Network Coded Cooperative Multicast in Integrated Terrestrial-Satellite Networks

Wireless services have been extended from connection-centric to content-centric and this brings rapid increasing data traffic. Considering the concurrent multiple requests for popular contents, multicast is a promising delivery scheme to exploit content reuse. Satellite multicast is superior to others due to the coverage. When terrestrial base stations (BSs) are integrated with the satellite, cooperative transmission is then enabled to handle the fading satellite channels as well as maximize data throughput. Therefore, this paper proposes a cooperative multicast scheme for content delivery in the integrated terrestrial-satellite networks (ITSN) which is further enhanced by network coding. To exploit bandwidth of both terrestrial base stations (BSs) and the satellite, this cooperative multicast scheme uses two-phase transmission. The satellite multicast contents to subscribers in an opportunistic manner with real-time data rate adaptation. Then terrestrial BSs retransmit the lost packets for reliable transmission. Ground users are allocated to subgroups for the channel diversities while network coding is applied to packet loss recovery with fewer retransmissions. Sufficient numerical results demonstrate the enhancement on network throughput brought by the cooperative multicast scheme.