Multicast data delivery carries distinct importance in mobile wireless environments, where bandwidth is limited and transmission channels are shared between users. The development of mobile multicast protocols consequently exhibits emerging interest. As the common approach of Any Source Multicast distribution is burdened with intricate routing procedures, the spread of multicast-enabled network infrastructure remains hesitant. I t is widely believed that simpler mechanisms for group distribution in Source Specific Multicast (SSM) will lead to a pervasive dissemination of multi-cast infrastructure and services. However, SSM is designed for the a priori known and changeless addresses of multicast sources and thus withstands any easy extension to mobility. This paper reviews the state-of-the-art in current work to extend SSM to Mobile IPv6 networks. The principle conceptual problems are discussed and analysed. Propositions for improvement and possible directions to proceed further in SSM source mobility are presented.