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Vlad Tabus,Dmitri Moltchanov,Yevgeni Koucheryavy,Ioan Tabus,Jaakko Astola 한국통신학회 2015 Journal of communications and networks Vol.17 No.2
This paper builds on a recent method, chain routing with even energy consumption (CREEC), for designing a wireless sensor network with chain topology and for scheduling the communication to ensure even average energy consumption in the network. In here a new suboptimal design is proposed and compared with the CREEC design. The chain topology in CREEC is reconfigured after each group of n converge-casts with the goal of making the energy consumption along the new paths between the nodes in the chain as even as possible. The new method described in this paper designs a single near-optimal Hamiltonian circuit, used to obtain multiple chains having only the terminal nodes different at different converge-casts. The advantage of the new scheme is that for the whole life of the networkmost of the communication takes place between same pairs of nodes, therefore keeping topology reconfigurations at a minimum. The optimal scheduling of the communication between the network and base station in order to maximize network lifetime, given the chosen minimum length circuit, becomes a simple linear programming problem which needs to be solved only once, at the initialization stage. The maximum lifetime obtained when using any combination of chains is shown to be upper bounded by the solution of a suitable linear programming problem. The upper bounds show that the proposed method provides near-optimal solutions for several wireless sensor network parameter sets.
Concept Design and Performance Evaluation of UAV-based Backhaul Link with Antenna Steering
Jiri Pokorny,Aleksandr Ometov,Pablo Pascual,Carlos Baquero,Pavel Masek,Alexander Pyattaev,Ainoa Garcia,Carlos Castillo,Sergey Andreev,Jiri Hosek,Yevgeni Koucheryavy 한국통신학회 2018 Journal of communications and networks Vol.20 No.5
At present, cellular coverage in many rural areas remainsintermittent. Mobile operators may not be willing to deployexpensive network infrastructure to support low-demand regions. For that reason, solutions for the rapid deployment of base stationsin areas with insufficient or damaged operator infrastructureare emerging. Utilization of unmanned aerial vehicles (UAVs) ordrones serving as data relays holds significant promise for deliveringon-demand connectivity as well as providing public safety servicesor aiding in recovery after communication infrastructure failurescaused by natural disasters. The use of UAVs in provisioninghigh-rate radio connectivity and bringing it to remote locations isalso envisioned as a potential application for fifth-generation (5G)communication systems. In this study, we introduce a prototypesolution for an aerial base station, where connectivity between adrone and a base station is provided via a directional microwavelink. Our prototype is equipped with a steering mechanism drivenby a dedicated algorithm to support such connectivity. Our experimentalresults demonstrate early-stage connectivity and signalstrength measurements that were gathered with our prototype. Our results are also compared against the free-space model. Thesefindings support the emerging vision of aerial base stations as partof the 5G ecosystem and beyond.
3GPP LTE-Assisted Wi-Fi-Direct: Trial Implementation of Live D2D Technology
Alexander Pyattaev,Jiri Hosek,Kerstin Johnsson,Radko Krkos,Mikhail Gerasimenko,Aleksandr Ometov,Pavel Masek,Sergey Andreev,Jakub Sedy,Vit Novotny,Yevgeni Koucheryavy 한국전자통신연구원 2015 ETRI Journal Vol.37 No.5
This paper is a first-hand summary on our comprehensive live trial of cellular-assisted device-to-device (D2D) communications currently being ratified by the standards community for next-generation mobile broadband networks. In our test implementation, we employ a full-featured 3GPP LTE network deployment and augment it with all necessary support to provide real-time D2D connectivity over emerging Wi-Fi-Direct (WFD) technology. As a result, our LTE-assisted WFD D2D system enjoys the required flexibility while meeting the existing standards in every feasible detail. Further, this paper provides an account on the extensive measurement campaign conducted with our implementation. The resulting real-world measurements from this campaign quantify the numerical effects of D2D functionality on the resultant system performance. Consequently, they shed light on the general applicability of LTE-assisted WFD solutions and associated operational ranges.