ISDN at NASA Lewis Research Center

An expository investigation of the potential impact of the Integrated Services Digital Network (ISDN) at NASA Lewis Research Center is described. To properly frame the subject, the paper contains a detailed survey of the components of Narrowband ISDN. The principles and objectives are presented as decreed by the Consultative Committee for International Telephone and Telegraph (CCITT). The various channel types are delineated and their associated service combinations are described. The subscriber-access network functions are explained pictorially via the ISDN reference configuration. A section on switching techniques is presented to enable the reader to understand the emergence of the concept of fast packet switching. This new technology is designed to operate over the high bandwidth, low error rate transmission media that characterizes the LeRC environment. A brief introduction to the next generation of networks is covered with sections on Broadband ISDM (B-ISDN), Asynchronous Transfer Mode (ATM), and Synchronous Optical Networks (SONET). Applications at LeRC are presented, first in terms of targets of opportunity, then in light of compatibility constraints. In-place pilot projects and testing are described that demonstrate actual usage at LeRC

MIRAI Architecture for Heterogeneous Network

One of the keywords that describe next-generation wireless communications is "seamless." As part of the e-Japan Plan promoted by the Japanese Government, the Multimedia Integrated Network by Radio Access Innovation project has as its goal the development of new technologies to enable seamless integration of various wireless access systems for practical use by 2005. This article describes a heterogeneous network architecture including a common tool, a common platform, and a common access. In particular, software-defined radio technologies are used to develop a multiservice user terminal to access different wireless networks. The common platform for various wireless networks is based on a wireless-supporting IPv6 network. A basic access network, separated from other wireless access networks, is used as a means for wireless system discovery, signaling, and paging. A proof-of-concept experimental demonstration system is available

Troli tong gas

Tong gas adalah sebahagian daripada keperluan rumah yang sangat penting untuk kegunaan dapur. LPG (Liquefied Petroleum Gas), atau petroleum gas biasanya digunakan untuk aplikasi perumahan (tong gas masak) dan tujuan komersial. LPG terutamanya terdiri daripada campuran hidrokarbon seperti propana (C3H8), propene (C3H6), n-butana (C4H10), isobutena (metil-propana), dan pelbagai butanes lain (C4H8) (Mustapa, Gitano Briggs, 2008). LPG disimpan cair dalam tong pada tekanan tinggi, tekanan wap sekitar 6 hingga 7 bar (Petrolium Nasional Berhad, 2013). Oleh itu, tong gas perlu diperbuat daripada silinder keluli bertekanan tinggi. Tong gas digunakan hampir di semua perumahan, termasuk rumah pangsa, kondominium dan apartment. Kebiasaan penghuni perumahan bertingkat yang tidak mempunyai lift terpaksa mengangkat tong gas menggunakan tenaga empat kerat, kadang kala menggunakan troli biasa untuk menggangkut tong gas tersebut bagi memudahkan dan meringankan kerja. Troli adalah peranti yang digunakan untuk membawa beban atau memindahkan bahan dari satu tempat ke yang lain. Untuk aplikasi yang berbeza pelbagai jenis troli digunakan Kebanyakan pekerja domestik juga menggunakan tenaga tulang empat kerat untuk kerja-kerja pemindahan troli .

Future benefits and applications of intelligent on-board processing to VSAT services

The trends and roles of VSAT services in the year 2010 time frame are examined based on an overall network and service model for that period. An estimate of the VSAT traffic is then made and the service and general network requirements are identified. In order to accommodate these traffic needs, four satellite VSAT architectures based on the use of fixed or scanning multibeam antennas in conjunction with IF switching or onboard regeneration and baseband processing are suggested. The performance of each of these architectures is assessed and the key enabling technologies are identified

Influence of the public transportation system on the air quality of a major urban center. A case study: Milan, Italy

A sampling campaign was conducted in the city of Milan, Italy before and during a transportation strike in January 2004. This strike provided a unique opportunity to investigate the influence of public transportation on the air quality in a major metropolitan area. Twenty-four air samples were collected each day around the city on January 2nd, 7th and 9th. The samples were analyzed for methane, carbon monoxide, non-methane hydrocarbons (NMHCs), halocarbons and alkyl nitrates. Significant differences in the mixing ratios were observed among the three days of sampling, with January 2nd showing the lowest concentrations as a result of decreased activity in the city during the holiday season. January 9th showed the highest NMHC concentrations because of increased vehicular activity in the city due to a public transportation strike. This paper investigates the correlation between the increased number of vehicles and decreased air quality because of a reduction in public transportation. Computer simulations were able to reproduce measurements of ozone production during the January 2004 strike and a July 2005 strike. The measurements and simulations suggest that reduced VOC emissions due to the existence of public transportation lowers peak ozone by 11-33% during the summer months. © 2008 Elsevier Ltd. All rights reserved

The role of HiPPI switches in mass storage systems: A five year prospective

New standards are evolving which provide the foundation for multi-gigabit per second data communication structures. The lowest layer protocols are so generalized that they encourage a wide range of application. Specifically, the ANSI High Performance Parallel Interface (HiPPI) is being applied to computer peripheral attachment as well as general data communication networks. The HiPPI Standards suite and technology products which incorporate the standards are introduced. The use of simple HiPPI crosspoint switches to build potentially complex extended 'fabrics' is discussed in detail. Several near term applications of the HiPPI technology are briefly described with additional attention to storage systems. Finally, some related standards are mentioned which may further expand the concepts above

Quality of Service over Specific Link Layers: state of the art report

The Integrated Services concept is proposed as an enhancement to the current Internet architecture, to provide a better Quality of Service (QoS) than that provided by the traditional Best-Effort service. The features of the Integrated Services are explained in this report. To support Integrated Services, certain requirements are posed on the underlying link layer. These requirements are studied by the Integrated Services over Specific Link Layers (ISSLL) IETF working group. The status of this ongoing research is reported in this document. To be more specific, the solutions to provide Integrated Services over ATM, IEEE 802 LAN technologies and low-bitrate links are evaluated in detail. The ISSLL working group has not yet studied the requirements, that are posed on the underlying link layer, when this link layer is wireless. Therefore, this state of the art report is extended with an identification of the requirements that are posed on the underlying wireless link, to provide differentiated Quality of Service

The rise and demise of Lucent Technologies

We analyze the rise and demise of Lucent Technologies from the time that it was spun off from AT&T in April 1996 to its merger with Alcatel in December 2006. The analysis, contained in the three sections that form the body of this paper, considers three questions concerning Lucent’s performance over the decade of its existence. 1.How was Lucent, with over $20 billion in sales in 1995 as a division of AT&T, able to almost double its size by achieving a compound growth rate of over 17 percent per year from 1995 to 1999? 2.What was the relationship between Lucent’s growth strategy during the Internet boom and the company’s financial difficulties in the Internet crash of 2001-2003 when the Lucent was on the brink of bankruptcy? 3.After extensive restructuring during the telecommunications industry downturn of 2001-2003, why was Lucent unable to re-emerge as an innovative competitor in the communications equipment industry when the industry recovered?Communications equipment; innovation; global competition; financialization

CSMA/RN: A universal protocol for gigabit networks

Networks must provide intelligent access for nodes to share the communications resources. In the range of 100 Mbps to 1 Gbps, the demand access class of protocols were studied extensively. Many use some form of slot or reservation system and many the concept of attempt and defer to determine the presence or absence of incoming information. The random access class of protocols like shared channel systems (Ethernet), also use the concept of attempt and defer in the form of carrier sensing to alleviate the damaging effects of collisions. In CSMA/CD, the sensing of interference is on a global basis. All systems discussed above have one aspect in common, they examine activity on the network either locally or globally and react in an attempt and whatever mechanism. Of the attempt + mechanisms discussed, one is obviously missing; that is attempt and truncate. Attempt and truncate was studied in a ring configuration called the Carrier Sensed Multiple Access Ring Network (CSMA/RN). The system features of CSMA/RN are described including a discussion of the node operations for inserting and removing messages and for handling integrated traffic. The performance and operational features based on analytical and simulation studies which indicate that CSMA/RN is a useful and adaptable protocol over a wide range of network conditions are discussed. Finally, the research and development activities necessary to demonstrate and realize the potential of CSMA/RN as a universal, gigabit network protocol is outlined