What Does Over-the-Air (OTA) Stand for?

The term 'Over-the-Air' (OTA) is widely used to describe the realm of wireless communication. OTA technology plays a crucial role in enabling remote management, configuration, and updates for devices, allowing them to seamlessly receive new software, firmware, or settings over a network. This technology finds extensive application in various industries, particularly in the Internet of Things (IoT), where it is often utilized for firmware updates and the efficient management of IoT SIM cards.

How OTA Works in IoT

Implementing OTA provisioning for SIM profiles involves the remote updating of various files, encompassing critical elements such as IMSI, MSISDN, preferred network settings, SMSC details, applets, and configuration parameters. Traditional SIM cards leverage Application-to-Person (A2P) SMS to facilitate OTA provisioning, allowing updates to be seamlessly delivered even when the device is offline. On the other hand, newer SIM cards support OTA updates through Hypertext Transfer Protocol (HTTP), thereby enabling the SIM card to retrieve updates from a central server. 

  • OTA-enabled devices. IoT devices are equipped with OTA capabilities from the design stage, including microcontrollers or microprocessors, memory, and wireless communication modules like Wi-Fi, cellular, or Low-Power Wide-Area Network (LPWAN) modules. 

  • OTA firmware/software management platform. An OTA management platform is used to manage the OTA process, working as a central hub for device management, software distribution, and monitoring. This platform enables administrators or developers to create, schedule, and deploy OTA updates to the connected devices. 

  • OTA update creation. This update can include bug fixes, security patches, feature enhancements, or entirely new versions of the software and is typically packaged into a firmware/software image file. 

  • Secure communication: Before an OTA update can be delivered, secure communication channels need to be established between the OTA management platform and the target devices. This includes encryption, digital signatures, and authentication protocols. 

  • Triggering the update. The OTA management platform sends a notification or command to the target devices, instructing them to check for available updates. This can be done by an administrator or automatically. 

  • Update verification. This involves communicating with the server and comparing the version or metadata of the installed software/firmware with the latest available version. 

  • Downloading the update. In case an update is available, the IoT device downloads the firmware/software image file from the OTA management platform over the established secure connection.  

  • Applying the update. Once the update is successfully downloaded, the IoT device verifies the integrity of the downloaded file through checksums or digital signatures. If the integrity check passes, the device applies the update, replacing the existing firmware or software with the new version.  

  • Update status reporting. The device communicates the update status back to the OTA management platform, indicating whether the update was successful or encountered any errors. This feedback allows administrators to monitor the progress of updates and take appropriate actions if issues arise. 

  • Rollback and recovery. In the event of a failed update or compatibility issues, OTA management platforms often provide mechanisms for rollback or recovery. This ensures that devices can revert to the previous working version or recover from update failures, minimizing downtime and potential disruptions.  

What Is eUICC and Its Relation to OTA?  

Unlike standard UICCs that necessitate manual SIM card swapping to switch to a different operator profile and network list, eUICC-enabled SIM cards possess the capability to store multiple profiles within a single physical card. This breakthrough allows for the seamless OTA provisioning of new profiles without the need for physically replacing the SIM card. Furthermore, rules can be defined to govern the behavior of these profiles, adding an additional layer of flexibility. 
 
In essence, the utilization of eUICC technology empowers subscribers to pause their relationship with one mobile network operator (MNO) and seamlessly resume it with another. For global deployments, managing contracts and guidelines with multiple carriers becomes a necessity, potentially requiring the establishment of new contracts for each deployment in different regions. By adopting OTA provisioning, disruptions that may arise from provisioning SIM cards during device usage can be mitigated, allowing for a smooth transition between operators. A Short Overview of eUICC (eSIM) and SIM in IoT - IoT SIM Card - 1NCE IoT Connectivity 

OTA and Multi-IMSI Cards 

For global deployments and scenarios where customers may need to switch carriers for better signal or lower data costs, managed provisioning with Multi-IMSI SIM cards is beneficial. Multi-IMSI SIM cards, unlike traditional SIM cards with a single IMSI, have several IMSIs that automatically switch between each other depending on the country. Adding a new profile to a Multi-IMSI SIM can be achieved through regular SIM OTA. It has a list of operators to connect to based on the primary carrier and roaming agreements. Switching to a network not on the IMSI's list involves changing identities which enables access to a new list of operators based on the new carrier and roaming agreements.