2,581 research outputs found

    The rise and demise of Lucent Technologies

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    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

    The MobyDick Project: A Mobile Heterogeneous All-IP Architecture

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    Proceedings of Advanced Technologies, Applications and Market Strategies for 3G (ATAMS 2001). Cracow, Poland: 17-20 June, 2001.This paper presents the current stage of an IP-based architecture for heterogeneous environments, covering UMTS-like W-CDMA wireless access technology, wireless and wired LANs, that is being developed under the aegis of the IST Moby Dick project. This architecture treats all transmission capabilities as basic physical and data-link layers, and attempts to replace all higher-level tasks by IP-based strategies. The proposed architecture incorporates aspects of mobile-IPv6, fast handover, AAA-control, and Quality of Service. The architecture allows for an optimised control on the radio link layer resources. The Moby dick architecture is currently under refinement for implementation on field trials. The services planned for trials are data transfer and voice-over-IP.Publicad

    A Proximity based Retransmission Scheme for Power Line Ad-hoc LAN

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    Power line as an alternative for data transmission is being explored, and also being used to a certain extent. But from the data transfer point of view, power line, as a channel is highly dynamic and hence not quite suitable. To convert the office or home wiring system to a Local Area Network (LAN), adaptive changes are to be made to the existing protocols. In this paper, a slotted transmission scheme is suggested, in which usable timeslots are found out by physically sensing the media. Common usable timeslots for the sender-receiver pair are used for communication. But these will not ensure safe packet delivery since packets may be corrupted on the way during propagation from sender to receiver. Therefore, we also suggest a proximity based retransmission scheme where each machine in the LAN, buffers good packet and machines close to the receiver retransmit on receiving a NACK.Comment: Already published in IJDP

    Coordinating heterogeneous IoT devices by means of the centralized vision of the SDN controller

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    The IoT (Internet of Things) has become a reality during recent years. The desire of having everything connected to the Internet results in clearly identified benefits that will impact on socio economic development. However, the exponential growth in the number of IoT devices and their heterogeneity open new challenges that must be carefully studied. Coordination among devices to adapt them to their users' context usually requires high volumes of data to be exchanged with the cloud. In order to reduce unnecessary communications and network overhead, this paper proposes a novel network architecture based on the Software-Defined Networking paradigm that allows IoT devices coordinate and adapt them within the scope of a particular context.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Identification of metrics used by decision makers to determine the efficacy of wireless communication systems in higher education

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    This research described the wireless network technologies that are available for use in higher education, determined the categories of metrics used to evaluate wireless network efficacy, and yielded a self-assessment instrument for guiding small college administrators considering wireless local area network systems.;The features and benefits of contemporary wireless systems in higher education were identified through a review of the professional journals, government publications, and standards industry documentation. The literature identified three categories of metrics beneficial for the evaluation of efficacy of wireless campus local area networks: cost, speed, and reliability. After identification of these categories of metrics, a modified Delphi technique was administered to ten wireless network experts in higher education. The expert group was made up of seven higher education wireless decision makers and three wireless industry professionals.;The wireless experts responded to Instrument One which identified 27 metrics in the three categories of metrics. The experts generated 19 essential metrics: four in the category of cost, seven in the category of speed, and eight in the category of reliability. Eight supplemental metrics were also identified in Instrument One: four in the category of cost, two in the category of speed, and two in the category of reliability.;Instrument Two generated 27 questions that could guide wireless decision makers in higher education. These metrics offer a timeless guide to wireless system planning on small college campuses. The self-assessment instrument will assist in gathering information specific to the small college environment, and in gathering current specifications for wireless network systems. The analysis of information gained from the use of this tool will help wireless campus networks to operate as an integrated part of teaching and learning

    WISP: a wireless information security portal

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    M.Sc.Wireless networking is a fairly new technology that is important in information technology (IT). Hotels, Airports, Coffee shops, and homes are all installing wireless networks at a record pace, making wireless networks the best choice for consumers. This popularity of wireless networks is because of the affordability of wireless networks devices, and the easy installation [11]. In spite of the popularity of the wireless networks, one factor that has prevented them from being even more widespread can be summed up in a single word: security. It comes as no surprise that these two – wireless and security – converge to create one of the most important topics in the IT industry today [11]. Wireless networks by nature bring about new challenges unique to its environment. One example of these new challenges is: “Signal overflow beyond physical walls”, and with these kinds of new challenges unique to wireless networks, we have new security risks. Hence wireless networks lend themselves to a host of attack possibilities and risks. That is because wireless networks provide a convenient network access point for an attacker, potentially beyond the physical security controls of the organization [7]. Therefore it is challenging for managers to introduce wireless networks and properly manage the security of wireless networks, Security problems of wireless networks are the main reason for wireless networks not being rolled out optimally [1]. In this dissertation, we aim to present to both specialist and non–specialists in the IT industry the information needed to protect a wireless network. We will first identify and discuss the different security requirements of wireless networks. After that we shall examine the technology that helps make wireless networks secure, and describe the type of attacks against wireless networks and defense techniques to secure wireless networks. The research will concentrate on wireless LANs (Local Area Networks), and leading wireless LAN protocols and standards. The result of the research will be used to create WISP (A Wireless Information Security Portal). WISP will be a tool to support the management of a secure wireless network, and help assure the confidentiality, integrity, and availability of the information systems in a wireless network environment

    A review of personal communications services

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    This article can be accessed from the link below - Copyright @ 2009 Nova Science Publishers, LtdPCS is an acronym for Personal Communications Service. PCS has two layers of meaning. At the low layer, from the technical perspective, PCS is a 2G mobile communication technology operating at the 1900 MHz frequency range. At the upper layer, PCS is often used as an umbrella term that includes various wireless access and personal mobility services with the ultimate goal of enabling users to freely communicate with anyone at anytime and anywhere according to their demand. Ubiquitous PCS can be implemented by integrating the wireless and wireline systems on the basis of intelligent network (IN), which provides network functions of terminal and personal mobility. In this chapter, we focus on various aspects of PCS except location management. First we describe the motivation and technological evolution for personal communications. Then we introduce three key issues related to PCS: spectrum allocation, mobility, and standardization efforts. Since PCS involves several different communication technologies, we introduce its heterogeneous and distributed system architecture. IN is also described in detail because it plays a critical role in the development of PCS. Finally, we introduce the application of PCS and its deployment status since the mid-term of 1990’s.This work was supported in part by the National Natural Science Foundation of China under Grant No. 60673159 and 70671020; the National High-Tech Research and Development Plan of China under Grant No. 2006AA01Z214, and the Engineering and Physical Sciences Research Council (EPSRC) of UK under Grant EP/E060722/1
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