Abstract: The present invention optimizes data placement in reference to the service of cyclic re-broadcast, typical of a media server. When the media data to be re-broadcast and the cycle of the re-broadcast are known, it is possible, according to the present invention, to calculate the portions of all the media data that will be read simultaneously and place sequentially such portions of data, so that the search time of the read/write head in the data blocks of direct access devices, such as magnetic disks, magnetic disk arrays, read-and-write optical disks, and other storage devices, can be reduced. Using the inventive data placement technology, the search time of the read/write head can be significantly reduced and the efficiency of bandwidth use can be improved, without altering typical hardware devices.

Abstract: The present invention discloses a network access admission controller and the method used to determine its schedulability. The basic principle involves determining, for all the connections to be checked, if there is any time slot, among all the time slots within a cycle, that will satisfy the scheduling property without the possible misjudgment of schedulability found in the conventional technology. The inventive method of determining schedulability makes its judgment based on packets issued by all the connections and on each of these connections individually. In particular, a determination is made regarding whether there is a particular time slot, among all the time slots, corresponding to the cycle of connection under evaluation, such that all the time slots prior to it are capable of processing the previously issued packets from the connections having higher priority than this particular time slot.