SimtoLink: Plans can be preset by device model
A firmware package is the software package used to update device firmware. It usually contains the firmware binary, version information, a checksum such as MD5 or SHA256, and metadata. The firmware package is the carrier for a firmware upgrade. It is delivered to the device by OTA (over the air) or locally, and the device bootloader or upgrade module flashes and verifies it. A firmware package must stay complete and traceable, and it supports differential upgrades to lower data use.
Model, version, and cross-border download
Firmware packages are usually managed by device model, hardware version, and target version, and both full packages and incremental packages are supported. In cross-border scenarios, devices spread across many countries need to download the firmware package over an international IoT SIM. Data compression and differential upgrades can cut cross-border data cost markedly.
Package structure, signatures, and differentials
A firmware-package architecture usually includes: package structure, a header (version number, device type, size, checksum) plus the firmware body; version management, with several versions kept side by side and upgrade-path constraints, for example allowing an upgrade only from A to B; security, with signature verification and encrypted transfer, to prevent tampering and man-in-the-middle attacks; differential support, generating an incremental package that transfers only the changed part and lowers the download size.
Technical traits: both full and incremental modes; resume and retry; a check before the upgrade and verification after it; a rollback mechanism. In cross-border scenarios, firmware distribution needs to consider multi-region CDNs and network stability when one SIM roams across many countries.
Use in IoT and cross-border scenarios
Firmware packages are widely used in charging equipment, for firmware updates of charging piles and stations, where a cross-border charging network needs to push one firmware package to devices in many countries; industrial equipment, for firmware upgrades of PLCs, gateways, and sensors; vehicles and logistics, for firmware updates of in-vehicle terminals and logistics trackers; and consumer electronics, for OTA upgrades of smart meters and smart-home devices. SimtoLink provides a stable connection for cross-border IoT devices and supports secure, efficient delivery of firmware packages.
Source: https://www.simtolink.com/support/globalsim/firmware-package.html