• 한국정보과학회논문지:정보통신
• /
• 제37권1호
• /
• pp.50-56
• /
• 2010

이 논문은 대규모 무선 센서 네트워크의 전체 운영 시간을 늘이기 위해 모바일 싱크를 이용한 효율적인 데이터 수집 방법을 제안한다. 클러스터링을 통해 센서 네트워크를 나눈 다음 모바일 싱크가 각 클러스터를 방문하여 데이터를 수집한다. 모바일 싱크와 클러스터 헤드 사이의 메시지 전달을 통해 에너지 소비 효율은 높이며 모바일 싱크의 단점인 데이터 수집 시간을 최소화할 수 있는 프로토콜을 제안한다. 네트워크 확장성을 위해 센서 네트워크 구조는 클러스터내에서 싱글 홉 전송보다는 멀티홉 전송을 지원해야 한다. 멀티홉 전송시 발생하는 중간 노드의 과도한 에너지 소비를 개선하기 위해 주행 경로와 연계된 데이터 병합 과정을 제안한다. 실험결과는 제안 모델이 기존 방법들보다 에너지 소비 및 데이터 수집 시간 측면에서 효율적임을 보여준다.

• 한국멀티미디어학회논문지
• /
• 제19권8호
• /
• pp.1460-1465
• /
• 2016

In this paper, we propose an energy efficient and multimedia traffic friendly MAC protocol (EEMF-MAC) that controls sender's wakeup period based on the data packet's transmission urgency and the receiver's wakeup periods based on the received data packet traffic loads. The protocol is useful for applications such as object tracking, real time data gathering, in which priority-based packet transmission is required. The basic idea of EEMF-MAC is that it uses the priority concept with transmission urgency of sender's data packet to reduce the transmission delay of the urgent data and it also uses duty cycling technique in order to achieve energy efficiency. EEMF-MAC showed a better performance in energy efficiency and packet transmission delay compared to existing protocols, RI-MAC and EE-RI-MAC.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제6권1호
• /
• pp.270-286
• /
• 2012

In this paper, we propose a novel routing protocol called the Cartography Enhanced OLSR (CE-OLSR) for multi hop mobile ad hoc networks (multi hop MANETs). CE-OLSR is based on an efficient cartography gathering scheme and a stability routing approach. The cartography gathering scheme is non intrusive and uses the exact OLSR reduced signaling traffic, but in a more elegant and efficient way to improve responsiveness to the network dynamics. This cartography is a much richer and accurate view than the mere network topology gathered and used by OLSR. The stability routing approach uses a reduced view of the collected cartography that only includes links not exceeding a certain distance threshold and do not cross obstacles. In urban environments, IEEE 802.11 radio signals undergo severe radio shadowing and fading effects and may be completely obstructed by obstacles such as buildings. Extensive simulations are conducted to study the performances of CE-OLSR and compare them with those of OLSR. We show that CE-OLSR greatly outperforms OLSR in delivering a high percentage of route validity, a much higher throughput and a much lower average delay. In particular the extremely low average delay exacerbated by CE-OLSR makes it a viable candidate for the transport of real time data traffic in multi hop MANETs.

• Journal of Communications and Networks
• /
• 제13권1호
• /
• pp.17-25
• /
• 2011

A convergecast is a popular routing scheme in wireless sensor networks (WSNs) in which every sensor node periodically forwards measured data along configured routing paths to a base station (BS). Prolonging lifetimes in energy-limited WSNs is an important issue because the lifetime of a WSN influences on its quality and price. Low-energy adaptive clustering hierarchy (LEACH) was the first attempt at solving this lifetime problem in convergecast WSNs, and it was followed by other solutions including power efficient gathering in sensor information systems (PEGASIS) and power efficient data gathering and aggregation protocol (PEDAP). Our solution-chain routing with even energy consumption (CREEC)-solves this problem by achieving longer average lifetimes using two strategies: i) Maximizing the fairness of energy distribution at every sensor node and ii) running a feedback mechanism that utilizes a preliminary simulation of energy consumption to save energy for depleted Sensor nodes. Simulation results confirm that CREEC outperforms all previous solutions such as LEACH, PEGASIS, PEDAP, and PEDAP-power aware (PA) with respect to the first node death and the average lifetime. CREEC performs very well at all WSN sizes, BS distances and battery capacities with an increased convergecast delay.

• 한국통신학회논문지
• /
• 제34권5B호
• /
• pp.443-448
• /
• 2009

본 논문에서는 에너지가 제한적인 무선 센서네트워크에서 MIMO 기반 협력통신을 가능하게 하는 훈련심볼의 오버헤드와 데이터 수집노드(DGN)의 속도의 임계값을 제안한다. 두개의 송수신 안테나가 있는 경우에 대하여 에너지 효율과 지연값에 대한 성능을 분석하였다. 센서로부터 데이터 수집노드까지 장거리 통신을 할 경우에 대하여 기존의 SISO 보다 에너지를 적게 소모하는 MIMO 기반 협력통신 무선 센서 네트워크의 속도와 훈련심볼의 오버헤드 임계값들을 구하였으며 이들의 상관관계도 분석하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제6권10호
• /
• pp.2529-2547
• /
• 2012

In this paper, we use a quadrotor-based mobile sink to gather sensor data from the terrestrial deployed wireless sensor network. By analyzing the flight features of the mobile sink node, we theoretically study the flight constraints of height, velocity, and trajectory of the mobile sink node so as to communicate with the terrestrial wireless sensor network. Moreover, we analyze the data amount which the mobile sink can send when it satisfies these flight constraints. Based on these analysis results, we propose a data acquisition approach for the mobile sink node, which is discussed detailed in terms of network performance such as the transmission delay, packet loss rate, sojourning time and mobile trajectory when given the flying speed and height of the mobile sink node. Extensive simulation results validate the efficiency of the proposed scheme.

• Journal of Electrical Engineering and Technology
• /
• 제13권2호
• /
• pp.998-1007
• /
• 2018

The advent of Wireless Sensor Networks (WSN) has led to their use in numerous applications. Sensors are autonomous in nature and are constrained by limited resources. Designing an autonomous topology with criteria for economic and energy conservation is considered a major goal in WSN. The proposed honey-hive clustering consumes minimum energy and resources with minimal transmission delay compared to the existing approaches. The honey-hive approach consists of two phases. The first phase is an Intra-Cluster Min-Max Discrepancy (ICMMD) analysis, which is based on the local honey-hive data gathering technique and the second phase is Inter-Cluster Frequency Matching (ICFM), which is based on the global optimal data aggregation. The proposed data aggregation mechanism increases the optimal connectivity range of the sensor node to a considerable degree for inter-cluster and intra-cluster coverage with an improved optimal energy conservation.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제15권4호
• /
• pp.1317-1341
• /
• 2021

Nowadays, the Internet of Things (IoT) is adopted to enable effective and smooth communication among different networks. In some specific application, the Wireless Sensor Networks (WSN) are used in IoT to gather peculiar data without the interaction of human. The WSNs are self-organizing in nature, so it mostly prefer multi-hop data forwarding. Thus to achieve better communication, a cross-layer routing strategy is preferred. In the cross-layer routing strategy, the routing processed through three layers such as transport, data link, and physical layer. Even though effective communication achieved via a cross-layer routing strategy, energy is another constraint in WSN assisted IoT. Cluster-based communication is one of the most used strategies for effectively preserving energy in WSN routing. This paper proposes a Bio-inspired cross-layer routing (BiHCLR) protocol to achieve effective and energy preserving routing in WSN assisted IoT. Initially, the deployed sensor nodes are arranged in the form of a grid as per the grid-based routing strategy. Then to enable energy preservation in BiHCLR, the fuzzy logic approach is executed to select the Cluster Head (CH) for every cell of the grid. Then a hybrid bio-inspired algorithm is used to select the routing path. The hybrid algorithm combines moth search and Salp Swarm optimization techniques. The performance of the proposed BiHCLR is evaluated based on the Quality of Service (QoS) analysis in terms of Packet loss, error bit rate, transmission delay, lifetime of network, buffer occupancy and throughput. Then these performances are validated based on comparison with conventional routing strategies like Fuzzy-rule-based Energy Efficient Clustering and Immune-Inspired Routing (FEEC-IIR), Neuro-Fuzzy- Emperor Penguin Optimization (NF-EPO), Fuzzy Reinforcement Learning-based Data Gathering (FRLDG) and Hierarchical Energy Efficient Data gathering (HEED). Ultimately the performance of the proposed BiHCLR outperforms all other conventional techniques.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제9권9호
• /
• pp.3396-3411
• /
• 2015

Sensors used in Wireless Sensor Networks (WSN) have mostly limited capacity which affects the performance of their applications. One of the data-gathering methods is to use mobile sinks to visit these sensors so that they can save their limited battery energies from forwarding data packages to static sinks. The main disadvantage of employing mobile sinks is the delay of data collection due to relative low speed of mobile sinks. Since sensors have very limited memory capacities, whenever a mobile sink is too late to visit a sensor, that sensor's memory would be full, which is called a 'memory overflow', and thus, needs to be purged, which causes loss of collected data. In this work, a method is proposed to generate mobile sink tours, such that the number of overflows and the amount of lost data are minimized. Moreover, the proposed method does not need either the sensor locations or sensor memory status in advance. Hence, the overhead stemmed from the information exchange of these requirements are avoided. The proposed method is compared with a previously published heuristic. The simulation experiment results show the success of the proposed method over the rival heuristic with respect to the considered metrics under various parameters.

• 한국산학기술학회논문지
• /
• 제11권7호
• /
• pp.2638-2647
• /
• 2010

긴 preamble을 사용하는 비동기식 MAC 프로토콜의 문제점을 개선하기 위해 나온 프로토콜이 X-MAC 이다. 본 논문에서는 X-MAC의 문제점을 해결하기 위하여 Express-MAC이라는 새로운 MAC프로토콜을 제안하였다. 무선센서 네트워크는 주로 이벤트 데이터나 상황정보를 인지하는 목적에 많이 사용된다. 특히 침입감지 같은 이벤트 감지를 목적으로 하는 센서네트워크의 전송 패턴은 매우 간헐적이면서도 한 번의 이벤트 발생 시 연속적으로 일어나는 것이 대부분이다. EX-MAC은 위와 같은 센서 네트워크의 주요 전송 패턴을 반영하여 첫 이벤트 발생 시 데이터 전송에서 멀티 홉 경로의 채널 예약 및 awake 구간의 전송 시간 예약 방식을 사용하였다. 전송 경로상의 awake 시간 예약은 연속적인 데이터 전송의 단대단 지연 성능을 향상시켰으며 데이터 송수신 노드의 preamble 길이를 줄임으로써 에너지 소비 측면에서도 효율성을 증대시켰다.