Efficient mobile multicast with QoS support using context transfer

There is a challenge for optimised Quality of Service (QoS) support of multicast services in mobile IPv6 infrastructures based on heterogeneous wireless networks. Efficient technologies are required able to support: Seamless handover and “Optimal” decisions for selection of access networks for mobile services, according application and network QoS criteria. To ensure seamless operation of multicast transport services, the Context Transfer protocol is used, which is currently a focus of standardisation in IETF [LMPK 04]. Another protocol under standardisation, i.e. the Candidate Access Router Discovery (CARD) protocol, is used to choose “optimal” access networks based on the mobile node's requirements for Candidate Access Router (CAR)'s capabilities [LSCFS 04]. This paper describes different open issues for design and development of efficient mobile multicast services with QoS support. The work is based on the mobile QoS architecture for seamless integration of heterogeneous wireless networks and broadcast media in IPv6 environment, developed in EU IST project DAIDALOS [DAIDALOS]. The main focus is the seamless handover based on efficient context transfer of mobile multicast services for source specific and any source multicast applications. The multicast context transfer depends on the kind of mobility: client (multicast receiver) and sender (multicast source) mobility, as well as on the requirements for QoS support with resource reservation of the multicast communication. Directly interacting with the seamless handover, are the management strategies for selection of new access network with capabilities, which are optimised in respect of the preferences of the mobile node. The paper addresses protocols and data structures, as well as QoS management issues aimed to optimise the context transfer for mobile multicast clients. Attributes describing the capabilities of access networks used for multicast handover decisions, as well as QoS management strategies for active learning of access router performance parameters for optimised multicast client mobility are proposed.