| 1. |
- Nakamura, M., et al.
(author)
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Experimental verification of SDN/NFV in integrated mmwave access and mesh backhaul networks
- 2021
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In: IEICE transactions on communications. - : Institute of Electronics, Information and Communication, Engineers, IEICE. - 0916-8516 .- 1745-1345. ; E104B:3, s. 217-228
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Journal article (peer-reviewed)abstract
- In this paper, a Proof-of-Concept (PoC) architecture is constructed, and the effectiveness of mmWave overlay heterogeneous network (HetNet) with mesh backhaul utilizing route-multiplexing and Multi-access Edge Computing (MEC) utilizing prefetching algorithm is verified by measuring the throughput and the download time of real contents. The architecture can cope with the intensive mobile data traffic since data delivery utilizes multiple backhaul routes based on the mesh topology, i.e. route-multiplexing mechanism. On the other hand, MEC deploys the network edge contents requested in advance by nearby User Equipment (UE) based on pre-registered context information such as location, destination, demand application, etc. to the network edge, which is called prefetching algorithm. Therefore, mmWave access can be fully exploited even with capacity-limited backhaul networks by introducing the proposed algorithm. These technologies solve the problems in conventional mmWave HetNet to reduce mobile data traffic on backhaul networks to cloud networks. In addition, the proposed architecture is realized by introducing wireless Software Defined Network (SDN) and Network Function Virtualization (NFV). In our architecture, the network is dynamically controlled via wide-coverage microwave band links by which UE's context information is collected for optimizing the network resources and controlling network infrastructures to establish backhaul routes and MEC servers. In this paper, we develop the hardware equipment and middleware systems, and introduce these algorithms which are used as a driver of IEEE802.11ad and open source software. For 5G and beyond, the architecture integrated in mmWave backhaul, MEC and SDN/NFV will support some scenarios and use cases.
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| 2. |
- Nakamura, M., et al.
(author)
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Performance evaluation of prefetching algorithm for real-time edge content delivery in 5G system
- 2019
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In: IEEE Vehicular Technology Conference. - : IEEE. - 9781728112206
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Conference paper (peer-reviewed)abstract
- Recently, high-density deployment of mmWave small cell base stations has been focused as a means to cope with the rapidly increasing mobile data traffic. MmWave overlay heterogeneous network (HetNet) is proposed to realize eMBB, however laying cost of backbone utilizing high-capacity optical fibers is very costly to support ultra- broadband accesses. On the other hand, Multi- access Edge Computing (MEC) is proposed to reduce mobile data traffic on backhaul networks. MEC deploys contents requested by User Equipment (UE) nearby in advance based on registered context information e.g. location, destination, and required contents to the orchestrator. Therefore, it is possible to utilize mmWave access under existing backhaul networks by introducing prefetching algorithm. The architecture is enabled by wireless Software Defined Network (SDN) technology. In this paper, Proof-of-Concept (PoC) architecture is proposed, and the effectiveness of mmWave HetNet with MEC utilizing prefetching algorithm is confirmed by measuring the download time of real content.
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| 3. |
- Sousa, Ronaldo, et al.
(author)
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The role of anthropogenic habitats in freshwater mussel conservation
- 2021
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In: Global Change Biology. - : John Wiley & Sons. - 1354-1013 .- 1365-2486. ; 27, s. 2298-2314
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Journal article (peer-reviewed)abstract
- Anthropogenic freshwater habitats may provide undervalued prospects for long-term conservation as part of species conservation planning. This fundamental, but overlooked, issue requires attention considering the pace that humans have been altering natural freshwater ecosystems and the accelerated levels of biodiversity decline in recent decades. We compiled 709 records of freshwater mussels (Bivalvia, Unionida) inhabiting a broad variety of anthropogenic habitat types (from small ponds to large reservoirs and canals) and reviewed their importance as refuges for this faunal group. Most records came from Europe and North America, with a clear dominance of canals and reservoirs. The dataset covered 228 species, including 34 threatened species on the IUCN Red List. We discuss the conservation importance and provide guidance on how these anthropogenic habitats could be managed to provide optimal conservation value to freshwater mussels. This review also shows that some of these habitats may function as ecological traps owing to conflicting management practices or because they act as a sink for some populations. Therefore, anthropogenic habitats should not be seen as a panacea to resolve conservation problems. More information is necessary to better understand the trade-offs between human use and the conservation of freshwater mussels (and other biota) within anthropogenic habitats, given the low number of quantitative studies and the strong biogeographic knowledge bias that persists.
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| 4. |
- Tran, G. K., et al.
(author)
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Outdoor Experiment of mmWave Meshed Backhaul for Realtime Edge Content Delivery
- 2019
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In: 2019 IEEE Wireless Communications and Networking Conference Workshop, WCNCW 2019. - : IEEE. - 9781728109220
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Conference paper (peer-reviewed)abstract
- In recent years, ultra-broadband communication using densification of millimeter-wave (mmWave) small cell base station (SC-BS) has attracted attention owing to its ability to accommodate increasing mobile data traffic. To make full use of mmWave access, deploying ultra-broadband backhauling lines such as optical fibers everywhere is an extremely expensive approach. mmWave meshed network is therefore a cost-efficient wireless backhaul architecture for mmWave overlay cellular network. Owing to its wide bandwidth and flexibility in link connection via beam steering and multi-hop relay, mmWave meshed network is furthermore suitable for dynamic construction of backhauling in adaptation to change of user traffic's distribution via adaptive allocation of backhaul resources of densely co-located users (UE). On the other hand, as users nowadays want to experience services everywhere without disruption even when moving, it is desirable that UE-specific multimedia contents are located as close as possible to the UE via Mobile Edge Computing (MEC) technology. Covering all the above requirements, this paper aims to construct a real UE-centric edge content delivery system in which content server is re-located in adaptation to UE's context information e.g. location, via dynamic routing over mmWave meshed backhaul network, enabled by Software Defined Network (SDN) technology. Using our developed WiGig device based testbed, outdoor experiment campaign is conducted in the university campus with various measurement scenarios. This paper describes the overall testbed architecture and the conducted outdoor experiment with preliminary results revealing the effectiveness of the proposed system.
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