• 제목/요약/키워드: Source node

검색결과 597건 처리시간 0.024초

Ad-hoc 센서 네트워크를 위한 최적 라우팅 경로 설정 알고리즘 (Optimal Routing Path Selection Algorithm in Ad-hoc Wireless Sensor Network)

  • 장인훈;심귀보
    • 한국지능시스템학회논문지
    • /
    • 제15권6호
    • /
    • pp.736-741
    • /
    • 2005
  • 다단계 호핑(multi-hop) 무선 센서네트워크의 라우팅 경로를 설정하는데 있어서 데이터 전송의 요구가 있는 경우에만 경로를 만드는 Demand-Driven 방식의 대표적인 방법이 DSR(Dynamic Source Routing)인데 라우트 레코드를 패킷에 실어 보내기 때문에 이 또한 센서노드들의 수가 많아질수록 패킷이 무거워질 수밖에 없다. 본 논문에서는 DSR 프로토콜을 기반하면서도 라우팅 테이블을 적절히 이용하여 노드 수 증가에 대해 고정된 패킷크기를 가지도록 하였으며 라우팅 비용함수를 적용하여 각 센서노드들의 전원 소모량, 이동성(Mobility), 네트워크 내에서의 Traffic, 거리(Hop) 등을 복합적으로 고려한 안정적이고 신뢰성 있는 최적의 라우팅 설정알고리즘을 제안한다.

Minimizing Cost and Delay in Shared Multicast Trees

  • Koh, Seok-Joo;Yi, Jong-Hwa;Hahm, Jin-Ho;Chin, Byoung-Moon;Park, Chee-Hang
    • ETRI Journal
    • /
    • 제22권1호
    • /
    • pp.30-37
    • /
    • 2000
  • Existing tree construction mechanisms are classified into source-based trees and center-based trees. The source-based trees produce a source-rooted tree with a low delay. However, for the applications with multiple senders, the management overheads for routing tables and resource reservations are too high. The center-based trees are easy to implement and manage, but a priori configuration of candidate center nodes is required, and the optimization mature such as tree cost and delay is not considered. In this paper, we propose a new multicast tree building algorithm. The proposal algorithm basically builds a non-center based shared tree. In particular, any center node is not pre-configured. In the purposed algorithm, a multicast node among current tree nodes is suitably assigned to each incoming user: Such a node is selected in a fashion that tree cost and the maximum end-to-end delay on the tree are jointly minimized. The existing and proposed algorithms are compared by experiments. In the simulation results, it is shown that the proposed algorithm approximately provides the cost saving of 30% and the delay saving of 10%, compared to the existing approaches. In conclusion, we see that the cost and delay aspects for multicast trees can be improved at the cost of additional computations.

  • PDF

상황정보를 이용한 ad hoc network의 ODDMRP clustering 기법에 관한 연구 (A study on ODDMRP clustering scheme of Ad hoc network by using context aware information)

  • 지삼현;이강환
    • 한국정보통신학회:학술대회논문집
    • /
    • 한국해양정보통신학회 2008년도 춘계종합학술대회 A
    • /
    • pp.890-893
    • /
    • 2008
  • 자율성 및 이동성 갖는 네트워크 구조의 하나인 MANET(Mobile Ad-Hoc Networks)은 각 node들은 그 특성에 따라서 clustering service을 한다. node의 전송과정 중 path access에 대하여 중요성 또한 강조되고 있다. 일반적인 무선 네트워크 상에서의 node들은 clustering을 하게 되는데 그 과정에서 발생되는 여러 가지 문제점을 가지고 전송이 이루어진다. 모든 node들이 송, 수신상의 전송 범위(Beam forming area)가지고 있으며, 이러한 각 node들의 전송범위 내에 전송이 이루어지는 전통적인 전송기술 mechanism을 찾는다. 이러한 전송상황에서의 송신하는 node와 수신된 node간에 발생되고 있는 중복성의 문제점으로 즉, 상호적용에 의한 네트워크 duplicate(overlapping)이 크게 우려가 되고 있다. 이러한 전송상의 전송 범위 중첩, node간의 packet 간섭현상, packet의 중복수신 및 broadcasting의 storming현상이 나타난다. 따라서 본 논문에서는 상황정보의 속성을 이용한 계층적 상호 head node들의 접근된 위치와 연계되는 전송속도, 보존하고 있는 head node들의 에너지 source value, doppler효과를 통한 head node의 이동방향 등 분석한다. 분석된 방법으로 전송상의 계층적 path가 구성된 경험적 path 속성을 통한 네트워크 connectivity 신뢰성을 극대화 할 뿐만 아니라 네트워크의 전송 범위 duplicate을 사전에 줄일 수 있고 전송망의 최적화를 유지할 수 있는 기법의 하나인 상황정보를 이용한 ad hoc network의 ODDMRP(Ontology Doppler effect-based Dynamic Multicast Routing Protocol) clustering 기법을 제안한다.

  • PDF

노드 밀집도 기반 애드학 라우팅 (Node Density Based Routing in Ad Hoc Networks)

  • 김상경;최승식
    • 정보처리학회논문지C
    • /
    • 제12C권4호
    • /
    • pp.535-542
    • /
    • 2005
  • 본 논문은 새로운 대체경로 확보 방안을 통하여 라우팅 성능을 개선하는 요구형 애드학 라우팅 프로토콜인 Node Density Based Routing(NDBR)을 제안한다. 모바일 노드들의 이동이나 전력 고갈 등으로 인해 애드학 망의 연결은 장애를 일으킬 가능성이 매우 높기 때문에 발신지에서 목적지까지의 연결 설정 시 대체경로를 확보해 두는 것이 중요하다. NDBR은 목적지까지의 대체경로들을 확보하기 위해 상대적으로 더 많은 이웃 노드들을 갖는 중간 노드들로 구성되는 연결 설정을 목표로 하며 이를 위해 노드 밀집도라는 새로운 경로선택기준을 도입한다. NDBR은 경로 장애 발생 시 발신지에 의한 경로재탐색 절차 없이 목적지에 대한 도달성을 향상시킴으로써 경로장애의 영향을 국소화시키고, 제어 트래픽에 의한 오버헤드를 줄이며, 경로재설정 시간을 감소시킬 수 있다 본 논문에서는 노드 밀집도를 이용하여 대체경로를 포함하는 경로설정 절차와 경로 상의 중간 노드에서 대체경로 정보를 유지하여 활용하는 방법에 대해 기술하고 시뮬레이션을 통한 기존 프로토콜과의 비교를 통해 라우팅 성능이 개선됨을 보였다.

Time Switching for Wireless Communications with Full-Duplex Relaying in Imperfect CSI Condition

  • Nguyen, Tan N.;Do, Dinh-Thuan;Tran, Phuong T.;Voznak, Miroslav
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제10권9호
    • /
    • pp.4223-4239
    • /
    • 2016
  • In this paper, we consider an amplify-and-forward (AF) full-duplex relay network (FDRN) using simultaneous wireless information and power transfer, where a battery-free relay node harvests energy from the received radio frequency (RF) signals from a source node and uses the harvested energy to forward the source information to destination node. The time-switching relaying (TSR) protocol is studied, with the assumption that the channel state information (CSI) at the relay node is imperfect. We deliver a rigorous analysis of the outage probability of the proposed system. Based on the outage probability expressions, the optimal time switching factor are obtained via the numerical search method. The simulation and numerical results provide practical insights into the effect of various system parameters, such as the time switching factor, the noise power, the energy harvesting efficiency, and the channel estimation error on the performance of this network. It is also observed that for the imperfect CSI case, the proposed scheme still can provide acceptable outage performance given that the channel estimation error is bounded in a permissible interval.

A Genetic Algorithm Based Source Encoding Scheme for Distinguishing Incoming Signals in Large-scale Space-invariant Optical Networks

  • Hongki Sung;Yoonkeon Moon;Lee, Hagyu
    • Journal of Electrical Engineering and information Science
    • /
    • 제3권2호
    • /
    • pp.151-157
    • /
    • 1998
  • Free-space optical interconnection networks can be classified into two types, space variant and space invariant, according to the degree of space variance. In terms of physical implementations, the degree of space variance can be interpreted as the degree of sharing beam steering optics among the nodes of a given network. This implies that all nodes in a totally space-invariant network can share a single beam steering optics to realize the given network topology, whereas, in a totally space variant network, each node requires a distinct beam steering optics. However, space invariant networks require mechanisms for distinguishing the origins of incoming signals detected at the node since several signals may arrive at the same time if the node degree of the network is greater than one. This paper presents a signal source encoding scheme for distinguishing incoming signals efficiently, in terms of the number of detectors at each node or the number of unique wavelengths. The proposed scheme is solved by developing a new parallel genetic algorithm called distributed asynchronous genetic algorithm (DAGA). Using the DAGA, we solved signal distinction schemes for various network sizes of several topologies such as hypercube, the mesh, and the de Brujin.

  • PDF

Enhanced Hybrid Routing Protocol for Load Balancing in WSN Using Mobile Sink Node

  • Kaur, Rajwinder;Shergi, Gurleen Kaur
    • Industrial Engineering and Management Systems
    • /
    • 제15권3호
    • /
    • pp.268-277
    • /
    • 2016
  • Load balancing is a significant technique to prolong a network's lifetime in sensor network. This paper introduces a hybrid approach named as Load Distributing Hybrid Routing Protocol (LDHRP) composed with a border node routing protocol (BDRP) and greedy forwarding (GF) strategy which will make the routing effective, especially in mobility scenarios. In an existing solution, because of the high network complexity, the data delivery latency increases. To overcome this limitation, a new approach is proposed in which the source node transmits the data to its respective destination via border nodes or greedily until the complete data is transmitted. In this way, the whole load of a network is evenly distributed among the participating nodes. However, border node is mainly responsible in aggregating data from the source and further forwards it to mobile sink; so there will be fewer chances of energy expenditure in the network. In addition to this, number of hop counts while transmitting the data will be reduced as compared to the existing solutions HRLBP and ZRP. From the simulation results, we conclude that proposed approach outperforms well than existing solutions in terms including end-to-end delay, packet loss rate and so on and thus guarantees enhancement in lifetime.

Optimizations for Mobile MIMO Relay Molecular Communication via Diffusion with Network Coding

  • Cheng, Zhen;Sun, Jie;Yan, Jun;Tu, Yuchun
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제16권4호
    • /
    • pp.1373-1391
    • /
    • 2022
  • We investigate mobile multiple-input multiple-output (MIMO) molecular communication via diffusion (MCvD) system which is consisted of two source nodes, two destination nodes and one relay node in the mobile three-dimensional channel. First, the combinations of decode-and-forward (DF) relaying protocol and network coding (NC) scheme are implemented at relay node. The adaptive thresholds at relay node and destination nodes can be obtained by maximum a posteriori (MAP) probability detection method. Then the mathematical expressions of the average bit error probability (BEP) of this mobile MIMO MCvD system based on DF and NC scheme are derived. Furthermore, in order to minimize the average BEP, we establish the optimization problem with optimization variables which include the ratio of the number of emitted molecules at two source nodes and the initial position of relay node. We put forward an iterative scheme based on block coordinate descent algorithm which can be used to solve the optimization problem and get optimal values of the optimization variables simultaneously. Finally, the numerical results reveal that the proposed iterative method has good convergence behavior. The average BEP performance of this system can be improved by performing the joint optimizations.

Energy-efficient data transmission technique for wireless sensor networks based on DSC and virtual MIMO

  • Singh, Manish Kumar;Amin, Syed Intekhab
    • ETRI Journal
    • /
    • 제42권3호
    • /
    • pp.341-350
    • /
    • 2020
  • In a wireless sensor network (WSN), the data transmission technique based on the cooperative multiple-input multiple-output (CMIMO) scheme reduces the energy consumption of sensor nodes quite effectively by utilizing the space-time block coding scheme. However, in networks with high node density, the scheme is ineffective due to the high degree of correlated data. Therefore, to enhance the energy efficiency in high node density WSNs, we implemented the distributed source coding (DSC) with the virtual multiple-input multiple-output (MIMO) data transmission technique in the WSNs. The DSC-MIMO first compresses redundant source data using the DSC and then sends it to a virtual MIMO link. The results reveal that, in the DSC-MIMO scheme, energy consumption is lower than that in the CMIMO technique; it is also lower in the DSC single-input single-output (SISO) scheme, compared to that in the SISO technique at various code rates, compression rates, and training overhead factors. The results also indicate that the energy consumption per bit is directly proportional to the velocity and training overhead factor in all the energy saving schemes.

Novel Two-Level Randomized Sector-based Routing to Maintain Source Location Privacy in WSN for IoT

  • Jainulabudeen, A.;Surputheen, M. Mohamed
    • International Journal of Computer Science & Network Security
    • /
    • 제22권3호
    • /
    • pp.285-291
    • /
    • 2022
  • WSN is the major component for information transfer in IoT environments. Source Location Privacy (SLP) has attracted attention in WSN environments. Effective SLP can avoid adversaries to backtrack and capture source nodes. This work presents a Two-Level Randomized Sector-based Routing (TLRSR) model to ensure SLP in wireless environments. Sector creation is the initial process, where the nodes in the network are grouped into defined sectors. The first level routing process identifies sector-based route to the destination node, which is performed by Ant Colony Optimization (ACO). The second level performs route extraction, which identifies the actual nodes for transmission. The route extraction is randomized and is performed using Simulated Annealing. This process is distributed between the nodes, hence ensures even charge depletion across the network. Randomized node selection process ensures SLP and also avoids depletion of certain specific nodes, resulting in increased network lifetime. Experiments and comparisons indicate faster route detection and optimal paths by the TLRSR model.