Patent attributes
Disclosed is a group admission system having a client and a server that belongs to a closed group within which contents are available. The client determines whether it is permissible to request to join the group to be a member device thereof based on the number of groups that the client is in and the maximum number of groups that the client is permitted to be in. If permissible, the client transmits a registration request to the server with information unique to the client. The server determines whether to permit the client to join the group by registering with the server based on the number of member devices registered with the server and the maximum number of member devices registerable with the server. If it is permitted, the server registers the unique information, and transmits group identification information to the client. The client receives and stores the group identification information.