Multi-IMSI technology

Multi-IMSI technology enables a SIM to utilise two or more IMSIs (or profiles for eUICC SIMs). An IMSI is a number that uniquely identifies and authenticates a subscriber (and the IoT device containing the SIM) on the cellular network of the operator that provided the IMSI. The operator that provided the IMSI is called the home network operator and provides connectivity and other services to the IoT device.

Having access to multiple IMSIs enables devices to:

  • Resolve connectivity issues by rotating through IMSIs that belong to different network operators.
  • Switch to an IMSI (from the same operator or a different operator) with more favourable roaming agreements.
  • Localise the IoT device to a local network operator to, for example, avoid roaming restrictions in the local country.

Eseye AnyNet SIMs

An AnyNet Multi-IMSI SIM supports up to ten IMSIs (or profiles) which enables the IoT device to utilise up to ten different operator networks and all of their roaming partners without having to physically change the SIM.

Eseye preconfigures the order of IMSIs in the SIM before shipping them to customers. For AnyNet+ SIM eUICC SIMs, Eseye can download and enable different step 2 profiles over-the-air.

IMSI rotation

When an IoT device with an AnyNet multi-IMSI SIM first starts up, the device attempts to connect to a network using the currently active IMSI or bootstrap profile (for eUICC-enabled devices). If the device fails to connect to a network (or connects but subsequently loses connection), the AnyNet SIM waits three minutes for a successful reconnection before automatically rotating to the next IMSI and triggering the device to refresh its IMSI details.

IMSI rotation enables a single AnyNet SIM to provide global connectivity options. Once connected to a network, the Connectivity Management Platform can then further optimise the network choice based on rules configured for each SIM.

Example IMSI rotation procedure

In the following example, a device contains a multi-IMSI SIM that fails to connect to the home network (operator A). The SIM waits three minutes for the device to reconnect and then rotates to the next available IMSI and sends a UICC refresh command to the modem in the IoT device.

The modem uses the new IMSI to try and reconnect to Operator B's network but fails. However, because Operator B has a roaming agreement with Operator C, the device successfully connects to Operator C's network using the roaming agreement available to Operator B's IMSI.

Once connected, the Connectivity Management Platform (CMP) can localise the IoT device to the home network or steer the device to another roaming partner.

IMSI switching

After an IoT device successfully connects to a network, Eseye can automatically switch the SIM to a different IMSI using the:

After an IMSI switch, the IP address of the IoT device changes because the Eseye data centre that assigns the IP address uses different IP address ranges for each network operator.