Due to the low-level nature of SMS Forge, which interacts directly with the cellular hardware (modem or baseband) of the device, compatibility cannot be universally guaranteed, unlike applications that use standard Android APIs.

The Android ecosystem is characterized by a wide variety of factors that complicate direct hardware access:

• System-on-Chip (SoC): The internal processor architecture (e.g., Qualcomm Snapdragon, MediaTek, Exynos).
• Protection Systems: Security mechanisms at the hardware and software (kernel) level that can restrict access to the baseband’s device files.
• Communication Interfaces: Not all devices uniformly expose the baseband access devices (/dev/*).

• Correct operation has been verified on various Snapdragon and MediaTek SoCs.
• Testing has been performed on devices from various manufacturers (Samsung, Xiaomi, etc.).
• I will continue testing and working to improve compatibility with more devices.

Even if baseband access is successful, each modem has its own firmware and may impose restrictions on the received AT commands:

1. Rejection of Specific Settings: The SMS Forge code attempts to maximize the success rate, but certain combinations of PDU settings may be directly rejected or ignored by the baseband.
2. Forced Configurations: The baseband may internally overwrite certain PDU settings. For example, a terminal’s baseband could ignore the Service Centre specified by the user and force the one configured by default in the system or on the SIM. It is also possible for the modem to capture status reports (TP-SRR) exclusively for its own management.
3. Compatible modem don’t seem to work: In some cases, even after successfully verifying the selected device, it may be impossible to send the SMS (error). This can happen mainly if a valid device has been selected, but there is no working SIM card on it, either because it is not inserted, unlocked, etc. It can also occur with MultiSIM devices, where the selected device may be referring to a different SIM slot, and you can usually select another working one.

SMS Forge is focused on maximizing compatibility across a wide range of devices, eliminating the historical barrier that limited the use of this type of tool to only specific models.

Future research will seek to further expand this compatibility range and even explore the possibility of not requiring root permissions on some devices.