• Title/Summary/Keyword: communication networks

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A Revised MintRoute Protocol for (m,k)-firm Streams in Wireless Sensor Networks (무선 센서 네트워크에서 (m,k)-firm 스트림을 위한 MintRoute 프로토콜의 확장)

  • Kim, Ki-Il
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.9
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    • pp.2050-2055
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    • 2012
  • Since the wireless sensor networks become pervasive, various application-specific requirement have been emerged and suggested. Among them, reliability and real-time service are ones of big research challenges since sensed information is useless if a packet is lost and delivered later than deadline. Even though many research works have been proposed, they was designed to meet one of both requirements. To solve above problem, in this paper, we propose how to extend current protocol to meet two requirements together. More detailed, Mint Route protocol is revised to meet specific real-time requirement, (m,k)-firm stream in wireless sensor networks. Since the main operations in MintRoute are very similar to definition of (m,k)-firm stream, extension is achieved by modifying some parts of procedure. Finally, the simulation results are given and analyzed to validate the its suitability for reliable and real-time requirement.

Design and Analysis of Resource Management Architecture for Network Mobility (네트워크 이동성을 위한 자원 관리 구조의 설계와 분석)

  • 백은경;조호식;최양희
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.7B
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    • pp.628-640
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    • 2004
  • The demand for next generation networks can be condensed into always-best-connected, ubiquitous, mobile, all-lP, and converged networks. IPv6 has been introduced for all-IP ubiquitous communications, and vehicles are coming to represent an important communication platform. In this paper. we propose various resource management schemes for in-vehicle mobile networks, which are adaptive to different hardware configurations. We focus on power and wireless bandwidth since they are critical resources for mobile communications. Based on the mobility characteristics of in-vehicle networks, we propose vehicle-aware power saving schemes. The main idea behind these power saving schemes is to adjust mobile router (MR) advertisement interval and binding lifetime. In addition, according to different wireless environments, we propose adaptive bandwidth management schemes using multihoming: best-connected MR selection based on location, and high-data-rate MR selection based on priority By mathematical analysis, it is shown that our schemes save power prominently for both the dormant nodes and active nodes. In addition, simulation results show that proposed multiple mobile router architecture outperforms previous simple redundant router architecture in preserving session and providing sufficient bandwidth.

Ad Hoc Routing Method Based on Betweenness Centrality and Location Information for Unmanned Ground System Networks (지상 무인로봇체계 네트워크를 위한 매개 중심도와 위치정보 기반 Ad Hoc 라우팅)

  • Ahn, Hyochun;Yim, Jinhyuk;Ko, Young-Bae;Choi, HyungSeok;Kwon, DaeHoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.4
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    • pp.441-450
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    • 2016
  • Wireless multi-hop communication is one of the key technologies to operate Unmanned Ground System (UGS) networks efficiently. Conventionally a lot of routing protocol has been developed and studied for multi-hop networks like Mobile Ad-hoc Network (MANET). However, the routing protocol for the unique environment of the UGS requires further studies, since conventional routing protocols cannot be used itself for UGS networks. In this paper, we propose the Betweenness Centrality based Geographic Routing (BCGR) which considers the main function of UGS. BCGR utilizes expanded ego betweenness centrality, mobility and location information error, respectively. We have conducted a simulation study for evaluating the performance of the BCGR using ns-3, and our simulation results show that BCGR outperforms the conventional routing protocols such as AODV and GPSR in terms of end-to-end transmission reliability, throughput and delay.

Energy-Efficient Face Routing Protocol Considering Radio Range in Wireless Sensor Networks (무선 센서 네트워크에서 무선 반경을 고려한 에너지 효율적인 페이스 라우팅 프로토콜)

  • Cho, Hyunchong;Kim, Sangdae;Kim, Cheonyong;Kim, Sang-Ha;Hwang, Chi-Jung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.6
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    • pp.1058-1069
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    • 2015
  • In wireless sensor networks, geographic routing is known as an efficient method to transmit the data packet using the location information. Geographic routing relies on two techniques: greedy forwarding and face routing. Face routing helps to recover from greedy routing fail and is based on the planar graph in which does not cross each edge. However, the planarization causes frequently short transmission of data packet because it removes other edges except the shortest one. In other words, since the planarization removes the long edges, face routing could not exploit the efficient removed edges of communication graph. This problem brings about the excessive energy consumption of nodes. In this paper, we propose an energy efficient face routing protocol in wireless sensor networks. This proposed protocol searches the removed edges and transmits them via the edges. Simulation shows that the proposed protocol is more efficient in terms of energy consumption than the previous face routing.

Throughput Performance Evaluation According to The State Change of A Primary Ship in Maritime Cognitive Radio Networks (해상 인지 무선 네트워크에서 선순위 선박의 상태 변화를 고려한 수율 성능 평가)

  • Nam, Yujin;Lee, Seong Ro;So, Jaewoo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.6
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    • pp.1148-1156
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    • 2015
  • The maritime cognitive radio networks (MCRNs) provide the high throughput with a low communication cost because the secondary ships opportunistically access to unused licensed bands of primary ships. In the ground cognitive radio networks, the busy and idle state of a primary user during a frame is not nearly changed because the state of the primary user are slowly changed. However, the state of the primary ship in the MCRNs may be frequently changed in the frame. Therefore, this paper evaluates the throughput of a primary ship and secondary ships in the MCRNs taking the state change of a primary ship into consideration when the fusion center uses the cooperative spectrum sensing. The simulation results show that trade-off between the throughput of a primary ship and that of secondary ships according to the system parameter such as the cooperative spectrum sensing scheme, the number of secondary ships, and the target detection probability.

CASPER: Congestion Aware Selection of Path with Efficient Routing in Multimedia Networks

  • Obaidat, Mohammad S.;Dhurandher, Sanjay K.;Diwakar, Khushboo
    • Journal of Information Processing Systems
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    • v.7 no.2
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    • pp.241-260
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    • 2011
  • In earlier days, most of the data carried on communication networks was textual data requiring limited bandwidth. With the rise of multimedia and network technologies, the bandwidth requirements of data have increased considerably. If a network link at any time is not able to meet the minimum bandwidth requirement of data, data transmission at that path becomes difficult, which leads to network congestion. This causes delay in data transmission and might also lead to packet drops in the network. The retransmission of these lost packets would aggravate the situation and jam the network. In this paper, we aim at providing a solution to the problem of network congestion in mobile ad hoc networks [1, 2] by designing a protocol that performs routing intelligently and minimizes the delay in data transmission. Our Objective is to move the traffic away from the shortest path obtained by a suitable shortest path calculation algorithm to a less congested path so as to minimize the number of packet drops during data transmission and to avoid unnecessary delay. For this we have proposed a protocol named as Congestion Aware Selection Of Path With Efficient Routing (CASPER). Here, a router runs the shortest path algorithm after pruning those links that violate a given set of constraints. The proposed protocol has been compared with two link state protocols namely, OSPF [3, 4] and OLSR [5, 6, 7, 8].The results achieved show that our protocol performs better in terms of network throughput and transmission delay in case of bulky data transmission.

An Efficient Broadcast Technique for Vehicular Networks

  • Ho, Ai Hua;Ho, Yao H.;Hua, Kien A.;Villafane, Roy;Chao, Han-Chieh
    • Journal of Information Processing Systems
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    • v.7 no.2
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    • pp.221-240
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    • 2011
  • Vehicular networks are a promising application of mobile ad hoc networks. In this paper, we introduce an efficient broadcast technique, called CB-S (Cell Broadcast for Streets), for vehicular networks with occlusions such as skyscrapers. In this environment, the road network is fragmented into cells such that nodes in a cell can communicate with any node within a two cell distance. Each mobile node is equipped with a GPS (Global Positioning System) unit and a map of the cells. The cell map has information about the cells including their identifier and the coordinates of the upper-right and lower-left corner of each cell. CB-S has the following desirable property. Broadcast of a message is performed by rebroadcasting the message from every other cell in the terrain. This characteristic allows CB-S to achieve an efficient performance. Our simulation results indicate that messages always reach all nodes in the wireless network. This perfect coverage is achieved with minimal overhead. That is, CB-S uses a low number of nodes to disseminate the data packets as quickly as probabilistically possible. This efficiency gives it the advantage of low delay. To show these benefits, we give simulations results to compare CB-S with four other broadcast techniques. In practice, CB-S can be used for information dissemination, or to reduce the high cost of destination discovery in routing protocols. By also specify the radius of affected zone, CB-S is also more efficient when broadcast to a subset of the nodes is desirable.

A Study on the Improvement Policy for Entering Telecommunication Business of Private Network Holders (자가망 사업자의 통신사업 진입에 따른 개선 방안)

  • 이동식;김기문
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.6 no.8
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    • pp.1200-1205
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    • 2002
  • Construction of Private networks is becoming easier due to the openness of telecommunication market, rapidly developing telecommunication technology. The size of existing private networks is becoming huge which resulted in surplus of capacity of the networks. These trends will generate a problem of efficient use of national telecommunication resources and which will be a factor for the structure of domestic telecommunication market which will have a big impact on the existing telecommunication carriers. Therefore, national policy of private network issues should be considered along with the national efforts for the information infrastructure, control of telecommunication market, fairness of competition, strength Power of national competition. In this paper it will be suggested that the efficient policy on the issue of domestic private network, by analyzing present situation, status quo, laws, regulation and procedure for domestic private networks and comparing it with those of U.S.A, Japan, EU.

Analysis for Protocol Layer Technical Requirements of Wireless Mesh Networks Optimization (무선 메쉬 네트워크의 최적화를 위한 프로토콜 계층별 기술적 요구사항에 관한 분석)

  • Lee, Soon-Sik;Yun, Sang-Man;Lee, Sang-Wook;Jeon, Seong-Geun;Lee, Woo-Jae
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.1
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    • pp.77-88
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    • 2010
  • Wireless Mesh Networks are consist of mobility mesh clients and mesh routers. WMNs can communicate with heterogeneous networks such as IEEE 802.11, IEEE 802.15, IEEE 802.16 and sensor networks. WMNs which is based on ad hoc network are on research and developing to enhance WLANs, WPANs, or WMANs. WMNs can offer environment to serve human, service to person area, campus, and metro. But WMNs has many problems to solve about enhancing performance and generalization. Among them, Existing protocol layers has many problems enhancing to optimize WMNs. This document issues problems about WMNs in protocol layer and suggest the solutions. Also, suggests the requirements and the methods of QoS supporting issue.

A Traffic Aware Demand-Wakeup MAC(TADW-MAC) Protocol for Wireless Sensor Networks (무선 센서 네트워크에서 트래픽에 적응적인 Demand-Wakeup MAC 프로토콜)

  • Kim, Hye-Yun;Kim, Seong-Cheol
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.1
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    • pp.180-186
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    • 2017
  • In this paper we propose a traffic aware Demand Wakeup MAC(TADW-MAC) protocol, in which low data delay and high throughput can be achieved, for wireless sensor networks. With the TADW-MAC protocol, the problem of the DW-MAC protocol, which schedules only one packet to deliver during the Sleep period in a multi-hop transmission is resolved. DW-MAC is not adequate for the applications such as object tracking and fire detection, in which busty data should be transmitted in a limited time when an event occurs [6-8]. When an event occurs, duty cycle can be adjusted in the TADW-MAC protocol to get less energy consumption and low latency. The duty cycle mechanism has been widely used to save energy consumption of sensor node due to idle listening in wireless sensor networks. But additional delay in packet transmission may be increased in the mechanism. Our simulation results show that TADW-MAC outperforms RMAC and DW-MAC in terms of energy efficiency while achieving low latency.