A5052591259- Advanced MIMO Systems Optimization
- Wireless Communication Networks Research
- Telecommunications and Broadcasting Technologies
- Cognitive Radio Networks and Spectrum Sensing
- Wireless Networks and Protocols
- Millimeter-Wave Propagation and Modeling
- Cooperative Communication and Network Coding
- Advanced Wireless Network Optimization
- Power Line Communications and Noise
- Advanced Wireless Communication Techniques
- Advanced Polymer Synthesis and Characterization
- Software-Defined Networks and 5G
- Network Traffic and Congestion Control
- Satellite Communication Systems
- IoT Networks and Protocols
- IPv6, Mobility, Handover, Networks, Security
- Energy Efficient Wireless Sensor Networks
- Advanced Wireless Communication Technologies
- PAPR reduction in OFDM
- Caching and Content Delivery
- Dendrimers and Hyperbranched Polymers
- Internet of Things and Social Network Interactions
- Microwave Engineering and Waveguides
- Wireless Sensor Networks and IoT
- IoT and Edge/Fog Computing
National Institute of Information and Communications Technology
2014-2024
Naval Hospital Yokosuka Japan
2017
Advanced Telecommunications Research Institute International
2016
National Institute on Consumer Education
2008-2014
Tokyo Institute of Technology
1990-2006
The next-generation wireless networks are evolving into very complex systems because of the diversified service requirements, heterogeneity in applications, devices, and networks. network operators need to make best use available resources, for example, power, spectrum, as well infrastructures. Traditional networking approaches, i.e., reactive, centrally-managed, one-size-fits-all conventional data analysis tools that have limited capability (space time) not competent anymore cannot satisfy...
This article proposes a novel Airborne Internet of Things Network (AIN) system architecture for monitoring water quality, combining existing wireless technologies with the aid low altitude platform (LAP) to relay data over long distances in hilly terrain. The proposed consists quality sensors, smart utility network (SUN) devices, range (LoRa) an LAP air balloon, and Wi-Fi devices. A measurement campaign was conducted assess system, focusing on communication link reliability stability...
3GPP has been engaged in further advancing the evolved E-UTRAN and UTRAN based radio access network technologies. NR is 3rd Generation Partnership Project (3GPP) endeavor for outlining standardization of 5G advanced technology. released first set standards, that is, non-standalone specifications. As LTE technology massively deployed broadly accepted, transition from to very critical, it maximum importance backward compatibility with considered. identified several architecture options 5G....
This paper introduces the concept, features and architecture of a software defined cognitive radio system: Cognitive Wireless Clouds (CWC) that can realize user-centric scalable network based on unique spectrum access, cross-network signaling, optimization, fast reconfiguration methods. Then, this shows results feasibility studies (SDCR) terminal access to CWC. includes configuration SDCR measurement data for sensing period by using packages W-CDMA IEEE802.11a.
The Project Authorization Request (PAR) for the IEEE P1900.4 Working Group (WG), under Standards Coordinating Committee 41 (SCC41) was approved in December 2006, leading to this WG being officially launched February 2007 [1]. scope of standard is devise a functional architecture comprising building blocks enable coordinated network-device distributed decision making, with goal aiding optimization radio resource usage, including spectrum access control, heterogeneous wireless networks. This...
TV White Spaces technology is a means of allowing wireless devices to opportunistically use locally-available channels (TV Spaces), enabled by geolocation database. The database informs the device which can be used at given location, and in UK/EU case, transmission powers (EIRPs) on each channel based technical characteristics device, an assumed interference limit protection margin edge primary service coverage area(s). UK regulator, Ofcom, has initiated large-scale Pilot devices....
In this paper, we conceive an advanced neutral host micro operator (NH-{\mu}O) network approach providing venues with services tailored to their specialized/specific requirements and/or local context related that the mobile operators (MNOs) are poorly-suited it, as well broadband experience users from MNOs in a venue where only single infrastructure is mandated under shared spectrum access framework. A radio slicing concept conceived support and optimize both slice instance (SI) use cases...
The shared resource access wireless communication system is regarded as an efficient paradigm that allows the mobile network operators to have extended coverage and satisfy their subscribers' high capacity demands while keeping capital operational expenditure in check. On other hand, dual connectivity (DC), a small cell enhancement feature, subscribers two simultaneous connections increasing throughput enhancing mobility robustness. coordinated multipoint (CoMP) transmission/reception...
We investigate an advanced two-phase shared spectrum access communication scheme as efficient approach to enhance the spectral utilization of a network. In first phase, we devise spectrum-sharing policy based on demands, fairness, and so on, which utilizes priority in fulfilling operators' envision secure operator-specific information sharing where no critical is exchanged between operators. second macro cell network (MCN) benefits through offloading services offered by small (SCN). This...
The small cell network (SCN) is one of the emerging technologies for next generation wireless systems. It can provide lots advantages, such as enlargement coverage, boost peak data rate, improvement link quality, flexibility deployment, etc. In SCN, a specific scenario, where density base stations (SBS) much higher than that user equipments (UE), becomes popular topic recently. Because high SBSs, it offer diversity SBS selection and, hence, improve system performance. Besides, under this...
To cope with the increasingly diversifying services, QoS, and network architectures, virtualization is a promising technology that enables concurrent deployment of multiple technologies on shared network. However, traditional research preliminarily focuses wired environment for wireless not well studied. Considering in near-future, various will play most important role access networks multi-mode terminals become more popular, it crucial to extend concept networks. We refer building such...
The success of a rural wireless monitoring system depends on establishing reliable link over the TCP/IP communication protocol in challenging terrain and elevation profile. Several studies have shown that reliability area can neither be predicted with high accuracy nor precisely modeled using existing mathematical channel modeling tools. Hence, use empirical approach to infer reliability. This work focuses revival hydrological/water emphasis located Tasik Chini, lake UNESCO biosphere status....
Small cells deployment is one of the most significant long-term strategic policies mobile network operators. In heterogeneous networks (HetNets), small serve as offloading spots in radio access to offload macro users (MUs) and their associated traffic from congested macrocells. this paper, we perform analytical analysis investigate how channel propagation impairments such multipath fading, shadowing, cell base station density affect MUs' (SCN). particular, exploit composite fading channels...
IEEE P1900.4 is an emerging standard for optimized radio resource utilization where cognitive technologies are used efficient spectrum utilization. In this paper, we design and implement a wireless network system based on open documents of P1900.4, evaluate its performance using UDP streaming HTTP download. Our experiments show interesting results that total throughput in the HDP improved by 30% although some individual terminals can not necessarily obtain better throughput. Also, it shown...
This paper introduces two cognitive radio (CR) systems: (a) heterogeneous type CR and (b) spectrum sharing regarding its definition, usage model, fundamental system architecture, developed prototype.
A field experiment of TV White Space (TVWS) communications was conducted using developed systems following IEEE 802.22 and 802.11af standards succeeded to have the world first throughput, distance, application testing. The system achieved throughput 4.5 Mbps for uplink 5.2 downlink over 12.7 km. Also, feasibility applications such as web browsing, video streaming talk confirmed in multi-hop network where a backbone link access area expansion. Furthermore, aggregating bandwidth two...
Multipath TCP (MPTCP), which enables the use of multiple wireless links (e.g., Wi-Fi and LTE) for data transmissions, is an excellent technology evolving multi-homing devices in mobile networks. This paper explores concepts feasibility realizing MPTCP with path awareness (PA), path-aware information leveraged to reinforce transmissions. In particular, when aware a network situation, device can facilitate mechanism that dynamically shifts traffic single vice versa. As result, PA could solve...
TV White Spaces (TVWS) technology allows wireless devices to opportunistically use locally-available channels enabled by a geolocation database. The UK regulator Ofcom has initiated pilot of TVWS in the UK. This paper concerns large- scale series trials under that pilot. purposes are test aspects white space technology, including device and database interactions, validity channel availability/powers calculations associated interference effects on primary services, performances devices, among...