USSD API
USSD has long been used for simple tasks, such as balance checking and top-up. The Gateway's management software suite, the HMC, features a simple and easy-to-use USSD page, allowing you to quickly check the balance of one or more SIMs and export it to an Excel file.
The USSD API adds the ability to make balance checks and other actions available through the JSON API.
You can get the status of the cellular modules - provider, cell tower, module's status and reception levels, which will enable the server sending the messages to the Gateway know if modules have stopped sending because some reception problem or the like, if, for example, it receives too many rejection cause codes for its text messages sent. You can even check the serial numbers, so you can see if it's a specific SIM that's always causing the issues.
You can configure the module to use a specific SIM position (1-4 or even 1-10, depending on the cellular card's model) and you can configure the module to use a specific cell tower (BTS lock). That will enable you to switch to a different SIM and have it connect to a different cell tower. Coupled with our advanced anti-blocking packages, it will allow you to avoid SIM blockage.