Reliable Mobile Multicast Transport for Multimedia Content Delivery

Efficient reliable multicast transport reducing the receiver processing overhead and allowing seamless continuation of the multicast service in case of handover is a challenge of today broadband infrastructures including content and mobile networks, The focus of this paper are protocol mechanisms aimed at scalable reliable point-to-multipoint content delivery from access routers to the attached multiple receivers in heterogeneous mobile IPv6 environment. In particular, the access router assistance of reliable content delivery is described, which includes the following tasks: Obtaining of data required by mobile multicast receivers based on interaction with the content network; Multicasting to mobile nodes using appropriate reliable multicast transport mechanisms; Support of the seamless handover of mobile multicast group members. The design issues and signalling overhead of the proposed scalable reliable multicast transport service including strategies for avoiding implosion and exposure is discussed. Important design concepts of the proposed protocol are: Access router assisted error control to mobile receivers using NACK-based retransmission scheme; Handover loss repair; Optimised receiver processing by using of dedicated channels for processing of retransmissions and handover repair; Scalable rate based multicast flow control for reliable transport services with minimum QoS guarantee. The scalable reliable multicast transport for mobile IPv6 is integrated into mobile IPv6 architecture based on the standard Internet multicast services using multicast listening (MLDv2) and routing (PIM-SM) protocols. The seamless handover is supported by context transfer between access routers, which allows the rapid re-establishment of multicast group membership and reliable transfer operations of the mobile node. The protocol is developed for the multimedia mobile broadcast Ipv6 environment of EU IST DAIDALOS project [1].