Communication system, method of processing message in communication system, and station-side unit and subscriber-side unit

Abstract

There is provided a communication system () such as an ATM-PON including a station-side unit () having a point-to-multipoint message generating unit (A) and a group designation message generating unit (B) and subscriber-side units (-to-N: N is a natural number) each having a point-to-multipoint message processing unit (A) and a state control unit (B). The station-side unit () sends a group designating message to some of the subscriber-side units (-=1 to N), thereby to designate some of the plurality of the subscriber-side units as a component constituting a group of units which are to receive a point-to-multipoint message, and only the subscriber-side units (-) controls to bring the reception and the processing on the point-to-multipoint message to a valid status. With this arrangement, only specified components constituting a group of units can be made to receive the point-to-multipoint message. Thus, it becomes possible to avoid unexpected erroneous operation which can be caused if information specific to a vendor of some of the subscriber-side units (-) is sent to all of the subscriber-side units. Moreover, it becomes possible to provide information to the specified components constituting a group of units within a very short period of time.