IEICE Transactions on Communications
Online ISSN : 1745-1345
Print ISSN : 0916-8516
Volume E93.B, Issue 3
Displaying 1-50 of 53 articles from this issue
Special Section on New Generation Network towards Innovative Future Society
  • Masayuki MURATA
    2010 Volume E93.B Issue 3 Pages 435
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    Download PDF (30K)
  • Dipankar RAYCHAUDHURI
    Article type: INVITED LETTER
    2010 Volume E93.B Issue 3 Pages 436-441
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL FREE ACCESS
    This position paper outlines the author's view on architectural directions and key technology enablers for the future mobile Internet. It is pointed out that mobile and wireless services will dominate Internet usage in the near future, and it is therefore important to design next-generation network protocols with features suitable for efficiently serving emerging wireless scenarios and applications. Several key requirements for mobile/wireless scenarios are identified - these include new capabilities such as dynamic spectrum coordination, cross-layer support, disconnection tolerant routing, content addressing, and location awareness. Specific examples of enabling technologies which address some of these requirements are given from ongoing research projects at WINLAB. Topics covered briefly include wireless network virtualization, the cache-and-forward (CNF) protocol, geographic (GEO) protocol stack, cognitive radio protocols, and open networking testbeds.
    Download PDF (692K)
  • Marcus BRUNNER, Henrik ABRAMOWICZ, Norbert NIEBERT, Luis M. CORREIA
    Article type: INVITED LETTER
    2010 Volume E93.B Issue 3 Pages 442-445
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL FREE ACCESS
    In this paper, we describe several approaches to address the challenges of the network of the future. Our main hypothesis is that the Future Internet must be designed for the environment of applications and transport media of the 21st century, vastly different from the initial Internet's life space. One major requirement is the inherent support for mobile and wireless usage. A Future Internet should allow for the fast creation of diverse network designs and paradigms and must also support their co-existence at run-time. We detail the technical and business scenarios that lead the development in the EU FP7 4WARD project towards a framework for the Future Internet.
    Download PDF (633K)
  • Nozomu NISHINAGA
    Article type: INVITED LETTER
    2010 Volume E93.B Issue 3 Pages 446-449
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL FREE ACCESS
    The National Institute of Information and Communications Technology (NICT) vision and five network targets of research and development (R&D) of the NeW-Generation Network (NWGN) are presented in this letter. The NWGN is based on new design concepts that look beyond the next generation network (NGN). The NWGN will maintain the sustainability of our prosperous civilization and help resolve various social issues and problems by using information and communication technologies (ICTs). NICT's vision for NWGN is also presented in this letter. Based on this vision, 19 items concerning social issues and future social outlook are analyzed, and the functional requirements of the NWGN are extracted. The requirements are refined and categorized into five network targets that must be developed for realizing the vision.
    Download PDF (733K)
  • Atsushi TAKAHARA
    Article type: INVITED LETTER
    2010 Volume E93.B Issue 3 Pages 450-453
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL FREE ACCESS
    We have been considering the architecture of the future carrier network which will be the successor to Next Generation Network (NGN). Our assessments have clarified the key problems that will arise in the era when NGN has matured. Based on our studies, we define the vision and the architecture that can solve these problems. This paper provides a snapshot of our work in order to contribute to research on the New Generation Network and beyond.
    Download PDF (188K)
  • Akihiro NAKAO
    Article type: INVITED LETTER
    2010 Volume E93.B Issue 3 Pages 454-457
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL FREE ACCESS
    Network virtualization has become a common research topic that many researchers consider a basis for defining a new generation network architectures. In this paper, we attempt to clarify the concept of network virtualization with its brief history, to introduce the benefit of network virtualization for the future network, to posit our strong belief in that the future network should adopt a form of a meta-architecture that accommodates multiple competing multiple architectures, and to identify challenges to achieving this architecture.
    Download PDF (939K)
  • Naoki WAKAMIYA, Masayuki MURATA
    Article type: INVITED LETTER
    2010 Volume E93.B Issue 3 Pages 458-461
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL FREE ACCESS
    A new generation network is requested to accommodate an enormous number of heterogeneous nodes and a wide variety of traffic and applications. To achieve higher scalability, adaptability, and robustness than ever before, in this paper we present new network architecture composed of self-organizing entities. The architecture consists of the physical network layer, service overlay network layer, and common network layer mediating them. All network entities, i.e. nodes and networks, behave in a self-organizing manner, where the global behavior emerges through their operation on local information and direct and/or indirect mutual interaction. The center of the architecture is so-called self-organization engines, which implement nonlinear self-organizing dynamics originating in biology, physics, and mathematics. In this paper, we also show some examples of self-organization engines.
    Download PDF (242K)
  • Hiroaki HARAI, Kenji FUJIKAWA, Ved P. KAFLE, Takaya MIYAZAWA, Masayuki ...
    Article type: LETTER
    2010 Volume E93.B Issue 3 Pages 462-465
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    Limitations are found in the recent Internet because a lot of functions and protocols are patched to the original suite of layered protocols without considering global optimization. This reveals that end-to-end argument in the original Internet was neither sufficient for the current societal network and nor for a sustainable network of the future. In this position paper, we present design guidelines for a future network, which we call the New Generation Network, which provides the inclusion of diverse human requirements, reliable connection between the real-world and virtual network space, and promotion of social potentiality for human emergence. The guidelines consist of the crystal synthesis, the reality connection, and the sustainable & evolutional guidelines.
    Download PDF (183K)
  • Masataka OHTA, Kenji FUJIKAWA
    Article type: LETTER
    2010 Volume E93.B Issue 3 Pages 466-469
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    IP− − is proposed as an Internet Protocol suitable for optical packet networking. As optical routers require much faster control than electric ones and lack of optical buffers other than those by fiber delay lines requires fixed time control, Internet Protocols must be at least as simple as IPv4 and much simpler than IPv6. IP− − also addresses issues of IP address space exhaustion and IP routing table explosion.
    Download PDF (235K)
  • Masahiko JINNO, Yukio TSUKISHIMA, Hidehiko TAKARA, Bartlomiej KOZICKI, ...
    Article type: PAPER
    2010 Volume E93.B Issue 3 Pages 470-477
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    A virtualized optical network (VON) is proposed as a key to implementing increased agility and flexibility into the future Internet and applications by providing any-to-any connectivity with the appropriate optical bandwidth at the appropriate time. The VON is enabled by introducing optical transparentization and optical fine granular grooming based on optical orthogonal frequency division multiplexing.
    Download PDF (1321K)
  • Ved P. KAFLE, Masugi INOUE
    Article type: PAPER
    2010 Volume E93.B Issue 3 Pages 478-489
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    The current Internet is not capable of meeting the future communication requirements of society, i.e., reliable connectivity in a ubiquitous networking environment. The shortcomings of the Internet are due to the lack of support for mobility, multihoming, security and heterogeneous network layer protocols in the original design. Therefore, to provide ubiquitous networking facilities to the society for future innovation, we have to redesign the future Internet, which we call the New Generation Network. In this paper, we present the Heterogeneity Inclusion and Mobility Adaptation through Locator ID Separation (HIMALIS) architecture for the New Generation Network. The HIMALIS architecture includes a new naming scheme for generating host names and IDs. It also includes a logical control network to store and distribute bindings between host names, IDs, locators and other information useful for providing support for network operation and control. The architecture uses such information to manage network dynamism (i.e., mobility, multihoming) and heterogeneity in network layer protocols. We verify the basic functions of the architecture by implementing and testing them using a testbed system.
    Download PDF (933K)
  • K. Habibul KABIR, Masahiro SASABE, Tetsuya TAKINE
    Article type: PAPER
    2010 Volume E93.B Issue 3 Pages 490-500
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    Custody transfer in delay tolerant networks (DTNs) provides reliable end-to-end data delivery by delegating the responsibility of data transfer among special nodes (custodians) in a hop-by-hop manner. However, storage congestion occurs when data increases and/or the network is partitioned into multiple sub-networks for a long time. The storage congestion can be alleviated by message ferries which move around the network and proactively collect data from the custodians. In such a scenario, data should be aggregated to some custodians so that message ferries can collect them effectively. In this paper, we propose a scheme to aggregate data into selected custodians, called aggregators, in a fully distributed and autonomous manner with the help of evolutionary game theoretic approach. Through theoretical analysis and several simulation experiments, taking account of the uncooperative behavior of nodes, we show that aggregators can be selected in a self-organized manner and the number of aggregators can be controlled to a desired value.
    Download PDF (3724K)
  • Masayoshi SHIMAMURA, Hiroyuki KOGA, Takeshi IKENAGA, Masato TSURU
    Article type: PAPER
    2010 Volume E93.B Issue 3 Pages 501-515
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    Introducing adaptive online data compression at network-internal nodes is considered for alleviating traffic congestion on the network. In this paper, we assume that advanced relay nodes, which possess both a relay function (network resource) and a processing function (computational and storage resources), are placed inside the network, and we propose an adaptive online lossless packet compression scheme utilized at these nodes. This scheme selectively compresses a packet according to its waiting time in the queue during congestion. Through preliminary investigation using actual traffic datasets, we investigate the compression ratio and processing time of packet-by-packet compression in actual network environments. Then, by means of computer simulations, we show that the proposed scheme reduces the packet delay time and discard rate and investigate factors necessary in achieving efficient packet relay.
    Download PDF (1473K)
  • Suyong EUM, Shin'ichi ARAKAWA, Masayuki MURATA
    Article type: PAPER
    2010 Volume E93.B Issue 3 Pages 516-524
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    Topological structure of peer-to-peer (P2P) networks affects their operating performance. Thus, various models have been proposed to construct an efficient topology for the P2P networks. However, due to the simultaneous failures of peers and other disastrous events, it is difficult to maintain the originally designed topological structure that provides the network with some performance benefits. For this reason, in this paper we propose a simple local rewiring method that changes the network topology to have small diameter as well as highly clustered structure. Moreover, the presented evaluation study shows how these topological properties are involved with the performance of P2P networks.
    Download PDF (501K)
  • Masato UCHIDA, Kei OHNISHI, Kento ICHIKAWA, Masato TSURU, Yuji OIE
    Article type: PAPER
    2010 Volume E93.B Issue 3 Pages 525-535
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    In this paper we propose a file replication scheme inspired by a thermal diffusion phenomenon for storage load balancing in unstructured peer-to-peer (P2P) file sharing networks. The proposed scheme is designed such that the storage utilization ratios of peers will be uniform, in the same way that the temperature in a field becomes uniform in a thermal diffusion phenomenon. The proposed scheme creates replicas of files in peers probabilistically, where the probability is controlled by using parameters that can be used to find the trade-off between storage load balancing and search performance in unstructured P2P file sharing networks. First, we show through theoretical analysis that the statistical behavior of the storage load balancing controlled by the proposed scheme has an analogy with the thermal diffusion phenomenon. We then show through simulation that the proposed scheme not only has superior performance with respect to balancing the storage load among peers (the primary objective of the present proposal) but also allows the performance trade-off to be widely found. Finally, we qualitatively discuss a guideline for setting the parameter values in order to widely find the performance trade-off from the simulation results.
    Download PDF (779K)
  • Sugang XU, Weiping REN, Hiroaki HARAI
    Article type: PAPER
    2010 Volume E93.B Issue 3 Pages 536-545
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    In this paper, we address the on-demand end-to-end optical network construction problem for grid applications in new generation large-scale multi-domain wavelength switched optical networks (WSON). According to users' requests for high-performance distributed computing, groups of dedicated end-to-end lightpaths among geographically distributed grid resources can be established dynamically forming multiple-lightpath optical networks for grid applications, namely, optical grid network (OGN). To facilitate the automated OGN construction, we introduce an optical grid network infrastructure providing an integrated and self-contained OGN service to grid users with totally distributed control. In this infrastructure, for easy construction, especially in a large-scale multi-domain WSON environment, we propose an overlay approach to construct OGNs in a peer-to-peer fashion, which conceals the communication architecture of the underlying heterogeneous optical networks. In particular, we propose an adaptive construction mechanism that can develop the OGN flexibly by adapting to the dynamically changed optical network circumstance. To enable users to take the advantage of the end-to-end lightpaths of WSON directly, a wavelength-oriented end-host configuration scheme is proposed. Experimental results on a developed prototype and an optical-fibre test-bed network successfully validate the proposal.
    Download PDF (1378K)
  • Seokhoon KIM, Intae RYOO
    Article type: LETTER
    2010 Volume E93.B Issue 3 Pages 546-550
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    This paper introduces a packet forwarding scheme based on interworking architecture that can provide quite a good QoS by minimizing processing delay which is the major part of the timeliness factor in New Generation IP-based networks. Based on path and resource reservation mechanism, the POSIA makes routers on the packet forwarding path synchronize with each other and then forward packets. We have shown that the POSIA outperforms the existing packet forwarding schemes like IntServ, DiffServ and MPLS through computer simulations using OPNET.
    Download PDF (434K)
Regular Section
  • Amane MIURA, Masataka OHIRA, Shoichi KITAZAWA, Masazumi UEBA
    Article type: PAPER
    Subject area: Devices/Circuits for Communications
    2010 Volume E93.B Issue 3 Pages 551-559
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    This paper proposes a new switched-beam eight-sector antenna for multi-gigabit wireless LAN in the 60-GHz band. Our antenna system introduces access-point (AP) and user-terminal (UT) antennas having the same sec θ pattern in the elevation plane so that the received signal power at the receiver is kept constant, independent of the position of the UT. For this system, an eight-sector antenna, a single-pole eight-throw (SP8T) switch, and a beam control unit are integrated as the switched-beam eight-sector antenna. The specifications of the antenna are wide bandwidth (≥3GHz), high-gain (≥13dBi at θ=66°), and wide coverage area in both azimuth (0° ≤ φ ≤ 180°) and elevation planes (0° ≤ θ ≤ 66°). The antenna beam is steered within the specified response time (which is short) by the Media Access Control (MAC). In our antenna, both high gain for a wide elevation angle and wide bandwidth are obtained by using the proposed closely spaced waveguide slot array antenna, which is used as each sector of the eight-sector antenna. The SP8T switch with the beam control unit enables 180° beam scan in the azimuth plane. In a component evaluation, the eight-sector antenna achieves a 10-dB return loss bandwidth of 8GHz with more than 40-dB port-to-port isolation. Radiation characteristics of the eight-sector antenna indicate that it covers 82% of the entire coverage area at the center frequency and that the coverage rate in the operating frequency band is from 78% to 88%. The performance of the SP8T switch and the beam control unit is verified by measuring the insertion loss at all eight ports and the switching response time. In the antenna system evaluation, measurement by using two prototype antennas as the AP and the UT antennas in the usage condition indicates that the measured received signal power meets the specified constant power for the specified wide elevation angle range, independent of the position of the UT. These experimental results verify the effectiveness of our proposed antenna for multi-gigabit WLAN.
    Download PDF (2599K)
  • Tingting ZHANG, Qinyu ZHANG, Naitong ZHANG, Hongguang XU
    Article type: PAPER
    Subject area: Transmission Systems and Transmission Equipment for Communications
    2010 Volume E93.B Issue 3 Pages 560-570
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    Due to the low complexity and cost characteristics of ultra-wideband (UWB) systems, a weighted acquisition algorithm based on energy detection is proposed in this paper. This method is divided into two steps to acquire the direct path (DP) component. Firstly, weighted energy detection is applied to determine which energy block the DP lies in by generalized likelihood ratio test (GLRT). A sub-optimal weighted vector is obtained, by which the closed form of detection performance is proposed. In the second step, the precise position of DP within the detected energy block is obtained by the statistical characteristics of the channel energy distributions. Key parameters that affect acquisition performance are studied by analytical and numerical methods. Simulations and experiments are carried out for performance and complexity comparison with traditional ones. The results show that weighted acquisition achieves better performance under relative low complexity conditions.
    Download PDF (397K)
  • Joon-Young CHOI, Kyungmo KOO, Jin Soo LEE
    Article type: PAPER
    Subject area: Network
    2010 Volume E93.B Issue 3 Pages 571-580
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    We consider a single-link multi-source network with FAST TCP sources. We adopt a continuous-time dynamic model for FAST TCP sources, and propose a static model to adequately describe the queuing delay dynamics at the link. The proposed model turns out to have a structure that reveals the time-varying network feedback delay, which allows us to analyze FAST TCP with due consideration of the time-varying network feedback delay. Based on the proposed model, we establish sufficient conditions for the boundedness of congestion window of each source and for the global asymptotic stability. The asymptotic stability condition shows that the stability property of each source is affected by all other sources sharing the link. Simulation results illustrate the validity of the sufficient condition for the global asymptotic stability.
    Download PDF (939K)
  • Chang-Yi LUO, Nobuyoshi KOMURO, Kiyoshi TAKAHASHI, Toshinori TSUBOI
    Article type: PAPER
    Subject area: Network
    2010 Volume E93.B Issue 3 Pages 581-589
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    In multi-hop ad hoc wireless networks, it is well known that TCP suffers severe performance degradation. This is due to its window-based approach to transmission control, which injects traffic bursts into the network. These bursts increase the frequency of contention in the MAC layer which forces the dropping of some packets. This paper proposes an efficient TCP with pacing, Paced TCP, to alleviate MAC contention and thus achieve better performance than the traditional TCP variants. Our design approach is a TCP that probe the available bandwidth of the network without affecting the stability of the network. Simulations show that Paced TCP not only achieves better performance but is also friendly to UDP traffic.
    Download PDF (803K)
  • Shoko OHTERU, Keiji KISHINE
    Article type: PAPER
    Subject area: Network
    2010 Volume E93.B Issue 3 Pages 590-599
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    The Burst ACK scheme enhances effective throughput by reducing ACK overhead when a transmitter sends sequentially multiple data frames to a destination. IEEE 802.11e is one such example. The size of the data frame body and the number of burst data frames are important burst transmission parameters that affect throughput. The larger the burst transmission parameters are, the better the throughput under error-free conditions becomes. However, large data frame could reduce throughput under error-prone conditions caused by signal-to-noise ratio (SNR) deterioration. If the throughput can be calculated from the burst transmission parameters and error rate, the appropriate ranges of the burst transmission parameters could be narrowed down, and the necessary buffer size for storing transmit data or received data temporarily could be estimated. In this paper, we present a method that features a simple algorithm for estimating the effective throughput from the burst transmission parameters and error rate. The calculated throughput values agree well with the measured ones for actual wireless boards based on the IEEE 802.11-based original MAC protocol. We also calculate throughput values for larger values of the burst transmission parameters outside the assignable values of the wireless boards and find the appropriate values of the burst transmission parameters.
    Download PDF (2251K)
  • Megumi SHIBUYA, Tomohiko OGISHI, Shu YAMAMOTO
    Article type: PAPER
    Subject area: Network
    2010 Volume E93.B Issue 3 Pages 600-608
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    P2P (Peer-to-Peer) file sharing architectures have scalable and cost-effective features. Hence, the application of P2P architectures to media streaming is attractive and expected to be an alternative to the current video streaming using IP multicast or content delivery systems because the current systems require expensive network infrastructures and large scale centralized cache storage systems. In this paper, we investigate the P2P progressive download enabling Internet video streaming services. We demonstrated the capability of the P2P progressive download in both laboratory test network as well as in the Internet. Through the experiments, we clarified the contribution of the FTTH links to the P2P progressive download in the heterogeneous access networks consisting of FTTH and ADSL links. We analyzed the cause of some download performance degradation occurred in the experiment and discussed about the effective methods to provide the video streaming service using P2P progressive download in the current heterogeneous networks.
    Download PDF (1645K)
  • Yanzan SUN, Honglin HU, Fuqiang LIU, Ping WANG, Huiyue YI
    Article type: PAPER
    Subject area: Wireless Communication Technologies
    2010 Volume E93.B Issue 3 Pages 609-619
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    This paper investigates dynamic spectrum access based on MAC-Layer spectrum sensing and prior channel pre-allocation strategy. We first combine channel utilization with channel state transition probability from idle to busy to reflect the channel opportunity quality in cognitive radio systems. Then a MAC-Layer spectrum sensing algorithm based on Channel Opportunity Quality Descending Order (COQDO) is proposed for the single secondary user scenario, so that the single secondary user can be provided with dynamic spectrum access. For the multi-secondary users scenario, in order to solve the channel collision problem among secondary users in dynamic spectrum access, a joint MAC-Layer spectrum sensing and prior channel pre-allocation algorithm is proposed and analyzed. Channel collision problem occurs when more than one secondary users detect the channel as idle and access it at the same time. Furthermore, the prior channel pre-allocation is optimized by using the conventional Color Sensitive Graph Coloring (CSGC) algorithm. Extensive simulation results are presented to compare our proposed algorithms with existing algorithms in terms of idle channel search delay and accumulated channel handoff delay.
    Download PDF (667K)
  • Atsushi NAGATE, Kenji HOSHINO, Teruya FUJII
    Article type: PAPER
    Subject area: Wireless Communication Technologies
    2010 Volume E93.B Issue 3 Pages 620-628
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    It is important to improve a cell-edge throughput of next generation mobile communication systems. Frequency reuse schemes such as three-cell reuse or fractional frequency reuse are suitable for achieving this goal. Another candidate is multi-link transmission; signals on different sub-carriers from adjacent base stations are received by a mobile. However, the orthogonality of these signals can collapse if a frequency offset between adjacent base stations is excessive; this loss triggers adjacent-channel interference. This paper proposes an interference canceller to solve this problem and confirms the effectiveness of the method through numerical analysis and computer simulations.
    Download PDF (1330K)
  • Jing HUANG, Ying WANG, Tong WU, Gen LI, Ping ZHANG
    Article type: PAPER
    Subject area: Wireless Communication Technologies
    2010 Volume E93.B Issue 3 Pages 629-639
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    In this paper, we investigate the antenna and node selection issues for amplify-and-forward (AF) and decode-and-forward (DF) multi-antenna relay networks in correlated channels. Based on the channel statistics, optimal selection criteria for antenna and relay node are derived jointly, aiming to maximize the ergodic capacity. Instantaneous channel knowledge-based selection schemes, motivated by traditional antenna selection algorithms, are investigated as well. It is shown that the proposed node selection schemes derived from antenna selection on relay nodes are feasible and effective in relay systems. Statistical selection shows considerable capacity gain compared to full complexity scheme and random selection strategy in AF mode, while instantaneous selection performs better in DF relaying. Furthermore, the proposed schemes are shown to be robust to channel estimation errors due to their correlation-oriented nature.
    Download PDF (514K)
  • Kilsoo JEONG, Kazuto YANO, Satoshi TSUKAMOTO, Makoto TAROMARU
    Article type: PAPER
    Subject area: Wireless Communication Technologies
    2010 Volume E93.B Issue 3 Pages 640-649
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    This paper proposes a new overlay transmission system for wireless LAN with RTS/CTS exchange. Conventional timing synchronization schemes may fail in the presence of inter-system interference, because they have not been designed for overlay transmission. In the proposed system, a transmitter estimates the transmission timing of the next wireless LAN DATA frame, and then sends its DATA frame at almost the same time as the estimated transmission timing to easily establish timing synchronization at the receiver. Moreover, we employ a tapped delay line adaptive array antenna at both transmitter and receiver to effectively suppress interference due to overlay transmission in a rich multipath propagation environment. The frame error rate performances of the proposed system and the IEEE 802.11a wireless LAN are evaluated through computer simulations that assume an exponentially decaying 8-path non-line-of-sight fading channel and include a timing synchronization process. Simulation results demonstrate that the proposed system can achieve overlay transmission while avoiding interference in a rich multipath propagation environment.
    Download PDF (927K)
  • Koichi ADACHI, Masao NAKAGAWA
    Article type: PAPER
    Subject area: Wireless Communication Technologies
    2010 Volume E93.B Issue 3 Pages 650-659
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    The bit error rate (BER) performance of multicode multi-carrier code division multiple access (MC-CDMA) severely degrades due to the inter-code interference (ICI) in a strong frequency-selective channel. Recently a spreading code group construction method was proposed for MC-CDMA. The Walsh-Hadmard (WH) codes are divided into a number of code groups such that the code orthogonality can be maintained within each group even in a strong frequency-selective channel; any code pair taken from different groups is not orthogonal. The number of spreading codes in each group is determined by the maximum time delay difference of the channel. In this paper, we point out that the number of codes in each group is determined by the distribution of time delay differences among the propagation paths of the channel, not the maximum time delay difference. Based on that observation, we show that more orthogonal spreading codes can exist in each code group. The conditional BER is derived taking into account the interference from other code groups and the achievable downlink BER performance using the proposed spreading code group construction is numerically evaluated in a frequency-selective Rayleigh fading channel.
    Download PDF (742K)
  • Susumu SASAKI, Supawan ANNANAB, Tetsuki TANIGUCHI, Yoshio KARASAWA
    Article type: PAPER
    Subject area: Wireless Communication Technologies
    2010 Volume E93.B Issue 3 Pages 660-669
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    We provide an efficient transmission scheme which embeds a pilot signal in the data signal for channel state information (CSI) based on the configuration of a multiple-input multiple-output (MIMO) system using space-time block coding (STBC) with an adaptive array (AA). A computer simulation and analysis show that the proposed scheme, which combines the advantage of an Alamouti-like STBC scheme and the pilot-based AA, can suppress the irreducible error due to random FM noise. The proposed scheme using a pilot minimizes the decoding delay, and is highly robust against fast fading. We show that the proposed scheme can significantly increase the data transmission rate by using the transmitter diversity based on STBC, and the accuracy of the proposed technique is exemplified by a computer simulation.
    Download PDF (901K)
  • Hiromasa FUJII, Hitoshi YOSHINO
    Article type: PAPER
    Subject area: Terrestrial Radio Communications
    2010 Volume E93.B Issue 3 Pages 670-678
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    Employing fractional frequency reuse (FFR) in OFDMA cellular systems is very attractive since it offers large capacity and single cell frequency reuse. However, its performance in practical environments, e.g. scheduling and arbitrary cell configurations, has not been well revealed. This paper analyzes the theoretical capacity and outage rate of an OFDMA cellular system employing FFR. Numerical examples show that FFR achieves higher capacity than the non-FFR equivalent when the outage rate is low.
    Download PDF (1209K)
  • Lin WANG, Qiang CHEN, Qiaowei YUAN, Kunio SAWAYA
    Article type: PAPER
    Subject area: Antennas and Propagation
    2010 Volume E93.B Issue 3 Pages 679-684
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    The modulated scattering antenna array (MSAA) is composed of one normal antenna element and several modulated scattering elements (MSEs). In this paper, a 2-element MSAA is used as the receiving antenna in a 2 × 2 multiple input multiple output (MIMO) system. MIMO performance of MSAA with various array spacing is measured to investigate the relation between the array spacing and the MIMO performance of the MSAA experimentally in the non-line-of-sight (NLOS) indoor environment. It is found that the error vector magnitude (EVM) and the channel capacity, which reflect MIMO performance, can be affected by the array spacing. The measured results of the MSAA were compared with that of two-dipole antenna array at the same condition.
    Download PDF (804K)
  • Ali MOQISEH, Mohammad M. NAYEBI
    Article type: PAPER
    Subject area: Sensing
    2010 Volume E93.B Issue 3 Pages 685-695
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    The Hough transform is known to be an effective technique for target detection and track initiation in search radars. However, most papers have focused on the simplistic applications of this technique which consider a 2-D data space for the Hough transform. In this paper, a new method based on xthe Hough transform is introduced for detecting targets in a 3-D data space. The data space is constructed from returned surveillance radar signal using the range and bearing information of several successive scans. This information is mapped into a 3-D x-y-t Cartesian data space. Targets are modeled with four parameters in this data space. The proposed 3-D Hough detector is then used to detect the existent targets in the 3-D surveillance space by mapping the returned signal of the radar from the data space to the parameter space. This detector, which is constructed of two detection stages, integrates the returned data of each target non-coherently along its 3-D trajectory in one parameter space cell related to this target. Hence, the detection performance will improve. The effectiveness of the new 3-D Hough detector is demonstrated through deriving the detection statistics analytically and comparing the results with those of several comprehensive simulations. The performance improvement of this detector is shown by comparing its detection range with the conventional detector. The proposed detector is also evaluated with real radar data and its efficiency is confirmed.
    Download PDF (619K)
  • Young H. JUNG, Hong-Sik KIM, Yoonsik CHOE
    Article type: PAPER
    Subject area: Multimedia Systems for Communications
    2010 Volume E93.B Issue 3 Pages 696-703
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    This paper describes a channel-adaptive packet scheduler for improved error control performance in a peer-cooperative distributed media streaming system. The proposed packet-scheduling algorithm was designed for the case in which streaming server peers rely on an error-recovery strategy using retransmission and application-layer automatic repeat request rather than error protection using forward error correction. The proposed scheduler can maximize retransmission opportunities and reduce the frame loss rate by using the observed channel status from each server peer. Simulation results show that the proposed algorithm enhances error-recovery performance in distributed multimedia streaming better than other schedulers.
    Download PDF (671K)
  • Zhaoxi FANG, Xiaolin ZHOU, Yu ZHU, Zongxin WANG
    Article type: PAPER
    Subject area: Broadcast Systems
    2010 Volume E93.B Issue 3 Pages 704-711
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    Selection relaying is a promising technique for practical implementation of cooperative systems with multiple relay nodes. However, to select the best relay, global channel knowledge is required at the selecting entity, which may result in considerable signaling overhead. In this paper, we consider the relay selection problem in dual-hop amplify-and-forward (AF) communication systems with partial channel state information (CSI). Relay selection strategies aiming at minimizing either the outage probability or the bit error rate (BER) with quantized CSI available are presented. We also propose a target rate based quantizer to efficiently partition the SNR range for outage minimized relay selection, and a target BER based quantizer for BER minimized relay selection. Simulation results show that near optimal performance is achievable with a few bits feedback to the selecting entity.
    Download PDF (306K)
  • Yasuyuki OKUMURA
    Article type: LETTER
    Subject area: Fiber-Optic Transmission for Communications
    2010 Volume E93.B Issue 3 Pages 712-715
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    This letter proposes a dynamic bandwidth allocation algorithm for access networks based PON (Passive Optical Network). It considers the mixture of transport layer protocols when responding to traffic congestion at the SNI (Service Node Interface). Simulations on a mixture of TCP (Transmission Control Protocol), and UDP (User Datagram Protocol) traffic flows show that the algorithm increases the throughput of TCP, improves the fairness between the two protocols, and solves the congestion problem at the SNI.
    Download PDF (284K)
  • Tran Trung DUY, Beongku AN, Hyung-Yun KONG
    Article type: LETTER
    Subject area: Network
    2010 Volume E93.B Issue 3 Pages 716-720
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    Cooperative transmission protocols attract a great deal of attention in recent years as an efficient way to increase the capacity of multi-hop wireless networks in fading environments. In this paper, we propose and analyze a cooperative transmission method, called Cooperative-Aided Skipping multi-Hop protocol (CASH), for multi-hop wireless networks with Rayleigh fading environments. For performance evaluation, we compare and verify the results of the theoretical analysis with the results of simulations.
    Download PDF (166K)
  • Abhishek ROY, Navrati SAXENA, Jitae SHIN
    Article type: LETTER
    Subject area: Network
    2010 Volume E93.B Issue 3 Pages 721-724
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    In this letter we propose a novel resource allocation and admission control strategy for OFDMA-based emerging LTE systems. Considering users' reneging and migration between service providers, we first prove that the optimal resource allocation problem, which maximizes the service provider's gross income is, NP-complete. Subsequently, we propose two different heuristics based on dynamic programming and greedy algorithms to get a near-optimal resource allocation and admission control strategy in computationally feasible time. Simulation results point out that the solutions offer increased gross income of the service provider, while offering low latency, adequate throughput and session acceptance.
    Download PDF (357K)
  • Yongsuk PARK, Taejoon PARK
    Article type: LETTER
    Subject area: Network
    2010 Volume E93.B Issue 3 Pages 725-728
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    In this letter, we present a route discovery protocol for ad hoc multi-hop cellular networks which uses directional information towards the base station. The proposed protocol, based on the reactive approach, reduces flooding as much as possible. To quantify this, we analyze its performance in terms of how much progress it makes per hop and how much reduction in routing packet number it achieves per route discovery. The analytical, as well as simulation, results demonstrate that the proposed protocol significantly reduces flooding overheads and finds a route to the base station in a robust manner.
    Download PDF (497K)
  • Naofumi AOKI
    Article type: LETTER
    Subject area: Network
    2010 Volume E93.B Issue 3 Pages 729-731
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    This study investigates a band extension technique for narrow-band telephony speech. The proposed technique employs full wave rectification that nonlinearly generates high-band overtones from the low band. In order to improve the conventional technique, this study investigates a frame-by-frame gain control based on the estimation of gain parameter from narrow-band telephony speech. A subjective evaluation indicates that the proposed technique outperforms the conventional technique.
    Download PDF (655K)
  • Jaeyoung HONG, Hanjin LEE, Suho YANG, Hyunsoo YOON
    Article type: LETTER
    Subject area: Network
    2010 Volume E93.B Issue 3 Pages 732-735
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    This letter proposes a novel mobile sensor deployment scheme for maximizing coverage. The basic idea is to force mobile sensors to move to predetermined target points that are the optimal layout in a distributed manner using Voronoi diagram data structure. A simulation shows that the result of the proposed scheme is quite close to the optimal result and outperforms previous works.
    Download PDF (200K)
  • Sho SHIMIZU, Wouter TAVERNIER, Kou KIKUTA, Masahiro NISHIDA, Daisuke I ...
    Article type: LETTER
    Subject area: Network
    2010 Volume E93.B Issue 3 Pages 736-740
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL FREE ACCESS
    The first global interoperability experiment of GMPLS controlled Ethernet with VLAN tag swapping between two different implementations is successfully demonstrated. High definition video streaming is realized through a newly established Layer 2 Label Switched Path (L2-LSP). The results of this experiment can be applied to designing reliable Layer 2 networks.
    Download PDF (571K)
  • Haibo SU, Shijun LIN, Yong LI, Li SU, Depeng JIN, Lieguang ZENG
    Article type: LETTER
    Subject area: Network Management/Operation
    2010 Volume E93.B Issue 3 Pages 741-744
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    In network tomography, most work to date is based on exploiting probe packet level correlations to infer the link loss rates and delay distributions. Some other work focuses on identifying the congested links using uncorrelated end-to-end measurements and link prior probability of being congested. In their work, the prior probabilities are identified by the matrix inversion with a number of measurement snapshots, and the algorithm to find the congested links is heuristic and not optimal. In this letter, we present a new estimator for the prior probabilities that is computationally simple, being an explicit function of the measurement snapshots. With these prior probabilities, the identification of the congested link set is equivalent to finding the solution for a probability maximization problem. We propose a fast bottom-up approach named FBA to find the solution for this problem. The FBA optimizes the solution step by step from the bottom up. We prove that the solution by the FBA is optimal.
    Download PDF (96K)
  • Sujin KIM, Na Young KIM, Youngok KIM, Joonhyuk KANG
    Article type: LETTER
    Subject area: Wireless Communication Technologies
    2010 Volume E93.B Issue 3 Pages 745-748
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    In this study, a computationally efficient ranging scheme exploiting a minimum mean square error (MMSE) and a matrix-pencil (MP) technique is proposed for the IEEE 802.15.4a chirp spread spectrum (CSS) system. Based on the characteristics of the CSS signal, a practical methodology for the MMSE process is devised and the appropriate values of parameters, which are cutoff bandwidth, number of samples and sampling duration in frequency domain, are investigated and numerically determined to enhance the performance. The performance of proposed scheme is analyzed in terms of the computational complexity and the ranging estimation errors. Simulation results demonstrate that the proposed scheme performs as well as the conventional scheme at remarkably reduced computational costs.
    Download PDF (189K)
  • Sanhae KIM, Myungsik YOO, Yoan SHIN
    Article type: LETTER
    Subject area: Wireless Communication Technologies
    2010 Volume E93.B Issue 3 Pages 749-752
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    The conventional TDoA (Time Difference of Arrival)-based and RSS (Received Signal Strength)-based location schemes create large positioning errors because of the various wireless channel effects such as path loss, shadowing, and NLoS (Non-Line-of-Sight) components of the multipath channels. In this paper, we propose an improved wireless location scheme which performs a weighted combination of the TDoA and RSS location schemes to improve a detection probability in the mobile-WiMAX femto-cell environments.
    Download PDF (567K)
  • Tran Trung DUY, Hyung Yun KONG
    Article type: LETTER
    Subject area: Wireless Communication Technologies
    2010 Volume E93.B Issue 3 Pages 753-756
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    In this paper, we consider the error performance of the regular triangular quadrature amplitude modulation (TQAM). In particular, using an accurate exponential bound of the complementary error function, we derive a simple approximation for the average symbol error rate (SER) of TQAM over Additive White Gaussian Noise (AWGN) and fading channels. The accuracy of our approach is verified by some simulation results.
    Download PDF (188K)
  • Guomei ZHANG, Shihua ZHU, Feng LI, Pinyi REN
    Article type: LETTER
    Subject area: Wireless Communication Technologies
    2010 Volume E93.B Issue 3 Pages 757-761
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    An improved soft-input soft-output (SISO) minimum mean-squared error (MMSE) detection method is proposed for joint coding and precoding OFDM systems under imperfect channel estimation. Compared with the traditional mismatched detection which uses the channel estimate as its exact value, the signal model of the proposed detector is more accurate and the influence of channel estimation error (CEE) can be effectively mitigated. Simulations indicate that the proposed scheme can improve the bit error rate (BER) performance with fewer pilot symbols.
    Download PDF (255K)
  • Ming DING, Shi LIU, Hanwen LUO, Wuyang JIANG, Jing LV
    Article type: LETTER
    Subject area: Wireless Communication Technologies
    2010 Volume E93.B Issue 3 Pages 762-765
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    In this letter, we propose a novel antenna selection algorithm for amplify-and-forward (AF) multiple-input multiple-output (MIMO) relay systems with Zero-Forcing (ZF) processing applied both at the source node and at the destination node. We obtain the optimum antenna selection criterion by deriving an iterative closed-form expression for capacity maximization.
    Download PDF (128K)
  • Seung-young PARK, Hyun-hee LEE, Kyung-goo JUNG
    Article type: LETTER
    Subject area: Wireless Communication Technologies
    2010 Volume E93.B Issue 3 Pages 766-770
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    In this letter, we propose a distributed channel assignment where each basestation selects a set of channels shared by multiple users through time domain scheduling for best effort services. The proposed scheme distributedly assigns the channels considering a cochannel interference from neighboring basestations and its own traffic load condition. The computer simulation demonstrates that the proposed scheme appropriately assigns the channels to the basestations taking into account these requirements.
    Download PDF (268K)
  • Wei-Cheng PAO, Yung-Fang CHEN, Dah-Chung CHANG
    Article type: LETTER
    Subject area: Wireless Communication Technologies
    2010 Volume E93.B Issue 3 Pages 771-775
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    A simple suboptimal power allocation method is proposed for SC-FDMA systems. It is known that the performance of constant power-based allocation methods is close to that of optimal solutions. In this letter, by utilizing the waterfilling condition inequality derived for SC-FDMA systems, a threshold is set to select subcarriers for loading constant power to these selected subcarriers. It offers competitive performance as confirmed by the simulation results.
    Download PDF (320K)
  • Naotaka SHIBATA, Koji YAMAMOTO, Hidekazu MURATA, Susumu YOSHIDA
    Article type: LETTER
    Subject area: Terrestrial Radio Communications
    2010 Volume E93.B Issue 3 Pages 776-779
    Published: March 01, 2010
    Released on J-STAGE: March 01, 2010
    JOURNAL RESTRICTED ACCESS
    A cooperative relaying system with transmission scheduling is investigated. Cooperative relaying is composed of multiple links because the source sends the data to more than one receiver, and the destination receives multiple data transmitted by more than one transmitter. Therefore, if the source can transmit the data when the channel gains of the links are high, it is not clear which channel gains should be high in order to achieve high spectral efficiency. In the present letter, the spectral efficiency of a cooperative relaying system is theoretically derived under the assumption that the source transmits the data only when the channel gains of links are above certain threshold values. Numerical results reveal that a high spectral efficiency can be achieved by assuring a high channel gain for the link with the highest average received power among links to the destination.
    Download PDF (229K)
feedback
Top