CABLE MODEM, COMMUNICATION METHOD AND COMMUNICATION NETWORK SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a cable MODEM for a CATV channel adopting a revision about how to assign a frequency band to a transmission line used by the CATV channel so as to ensure the security of communication and enhance the utilizing efficiency of operating frequencies in the unit of nodes thereby coping with increase in data communication amounts associated with digitized CATV channels. SOLUTION: A center facility 1 uses a MAC(Media Access Control) address registered in the cable MODEM 14 in each user's home 21 to assign an operating frequency to each cable MODEM 14. The center facility 1 does not share all of common frequency bands to nodes 20 (20A, 20B, 20n) connected to an optical fiber 10 acting like a transmission line for the CATV channel 9 but shares different frequency bands from nodes in the unit to the fiber 10 and manages the channels. Moreover, a node converter 6 is provided on the transmission line for the CATV channels 9 to differentiate converting frequencies of incoming and outgoing signals from each node 20.