Electronic device, method for using electronic device, and electronic device system for reserving bus usage time on a bus to conduct communications between electronic devices

This invention relates to a technique for controlling communication in an electronic device system, including devices, such as an Audio Visual device (hereinafter, "AV device") that deals with visual information and audio information, and an information processing device, connected by a communication bus. Especially, the technique operates to prevent a use of the electronic device system that exceeds data the transfer capacity of the communication bus. An IRD supplies broadcasting data on a bus a desired time period. When the IRD performs a reservation of the bus usage, the IRD request current bus usage information and information of the bus reservation from all devices connected by the bus, such as a DVD , a D-VTR , a D-VTR , a CAM , a TV , and a isochronous manager of the D-VTR . The isochronous manager and each device answer by sending the bus usage information to the IRD and reservation information. The IRD judges a possibility of the reservation from the answer information. If the reservation is possible, it performs the reservation operation. IF the reservation is impossible, then the reason is displayed on a TV . Therefore, it is possible to prevent a usage of a device that excesses the bus transferring capacity.