東芝グループにおけるスキル標準の開発と展開

A cellular mobile telephone system is usually divided into service areas that are employed for different mobility management needs. For instance, sites in the system are grouped into location areas that are used to find mobiles and terminate incoming calls. In this way, the system only needs to track the movement of users when they cross from one service area to another. Still, since the tracking is done using radio bandwidth that is needed for telephone calls, it is important to carefully design the service areas to minimize the mobility management load. The authors define the characteristics that are needed in the service areas for digital cellular systems and state the service area design problem as a graph partitioning optimization problem where the goal is to minimize the diameter of the resulting subgraphs. A heuristic technique is then proposed to design service areas in a systematic and efficient way. This technique achieves better utilization of system resources and produces service areas whose characteristics are close to optimal. >

One of the goals of digital cellular radio communication systems is described as reducing frequency spectrum congestion, for which the implementation of cellular packet switched data is considered. Due to the bursty nature of many data applications, one solution for conserving RF spectrum is to multiplex packet data from multiple mobile stations into RF channels. In essence, the packet-switched RF channels become an additional traffic concentration point. The author proposes such an adaptation to digital cellular mobile telephone systems and points to necessary extensions of the existing US cellular signaling standard to make such an implementation possible. >

In a digital TV system, the Conditional Access (CA) system is essential to protect programs from unauthorized access. However, the encryption technique alone is not sufficient to protect or control the use of contents after decryption. To provide flexible and complete Digital Rights Management (DRM) protection on the Digital Video Broadcasting (DVB) programs, we propose a method that adapts the MPEG- 21 REL technology and integrates it into a DVB-T system. By extending the Service Information (SI) section of a DVB stream to include an REL license, the transmitted content can be conveniently consumed and legally protected. Our design is verified by an experimental hardware system. The results show that the proposed method can provide both the conditional access functionality and the usage control of broadcasted contents.

Image coding plays a very important role in a digital TV system. In this paper we focus on the discussion of the image compression in DTV systems. We propose a regular, efficient algorithm, which has effectively much lower complexity. Our algorithm would require only 12 bits of coefficient wordlengths to achieve the CCITT/ISO specification. But the traditional method would need 12~18 bits to achieve the same specification. The hardware cost is about 35% higher than the traditional method. But the input block length to our design is 64, which is much higher than traditional algorithm, whose block length is generally between 8 and 16. This dictates that the throughput of our algorithm is about 2 to 4 time higher than the traditional algorithms.

To understand how people really interact with digital TV and digital video recorder (DVR) systems, 10 people were recruited, 6 with DVRs and 4 with non-DVR digital cable or satellite TV systems. Video-recording equipment was set up in their homes to record their TV viewing. The person viewing as well as the TV content being viewed were recorded as the person watched TV. Afterwards, the recordings were reviewed and analyzed by the experimenter together with the viewer, who then described his or her behavior. The results show that overall the most common way people interacted with TV was in avoiding advertisements and finding new programming to watch when the current show ended. These results can be used to find ways to improve how users experience TV systems.

Depois de quase uma década das diretrizes estabelecidas sobre o sistema digital de TV no Brasil é importante esclarecer como as emissoras se adaptaram, em especial as regionais, uma vez que são elas que possuem maior proximidade com o público local e, ao mesmo tempo, por motivos comerciais, podem ter mais dificuldades para implementar a digitalização total do sistema. Portanto, ao estabelecer tal apontamento o presente artigo contribui com o desenvolvimento e os estudos do sistema digital adquirido pelas emissoras regionais localizadas na região de Campinas, São Paulo, Brasil. Compreende-se que o sistema digital brasileiro teve um grande planejamento técnico, subdividido em várias categorias, mas paralisou-se ao ser posto em prática nas emissoras.

Optimal Paging in Cellular Mobile Telephone Systems

Digital TV systems are becoming increasingly complex. Less-technically-inclined people may find these systems difficult to use. This qualitative usability study observed less-technically-inclined people using a typical multi-device, multi-remote-control digital TV system after having been instructed by a more-technically-inclined member of their household, who had also just discovered how to use the system. The results showed that, overall, the problems experienced by the less-technically-inclined people were similar in nature to those experienced by the more-technically-inclined household member. The most serious problems involved determining which remote control to use for a given function, making remote control mode errors, and having difficulty going back to TV from recordings and locked channels.

Cellular mobile telephone systems are rapidly going into service throughout the Continental United States. They are being installed in a large variety of vehicles both of domestic and of foreign manufacture. In this paper we discuss the physical, climatic, and electronic environments which cellular telephones may expect to encounter in nationwide service. We also discuss procedures used to evaluate the ability of a cellular phone to operate without failure in these environments and to avoid interfering with the increasingly complex vehicular electronic systems.

Cellular mobile telephone systems are rapidly going into service throughout the Continental United States. They are being installed in a large variety of vehicles both of domestic and of foreign manufacture. In this paper we discuss the physical, climatic, and electronic environments which cellular telephones may expect to encounter in nationwide service. We also discuss procedures used to evaluate the ability of a cellular phone to operate without failure in these environments and to avoid interfering with the increasingly complex vehicular electronic systems.

Superstorm Sandy, and similar disasters, have demonstrated the vulnerability of the nation's cellular telephone systems. Difficulties include overloads when usage suddenly increases; physical destruction of tower sites; and lack of sustained backup power. In contrast, US terrestrial broadcasters have a proven track-record to supply emergency information reliably, over large geographical areas and for as long as needed, as witnessed in the New York and New Jersey areas as well as in New Orleans (Katrina). Furthermore, digital television service to the home is now extended to mobile digital television (mobile DTV) serving portable and handheld devices including those in high speed vehicles. Mobile DTV is currently deployed in 50 major US cities by more than 140 stations with many more in the planning stages. Recently, the ATSC (Advanced Television Systems Committee) has also standardized the Mobile Emergency Alert System (M-EAS). M-EAS can provide both the familiar text "crawl" emergency alerts, and more complex and useful rich media information such as maps and video. M-EAS can be implemented in stand-alone devices, in cellular telephones, and/or in accessory hardware for existing devices.

SUMMARYLong‐distance trips are generally under‐reported in typical household surveys, because of relative low frequency of these trips. This paper proposes to utilize location data from cellular phone systems in order to study long‐distance travel patterns. The proposed approach allows passive data collection on many travelers over a long period of time at low costs. The paper presents the results of a study that applies cellular phone technology to assess trips at the national level. The method was specifically designed to capture long distance trips, as part of the development of a national demand model conducted for the Economics and Planning Department of the Israel Ministry of Transport. The method allows the construction of origin–destination tables directly from the cellular phone positions. The paper presents selected results to illustrate the potential of the method for transportation planning and analysis. Copyright © 2011 John Wiley & Sons, Ltd.

At the present, the digital TV allows the access to a greater amount of content and to execute interactive applications. The remote control used to control the digital TV systems is, in most cases, still solved by the traditional infrared remote control, which has become a limiting factor on the user interaction with the TV. This paper introduces the design and development of an interaction device for use in the context of digital TV in Argentina. The proposed device can be considered an evolution of the classic remote control, in which the functionality of hand gesture recognition is implemented as a natural and friendly interface for controlling digital TV systems of the home. A gestural dictionary of 20 types of gestures was adopted. The recognized gestures are translated into control commands for digital TV systems. As the hand gesture recognition is a pattern classification problem, two techniques based on artificial neural networks were explored, in order to compare results and to select the tool that best fits the problem in question. The pattern classifier design was described in detail, in order to properly select the hardware platform, fulfilling requirements of low-cost and fast execution of pattern classification algorithms. An interaction device of low-cost and excellent recognition precision was developed, for enhancing and enriching the user experience.

The article following, written by one of the lead engineers in the project, describes the development of AMPS, the first cellular telephone system in the United States. As noted, the project ran for over 12 years and required the services of a vast number of engineers at AT&T's Bell Labs. The hundreds of millions of people currently using cellphones, smart phones, and all the other mobile wireless equipment available in the United States, as well as everywhere else in the world, often take these devices and the infrastructure behind them for granted. Until the cellular concept was recognized, it wasn 't clear that many mobile phones could simultaneously share the same channels in a local area. With the cellular concept agreed on, problems such as tracking of cell phones and handoff from cell to cell had to be resolved. Computerized base stations had to be designed and tested. A myriad other important development and design issues and problems had to be resolved. Dick Frenkiel very clearly describes the various engineering problems that had to be solved, step by step, sometimes quite painstakingly. He gives credit to the many teams of Bell engineers who worked on this project. He also points out policy issues involving the FCC that had to be resolved. Competition for scarce radio spectral space was fierce. Competing engineering companies and telephone operators had to be assuaged. In the meantime, I urge you to read on through this exciting description of the genesis of cellular telephony in the United States.

The cellular radio system is sometimes called a mobile phone system or a car phone system. Due to the daily needs of subscribers, cellular systems have expanded considerably all over the world. This article discusses the history of cellular systems and the difficulty of deploying them in the mobile radio environment, elaborating on employing digital cellular systems, Personal Communication Services (PCS) mobile satellite systems, and the future IMT‐2000 system.