CABLE NETWORK SYSTEM FOR PROVIDING IPTV SERVICE AND METHOD FOR CONTROLLING CABLE NETWORK SYSTEM

摘要

PURPOSE: A cable network system for providing an IPTV service and a method for controlling a cable network system are provided to shorten channel change time, thereby efficiently providing an IPTV service. CONSTITUTION: A DSID(Downstream Service IDentifier) list maintaining device(410) maintains a DSID list about a broadcast signal received from a cable headend. A broadcast signal confirming device(420) receives an IGMP(Internet Group Management Protocol) join message from an IPTV STB(Set-Top Box). The broadcast signal confirming device confirms the first broadcast signal related to the IGMP join message at the DSID list. A broadcast signal providing apparatus(430) provides the first broadcast signal to the IPTV STB.