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Communication Applications (communication + application)

Distribution by Scientific Domains
Engineering62%

Selected Abstracts

Friends night out,A working prototype of a blended lifestyle service enabled through IMS

BELL LABS TECHNICAL JOURNAL, Issue 4 2006
Tung Ching Chiang
This letter describes the design and implementation of a prototype application intended to demonstrate how the IP Multimedia Subsystem (IMS) platform could be used to create blended services that help enhance a user's lifestyle. Communication applications (e.g., group instant messaging and voice conferencing) are blended with collaboration services (e.g., shared Webbrowsing and shared streaming video) and location-based services to create a compelling scenario that makes planning a night out with friends both convenient and fun. Several IMS components and protocols are used to achieve the blending. A seamless user interface is created through the use of an integrated Session Initiation Protocol (SIP) client and a unified graphical user interface (GUI). This prototype, which is being showcased in major tradeshows around the world, is serving as a foundation for planning new features for Lucent Technologies' IMS portfolio. © 2006 Lucent Technologies Inc. [source]

Structural Characterization of Multi-Quantum Wells in Electroabsorption-Modulated Lasers by using Synchrotron Radiation Micrometer-Beams

ADVANCED MATERIALS, Issue 18 2010
Lorenzo Mino
Advanced optoelectronic devices require monolithic integration of different functions at chip level. This is the case of multi-quantum well (MQW) electro absorption modulated lasers (EMLs) realized by using the selective area growth (SAG) technique, and which can be employed in long-distance, high-frequency optical fiber communication applications. We demonstrate that a micrometer-resolved X-ray beam available at third-generation synchrotron radiation sources allows direct measurement of determinant structural parameters of MQW EML structures. [source]

Compact multiband slotted antenna for wireless communication applications

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2009
Yi-Chieh Lee
Abstract New design of a compact antenna with slotted structure for multioperating bands of wireless communication systems is presented. By using compact configuration and slot designs on printed circuit board, the proposed antenna has the multiband measured operations for covering the 2.4-GHz WLAN (2.4,2.484 GHz), the WiMAX (IEEE 802.16e in the Taiwan: 2.5,2.69/3.5,3.65 GHz), and the 5-GHz WLAN (5.15,5.35/5.725,5.825 GHz) bands. Several properties of the proposed compact antenna for multiband operation such as impedance bandwidth, radiation pattern, and measured gain have been numerically and experimentally investigated. © 2008 Wiley Periodcals, Inc. Microwave Opt Technol Lett 51: 502,503, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24094 [source]

A novel reconfigurable circular polarization patch antenna

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 7 2008
Jun Ouyang
Abstract A novel design of a microstrip patch antenna with switchable branches is proposed to achieve circular polarization diversity. Two branches are incorporated into the patch and two switches are utilized to switch the branches on and off. By turning the switches on or off, this antenna can radiate with either right-handed circular polarization or left-handed circular polarization using the same feeding probe. Experimental results validate this concept. This design demonstrates useful features for wireless communication applications and future planetary missions. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1921,1923, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23537 [source]

Networking as a Means to Strategy Change: The Case of Open Innovation in Mobile Telephony

THE JOURNAL OF PRODUCT INNOVATION MANAGEMENT, Issue 6 2007
Koen Dittrich
The purpose of this article is to investigate how innovation networks can be used to deal with a changing technological environment. This study combines different concepts related to research and development (R&D) collaboration strategies of large firms and applies these concepts to R&D alliance projects undertaken by Nokia Corporation in the period 1985,2002. The research methodology is a combination of in-depth semistructured interviews and a large-scale quantitative analysis of alliance agreements. For the empirical analysis a distinction is made between exploration and exploitation in innovation networks in terms of three different measures. As a first measure, the difference between exploration and exploitation strategies by means of the observed capabilities of the partners of the contracting firms is investigated. The second measure is related to partner turnover. The present article argues that in exploration networks partner turnover will be higher than in exploitation networks. As a third measure, the type of alliance contract will be taken; exploration networks will make use of flexible legal organizational structures, whereas exploitation alliances are associated with legal structures that enable long-term collaboration. The case of Nokia has illustrated the importance of strategic technology networks for strategic repositioning under conditions of change. Nokia followed an exploitation strategy in the development of the first two generations of mobile telephony and an exploration strategy in the development of technologies for the third generation. Such interfirm networks seem to offer flexibility, speed, innovation, and the ability to adjust smoothly to changing market conditions and new strategic opportunities. These two different strategies have led to distinctly different international innovation networks, have helped the company in becoming a world leader in the mobile phone industry, and have enabled it to sustain that position in a radically changed technological environment. This study also illustrates that Nokia effectively uses an open innovation strategy in the development of new products and services and in setting technology standards for current and future use of mobile communication applications. This article presents one of the first longitudinal studies, which describes the use of innovation networks as a means to adapt swiftly to changing market conditions and strategic change. This study contributes to the emerging, but still inconsistent, literature on explorative and exploitative learning by means of strategic technology networks. [source]

Efficient IP-multicast via Inmarsat BGAN, a 3GPP satellite network

INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 5 2007
Paul Febvre
Abstract This paper outlines a number of challenges associated with supporting IP-multicast services efficiently across the Inmarsat Broadband Global Area Network (BGAN) 3GPP-based satellite network operating over the Imarsat-4 satellite constellation. The paper presents a network architecture that extends the 3GPP reference architecture to allow IP-multicast to be delivered when the Core Network is in a 3GPP Release-4 (non-MBMS compliant) configuration. This paper further extends the service and system concepts defined in 3GPP MBMS to provide improved flexibility and accountability, and improved scalability and efficiency when operating with the Inmarsat-4 BGAN TDM/TDMA air interface. This paper describes a number of radio resource management techniques that were deployed in a test system and the validation testing that was undertaken to support multimedia distribution and VoIP-based netted communications applications. The tuning of application and system behaviour to achieve acceptable performance is described in outline. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Performance of a turbo-coded CDMA system in a mobile satellite channel

INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 4 2005
Jin Young Kim
Abstract The bit error rate (BER) performance of a turbo-coded code-division multiple-access (CDMA) system operating in a satellite channel is analysed and simulated. The system performance is compared for various constituent decoders, including maximum a posteriori probability (MAP) and Max-Log-MAP algorithms, and the soft-output Viterbi algorithm. The simulation results indicate that the Max-Log-MAP algorithm is the most promising among these three algorithms in overall terms of performance and complexity. It is also shown that, for fixed code rate, the BER performance is improved substantially by increasing the number of iterations in the turbo decoder, or by increasing the interleaver length in the turbo encoder. The results in this paper are of interest in CDMA-based satellite communications applications. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Planar ultrawideband antenna array for short-range wireless communications

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2010
Osama M. H. Ahmed
Abstract In this article, novel 2-element and 4-element planar ultrawideband (UWB) antenna arrays with bidirectional radiation patterns based on identical UWB antenna elements for UWB communications applications have been proposed, simulated and experimentally investigated. Each array is constructed by means of feeding omni-directional printed UWB monopole antennas with a UWB power divider. The proposed 2-element antenna array yields an impedance bandwidth of 110% (3.1,10.6 GHz) covering the whole UWB frequency bandwidth while the impedance bandwidth is multi-band in case of the 4-element antenna array because of the increasing effect of mutual coupling among antenna elements. The calculated gain of the 2-element and 4-element array is quite stable with about 3 and 6 dB higher than that of the single element, respectively. Both measured and calculated E-plane radiation patterns of the array and the single element are almost the same while the H-plane radiation patterns of the array are distinctively bidirectional compared to the omni-directional pattern of the single element. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1061,1066, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25140 [source]