Hi I am planning to buy a USB wireless data card to send SMS. So in some document I have read that when I connect the USB modem to a PC windows assigns a COM port to it. So can I send and read SMS with this USB data card(This card supports SMS and voice calls) using rxtx com api?
RxTx is only a low level way of sending and receiving data over a serial port. You'd still need to know how to 'talk' to this device of yours. So unless you have some sort of manual describing the protocol of the device or you have an SDK that defines the protocol for you, its not going to happen.