Eco Models in Heteregeneous Peer-topeer (P2P) Systems

研究成果の概要 (和文) : 情報システムは、コンピュータ、センサ等の種々の情報機器を含んだ異種なものとなってきている。こうしたシステムでは、これまでの応答時間、スループット等の性能目標に加えて、新たにシステム全体の消費電力の低減が重要となってきている。本研究では、自律的な対等なプロセスから構成される完全分散型の大規模P2Pシステムを考える。ピア間の自律的な協調動作により、システム全体の消費電力を低減できる分散型システムの新しいモデル、特に消費電力については実際のコンピュータの消費電力の実測に基づいて、消費電力のモデルの構築を行った。このモデルに基づいて、ピア間の分散型の協調動作方式を研究し、評価を行った。研究成果の概要 (英文) : Information systems are composed of nodes like computers and sensors interconnected in networks. Here, we have to reduce the total electric energy consumed by nodes in addition to achieving traditional performance objectives. In this research, we proposed a power consumption model of a node to perform application processes. We first measure the total electric power of types of computers to perform application processes and then abstract essential parameters which dominate the power consumed by nodes. The power consumption model which we proposed is referred to as simple power consumption (SPC) model. Here, a computer consumes maximum poser [W] if at least one process is performed, otherwise consumes minimum power. Based on the SPC model, we proposed the energy-aware server selection (EA) algorithm and evaluated the EA model. In the evaluation, we showed not only the total power consumption of a server cluster but also the average execution time of each process are reduced

NOMA-based 802.11g/n: PHY analysis and MAC implementation

Industry 4.0 can be considered as the industrial revolution of the current century. Among others, one of its main objectives is the replacement of wired communications by wireless connectivity. The idea is to overcome the main drawbacks of the current wired ecosystem: the lack of mobility, the deployment costs, cable damage and the difficulties with scalability. However, for this purpose, the nature and requirements of the industrial applications must be taken into account, in particular, the proposed communications protocols must support very low loss rates and a strong robustness against failures. This is a very challenging condition due to the nature of the industrial environments (interference with other communication systems, reflections with metallic objects ...). In addition, another characteristic of the industrial applications is the strict requirement related to the latency. On the other hand, industrial applications are not only based on high challenging services, but also exist more flexible requirement applications, such as, web browser, email, video content or complementary information. Those services are considered Best Effort (BE) services. Eventually, in some wireless applications both critical and BE services have to be offered. For those cases, Non-Orthogonal Multiplexing Access (NOMA) technology together with the IEEE 802.11g/n standard is proposed in this document as the physical layer solution. The IEEE 802.11g/n standard has been modified in order to accommodate NOMA schemes, and then, comprehensive simulations are conducted to check and analyze the behavior of the proposed system. It has been determined that through NOMA technology it is possible to obtain better results in certain cases than those achieved in a transmission cases that implements the IEEE 802.11g/n standard in TDM/FDM basis

NOMA-based 802.11g/n: PHY analysis and MAC implementation

Industry 4.0 can be considered as the industrial revolution of the current century. Among others, one of its main objectives is the replacement of wired communications by wireless connectivity. The idea is to overcome the main drawbacks of the current wired ecosystem: the lack of mobility, the deployment costs, cable damage and the difficulties with scalability. However, for this purpose, the nature and requirements of the industrial applications must be taken into account, in particular, the proposed communications protocols must support very low loss rates and a strong robustness against failures. This is a very challenging condition due to the nature of the industrial environments (interference with other communication systems, reflections with metallic objects ...). In addition, another characteristic of the industrial applications is the strict requirement related to the latency. On the other hand, industrial applications are not only based on high challenging services, but also exist more flexible requirement applications, such as, web browser, email, video content or complementary information. Those services are considered Best Effort (BE) services. Eventually, in some wireless applications both critical and BE services have to be offered. For those cases, Non-Orthogonal Multiplexing Access (NOMA) technology together with the IEEE 802.11g/n standard is proposed in this document as the physical layer solution. The IEEE 802.11g/n standard has been modified in order to accommodate NOMA schemes, and then, comprehensive simulations are conducted to check and analyze the behavior of the proposed system. It has been determined that through NOMA technology it is possible to obtain better results in certain cases than those achieved in a transmission cases that implements the IEEE 802.11g/n standard in TDM/FDM basis