Digital Storage Media Command Research Articles

재구성이 가능한 범용 DSM-CC 아키텍처와 사용자 선호도 기반의 캐시 관리 전략

GEM(Globally Executable MHP) 기반의 MHP(Multimedia Home Platform), OCAP(OpenCable Application Platform), ACAP(Advanced Common Application Platform) 등은 현재 디지털 방송의 대표적인 미들웨어이다. 이러한 미들웨어에 사용된 MPEG-2와 DSM-CC(Digital Storage Media-Command and Control) 프로토콜 표준은 많은 부분이 유사하다는 특징을 가지고 있지만 각 DTV 미들웨어가 필요로 하는 정보와 데이터 구조가 조금씩 차이가 있다. 이는 결과적으로 미들웨어간의 비호환성을 야기한다. 본 논문에서는 다양한 미들웨어 표준을 모두 지원할 수 있는 통합 DTV 미들웨어를 개발하기 위한 노력의 일환으로써, 재구성이 가능한 범용 DSM-CC 아키텍처를 제안한다. 첫째, 모든 GEM 기반의 미들웨어가 공통적으로 필요로 하는 DSM-CC 컴포넌트를 정의하였다. 둘째, 각 미들웨어가 필요로 하는 정보와 데이터 구조를 XML 형태로 정의하여 별도의 수정 없이 정적, 혹은 동적으로 특정 미들웨어에 맞추어 적용할 수 있도록 하였다. 또한, 셋탑박스의 전체적인 성능과 연관성이 높은 어플리케이션 응답시간과 DSM-CC 모듈의 사용빈도를 향상시키기 위해 사용자의 선호도를 고려한 캐시 관리 전략을 제안하고, 제안된 캐시 관리 전략이 응답시간을 줄이는데 효과적임을 실험을 통해서 확인하였다. In current digital broadcasting systems, GEM(Globally Executable MHP)-based middlewares such as MHP(Multimedia Home Platform), OCAP(OpenCable Application Platform), ACAP(Advanced Common Application Platform) are the norm. Despite much of the common characteristics shared, such as MPEG-2 and DSM-CC(Digital Storage Media-Command and Control) protocols, the information and data structures they need are slightly different, which results in incompatibility issues. In this paper, in line with an effort to develop an integrated DTV middleware, we propose a general-purpose, reconfigurable DSM-CC architecture for supporting various standard GEM-based middlewares without code modifications. First, we identify DSM-CC components that are common and thus can be shared by all GEM-based middlewares. Next, the system is provided with middleware-specific information and data structures in the form of XML. Since the XML information can be parsed dynamically at run time, it can be interchanged either statically or dynamically for a specific target middleware. As for the performance issues, the response time and usage frequency of DSM-CC module highly contribute to the performance of STB(Set-Top-Box). In this paper, we also propose an efficient application cache management strategy and evaluate its performance. The performance result has shown that the cache strategy reflecting user preferences greatly helps to reduce response time for executing application.

A DAVIC-based video-on-demand system over IP networks

This paper describes the design and implementation of a video-on-demand system which is DAVIC compliant so as to ensure interoperability across vendors, applications and services. The system is based on a client-server architecture comprising the service gateway, the video server and the clients (which are the set-top units). Interoperability is accomplished through the use of DAVIC stipulated CORBA-based Digital Storage Media-Command and Control (DSM-CC) protocols and ATM pre-established permanent virtual circuits. The former is adopted for communication among the different system entities over the network while the latter handles the real-time audio/video transportation. The proposed system has successfully completed an interoperability test conducted with Panasonic Singapore Laboratories, JVC Singapore and the Nanyang Technological University over the Singapore ONE ATM Testbed attesting to its compliance to DAVIC's interoperability standards.

A DAVIC-based video-on-demand system over ATM networks

This paper describes the design and implementation of a video-on-demand system which is DAVIC compliant so as to ensure interoperability across vendors, applications and services. The system is based on a client-server architecture comprising the service gateway, the video server and the clients (which are the set-top units). Interoperability is accomplished through the use of DAVIC stipulated CORBA-based Digital Storage Media-Command and Control (DSM-CC) protocols and ATM pre-established permanent virtual circuits. The former is adopted for communication among the different system entities over the network while the latter handles the real-time audio/video transportation. The proposed system has successfully completed an interoperability test conducted with Panasonic Singapore Laboratories, JVC Singapore and the Nanyang Technological University over the Singapore ONE ATM Testbed attesting to its compliance to DAVIC's interoperability standards.

A VoD Application Implemented in Java

This article describes an implementation of a Video-on-Demand (VoD) system for the VoD interoperability test laboratory of the National Institute of Standards and Technology. It describes how Java can be used to implement the client side of a DAVIC based client-server system, which consists of a video server and a Set-Top Unit (STU) client. The communication between the video server and the STU is based on the Digital Storage Media Command and Control (DSM-CC) protocols. The VoD application is defined as a set of Java classes. These classes implement the graphical interfaces for user navigation and control. While this system is compliant with DAVIC specifications, it also permits an elegant integration of DAVIC services to the Internet environment.

Multimedia information broadcasting using digital TV channels

The structure of a new system used to broadcast multimedia information within a digital TV channel is outlined. The proposed scheme is based on the the Digital Storage Media Command and Control (DSM-CC) functions, and uses a newly developed protocol that allows to efficiently convey multimedia information. Such information has the same characteristics of HTML files used in WWW environments, as it may contain text, images, sounds and animation organized as an hypertext. The transport structure used is the MPEG-2 Transport Stream, which is the most standardized platform for the development of new digital TV services. A prototype software was developed to encode the file system by means of DSM-CC operations and include it in a MPEG-2 compatible Transport Stream.

An introduction to digital storage media-command and control

Digital storage media-command and control (DSM-CC) is a very recent ISO/IEC standard developed for the delivery of multimedia broadband services. Open protocols in this area are essential for the widespread deployment of such services. Total interoperability between service providers and consumers will require many different aspects of broadband service delivery to be addressed. This article gives an introductory overview of the different functions covered by the DSM-CC standard. Its purpose is to convey the scope of the DSM-CC standard and the basic reference model that underpinned the development of the standard.

Digital storage of media-command and control protocol applied to ATM

Digital storage media-command and control (DSM-CC) is a set of protocols for the delivery of integrated video-based multimedia services over networks, including delivery over residential broadband networks to homes. Open protocols in this area are essential for widespread deployment of interactive multimedia services to homes. After describing the basic reference model of DSM-CC and its concept of session and multiresource connection, this paper examines how DSM-CC can work over broadband ATM networks. A series of ATM network architectures is described along with the DSM-CC and Q.2931 message flows that together set up sessions and allocate connections between servers and clients. The characteristics of each ATM network architecture are briefly discussed.