Patent ID: 6496507
Filing Date: 2002-12-17
Classification: H04L

Abstract:
A system switching control device comprising:a first system cell storage section for temporarily storing cells supplied thereto; a second system cell storage section for temporarily storing cells supplied thereto; a switching section for executing system switching operation for changing its connection between the first system cell storage section and the second system cell storage section so that cells inputted thereto will be selectively supplied to one of the cell storage sections and thereby the cell storage section that is supplied with the cells will be designated as an operating system cell storage section and the other cell storage section that is not supplied with the cells will be designated as a standby system cell storage section; a timer section for counting a time concerning a system switching time U(s) after the system switching operation which is executed by the switching section; a system control section which is connected to the first system cell storage section, the second system cell storage section and the timer section, which reads out cells from the standby system cell storage section during the system switching time U(s) just after the system switching operation executed by the switching section, and reads out cells from the operating system cell storage section during a period after the system switching time U(s); a circuit cell storage section for temporarily storing the cells read out by the system control section from the standby system cell storage section and the operating system cell storage section; and a cell circuit section for packing the cells supplied from the circuit cell storage section in appropriate frames and transmitting the frames, wherein: the circuit cell storage section has an enough storage capacity by which all the cells which accumulated in the operating system cell storage section during the system switching time U(s) can be moved into the circuit cell storage section during the period after the system switching time U(s).