A system for and method of detecting a connection of a text telephony (TTY) device to communication device, such as, a mobile telephone. The communication device provides a TTY bearer bit to its communication network upon detecting that a TTY device is connected to it. The connection between the communication device and the TTY device can be made using a smart cable or a connector cable. The detection that a TTY device is connected to the communication device is automatic and does not require the user of the communication device to enter a code or any other input to the communication device.