Abstract The rapid spread in the use of smartphones and cloud-based services has accelerated the speed of evolution of telecommunications application software, resulting in a great diversity of such software. While the quality of experience (QoE) of telecommunications services has been directly related to network performance in the past, the current situation is not that simple. This is because the QoE of telecommunications applications is affected not only by network performance, but also by server and terminal performance to a great extent. In this article we propose a framework for improving user QoE, and we introduce recent research and development activities underway at NTT intended to achieve this goal.
Abstract This article introduces a quality-monitoring model that can be used to estimate end-users' quality of experience of Internet protocol television services using packet header information. This model can be used for in-service quality monitoring.
Abstract The recent proliferation of smartphones and tablet terminals has resulted in the rapid development of video applications. However, in wireless access lines such as those for LTE (Long Term Evolution) and 3G (third-generation) services, packet loss rates and variations in the delay are larger than those in fixed access lines. As a result, video services implemented in TCP (transmission control protocol), known as progressive download (PDL)-based video services, are especially pervasive on wireless access lines.
In this article, we introduce a method of playback state estimation of PDL-based video services. This method makes it possible to accurately estimate the playback state, which will improve the efficiency of monitoring the quality of video services in network and service operation processes.
Abstract Corporate application services using cloud computing are coming into wide use. These services include SaaS (Software as a Service), a delivery model for cloud-hosted software applications, and are provided via networks. Therefore, the state of the network and of the user terminal determines whether the performance assumed in the application development is achieved. This article describes methods we developed for estimating the waiting time experienced by the user and for determining whether or not a decrease in performance was caused by the user terminal. These methods make it possible to visualize application performance and to provide support when performance declines in browser-based applications, which are the main type of corporate application services.
Abstract Technological advances in three-dimensional (3D) video enable users to watch 3D video content. However, watching such content may cause visual discomfort and fatigue. This article gives an outline of the relationship between 3D video degradation factors and quality of experience (QoE) and introduces QoE assessment methodologies and standardization activities.
Abstract The 1960s brought about the advent of the intense development of semiconductor devices for industrial and commercial applications. Since then, NTT has taken the initiative in introducing semiconductor devices into telecommunication networks to realize highly reliable and miniaturized equipment with high performance.
This article reviews the failure physics approach we have been using to develop highly reliable semiconductor devices. It also summarizes our findings regarding device failures in field use and discusses a failure rate prediction model based on the findings.
Abstract The recent prevalence of IP (Internet protocol) based services has increased the demand for transport network technology that can efficiently accommodate both packet-based and circuit-based traffic while achieving almost the same operation and maintenance capabilities as traditional transport networks such as synchronous digital hierarchy or optical transport networks. Thus, ITU-T (International Telecommunication Union, Telecommunication Standardization Sector) has developed a packet transport technology called MPLS-TP (multiprotocol label switching-transport profile) in collaboration with IETF (Internet Engineering Task Force).
This article introduces the overview and history of MPLS-TP standardization.