Dynamic multicast groups with adaptive path selection in MMR WiMAX networks

Tactical communication architectures are evolving to support mobile broadband multimedia in NLOS environments. Multihop wireless systems have the potential to improve coverage and capacity over single-hop radio access systems. The IEEE 802.16 standard, also known as WiMAX, is a recent long-range broadband technology with mobility support, and the IEEE 802.16j substandard extends the range of mobile WiMAX by means of relay networking. In tactical communications in extreme scenarios, such as those needed in the military, there is an increasing interest in such networks, which allow viable solutions to common problems: high-capacity delivering. This paper presents the first dynamic path selection protocol for WiMAX relay networks that is fully embedded in the MAC layer. The MAC-layer approach is more efficient than solutions depending on higher layers. Moreover, we show that our approach can support dynamic group management for multicast communications following a cross-layer schema. As a result, multicast group switching becomes transparent to mobile end nodes receiving audio and video streaming services in tactical networks, unlike conventional solutions relying on higher layers. Also, we demonstrate that, with our approach, handover between WiMAX relay stations is transparent to mobile terminals receiving multimedia streaming.