Electronics and Communications in Japan (Part I: Communications)最新文献

{"title":"Fair bandwidth allocation method for broadband packet network","authors":"Yukihiro Yoshida,&nbsp;Yasunobu Kasahara,&nbsp;Yoichi Maeda","doi":"10.1002/ecja.20266","DOIUrl":"10.1002/ecja.20266","url":null,"abstract":"<p>As broadband Internet access channels such as ADSL and FTTH become more widely used, network compression by power users becomes a problem. In order to deal with this problem, bandwidth control that assigns bandwidth among users in a fair manner is needed. In this paper, we studied the DRR method, which is known to allow fair bandwidth allocation and to be highly realizable. A new method that resolves the problem of realizability at high speeds in the range of gigabits and tens of gigabits typical of the DRR method is proposed. By this method, it is possible to realize fair allocation of bandwidth even if the channel speed is increased to several gigabits or several tens of gigabits. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(8): 50–56, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20266 Copyright © 2004 Wiley Periodicals, Inc.Copyright © 2007 Wiley Periodicals, Inc.</p>","PeriodicalId":100405,"journal":{"name":"Electronics and Communications in Japan (Part I: Communications)","volume":"90 8","pages":"50-56"},"PeriodicalIF":0.0,"publicationDate":"2007-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/ecja.20266","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83193001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characteristics of a buck converter with new control scheme using a triangle waveform modulated by output voltage","authors":"Jinbin Zhao,&nbsp;Terukazu Sato,&nbsp;Takashi Nabeshima,&nbsp;Tadao Nakano","doi":"10.1002/ecja.20256","DOIUrl":"https://doi.org/10.1002/ecja.20256","url":null,"abstract":"<p>In this paper, the authors propose a new control scheme in which the output voltage is fed back into a triangle waveform of a control circuit to improve the transient response of a switching converter. The circuit structure of the proposed system is very simple and will therefore reduce the size and weight of the apparatus and have reduced production costs. Also, because an error amplifier is not used, the circuit is not affected by switching noise or the like and the circuit is easy to design. In this paper, the proposed system is applied to a synchronous rectifying buck converter; the basic properties are analyzed and the system is verified experimentally. As a result, it was confirmed that the proposed scheme has superior regulation properties and transient response characteristics. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(7): 52–59, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20256</p>","PeriodicalId":100405,"journal":{"name":"Electronics and Communications in Japan (Part I: Communications)","volume":"90 7","pages":"52-59"},"PeriodicalIF":0.0,"publicationDate":"2007-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/ecja.20256","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91882166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A study of the application of mobile IP to IP-VPN and the development of mobile foreign agent","authors":"Hiraki Hata","doi":"10.1002/ecja.20385","DOIUrl":"https://doi.org/10.1002/ecja.20385","url":null,"abstract":"<p>Mobile IP is a protocol which provides a function by which a mobile node (MN) continuously retains a single IP address and continues to use the same IP address, even if the MN moves from the network to which it originally connected (Home Network) to another network. This paper is a study of the advantages of IPsec for MIP applied to IP-VPN, with a small number of terminals per node and where the subject devices are integrated devices such as non-personal computer terminals. In order to apply MIP to such an IP-VPN, a new MFA mode is proposed, in addition to the FA mode and CoA mode which have previously been provided to Mobile IP. In the MFA mode, both the MN and MFA move together. Furthermore, it is proposed to include an autoconfiguration function as well. This can be expected to result in reduced terminal shipping costs. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(7): 9–17, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20385</p>","PeriodicalId":100405,"journal":{"name":"Electronics and Communications in Japan (Part I: Communications)","volume":"90 7","pages":"9-17"},"PeriodicalIF":0.0,"publicationDate":"2007-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/ecja.20385","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91882167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A delta representation scheme for updating between versions of mobile phone software","authors":"Ryozo Kiyohara,&nbsp;Mariko Kurihara,&nbsp;Satoshi Mii,&nbsp;Shigenori Kino","doi":"10.1002/ecja.20348","DOIUrl":"https://doi.org/10.1002/ecja.20348","url":null,"abstract":"<p>In recent years the amount of software running on mobile phones has increased dramatically due to the start of data network connection services for mobile phones. As a result it has sometimes become necessary to repair defects in such products after they have been shipped to market. In this context, services have been launched that enable software to be updated after a terminal has been sold. The time taken for software to be updated is made up of the time taken to transmit the data to the handset via a mobile network or from a PC (which in turn depends on the amount of data being transmitted) and the time taken to overwrite the data on flash memory. A standard method for making the amount of data that needs to be transmitted to the handset small, is to only send delta data corresponding to those parts of the new version of the software that differ from the old version; it is generally necessary to make this delta as small as possible. Following a description of existing techniques for extracting deltas, in this paper we make multiple proposals regarding delta extraction schemes that are designed with the structure of mobile phone software particularly in mind with a view to making the delta data transmitted to the handset when updating software as small as possible; we then describe results of evaluations with actual mobile phones immediately prior to shipping. Both of the schemes that we propose are shown to allow a reduction of approximately 30 percent in the size of the delta when compared with standard delta representation mechanisms. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(7): 26–37, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20348</p>","PeriodicalId":100405,"journal":{"name":"Electronics and Communications in Japan (Part I: Communications)","volume":"90 7","pages":"26-37"},"PeriodicalIF":0.0,"publicationDate":"2007-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/ecja.20348","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91882165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transmit phase control to increase the minimum eigenvalue of the channel correlation matrix in the ETD system","authors":"Ryuichiro Shimura,&nbsp;Iwao Sasase","doi":"10.1002/ecja.20342","DOIUrl":"https://doi.org/10.1002/ecja.20342","url":null,"abstract":"<p>For conditions under which the channel conditions between the transmitting and receiving antennas are known on the transmitter side when TDD (Time Division Duplex) is used in the MIMO (Multi-Input Multi-Output) method, much attention has been devoted to E-SDM (Eigenbeam Space Division Multiplexing), in which the influence of CCI (Co-Channel Interference) is eliminated by making the different transmission signal sequences orthogonal in space by means of the eigenvectors of the channel matrix used as the transmission and reception weights. However, in such a system as E-SDM, in which eigenvectors of the channel matrix are used, more than two antennas are needed on the receiving side in order to perform eigenvalue decomposition of the channel matrix. In this paper, in order to realize a system using the eigenvectors as the transmission and reception weights even in a system with two transmitting antennas and one receiving antenna under TDD, the ETD (Eigenbeam Transmit Diversity) system is proposed. In this system, the concept of frequency diversity is applied, in which identical signals are transmitted on two subcarriers on one transmitting antenna, so that a MIMO system is virtually realized with subcarriers of the OFDM (Orthogonal Frequency Division Multiplexing) in place of receiving antennas in the row direction of the channel matrix. In the ETD system, the minimum eigenvalue of the channel matrix can be made larger by adaptively interchanging the signals among antennas and by transmission phase control. Hence, the BER characteristics of the signal sequence by which the minimum eigenvalue is multiplied can be improved. The characteristics are evaluated by computer simulations. It is shown that the proposed system is superior in terms of BER characteristics to the transmission diversity system in which transmission phase control is carried out among the antennas. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(7): 38–51, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20342</p>","PeriodicalId":100405,"journal":{"name":"Electronics and Communications in Japan (Part I: Communications)","volume":"90 7","pages":"38-51"},"PeriodicalIF":0.0,"publicationDate":"2007-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/ecja.20342","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91882765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stress dependence of transmission frequency of a fiber Fabry-Perot etalon buried in a fiber ferrule","authors":"Mitsuhiro Tateda,&nbsp;Kento Komaki,&nbsp;Yuki Yamaguchi","doi":"10.1002/ecja.20386","DOIUrl":"https://doi.org/10.1002/ecja.20386","url":null,"abstract":"<p>The transmission characteristics of a fiber Fabry-Perot etalon formed by mirror-finishing both ends of an optical fiber are dependent on the external stress applied. A theoretical study and an experimental confirmation of a fiber Fabry-Perot etalon with a ferrule diameter of 2.5 mm and a resonator length of 4 mm are carried out to investigate variations of the transmission frequencies as a function of the stress. It is confirmed that there is a proportional relationship of 1.5 GHz/N and −0.1 GHz/N in the transmission frequency variations versus the stress in the axial and radial directions. Arbitrary transmission frequencies within FSR can be obtained by adjustment of the stress at values less than 17 N, so that the fiber Fabry-Perot etalon can be used as a tunable optical frequency filter. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(7): 1– 8, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20386</p>","PeriodicalId":100405,"journal":{"name":"Electronics and Communications in Japan (Part I: Communications)","volume":"90 7","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2007-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/ecja.20386","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91882164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stability design for on-board distributed power system","authors":"Seiya Abe,&nbsp;Masahiko Hirokawa,&nbsp;Toshiyuki Zaitsu,&nbsp;Tamotsu Ninomiya","doi":"10.1002/ecja.20356","DOIUrl":"https://doi.org/10.1002/ecja.20356","url":null,"abstract":"<p>Recently, on-board distributed power systems consisting of bus converter and POL have usually been used for IT infrastructure equipment. However, even if each converter has stable operation, the bus voltage may oscillate and the system may be unstable, depending on the bus converter design; this has been a serious problem in recent years. Solution of the issue is highly desirable, and in order to improve the system stability various techniques have been discussed. This paper investigates the improvement of the system stability by the control method. The availability of full-regulated bus converter is especially examined. It is determined that the full-regulated method is the optimal control method for the bus converter because a full-regulated bus converter can reduce bus voltage oscillation and adjust to input voltage variations flexibly by regulation. A stability design process is proposed for an on-board distributed power system using a full-regulated bus converter. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(7): 18–25, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20356</p>","PeriodicalId":100405,"journal":{"name":"Electronics and Communications in Japan (Part I: Communications)","volume":"90 7","pages":"18-25"},"PeriodicalIF":0.0,"publicationDate":"2007-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/ecja.20356","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91882764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photonic lattice-type self-routing switching network","authors":"Nagao Ogino Member","doi":"10.1002/ecja.4410750803","DOIUrl":"https://doi.org/10.1002/ecja.4410750803","url":null,"abstract":"The asynchronous transfer mode (ATM) is considered as a fundamental technique in constructing the broadband ISDN. High-speed switching is required in the ATM switching equipment, which forms the core of the ATM network. Then it is desirable to apply the self-routing switching network. Various self-routing switching networks have been proposed including the Banyan network, as well as its improvements. This network is composed of the multistage connection of 2 × 2 switches. However, problems remain in such switching networks, for example, the hardware scale in the large network and the hardware reliability. \u0000 \u0000 \u0000 \u0000This paper proposes anew a photonic lattice-type self-routing network with the following features: (1) the system has essentially a bus structure and excellent expandability; (2) by its structure, the hardware scale increases only slowly in proportion to the number of accommodated circuits. This is an advantage in the large-scale network; (3) again by its structure, it is possible to deroute the cells thereby avoiding the point of failure which improves the reliability; (4) by restricting the number of cell transfer paths to a certain number, a relatively simple routing control circuit can be employed based on the optical switching circuit; and (5) by the application of the optical switch, the transfer delay of the cell is reduced greatly.","PeriodicalId":100405,"journal":{"name":"Electronics and Communications in Japan (Part I: Communications)","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2007-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87291595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impacts of distributed Raman amplification transmission technologies on terrestrial large-capacity WDM systems","authors":"Hiroji Masuda,&nbsp;Masahito Tomizawa,&nbsp;Yutaka Miyamoto,&nbsp;Kazuo Hagimoto","doi":"10.1002/ecja.20340","DOIUrl":"10.1002/ecja.20340","url":null,"abstract":"<p>The impact of distributed Raman amplification (DRA) technologies on long-distance large-capacity transmission systems is discussed from the viewpoint of improving the signal-to-noise ratio (SNR). First, we show the characteristics of this technology, which has brought significant improvement to the SNR, and its trends, the basic configuration for our proposed DRA system (a DRA/EDFA hybrid configuration), and safety aspects for high-power pumped light. In addition, we show the merits of the DRA system, including the amount of improvement in the optical SNR, transmission fiber (DSF and SMF) dependence, and superiority of DSF over SMF (about 2 to 3 dB). Furthermore, in a long-distance large-capacity wavelength division multiplexing transmission field trial using DRA in the L band on DSF, we confirm good transmission characteristics. In other words, the impact of DRA technologies lies in the significant improvement of the SNR in terrestrial long-distance large-capacity optically amplified transmission systems with field-installed fibers, and in the improvement of performance in systems utilizing these technologies. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(6): 20–28, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20340</p>","PeriodicalId":100405,"journal":{"name":"Electronics and Communications in Japan (Part I: Communications)","volume":"90 6","pages":"20-28"},"PeriodicalIF":0.0,"publicationDate":"2007-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/ecja.20340","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81016769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Double-sided permeable wave absorber","authors":"Takashi Nakamura,&nbsp;Chikamasa Dota,&nbsp;Risaburo Sato","doi":"10.1002/ecja.20369","DOIUrl":"10.1002/ecja.20369","url":null,"abstract":"<p>A new double-sided electromagnetic wave absorber allowing transmission is proposed. In the conventional permeable wave absorber, a resistive film is attached to a lossless dielectric layer. However, this is not nonreflective for an incident wave on the resistive film side. In the present paper, a basic structure is considered in which there is no reflection on both sides of the absorber. A simple structure made of two resistive films inserted between three dielectric layers is proposed. The nonreflection condition of the present wave absorber is derived by means of the equivalent circuit, and the reflection and transmission characteristics are derived for given permittivities of the dielectric layers. It is found that the bandwidth of the reflection coefficient does not significantly depend on the permittivity of the inner layer and that the permittivity of the outer layers is increased and that of the inner layer is decreased in order to make the transmission coefficient smaller. The wave absorber is fabricated and measured for confirmation of the validity of the theory. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(6): 1–8, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20369</p>","PeriodicalId":100405,"journal":{"name":"Electronics and Communications in Japan (Part I: Communications)","volume":"90 6","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2007-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/ecja.20369","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73282167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}