Abstract: A solution for allowing conditional access to IP-based broadcast services in a passive optical network is disclosed. When a subscriber requests broadcast services by selecting a broadcast channel, an IP set-top converts the request into an IGMP join message and forwards the message to an ONU/ONT, a unit on the subscriber's side. The ONU/ONT delivers the message to an OLT interworking with a router while storing mapping information of the port that received the message and a MAC address of the selected channel. Thereafter, the OLT extracts information on MAC address of the IP set-top box and the requested broadcast data. The OLT compares the extracted information to the subscriber's subscription information and determines whether to provide the requested broadcast services. If the broadcast services may be provided, the broadcast data provided from the broadcast server is transmitted to the IP set-top box via ONU/ONT based on the stored mapping information.

Abstract: Disclosed is a temperature controller and method for maintaining an optical-communication device at a constant temperature regardless of ambient temperature variation.

Abstract: A temperature compensation device for an optical communication device or the like is constructed so that an error value, which is the difference between the current temperature and a reference temperature, is subjected to digital processing in a temperature comparison unit. A digital error voltage value is calculated and digital PID control is performed instead of analog PID which requires electric components such as a power op-amp, a resistor (R), and a capacitor (C). According to this construction it is possible to reduce the number of electric parts. It is also possible to accept various types of temperature sensors while using only one PCB regardless of the types of temperature sensors utilized.

Abstract: A temperature compensation device for an optical communication device or the like is constructed so that an error value, which is the difference between the current temperature and a reference temperature, is subjected to digital processing in a temperature comparison unit. A digital error voltage value is calculated and digital PID control is performed instead of analog PID which requires electric components such as a power op-amp, a resistor (R), and a capacitor (C). According to this construction it is possible to reduce the number of electric parts. It is also possible to accept various types of temperature sensors while using only one PCB regardless of the types of temperature sensors utilized.

Abstract: Disclosed is a temperature controller and method for maintaining an optical-communication device at a constant temperature regardless of ambient temperature variation.