A multi-media file system for conmmunicating information between a multi-media client and a network storage device over a network. The file system includes a cluster that comprises one cluster manager and at least one file manager with each network storage device. The cluster manager is located on a client, includes an admission controller for controlling the admission of a request from a client for a file operation upon a selected file. A network bandwidth request from the admission controller is responded to by a network status determiner included in the cluster manager. The network status determiner determines the available network bandwidth. Each file manager is located on one of the clients. The file managers manage file maintenance procedures of corresponding files located on the network storage device. Each file manager includes a disk status determiner for determining the available disk bandwidth. The disk status determiner responds to a request from the admission controller.

A system is provided to deliver complete files from a server to a maximum number of clients, while at the same time minimizing cumulative waiting time through the utilization of a prioritization heuristic in which there are two competing priorities. As to the first priority, the highest priority is given to those clients most in danger of not receiving a complete file by a predetermined deadline. The second priority is set to minimize the waiting time for the delivery of files by sending the files only to those clients that are capable of receiving the data fastest. An exponential curve system is utilized as a tie breaker between the two competing priorities in which the weight of each priority is determined. As a result, in terms of distribution from a single server to multiple clients, the calculation of the weighted priority is a real number derived from user parameters such as log-in characteristics, the due date, and the amount of the file remaining to be transmitted. The characteristics of the client are derived through information sent back to the server from each client with the average throughput to the particular client being calculated either at the client side or by the server itself.

The invention concerns a method for access to a transmission channel shared between several stations, characterised in that it includes iteratively: an operation (302) of estimating requirements of each of the stations for access to the transmission channel, an operation of determining groups (303 and 307) of stations taking into account the estimated access requirements of the stations, at least one of the groups of stations being said to be "collective", an operation of allocating (308), to each of the groups, access rights each corresponding to an interval of time during which the stations which do not form part of the group are not authorised to access the transmission channel, and during which, if the group is collective, each station which it includes gains access to the transmission channel according to a contention method.

An information processing apparatus and method and a program storage medium by which a recording medium of an apparatus connected to a network to which the information processing apparatus is connected can be utilized effectively wherein if reservation of recording of a predetermined program is performed for a video recorder, then a data amount necessary to record the reserved program is calculated. Then, those of apparatus connected to a network which include a recording medium which can record the calculated data amount are searched for. In response to a result of the search, a distribution of data amounts to be recorded into the recording media of those apparatus is determined. Then, areas are secured in the recordable areas of the recording media so that the determined data amount may be recorded.

A program transmitting/receiving system has a center device and a terminal device connected through a communication device to the center device. The center device has a program information memory, a program information transmitter, a broadcasting device, and a request program transmitter. The terminal device has a program information receiver, a program receiver, an image information generator, a program request signal transmitter, and a request program receiver. The memory stores a program information. The program information transmitter transmits the program information to the terminal device. The broadcasting device broadcasts the program to the terminal device in accordance with a schedule, and stores the program. The request program transmitter receives a request signal of the program from the terminal device, and transmits the program corresponding to the request signal to the terminal device. Then, the program information receiver receives the program information. The a program receiver receives the program. The image information generator generates an image information for a program selection of a user on the basis of the program information. The program request signal transmitter transmits the request signal of the program selected by the user to the center device, if the program selected in accordance with the image information is a past broadcast program. The request program receiver receives the program corresponding to the request signal.