Electronics and Telecommunications Research Institute

Han Seung Koo

Soo In Lee

O Hyung Kwon

Nam Ho Hur

Young Ho Jeong

Dong Joon Choi

Soon Choul Kim

Yun Jeong Song

Eun Jung Kwon

Heejeong Kim

Yang Su Kim

Jae Ho Lee

Sang Jung Ra

Doh-Wook Kim

Disclosed are a method and apparatus for estimating symbol timing in a non-synchronized OFDM system. The present invention includes synchronizing a frame of a received signal, estimating the symbol timing of each symbol of the frame based on the synchronization, compensating for the symbol timing using a phase difference attributable to a Symbol Timing Offset (STO), variably changing within a Cyclic Prefix (CP) interval due to the frequency offset of a sampling clock and thermal noise, and performing channel equalization using a preamble based on output including corrected phase rotation.

Method and apparatus for compensating for variable symbol timing using cyclic prefix in non-synchronized OFDM system

An apparatus for combining a broadcasting channel may include a channel detector to detect a vacant Radio Frequency (RF) broadcasting channel used by a photoelectric converter that converts a first broadcast program as an optical signal to a first RF signal, a broadcast receiving interface to receive at least one second broadcast program, a broadcast modulator to generate a second RF signal by modulating the second broadcast program using the vacant RF broadcasting channel, and a channel combiner to combine a broadcasting channel used for the first RF signal and the vacant RF broadcasting channel.

Method and apparatus for inserting broadcast program by detecting available channel over hybrid fiber coax network or optical cable network

A mutual authentication method in a Downloadable Conditional Access System (DCAS) is provided. The mutual authentication method may receive authentication-related information about authentication between an authentication unit and a security module (SM) from a Trusted Authority (TA), generate an authentication session key using the authentication-related information, transmit the authentication session key by the authentication unit to the SM through a Cable Modem Termination System (CMTS), and control a Conditional Access System (CAS) software to be downloaded to the SM from the authentication unit, when the authentication is completed by the authentication session key.

Mutual authentication apparatus and method in downloadable conditional access system

An apparatus and method for fast load balancing bandwidth allocation based on a binary search may be provided, wherein the apparatus may include a bandwidth allocation request receiving unit to receive a bandwidth allocation request signal from at least one modem, and a bandwidth allocation processing unit to allocate a bandwidth to an upstream channel of the at least one modem, using a load balancing algorithm, in response to the received bandwidth allocation request signal.

Apparatus and method for fast load balancing bandwidth allocation based on binary search

There is provided a remote entitlement processing module integration processing device. The remote entitlement processing module integration processing device includes: a remote entitlement processing module generating and managing remote smart cards (RSCs) having the number corresponding to the number of host terminals managed by the remote entitlement processing module integration processing device; and a descrambler transferring channel selection information in response to a selection of a pay channel by a user to the remote entitlement processing module and descrambling a scrambled channel signal using a control word (CW) received as a response to the channel selection information, thereby making it possible to minimize dependency between a subscriber device and a conditional access system.

Remote entitlement processing module integration processing device and method

Disclosed is a mutual authentication method and apparatus in a CAS including a headend system and DCAS host. In particular, example embodiments relate to a mutual authentication method and apparatus in DCAS, wherein the mutual authentication is performed between an authentication server of the headend system and an SM of a DCAS host, and then CAS software is downloaded to the SM. According to the example embodiments, there is provided a mutual authentication protocol between the authentication server of the headend and the SM of the DCAS host in a cable network, and also provided a mutual authentication method and apparatus in the DCAS where a substantial authentication based on a hardware, such as a smart card or a cable card, is not needed.

Method and apparatus for mutual authentication in downloadable conditional access system

A method of operating a headend system for a downloadable conditional access service, the method including: receiving, by an Authentication Proxy (AP) server, basic authentication information from a Downloadable Conditional Access System (DCAS) host, the basic authentication information being required to authenticate the DCAS host; transmitting, by the AP server, the basic authentication information to an external trusted authority device which authenticates the DCAS host; generating, by the AP server, a session key for encrypting/decrypting a secure micro client using a session key sharing factor; obtaining, by the AP server, download-related information of the secure micro client from a DCAS Provisioning Server (DPS); and commanding, by the AP server, an Integrated Personalization System (IPS) server to download the secure micro client to the DCAS host based on the download-related information, the secure micro client being encrypted by the session key.

Headend system for downloadable conditional access service and method of operating the same

A security control method in a cable network dynamic multicast session, and more particularly, a method of controlling forward secrecy and backward secrecy in a Data Over Cable Service Interface Specifications (DOCSIS) 3.0 network dynamic multicast session is provided. A security control method in a cable network dynamic multicast session, includes: maintaining a multicast group that is allocated with a first Downstream Service Identifier (DSID) and a first Security Association Identifier (SAID) and that is joined by a first cable modem and a second cable modem; receiving a LeaveMulticastSession message from the second cable modem; exchanging, corresponding to the LeaveMulticastSession message, a Dynamic Bonding Change (DBC) message for changing a multicast parameter with the second cable modem; and updating a first Traffic Encryption Key (TEK) corresponding to the first DSID with a second TEK.

Cable network system and method for controlling security in cable network encrypted dynamic multicast session

Provided are a method of configuring a hierarchical network of user groups and resource groups, and a key distribution center. The method includes the steps of: analyzing hierarchical connection relationships between respective user groups and respective resource groups, comparing redundancy rates of the respective hierarchical connection relationships, and determining a connection mode having a larger redundancy rate; separating the respective user groups and resource groups and hierarchically connecting the user groups with the resource groups, according to the determined connection mode; comparing hierarchical connections between the respective separated user groups and resource groups, and removing an overlapping hierarchical connection; and recombining the separate hierarchical connections except for the overlapping hierarchical connection, and configuring an entire network.

Method of configuring hierarchical network of user group and resource group and key distribution center

Provided are a multi-channel tuning receiver, including: a broadband radio frequency (RF) tuner to receive a broadband signal, divide the broadband signal into a plurality of signals, tune the divided signals, combine the tuned signals into a single signal, and output the combined single signal; an analog-to-digital (A/D) converter to convert the combined single signal to digital signal; a channelizer to extract only a bonded channel from the digital signal; and a plurality of demodulators to demodulate the bonded channel, and a multi-channel tuning method thereof.

Growing community of inventors

Daejeon, South Korea

Han Seung Koo