Patent ID: 7945936

Claim:
A multicasting system, comprising: a delivery server to multicast a content via at least one upper router and a plurality of lower routers; a plurality of client devices to play the content multicast by the delivery server; and an upper router controller to control the upper router, at least one of the client devices including an individual storage unit to store an identifier of at least part of the content to be multicast by the delivery server and session information related to multicasting of the content with the identifier mapped to the session information, a content retrieving unit to retrieve the content from the delivery server in accordance with the identifier and the session information of the content stored on the individual storage unit, and a content playing unit to play the retrieved content, the delivery server including a content delivery unit to deliver the content to the at least one of the client devices, the upper router controller including a session information retrieving unit to retrieve, from the at least one of the client devices, the session information of content to be multicast within a book scheduling period stored on the individual storage unit, a book scheduling unit to determine a priority order of multicast addresses within the book scheduling period in accordance with the retrieved session information and schedule, based on the determined priority order and a permitted workload of an access network connecting the upper router to the lower router, the multicast addresses in which each lower router participates within the book scheduling period to produce book scheduling results, and a schedule information notifier to notify the at least one of the client devices of the book scheduling results, and the at least one of the client devices further including a switch time addition unit to add, to the session information of the content stored on the individual storage unit, information relating to channel switch time of each content to be multicast within the book scheduling period in accordance with the book scheduling information, and a display controller to display a channel switch time of the content stored in the individual storage unit in a recognizable manner within the book scheduling period based on the information relating to channel switch time.