sim1 and com.nokia.multisim.networkid.sim2
com.nokia.multisim.networksignal.sim1 and com.nokia.multisim.networksignal.sim2
com.nokia.multisim.networkstatus.sim1 and com.nokia.multisim.networkstatus.sim2

The following table describes the behavior of certain pre-existing single-SIM system properties when they are used in a MIDlet run on a dual-SIM device.

**Table:** Return values for pre-existing system properties on dual-SIM devices
System property	Return value (depending on listed factors)
Number of SIMs inserted	1 (SIM1)	2	2	2	2
Preferred SIM	N/A	"Ask every time" for all	SIM2 for SMS, "Ask every time" for others	SIM2 for all	"Ask every time" for all
MIDlet has already established a connection, which triggered a SIM selection prompt	N/A	No	No	No	Yes, SIM1 was selected
`com.nokia.mid.cellid`	Value from SIM1	`null`	`null`	Value from SIM2	Value from SIM1
`com.nokia.mid.countrycode`	Value from SIM1	`null`	`null`	Value from SIM2	Value from SIM1
`com.nokia.mid.imsi`	Value from SIM1	`null`	`null`	Value from SIM2	Value from SIM1
`com.nokia.mid.lac`	Value from SIM1	`null`	`null`	Value from SIM2	Value from SIM1
`com.nokia.mid.msisdn`	Value from SIM1	`null`	`null`	Value from SIM2	Value from SIM1
`com.nokia.mid.networkid`	Value from SIM1	`null`	`null`	Value from SIM2	Value from SIM1
`com.nokia.mid.ons`	Value from SIM1	`null`	`null`	Value from SIM2	Value from SIM1
`com.nokia.mid.spn`	Value from SIM1	`null`	`null`	Value from SIM2	Value from SIM1
`wireless.messaging.sms.smsc`	Value from SIM1	`null`	Value from SIM2	Value from SIM2	Value from SIM1