SoftSIMs


In order that SIMs may be remotely provisioned with new profiles it requires that the SIM card/device/eSIM contains software called a “Local Profile Assistant” (LPA) by the GSMA.

SoftSIMs differ from eSIMs in that SoftSIMs rely on a proprietary LPA solely in the device whereas eSIMs have the LPA functionality divided between the device and eSIM.

This has the advantage of lowering the BOM cost but presents potential security challenges.

SoftSIMs fall into two different categories – programmable SIM cards and integrated SoftSIMs. Programmable SIM cards look like normal removable SIM cards but have an STK applet ( as LPA ) loaded on them to facilitate remote SIM provisioning by communicating with an RSP platform. Integrated SoftSIMs remove the need for a physical SIM card, instead using proprietary integrated software in the device to perform the role of the LPA.
Both kinds of devices need both a “provisioning profile” for bootstrap purposes and at least one “operational profile” to provide service during normal operation.

PROVISIONING PROFILES

Cloud9 have supplied several programmable SIM card suppliers with their customised provisioning profile. This profile provides global coverage in just about any country in the world. 
A UK MSISDN is allocated to the SIM when the provisioning profile first registers with a network. This provides a mechanism for SMSs to be received by the handset. Sending SMS codes to the handset has become the de facto standard for registering to services such as WeChat. The Cloud9 provisioning solution allow SMS’s to be delivered to the SIM even after switching to the operational profile, by home routing the messages and forwarding them to the customer for delivery when the customer informs us that the IMSI switch has taken place over one of the Cloud9 APIs.

PROPRIETARY REMOTE SIM PROVISIONING PLATFORM

It is possible to easily implement a proprietary remote SIM provisioning platform using the Cloud9 STK applet. This applet is placed on the SIM. USSD commands are sent to the Cloud9 USSD Gateway and relayed over a VPN to the customer’s server. The server can update profile parameters simply by parsing a response string that is sent back to the Applet for it to process and update the electrical profile on the SIM.

OPERATIONAL PROFILES

Cloud9 also have a portfolio of operational profiles that provide great data, voice and SMS pricing in many countries around the world.
These include the Cloud9 profile and profiles from several donor IMSI providers.