Adaptive multimedia multi-party communication in ad hoc environments

Adaptivity is a key issue for enhanced multimedia communication in wireless environments, where the network QoS for a whole session cannot be guaranteed. Within this paper we propose a set of mechanisms to provide adaptive multimedia multi-party communication according to user-defined QoS levels over self-organizing ad hoc network extensions connected to IP access networks. We use special extensions to SIP/SDPng based on XML to negotiate alternative application defined QoS levels and adaptation paths and optionally couple local resource management with network layer QoS. At the network layer, we propose the MMARP (Multicast MANET Routing Protocol) which provides efficient multicast communications within ad hoc network extension to public infrastructure based access networks. MMARP is able to deal with the complexity of supporting traditional IP nodes whilst inter-operating smoothly with fixed IP networks. An adaptive application architecture is demonstrated that uses the E2ENP and allows multimedia applications to reconfigure themselves in realtime to match the specific network conditions in order to preserve the user-perceived QoS. Thus, an integration of application layer QoS as defined by the user and network layer QoS is achieved.