With improvement of network performance, content distribution services such as live streaming have been widely spread. For these services, it is effective to use a multicast distribution system. However, conventional multicast distribution systems are best-effort services using the Internet, which do not guarantee the Quality of Services (QoS). On the other hand, Software Defined Network (SDN) and In-network cache are attracted much attention as new frameworks which are different from the conventional network. In this paper, we propose a multicast distribution system with functions of placement and retransmission, exploiting In-network cache for QoS guarantee and time-shift viewing. We implement a prototype system using OpenFlow, and evaluated the performance on the proposed system through computer emulations.

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Due to the recent popularization of mobile devices such as smartphones, we can collect many mobile sensor data from them. By creating the spatial indexes for the nodes that manage the sensor data, the system can speed up the selection of their necessary nodes. However, conventional indexing methods cannot reduce the number of indexes effectively since they do not manage the data considering their spatial differences. By merging the range information of an index with others based on their distances, the number of indexes can be reduced. Hence, In this paper, we propose an efficient indexing method for mobile sensor data collection on integrated sensor networks. Our evaluation revealed that our proposed method can reduce the number of indexes and traffic for constructing indexes.

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