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Mikio Iwamura

Bio: Mikio Iwamura is an academic researcher from NTT DoCoMo. The author has contributed to research in topics: Base station & Mobile station. The author has an hindex of 26, co-authored 256 publications receiving 4039 citations.


Papers
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Journal ArticleDOI
Patrick Agyapong1, Mikio Iwamura1, Dirk Staehle1, Wolfgang Kiess1, Anass Benjebbour1 
TL;DR: A two-layer architecture is proposed, consisting of a radio network and a network cloud, integrating various enablers such as small cells, massive MIMO, control/user plane split, NFV, and SDN, to address the challenges placed on 5G mobile networks.
Abstract: This article presents an architecture vision to address the challenges placed on 5G mobile networks. A two-layer architecture is proposed, consisting of a radio network and a network cloud, integrating various enablers such as small cells, massive MIMO, control/user plane split, NFV, and SDN. Three main concepts are integrated: ultra-dense small cell deployments on licensed and unlicensed spectrum, under control/user plane split architecture, to address capacity and data rate challenges; NFV and SDN to provide flexible network deployment and operation; and intelligent use of network data to facilitate optimal use of network resources for QoE provisioning and planning. An initial proof of concept evaluation is presented to demonstrate the potential of the proposal. Finally, other issues that must be addressed to realize a complete 5G architecture vision are discussed.

553 citations

Journal ArticleDOI
Mikio Iwamura1, Kamran Etemad2, Mo-Han Fong3, R Nory4, R Love4 
TL;DR: Support for carrier aggregation requires enhancement to the LTE Release 8/9 PHY, MAC, and RRC layers while ensuring that LTE Release 10 maintains backward compatibility to LTE Release8/9.
Abstract: Carrier aggregation is one of the most distinct features of 4G systems including LTEAdvanced, which is being standardized in 3GPP as part of LTE Release 10. This feature allows scalable expansion of effective bandwidth delivered to a user terminal through concurrent utilization of radio resources across multiple carriers. These carriers may be of different bandwidths, and may be in the same or different bands to provide maximum flexibility in utilizing the scarce radio spectrum available to operators. Support for this feature requires enhancement to the LTE Release 8/9 PHY, MAC, and RRC layers while ensuring that LTE Release 10 maintains backward compatibility to LTE Release 8/9. This article provides an overview of carrier aggregation use cases and the framework, and their impact on LTE Release 8/9 protocol layers.

382 citations

Patent
23 Jun 2009
TL;DR: In this article, the authors proposed a mobile communication method in which a mobile station performs a handover from a handoff source radio base station to a hand over target radio BS, which includes the steps of acquiring, at the handover target radio base stations, from a switching center, a key for calculating a first key for generating a certain key used in a communication between the target radio station and the mobile station.
Abstract: The present invention relates to a mobile communication method in which a mobile station performs a handover from a handover source radio base station to a handover target radio base station. The mobile communication method includes the steps of: (A) acquiring, at the handover target radio base station, from the handover source radio base station or a switching center, a key for calculating a first key for generating a certain key used in a communication between the handover target radio base station and the mobile station; and (B) acquiring, at the handover target radio base station, from the switching center, a second key for calculating a first key for generating a certain key used in a communication between a next handover target radio base station and the mobile station.

225 citations

Patent
13 Jun 2011
TL;DR: In this article, the authors present a mobile communication method which includes the steps of: transmitting, from a handover source radio base station to a swithcing center, a handoff request including an NCC, a PCI and a K eNB *; changing, at the swithcecent center, the NCC; and generating at the mobile station, the first key on the basis of NCC and the PCI included in the handover command.
Abstract: In a mobile communication method according to the present invention includes the steps of: transmitting, from a handover source radio base station to a swithcing center, a handover request including an NCC, a PCI and a K eNB *; changing, at the swithcing center, the NCC, changing, at the swithcing center, the K eNB * on the basis of the PCI, and transmitting, from the swithcing center to the handover target radio base station, the handover request including the changed NCC and the changed K eNB *; generating, at the handover target radio base station, a first key on the basis of the K eNB *; and generating, at the mobile station, the first key on the basis of the NCC and the PCI included in a handover command.

151 citations

Patent
Mikio Iwamura1
13 Mar 2013
TL;DR: In this article, a mobile station UE is provided with an access right management unit for managing a CSG-ID corresponding to a cell which permits the UE to access thereto, a measurement unit for measuring the radio quality of the CSG cell defined as an object to be measured, and a measurement report transmission unit for, only when the radio QoS of a cell corresponding to the CS G-ID managed by the access right manager satisfies a report condition.
Abstract: A mobile station UE is provided with an access right management unit for managing a CSG-ID corresponding to a CSG cell which permits the mobile station UE to access thereto, a measurement unit for measuring the radio quality of a CSG cell defined as an object to be measured, and a measurement report transmission unit for, only when the radio quality of a CSG cell corresponding to the CSG-ID managed by the access right management unit out of the radio qualities of CSG cells measured by the measurement unit satisfies a report condition, transmitting a measurement report including at least the radio quality of the CSG cell corresponding to the CSG-ID.

118 citations


Cited by
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Journal ArticleDOI
TL;DR: This survey makes an exhaustive review of wireless evolution toward 5G networks, including the new architectural changes associated with the radio access network (RAN) design, including air interfaces, smart antennas, cloud and heterogeneous RAN, and underlying novel mm-wave physical layer technologies.
Abstract: The vision of next generation 5G wireless communications lies in providing very high data rates (typically of Gbps order), extremely low latency, manifold increase in base station capacity, and significant improvement in users’ perceived quality of service (QoS), compared to current 4G LTE networks. Ever increasing proliferation of smart devices, introduction of new emerging multimedia applications, together with an exponential rise in wireless data (multimedia) demand and usage is already creating a significant burden on existing cellular networks. 5G wireless systems, with improved data rates, capacity, latency, and QoS are expected to be the panacea of most of the current cellular networks’ problems. In this survey, we make an exhaustive review of wireless evolution toward 5G networks. We first discuss the new architectural changes associated with the radio access network (RAN) design, including air interfaces, smart antennas, cloud and heterogeneous RAN. Subsequently, we make an in-depth survey of underlying novel mm-wave physical layer technologies, encompassing new channel model estimation, directional antenna design, beamforming algorithms, and massive MIMO technologies. Next, the details of MAC layer protocols and multiplexing schemes needed to efficiently support this new physical layer are discussed. We also look into the killer applications, considered as the major driving force behind 5G. In order to understand the improved user experience, we provide highlights of new QoS, QoE, and SON features associated with the 5G evolution. For alleviating the increased network energy consumption and operating expenditure, we make a detail review on energy awareness and cost efficiency. As understanding the current status of 5G implementation is important for its eventual commercialization, we also discuss relevant field trials, drive tests, and simulation experiments. Finally, we point out major existing research issues and identify possible future research directions.

2,624 citations

Journal ArticleDOI
TL;DR: A general probable 5G cellular network architecture is proposed, which shows that D2D, small cell access points, network cloud, and the Internet of Things can be a part of 5G Cellular network architecture.
Abstract: In the near future, i.e., beyond 4G, some of the prime objectives or demands that need to be addressed are increased capacity, improved data rate, decreased latency, and better quality of service. To meet these demands, drastic improvements need to be made in cellular network architecture. This paper presents the results of a detailed survey on the fifth generation (5G) cellular network architecture and some of the key emerging technologies that are helpful in improving the architecture and meeting the demands of users. In this detailed survey, the prime focus is on the 5G cellular network architecture, massive multiple input multiple output technology, and device-to-device communication (D2D). Along with this, some of the emerging technologies that are addressed in this paper include interference management, spectrum sharing with cognitive radio, ultra-dense networks, multi-radio access technology association, full duplex radios, millimeter wave solutions for 5G cellular networks, and cloud technologies for 5G radio access networks and software defined networks. In this paper, a general probable 5G cellular network architecture is proposed, which shows that D2D, small cell access points, network cloud, and the Internet of Things can be a part of 5G cellular network architecture. A detailed survey is included regarding current research projects being conducted in different countries by research groups and institutions that are working on 5G technologies.

1,899 citations

Journal ArticleDOI
TL;DR: This paper analyzes the MEC reference architecture and main deployment scenarios, which offer multi-tenancy support for application developers, content providers, and third parties, and elaborates further on open research challenges.
Abstract: Multi-access edge computing (MEC) is an emerging ecosystem, which aims at converging telecommunication and IT services, providing a cloud computing platform at the edge of the radio access network MEC offers storage and computational resources at the edge, reducing latency for mobile end users and utilizing more efficiently the mobile backhaul and core networks This paper introduces a survey on MEC and focuses on the fundamental key enabling technologies It elaborates MEC orchestration considering both individual services and a network of MEC platforms supporting mobility, bringing light into the different orchestration deployment options In addition, this paper analyzes the MEC reference architecture and main deployment scenarios, which offer multi-tenancy support for application developers, content providers, and third parties Finally, this paper overviews the current standardization activities and elaborates further on open research challenges

1,351 citations

Journal ArticleDOI
TL;DR: Propagation parameters and channel models for understanding mmWave propagation, such as line-of-sight (LOS) probabilities, large-scale path loss, and building penetration loss, as modeled by various standardization bodies are compared over the 0.5–100 GHz range.
Abstract: This paper provides an overview of the features of fifth generation (5G) wireless communication systems now being developed for use in the millimeter wave (mmWave) frequency bands. Early results and key concepts of 5G networks are presented, and the channel modeling efforts of many international groups for both licensed and unlicensed applications are described here. Propagation parameters and channel models for understanding mmWave propagation, such as line-of-sight (LOS) probabilities, large-scale path loss, and building penetration loss, as modeled by various standardization bodies, are compared over the 0.5–100 GHz range.

943 citations

Journal ArticleDOI
TL;DR: This article provides a comprehensive review on emerging and enabling technologies related to the 5G system that enables IoT, such as 5G new radio, multiple-input–multiple-output antenna with the beamformation technology, mm-wave commutation technology, heterogeneous networks (HetNets), the role of augmented reality (AR) in IoT, which are discussed in detail.
Abstract: Recently, wireless technologies have been growing actively all around the world. In the context of wireless technology, fifth-generation (5G) technology has become a most challenging and interesting topic in wireless research. This article provides an overview of the Internet of Things (IoT) in 5G wireless systems. IoT in the 5G system will be a game changer in the future generation. It will open a door for new wireless architecture and smart services. Recent cellular network LTE (4G) will not be sufficient and efficient to meet the demands of multiple device connectivity and high data rate, more bandwidth, low-latency quality of service (QoS), and low interference. To address these challenges, we consider 5G as the most promising technology. We provide a detailed overview of challenges and vision of various communication industries in 5G IoT systems. The different layers in 5G IoT systems are discussed in detail. This article provides a comprehensive review on emerging and enabling technologies related to the 5G system that enables IoT. We consider the technology drivers for 5G wireless technology, such as 5G new radio (NR), multiple-input–multiple-output antenna with the beamformation technology, mm-wave commutation technology, heterogeneous networks (HetNets), the role of augmented reality (AR) in IoT, which are discussed in detail. We also provide a review on low-power wide-area networks (LPWANs), security challenges, and its control measure in the 5G IoT scenario. This article introduces the role of AR in the 5G IoT scenario. This article also discusses the research gaps and future directions. The focus is also on application areas of IoT in 5G systems. We, therefore, outline some of the important research directions in 5G IoT.

896 citations