Home gateway system for providing optical communication packet data interface function and home broadcast service providing method using the same

A home broadcast service providing method by using a home gateway providing an optical communication packet data interface function, the method comprising the steps of:

• (a) dividing an optical signal received from an access network into an IP (Internet protocol) network's packet data signal and a broadcast network's broadcast stream signal;
• (b) transmitting the IP network's packet data signal to an ONU (optical network unit) module of the home gateway and packetizing the IP networks packet data signal, and then transmitting the packetized IP network's packet data signal to a Layer 2 Ethernet switch of the home gateway though an IP WAN (wide area network) port of the Layer 2 Ethernet switch;
• (c) transmitting the broadcast network's broadcast stream signal to a broadcast packet to IP multicast packet module of the home gateway, converting the broadcast network's broadcast stream signal into an IP multicast packet, and then transmitting the resulting IP multicast packet to the Layer 2 Ethernet switch;
• (d) processing the IP network's IP multicast packet and the IP multicast packet into which the broadcast stream signal has been converted according to a Layer 2 multicast MAC (medium access channel) table to then transmit the processed packets to a destination port, and transmitting an unicast packet received from the IP network to a control processor of the home gateway though a CPU (central processing unit) port of the Layer 2 Ethernet switch;
• (e) performing required functions of the control processor, including a NAT/PAT (network address translation to port address translation) function with respect to the unicast packet received from the Layer 2 Ethernet switch, and then retransmitting the resulting packet to the Layer 2 Ethernet switch to then transmit the retransmitted packet to a destination port;
• and
• (f) deleting a currently-serviced broadcast channel, wherein the step of deleting comprises the steps of:
• when an IGMP (Internet group management protocol) LEAVE message is received from a port of the Layer 2 Ethernet switch by an IGMP snooping function or when the control processor recognizes termination of a multicast membership recognized though periodic monitoring of IGMP QUERY and IGMP REPORT messages, deleting a requested port from a channel identifier member table;
• deleting the requested port from the Layer 2 multicast MAC table;
• checking whether another member exists in the channel identifier member table;
• judging the result of the checking step;
• terminating the step of deleting the currently-serviced broadcast channel without taking any action if another member exists in the channel identifier member table;
• returning a corresponding multicast address to a multicast address pool if another member does not exist in the channel identifier member table;
• commanding a corresponding tuner to return to an idle state;
• commanding a multicast packet generator to delete a corresponding channel identifier to multicast address map;
• and
• returning the corresponding tuner to an idle tuner pool and then terminating the step of deleting the currently-serviced broadcast channel.