Abstract: Over the air (OTA) is a platform by which GSM provider can send and receive services from and to SIM card. Such OTA Platform are expensive and implemented on operator side only. If SIM vendor want to perform online testing of SIM services they need an special online account with Operator to access their OTA service. To overcome this limitation, GSM modem can be used to perform online testing without special access of operator OTA server with support of “exposesd” API of GSM modem.