A hybrid storage technology for low power consumption and high I/O performance in an IPTV set-top box

A new method of prefetching data blocks from the NVCache to the page cache in main memory and cascading prefetching n-blocks from a hard disk to the NVCache together was proposed to reduce the spin-up frequency of a hybrid hard disk drive and thus enhance I/O performance.The proposed method consists of three steps:1) Analyzing the pattern of read requests in block units;2) Determining the number of blocks prefetched to the NVCache;3) Replacing blocks in the NVCache according to the block replacement policy.The proposed method can reduce the latency time of a hybrid hard disk and optimize the power consumption of an IPTV set-top box.Experimental results show that the proposed method provides better average response time compared to an existing adaptive multistream prefetching(AMP) method by 25.17%.It also reduces by 20.83% the average power consumption over that of the existing external caching in energy saving storage system(EXCES) method.

Storing and Searching Metadata for Digital Broadcasting on Set-Top Box Environments

Digital broadcasting is a novel paradigm for the next generation broadcasting. Its goal is to provide not only better quality of pictures but also a variety of services that is impossible in traditional airwaves broadcasting. One of the important factors for this new broadcasting environment is the interoperability among broadcasting applications since the environment is distributed. Therefore the broadcasting metadata becomes increasingly important and one of the metadata standards for a digital broadcasting is TV-Anytime metadata. TV-Anytime metadata is defined using XML schema, so its instances are XML data. In order to fulfill interoperability, a standard query language is also required and XQuery is a natural choice. There are some researches for dealing with broadcasting metadata. In our previous study, we have proposed the method for efficiently managing the broadcasting metadata in a service provider. However, the environment of a Set-Top Box for digital broadcasting is limited such as low-cost and low-setting. Therefore there are some considerations to apply general approaches for managing the metadata into the Set-Top Box. This paper proposes a method for efficiently managing the broadcasting metadata based on the Set-Top Box and a prototype of metadata management system for evaluating our method. Our system consists of a storage engine to store the metadata and an XQuery engine to search the stored metadata and uses special index for storing and searching. Our two engines are designed independently with hardware platform therefore these engines can be used in any low-cost applications to manage broadcasting metadata.

数字家庭技术专栏(六):数字Set-Top Box技术解析

消费性电子产品(Consumer Electronics)近来比信息科技产业更引人注目，因为尽管经济景气自2001年起就逐步下滑，消费性电子产品市场仍持续地成长。今日，数字电视(DTV)已成为快速兴起的消费性电子产品之一。我们能利用它的平台功能发展家庭多媒体平台(multimedia home platform；MHP)，提供个人计算机(PC)之外，另一个能与因特网连接(Internet)的管道，让我们拥有更丰富的多媒体生活。这也意味着庞大的商机。由于DTV接收数据的方式和机上盒(STB)相似，我们可藉由研究STB的架构来了解DTV。

Research and Application of VOD System on Teaching

Structure and working theory of VOD system on teaching is discussed in this paper. The 50M data stream adapter is effective to debase the needs for video server and to enhance the ratio of performance to price.The flow chart for NVOD/TVOD is displayed and a 64-channel VOD system for teaching was construted.