• Title/Summary/Keyword: Access Network Selection

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Genetic Algorithm based Resource Management for Cognitive Mesh Networks with Real-time and Non-real-time Services

  • Shan, Hangguan;Ye, Ziyun;Bi, Yuanguo;Huang, Aiping
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.8
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    • pp.2774-2796
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    • 2015
  • Quality-of-service (QoS) provisioning for a cognitive mesh network (CMN) with heterogeneous services has become a challenging area of research in recent days. Considering both real-time (RT) and non-real-time (NRT) traffic in a multihop CMN, [1] studied cross-layer resource management, including joint access control, route selection, and resource allocation. Due to the complexity of the formulated resource allocation problems, which are mixed-integer non-linear programming, a low-complexity yet efficient algorithm was proposed there to approximately solve the formulated optimization problems. In contrast, in this work, we present an application of genetic algorithm (GA) to re-address the hard resource allocation problems studied in [1]. Novel initialization, selection, crossover, and mutation operations are designed such that solutions with enough randomness can be generated and converge with as less number of attempts as possible, thus improving the efficiency of the algorithm effectively. Simulation results show the effectiveness of the newly proposed GA-based algorithm. Furthermore, by comparing the performance of the newly proposed algorithm with the one proposed in [1], more insights have been obtained in terms of the tradeoff among QoS provisioning for RT traffic, throughput maximization for NRT traffic, and time complexity of an algorithm for resource allocation in a multihop network such as CMN.

Smart Grid Cooperative Communication with Smart Relay

  • Ahmed, Mohammad Helal Uddin;Alam, Md. Golam Rabiul;Kamal, Rossi;Hong, Choong Seon;Lee, Sungwon
    • Journal of Communications and Networks
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    • v.14 no.6
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    • pp.640-652
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    • 2012
  • Many studies have investigated the smart grid architecture and communication models in the past few years. However, the communication model and architecture for a smart grid still remain unclear. Today's electric power distribution is very complex and maladapted because of the lack of efficient and cost-effective energy generation, distribution, and consumption management systems. A wireless smart grid communication system can play an important role in achieving these goals. In this paper, we describe a smart grid communication architecture in which we merge customers and distributors into a single domain. In the proposed architecture, all the home area networks, neighborhood area networks, and local electrical equipment form a local wireless mesh network (LWMN). Each device or meter can act as a source, router, or relay. The data generated in any node (device/meter) reaches the data collector via other nodes. The data collector transmits this data via the access point of a wide area network (WAN). Finally, data is transferred to the service provider or to the control center of the smart grid. We propose a wireless cooperative communication model for the LWMN.We deploy a limited number of smart relays to improve the performance of the network. A novel relay selection mechanism is also proposed to reduce the relay selection overhead. Simulation results show that our cooperative smart grid (coopSG) communication model improves the end-to-end packet delivery latency, throughput, and energy efficiency over both the Wang et al. and Niyato et al. models.

Q Learning MDP Approach to Mitigate Jamming Attack Using Stochastic Game Theory Modelling With WQLA in Cognitive Radio Networks

  • Vimal, S.;Robinson, Y. Harold;Kaliappan, M.;Pasupathi, Subbulakshmi;Suresh, A.
    • Journal of Platform Technology
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    • v.9 no.1
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    • pp.3-14
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    • 2021
  • Cognitive Radio network (CR) is a promising paradigm that helps the unlicensed user (Secondary User) to analyse the spectrum and coordinate the spectrum access to support the creation of common control channel (CCC). The cooperation of secondary users and broadcasting between them is done through transmitting messages in CCC. In case, if the control channels may get jammed and it may directly degrade the network's performance and under such scenario jammers will devastate the control channels. Hopping sequences may be one of the predominant approaches and it may be used to fight against this problem to confront jammer. The jamming attack can be alleviated using one of the game modelling approach and in this proposed scheme stochastic games has been analysed with more single users to provide the flexible control channels against intrusive attacks by mentioning the states of each player, strategies ,actions and players reward. The proposed work uses a modern player action and better strategic view on game theoretic modelling is stochastic game theory has been taken in to consideration and applied to prevent the jamming attack in CR network. The selection of decision is based on Q learning approach to mitigate the jamming nodes using the optimal MDP decision process

Coast Evaluation Techniques for Mode Selection in Video Coding (동영상에서 모드 선택을 위한 코스트 평가 방법)

  • Song, Dae-Geon
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.13 no.6
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    • pp.275-280
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    • 2013
  • Recently, access networking BroadBand the high performance of the video equipment to the Internet via voice, video, multimedia services, such as dealing with the media information dissemination is becoming increasingly attracting attention. More video devices and network environments in the future to keep pace with the high-quality video using the form dealing with an increasingly diversified and shall utilization is expected. Among them, video encoding technology, image compression encoding technology of information technology is one of the central role. Video coding technology that requires a vast amount of information contained in the video signal and the appropriate amount of information to eliminate redundancy as the efficiency of the digital code representing video signal is developed as a technology is going. Therefore, this study applied to video coding mode selection in the cost evaluation methods to examine and to maximize the coding efficiency and the proposed method compared to the conventional method was confirmed excellence.

Library Services in Information Society (정보사회의 도서관봉사)

  • Chun Myung-Sook
    • Journal of the Korean Society for Library and Information Science
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    • v.27
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    • pp.161-181
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    • 1994
  • As information technologies are applied to the libraries in information society, the library services have been changing its feature. Therefore, the purpose of this paper is to explore and to establish a paradigm of the library services in information society. It is hypothesized that the application of information technologies leads to the change of the library services in information society. To prove the hypothesis, the data were collected from various research results carried out in the developed countries and by observing various libraries where the information technologies are extensively applied. The findings are as follows: 1. As information technologies are applied to the library, many new library services emerge for the society. 2. As the electronic data replace the paper data, the collection of a library becomes the collection of the libraries in the world. Therefore, the accessibility to the information network is more important than to own information in the library. Librarians select various electronic data according to the library policy which distinguishes their own library collection from others. The policy also solves the various problems related to weeding and preserving library collection. And the use of CD-ROM selection tools enable library users to select their own data. Now, the censorship becomes the concems of the library users, not the library. 3. The catalogs are reorganized for the electronic data for the international use. The most important information in the catalog is the location of the data and the multi access to the data are necessary. 4. As the information technologies are applied in book selection, cataloguing, information retreival and circulation, the library users are enable to service themselves in the library. And most of the routine works related to the information service are taken over by the library staffs. Professional librarians engage in user education, information marketing and fund raising. 5. Public libraries in information society serves those who have no access to the information. They help the illiterates. patients in the hospital, prisoners, and homeless in the city. Therefore, the information technologies enhance the role of librarians in professional work in the library as well as in the information society.

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Hybrid Spectrum Sharing with Cooperative Secondary User Selection in Cognitive Radio Networks

  • Kader, Md. Fazlul;Asaduzzaman, Asaduzzaman;Hoque, Md. Moshiul
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.7 no.9
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    • pp.2081-2100
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    • 2013
  • In this paper, we propose a cooperative hybrid spectrum sharing protocol by jointly considering interweave (opportunistic) and underlay schemes. In the proposed protocol, secondary users can access the licensed spectrum along with the primary system. Our network scenario comprises a single primary transmitter-receiver (PTx-PRx) pair and a group of M secondary transmitter-receiver (STx-SRx) pairs within the transmission range of the primary system. Secondary transmitters are divided into two groups: active and inactive. A secondary transmitter that gets an opportunity to access the secondary spectrum is called "active". One of the idle or inactive secondary transmitters that achieves the primary request target rate $R_{PT}$ will be selected as a best decode-and-forward (DF) relay (Re) to forward the primary information when the data rate of the direct link between PTx and PRx falls below $R_{PT}$. We investigate the ergodic capacity and outage probability of the primary system with cooperative relaying and outage probability of the secondary system. Our theoretical and simulation results show that both the primary and secondary systems are able to achieve performance improvement in terms of outage probability. It is also shown that ergodic capacity and outage probability improve when the active secondary transmitter is located farther away from the PRx.

Selective Decoding Schemes and Wireless MAC Operating in MIMO Ad Hoc Networks

  • Suleesathira, Raungrong;Aksiripipatkul, Jansilp
    • Journal of Communications and Networks
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    • v.13 no.5
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    • pp.421-427
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    • 2011
  • Problems encountered in IEEE 802.11 medium access control (MAC) design are interferences from neighboring or hidden nodes and collision from simultaneous transmissions within the same contention floors. This paper presents the selective decoding schemes in MAC protocol for multiple input multiple output ad-hoc networks. It is able to mitigate interferences by using a developed minimum mean-squared error technique. This interference mitigation combined with the maximum likelihood decoding schemes for the Alamouti coding enables the receiver to decode and differentiate the desired data streams from co-channel data streams. As a result, it allows a pair of simultaneous transmissions to the same or different nodes which yields the network utilization increase. Moreover, the presented three decoding schemes and time line operations are optimally selected corresponding to the transmission demand of neighboring nodes to avoid collision. The selection is determined by the number of request to send (RTS) packets and the type of clear to send packets. Both theoretical channel capacity and simulation results show that the proposed selective decoding scheme MAC protocol outperforms the mitigation interference using multiple antennas and the parallel RTS processing protocols for the cases of (1) single data stream and (2) two independent data streams which are simultaneously transmitted by two independent transmitters.

A Study on the Interface Selection Scheme of Mobile Nodes with Multiple Interfaces in Ubiquitous Environments (유비쿼터스 환경에서 다중 인터페이스를 탑재한 이동 단말의 인터페이스 선택 기법에 관한 연구)

  • Kim, Seong-Chul;Moon, Il-Young;Cho, Sung-Joon
    • Journal of Advanced Navigation Technology
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    • v.14 no.2
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    • pp.198-205
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    • 2010
  • Any user in Ubiquitous environments have to be able to access networks in anywhere and anytime. Thus interests and researches are increasing. In this paper, we propose an interface selection scheme that adaptively utilizes a proper interface, as the wireless channel condition changes, instead of utilizing only one interface while the node is in move. The proposed scheme can determine which interface would be the most proper one by measuring data rate, packet error rate (PER), and end-to-end delay of each interface. From the simulation results, it is verified that the proposed scheme is able to enhance packet transmission about 20% better.

Multimedia Service Discrimination Based on Fair Resource Allocation Using Bargaining Solutions

  • Shin, Kwang-Sup;Jung, Jae-Yoon;Suh, Doug-Young;Kang, Suk-Ho
    • ETRI Journal
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    • v.34 no.3
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    • pp.341-351
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    • 2012
  • We deal with a resource allocation problem for multimedia service discrimination in wireless networks. We assume that a service provider allocates network resources to users who can choose and access one of the discriminated services. To express the rational service selection of users, the utility function of users is devised to reflect both service quality and cost. Regarding the utility function of a service provider, total profit and efficiency of resource usage have been considered. The proposed service discrimination framework is composed of two game models. An outer model is a repeated Stackelberg game between a service provider and a user group, while an inner model is a service selection game among users, which is solved by adopting the Kalai-Smorodinsky bargaining solution. Through simulation experiments, we compare the proposed framework with existing resource allocation methods according to user cost sensitivity. The proposed framework performed better than existing frameworks in terms of total profit and fairness.

Exact Outage Probability of Two-Way Decode-and-Forward NOMA Scheme with Opportunistic Relay Selection

  • Huynh, Tan-Phuoc;Son, Pham Ngoc;Voznak, Miroslav
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.12
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    • pp.5862-5887
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    • 2019
  • In this paper, we propose a two-way relaying scheme using non-orthogonal multiple access (NOMA) technology. In this scheme, two sources transmit packets with each other under the assistance of the decode-and-forward (DF) relays, called as a TWDFNOMA protocol. The cooperative relays exploit successive interference cancellation (SIC) technique to decode sequentially the data packets from received summation signals, and then use the digital network coding (DNC) technique to encrypt received data from two sources. A max-min criterion of end-to-end signal-to-interference-plus-noise ratios (SINRs) is used to select a best relay in the proposed TWDFNOMA protocol. Outage probabilities are analyzed to achieve exact closed-form expressions and then, the system performance of the proposed TWDFNOMA protocol is evaluated by these probabilities. Simulation and analysis results discover that the system performance of the proposed TWDFNOMA protocol is improved when compared with a conventional three-timeslot two-way relaying scheme using DNC (denoted as a TWDNC protocol), a four-timeslot two-way relaying scheme without using DNC (denoted as a TWNDNC protocol) and a two-timeslot two-way relaying scheme with amplify-and-forward operations (denoted as a TWANC protocol). Particularly, the proposed TWDFNOMA protocol achieves best performances at two optimal locations of the best relay whereas the midpoint one is the optimal location of the TWDNC and TWNDNC protocols. Finally, the probability analyses are justified by executing Monte Carlo simulations.