Cellular IoT & M2M use cases often involve a high number of devices that need to be connected to a mobile network. For this to happen, devices must first be fitted with a SIM and network connectivity must be provisioned. When a project includes hundreds, thousands or even millions of devices that need to be connected to a mobile network, it is impossible to manually configure each SIM in each device. Efficiency is key in the technology industry, and automation can be enabled for each of the essential processes of the SIM lifecycle.

With EMnify’s purpose-built RESTful API, all these tasks can be automated. This allows EMnify customers to integrate existing systems and applications with EMnify's connectivity management platform by building the systems and process for automation that work best for a customer's business needs. This blog article outlines how EMnify’s auto-provisioning includes the automation of SIM ordering, activation and deactivation, connectivity testing, device configuration, tariff limit implementation, and SIM decommissioning. Practically, these actions can standardize how the SIMs arrive at a factory for installation, how the SIM is tested, and how the SIM is activated by the end users.

This article focuses on the SIM state management and its effect on EMnify customers’ monthly costs.

What are the SIM states and how can I manage them? 

The following diagram illustrates the different states:

• ‘Issued’- Initial state after the SIM got provisioned in the system. While SIM registration one can decide if the SIM shall remain in state ‘issued’ or if it shall become activated. Endpoints with ‘issued’ SIM will not be able to connect to the network.
• ‘Activated’- Once you activate the SIM its status becomes ‘Activated’, the SIM is opened for network access and can be used in endpoints for USSD, SMS and Data services.
• ‘Suspended’ - the SIM card is temporarily suspended and is blocked from network access but can be activated again at any time.
• ‘Terminated’ - the SIM has been permanently removed from the repository and cannot be restored for network access.

SIM status can be toggled from ‘issued’ to ‘activated’, from ‘activated’ to ‘suspended’, from ‘suspended’ back to ‘activated’ through API Call PATCH /api/v1/sim/{id}. Once the SIM has been activated, it is not possible to change the SIM status back to ‘issued’.

SIM status can be changed to ’terminated’ through API Call DELETE /api/v1/sim/{id} from any previous SIM state. Once a SIM has been terminated, there is no option to access it anymore and therefore it is not possible to recover it to any other status.

Further information on how you use the EMnify RestAPI can be found here.

How does the SIM status influence monthly charges?

At EMnify you can choose between two pricing models: With the pay as you go pricing model, your charges are calculated as the sum to the SIM hosting fees and the product usage fees (data traffic/SMS) whereas with the inclusive volume pricing model you will be charged the sum of the chosen inclusive volume fees and the fees for usage traffic excessing the inclusive volume.

Pay-as-you go:

• small monthly hosting fee for activated SIMs
• data traffic price per MB & SMS price per Rate Zone
• ideal for customers with different consumption

Inclusive volume:

• different volume sizes available
• inclusive volume per activated SIM, volume pooled across activated SIMs
• volume can be used up within all networks in the Rate Zone
• price per MB exceeding inclusive volume or traffic in different rate zones
• ideal for customers with predictable/stable data consumption

In both cases, the monthly charges will depend on the peak number of concurrently activated SIM cards within the billing period, not the total number of individual SIM being activated. The calculation is done with a 12 hour accuracy.

Example: If you have 200 SIMs, and all of them are activated for some amount of time within a given month, but there are never more than 100 activated at the same time —> monthly charges will be applied based on 100 SIMs. At the same time, the inclusive volume will also be granted only for 100 SIMs (but still pooled across all 200 SIMs, so all SIMs will benefit from the lower pricing of the inclusive volume).

In order for EMnify customers to benefit from this model, there are no suspension barriers in place and customers can suspend SIMs whenever they are not needed. There is no charge for suspending and reactivating your SIM cards. Also, as the connectivity configuration is based on the endpoint rather than the SIM, customers can prepare their setup and keep their SIMs in ‘issued’ or ‘suspended’ status until they are needed again.

Example: If you want to configure everything within the current month (do the endpoint configuration and SIM assignment) and start using the devices in the next month, you could activate the SIM cards at the beginning of next month in order save the monthly fees for the current month. That way, you only pay if you really use the SIM connectivity service provided by EMnify.