• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권12호
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• pp.4451-4466
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• 2014

We present joint radio selection and relay scheme that delivers data from a source to a sink in heterogeneous stationary sensor networks consisting of various radio interfaces. The proposed scheme finds the optimal relay nodes and their corresponding radio interfaces that minimize energy consumption throughout the network while satisfying the end-to-end packet deadline requirement. We formulate the problem of routing through radio interface selection into binary integer programs, and obtain the optimal solution by solving with an optimization solver. We examine a trade-off relationship between energy consumption and packet delay based on network level simulations. We show that given the end-to-end deadline requirement, our routing algorithm finds the most energy-efficient routing path and radio interface across mesh hops. We demonstrate that the proposed routing scheme exploits the given packet delivery time to turn into network benefit of reducing energy consumption compared to routing based on single radio interface.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권9호
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• pp.3151-3168
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• 2021

Internet of Things (IoT) connects several objects with embedded sensors and they are capable of exchanging information between devices to create a smart environment. IoT smart devices have limited resources, such as batteries, computing power, and bandwidth, but comprehensive sensing causes severe energy restrictions, lowering data quality. The main objective of the proposal is to build a hybrid protocol which provides high data quality and reduced energy consumption in IoT sensor network. The hybrid protocol gives a flexible and complete solution for sensor selection problem. It selects a subset of active sensor nodes in the network which will increase the data quality and optimize the energy consumption. Since the unused sensor nodes switch off during the sensing phase, the energy consumption is greatly reduced. The hybrid protocol uses Dijkstra's algorithm for determining the shortest path for sensing data and Ant colony inspired variable path selection algorithm for selecting active nodes in the network. The missing data due to inactive sensor nodes is reconstructed using enhanced belief propagation algorithm. The proposed hybrid method is evaluated using real sensor data and the demonstrated results show significant improvement in energy consumption, data utility and data reconstruction rate compared to other existing methods.

• 한국통신학회논문지
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• 제41권8호
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• pp.928-941
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• 2016

유선 데이터 네트워크(wired data network) 영역에서 가장 많은 에너지를 요구하는 영역은 액세스 네트워크(access network) 영역이다. 오늘날 그린 네트워킹(Green networking)은 유선 데이터 네트워크에서도 통합적인 에너지 관리를 통해 에너지 낭비와 $CO_2$ 배출 감소를 유도하기 위해 주요 관심분야가 되었다. 그러나 유선 액세스 네트워크의 에너지 소모량과 $CO_2$ 배출에 의한 환경적 영향에 대해서는 널리 알려져 있지 않으며, 그에 따른 범용적이고 정량적인 평가 기준도 매우 부족하다. 본 논문에서는 유선 액세스 네트워크의 에너지 소모량을 추정하는 기존의 모델링 기법들의 문제점을 비교 분석하고 하향식(top-down) 접근법을 이용하여 대규모 유선 액세스 네트워크의 에너지 소모량을 추정하는 모델링 기법을 제안한다. 또한 제안 모델로부터 도출된 추정치를 이용하여 액세스 네트워크들이 환경에 미치는 영향도를 산출하는 모델을 제안한다. 그리고 실제 사례를 적용하여 기존 모델과 제안 모델로부터 산출한 추정치와 해당 사례에 대한 기존의 조사와 실측 데이터와 비교 평가 한다.

• ETRI Journal
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• 제44권1호
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• pp.155-167
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• 2022

The Internet of Things (IoT) is a new paradigm that connects physical and virtual objects from various domains such as home automation, industrial processes, human health, and monitoring. IoT sensors receive information from their environment and forward it to their neighboring nodes. However, the large amounts of exchanged data are vulnerable to attacks that reduce the network performance. Most of the previous security methods for IoT have neglected the energy consumption of IoT, thereby affecting the performance and reducing the network lifetime. This paper presents a new multistep routing protocol based on cellular learning automata. The network lifetime is improved by a performance-based adaptive reward and fine parameters. Nodes can vote on the reliability of their neighbors, achieving network reliability and a reasonable level of security. Overall, the proposed method balances the security and reliability with the energy consumption of the network.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1330-1333
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• 2004

The methodology for modeling building energy consumption is well established for energy saving calculation in the temperate zone both for performance-based energy retrofitting contracts and measurement and verification (M&V) projects. Mostly, statistical regression models based on utility bills and outdoor dry-bulb temperature have been applied to baseline monthly and annual whole building energy use. This paper presents the application of neural networks (NN) to model landlord energy consumption of commercial buildings in Singapore. Firstly, a brief background information on NN and its application on the building energy research is provided. Secondly, five commercial buildings with various characteristics were selected for case studies. Monthly mean outdoor dry-bulb temperature ($T_0$), Relative Humidity (RH) and Global Solar Radiation (GSR) are used as network inputs and the landlord monthly energy consumption of the same period is the output. Up to three years monthly data are taken as training data. A forecast has been made for another year for all the five buildings. The performance of the NN analysis was evaluated using coefficient of variance (CV). The results show that NNs is powerful at predicting annual landlord energy consumption with high accuracy.

• Journal of Communications and Networks
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• 제14권1호
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• pp.75-90
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• 2012

Thin client computing trades local processing for network bandwidth consumption by offloading application logic to remote servers. User input and display updates are exchanged between client and server through a thin client protocol. On wireless devices, the thin client protocol traffic can lead to a significantly higher power consumption of the radio interface. In this article, a cross-layer framework is presented that transitions the wireless network interface card (WNIC) to the energy-conserving sleep mode when no traffic from the server is expected. The approach is validated for different wireless channel conditions, such as path loss and available bandwidth, as well as for different network roundtrip time values. Using this cross-layer algorithm for sample scenario with a remote text editor, and through experiments based on actual user traces, a reduction of the WNIC energy consumption of up to 36.82% is obtained, without degrading the application's reactivity.

• International Journal of Computer Science & Network Security
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• 제24권6호
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• pp.77-82
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• 2024

The Smart home energy consumption represents much of the total energy consumed in advanced countries. For this reason, the main objectif of this paper is to study the energy consumption profile by day for each home appliances: controllable appliances for example Washing machine, Tumble dryer and Air conditioning and uncontrollable appliances for example TV, PC, Lighting, Refrigerator and Electric heater. In this paper, we start with presentation of a smart home energy management systems. Next, we present the modeling and simulation of controllable appliances and uncontrollable appliances. Finally, concludes this paper with some prospects. The modeling and the simulation of a Smart home appliances is based on MATLAB/Simulink software.

• 정보처리학회논문지C
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• 제17C권5호
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• pp.433-440
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• 2010

무선 센서 네트워크에서 에너지 효율성, 전송 지연 그리고 확장성은 중요한 요구사항이며, 특히 다수의 노드로 구성된 무선 센서 네트워크의 경우 네트워크 라이프타임 연장을 위해 제한된 배터리 전력 내에서 각 노드의 에너지 소비를 최소화 시켜야한다. 또한 전송률을 향상시키기 위해서는 각 센서 노드의 에너지 소비를 최소화하기 위한 효율적인 알고리즘과 에너지 관리 기술이 요구된다. 본 논문은 무선 센서 네트워크 환경에서 센서 데이터 전송을 위해 경로의 겹침이 없는 다중경로 프로토콜을 제안한다. 제안한 방법은 다중경로를 검색하고 라우팅 테이블에 다중경로를 추가시켜 센서 데이터 전송의 감소를 통해 네트워크 오버헤드를 최소화 시킨다. 제안한 라우팅 프로토콜은 각 노드의 에너지 소비를 최소화하고, 싱크 노드가 수신 강도 범위 내, 외부에 위치하더라도 센서 네트워크의 생명주기를 연장할 수 있다. 실제 데이터를 이용하여 현실 모델에 맞게 센서 네트워크를 구축하고 제안 기법의 타당성을 검증하며, 전체 에너지의 소비량을 평가한다.

• 한국컴퓨터정보학회논문지
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• 제15권6호
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• pp.65-72
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• 2010

에드 혹 네트워크의 각 무선 단말기는 배터리 기반의 제한된 에너지로 동작하기 때문에 효율적인 에너지 사용에 관한 문제는 아주 중요하다. 시스템 수명을 연장하기 위해서는 단말 노드의 에너지 소비를 균형있게 유도하여 어느 특정 단말기의 에너지가 먼저 고갈되어 통신 단절을 초래하는 상황을 지연시켜야 한다. 또한 단말기 노드의 빈번한 이동 등으로 인해 신뢰성이 낮은 링크는 경로 설정시 고려해야 할 요소이다. 본 논문에서 제안하는 CMLR 방법은 잔여 에너지와 링크 에러율, 전송 소비 에너지를 고려한 새로운 비용 관계식을 이용하여 에너지 사용의 효율성을 증가시킨다. 이 방법은 전송 에너지 소모의 최소화와 노드 수명의 최대화 사이의 값을 절충하여 에너지 효율성을 높이고 균형있는 에너지 소비를 유도하여 네트워크 수명을 연장시키도록 하는 방법이다. 또한, 본 논문에서는 시뮬레이션을 통해 제안하는 CMLR의 성능을 검증하였으며, 네트워크 수명과 경로의 효율성 측면에서 볼 때 기존의 알고리즘보다 우수한 결과를 보여주었다.

• ETRI Journal
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• 제39권2호
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• pp.275-283
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• 2017

A green technology for reducing energy consumption has become a critical factor in ICT industries. However, for the telecommunications sector in particular, most network elements are not usually optimized for power efficiency. Here, we propose a novel energy-efficient packet switching method for use in an IP network for reducing unnecessary energy consumption. As a green networking approach, we first classify the network nodes into either header or member nodes. The member nodes then put the routing-related module at layer 3 to sleep under the assumption that the layer in the OSI model can operate independently. The entire set of network nodes is then partitioned into clusters consisting of one header node and multiple member nodes. Then, only the header node in a cluster conducts IP routing and its member nodes conduct packet switching using a specially designed identifier, a tag. To investigate the impact of the proposed scheme, we conducted a number of simulations using well-known real network topologies and achieved a more energy- efficient performance than that achieved in previous studies.