Techniques for implementing a push-to-talk feature in a mobile telecommunications environment (100) involve receiving an indication to activate a push-to-talk service for a first mobile device (130(2)) and identifying a group of mobile devices (130) associated with the push to-talk service for the first mobile device in response to the indication. The indication is received in an unstructured supplementary service data message. A notification relating to the indication to activate the push-to-talk service for the first mobile device is sent to one or more mobile devices from the identified group of mobile devices.