Abstract: Provided are a Downloadable Conditional Access System (DCAS), and a channel setting method and a message format for a 2-way communication between a terminal and an authentication server in the DCAS. The DCAS may include: a verification unit to verify an electronic signature and an integrity with respect to a message received from the authentication server; an extraction unit to extract network access information of the authentication server from the message in which the electronic signature and the integrity are verified; and a channel setting unit to set a communication channel with the authentication server based on the extracted network access information.

Abstract: Provided is a re-authentication apparatus in a Downloadable Conditional Access System (DCAS), the re-authentication apparatus includes: a receiving unit to receive a key request message from a Secure Micro (SM); a determination unit to determine whether to perform re-authentication depending on downloading of SM client image; an identification unit to identify an SM identifier using the key request message, when the re-authentication is performed as a result of the determination; an extraction unit to retrieve previous session information corresponding to the SM identifier and to extract keying information about the previous session information; and an encryption unit to control an encryption key about the SM client image to be reused, the SM client image being encrypted in a previous session based on the previous session information using the keying information.

Abstract: 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.

Abstract: A method where a Downloadable Conditional Access System Provisioning Server (DPS) detects a duplicated secure micro is provided. A method of detecting a duplicated secure micro, the method including: generating authentication time difference information associated with a value of a difference between a time when a host is finally authenticated in a first address and a time when the host is authenticated in a second address; comparing the authentication time difference information with a first reference value and a second reference value, the second reference value being less than the first reference value; and determining whether the secure micro is duplicated based on a result of the comparing.

Abstract: A method and apparatus of classifying downstream service flows for a cable modem is provided. A method of classifying downstream service flows, the method including: classifying a service flow based on a Quality of Service (QoS) using a destination address of an inputted packet; composing an internal header including corresponding service flow information based on the classifying of the service flow; and adding the internal header to the inputted packet.

Abstract: Provided is apparatus and method for transforming cable channel. The apparatus includes a data mixing unit for receiving and mixing a band data and a first broadband data, to thereby generate a second broadband data of a broadband cable channel, and a channel adapting unit for dividing a band data from the second broadband data received through the broadband cable channel, bypassing the second broadband data to a first subscriber apparatus and transmitting the band data to a second subscriber apparatus.

Abstract: Provided is a digital cable system and method for protecting a secure micro (SM) client, and more particularly, a digital cable system and method for protecting an SM program that can improve the security of an SM program through authentication of a host and integrity verification of the SM program. A method of protecting an SM program includes: receiving host authentication information associated with a host from a trusted authority; verifying validity of the secure micro program based on the host authentication information; and sending, to an authentication proxy, a HostStateInformation message that includes host state information associated with validity verification information of the SM program.

Abstract: Disclosed are payload formatting and deformatting methods for burst data loss recovery. The payload formatting method according to an embodiment of the present invention includes: generating an XOR operation packet by performing an XOR operation on the basis of a base layer packet and any one of enhancement layer packets of a group of pictures (GoP), the GoP including the base layer packet and the enhancement layer packets; and adding the XOR operation packet to the GoP.

Abstract: A method and an apparatus for providing video service according to example embodiments of the present invention are disclosed. The method for providing video service according to one example embodiment of the present invention comprises determining based on a predetermined reference whether it is necessary to set multiple bearers to provide the video service for a terminal, and when it is determined necessary to set the multiple bearers, setting an additional bearer, dividing a video source stream into a first stream and a second stream, assigning the first and second streams to a default bearer and the additional bearer, respectively, and transmitting the first and second streams to the terminal.

Abstract: A method and apparatus for management and transmission of a classified conditional access application to provide Downloadable Conditional Access System (DCAS) service according to disclosed embodiments is an effective managing method according to a type of a conditional access module in a software version in the DCAS. In particular, it relates to a method and apparatus which can continuously provide Pay per View (PPV) service during movement in a DCAS service operator (SO) network, such as maintaining independence of CAS SO in DCAS, provide adaptability to adapt to a variety of policies of the SO, and install an optimum application in a terminal.

Abstract: Provided are an apparatus and method for upstream transmission of variable bit rate traffic in a Hybrid Fiber Coaxial (HFC) network. The apparatus includes: a VoIP signal processing unit for digitizing a voice of a speaker to create a voice packet, detecting a mute section to suppress packet generation, and generating an Service identification (SID) packet in the mute section; a storage unit for storing the voice packet and the SID packet created by the VoIP signal processing unit and notifying information on the stored packets; a VoIP activity determining unit for determining a voice activity based on the information on the stored packets notified from the storage unit; and a packet processing unit for including the voice activity transferred from the VoIP activity determining unit in the packets from the storage unit to encapsulate them and transmit it to a network device.

Abstract: A method of controlling a download load of a Secure Micro (SM) client in a Downloadable Conditional Access System (DCAS) is provided. The method of controlling a download load of an SM client including: analyzing version information of SMs and version information of SM clients to control the download load generated in the DCAS, the version information of the SMs and the version information of the SM clients being provided from an Authentication Proxy (AP) server, and the SM clients being installed in the SMs; determining a download policy associated with a download time of a target SM client for the SMs based on a result of the analysis; and providing the AP server with the determined download policy.

Abstract: Provided is a method by which a cable modem reports a downstream packet resequencing status to a cable modem termination system, and more particularly, a method of effectively reporting detailed information on a packet resequencing status by further defining a packet resequencing-related event and event-related information in a message reporting the packet resequencing status. The method by which a cable modem reports a resequencing status of the resequenced packets includes the steps of: when a packet resequencing-related event occurs, generating a resequencing status message (CM-STATUS) including packet sequence numbers of packets causing the event; transmitting a band allocation request message for requesting a cable modem termination system to allocate an upstream band for transmission of the resequencing status message; and transmitting the resequencing status message to the cable modem termination system over the upstream band allocated by the band allocation request message.

Abstract: 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.

Abstract: Disclosed is a downloadable conditional access system (DCAS) including a key request unit to transmit a key request message to an authentication server, an authentication request unit to request authentication from the authentication server based on a key response message received from the authentication server in response to the key request message, and a session establishment unit to establish a session with the authentication server, based on an authentication response message received in response to the authentication request.

Abstract: Disclosed are a method and apparatus of scheduling a bandwidth in a cable network. The method includes receiving variable information set according to a condition of a network, calculating a packet time slot value in which a delay time gain is maximized using the received variable information; setting an algorithm allocating a bandwidth between channels of the network using the packet time slot value, and operating a Cable Modem Termination System (CMTS) according to the algorithm.

Abstract: A packet processing apparatus of a cable modem in hybrid fiber coaxial networks for processing a packet received from a cable modem termination system through a plurality of downstream channels is provided. A specific channel number is assigned to each channel and the cable modem termination system transmits downstream service identifier encoding information to the cable modem during an initializing process therebetween. The apparatus includes a plurality of channel receivers, each for generating an interface packet by inserting the channel number of a corresponding channel into the packet received through the corresponding channel; and an input controller that classifies the interface packet into a resequencing packet, which needs to be resequenced, and an ordinary packet, for which resequencing is not necessary, using the downstream service identifier encoding information and stores the resequencing packet and the ordinary packet.

Abstract: Provided is a method and apparatus for controlling an event of a cable modem and reporting a status of the cable modem, the method including: determining whether to periodically allocate a transmission bandwidth of a CM-STATUS message with respect to an event occurrence of the cable modem; setting an event control encoding that includes information regarding whether to periodically allocate the transmission bandwidth; and generating a MAC Domain Descriptor (MDD) message containing the event control encoding to transmit the generated MDD message.

Abstract: A method and apparatus for allocating upstream channel resources in a hybrid fiber coaxial (HFC) network are provided. A cable modem termination system (CMTS) previously provides cable modems (CMs) with a plurality of burst profiles through an extended interval usage code (IUC) of an upstream channel descriptor (UCD) message, and allocates resources to CMs by using an optimized burst profile according to an upstream channel status, thereby increasing transmission efficiency of an upstream channel.

Abstract: A method for installing different security clients for channels in a terminal in a conditional access system includes: searching one or more channels searchable in the terminal; requesting, for respective searched channels, security clients necessary for receiving pay programs to be transmitted through the searched channels, to a broadcasting station which takes charge of the searched channels; and downloading and installing, for respective searched channels, the requested security clients from the broadcasting station.