US Patent 7877328 Communication system communication method, contents processing device, and computer program

A communication system and so forth are provided by which registration or cancellation of a plurality of apparatus owned by a user can be executed efficiently. In the communication system, a content processing apparatus acquires a second source ID list of a content reproduction apparatus. If it is detected based on the second source ID list that the content reproduction apparatus is not yet registered in a management server and a recorder ID of the content processing apparatus is not yet registered in the second source ID list, the content processing apparatus recommends registration. If a registration instruction of the content reproduction apparatus is accepted, the content processing apparatus requests the management server to register the content reproduction apparatus. The content processing apparatus receives registration completion transmitted from the management server and adds a group ID stored in a first source ID list to the second source ID list of the content reproduction apparatus. If the registration instruction of the content reproduction apparatus into the management server is not accepted, then the content processing apparatus adds the recorder ID of the content processing apparatus to the second source ID list.