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  • Title/Summary/Keyword: stream transmission

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A Wireless Sink Congestion Control by Tournament Scheduling (토너먼트 스케줄링을 이용한 무선싱크 혼잡제어)

  • Lee, Chong-Deuk
    • Journal of Advanced Navigation Technology
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    • v.16 no.4
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    • pp.641-648
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    • 2012
  • The up-streams of the continuous streaming of data packets with lower importance level in the wireless sink node can cause congestion and delay, they affect on energy efficiency, memory size, buffer size, and throughput. This paper proposes a new wireless sink congestion control mechanism based on tournament scheduling. The proposed method consists of two module parts: stream decision module part and service differentiation module part. The final winner in the tournament controls congestion effectively, minimizes packet loss due to congestion, decreases energy consumption, and improves QoS. The simulation result shows that the proposed method is more effective and has better performance compared with those of congestion descriptor-based control method, reliability-based control method, and best-effort transmission control method.

Performance Comparison of SCTP and TCP over Linux Platform (리눅스 환경에서 SCTP와 TCP 프로토콜의 성능 비교)

  • Park, Jae-Sung;Koh, Seok-Joo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.8B
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    • pp.699-706
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    • 2008
  • This paper compares throughput performance of TCP and SCTP in a variety of network environments. For experiments, we construct a Linux-based testbed and consider a set of performance metrics such as MSS(Maximum Segment Size), transmission delay, and packet loss rate. In addition, we analyze the effect of SCTP multi-streaming on throughput. From the experimental results, we can see that SCTP provides throughput gain of approximately 20 over TCP. This performance gain comes from the distinctive features of SCTP such as chunk bundling, initial congestion window of 2 MTU and SACK(Selective ACK) based error control. In the lossy networks, we can see that SCTP multi-streaming transmissions can effectively overcome the so-called HoLB(Head-of-Line Blocking) phenomenon of TCP.

Authentication Mechanism for Efficient Multicast Service (효율적인 멀티캐스트 서비스를 위한 인증 기법)

  • Jung Yumi;Par Jung-Min;Chae Kijoon;Lee Sang-Ho;Nah Jaehoon
    • The KIPS Transactions:PartC
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    • v.11C no.6 s.95
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    • pp.765-772
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    • 2004
  • Multicast communication is simultaneous transmission of data to multiple receivers and saves considerably sender resources and network bandwidth. It has high risk to attack using group address and inherent complexity of routing packets to a large group of receivers. It is therefore critical to provide source authentication, allowing a receiver to ensure that received data is authentic. In this paper, we propose the multiple chain authentication scheme for secure and efficient multicast stream. To evaluate the performance of our scheme, we compare our technique with two other previously proposed schemes using simulation results. Our scheme provides non-repudiation of origin, low overhead by amortizing the signature operation over multiple packets, and high packet loss resistance.

An Analysis on Multiplexing Gain vs. Variable Input Bit Rate Relation for Designing the ATM Multiplexer (ATM 멀티플렉서의 설계를 위한 다중화이득과 가변입력비트율과의 관계 해석)

  • 여재흥;임인칠
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.29A no.8
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    • pp.34-40
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    • 1992
  • This paper shows a new relational formula of multiplexing gain versus variable input bit rates useful for designing Nx1 ATM(Asynchronous Transfer Mode) multiplexer which mixes several asynchronous bit streams with different transmission rates. The relation between multiplexing gain and input bit stream speeds is derived from the occupied mean lenght(the width per unit time) of cells and the occupation probability of the number of cells at an arbitrary instant when the rates of the periodic cell strams change randomly. And the relation between multiplexing gain and variable bit rates from different number of input bit streams is analyzed accordingly. Under the condition of unlimited multiplexing speed, the more number of input bit streams increases, the bigger the multiplexing gain becomes. While for the case which restricts the multiplexing speed to a limited value, the multiplexing gain becomes smaller contrarily as the number of input bit streams continues too invrease beyond a boundary value. It is shown that for designing an ATM multiplexer according to the latter case, the combination of input bit streams should be determined such as its total bit rate is lower thean, but most apprpaximate to, the multiplexed output speed. Also the general formula evaluating the most significant parameters which should be needed to design the multiplexer is derived.

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MIMO Channel Diagonalization: Linear Detection ZF, MMSE (MIMO 채널 대각화: 선형 검출 ZF, MMSE)

  • Yang, Jae Seung;Shin, Tae Chol;Lee, Moon Ho
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.16 no.1
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    • pp.15-20
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    • 2016
  • Compared to the MIMO system using the spatial multiplexing methods and the MIMO system using the diversity scheme achieved a high rate, but the lower the diversity gain to improve the data transmission reliability should separate the spatial stream at the MIMO receiver. In this paper, we compared Channel capacity detection methods with the Lattice code, the 3-user interference channel and linear channel interference detection methods ZF (Zero Forcing) and MMSE (Minimum Mean Square Error) detection methods. The channel is a Diagonal channel. In other words, Diagonal channel is confirmed by the inverse matrix satisfies the properties of Jacket are element-wise inverse to $[H]_N[H]_N^{-1}=[I]_N$.

Design and Implement of Terrestrial & Satellite integrated DMB receiver for Personalized Broadcasting Services (개인 휴대형 방송 서비스를 위한 지상파/위성 통합 DMB 수신기 설계 및 구현)

  • Cho, Yong-Hoon;Kim, Won-Yong;Choi, Soon-Pil;Oh, Se-In;Choi, Jeong-Hoon
    • Proceedings of the KIEE Conference
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    • 2007.04a
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    • pp.289-291
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    • 2007
  • The Digital Multimedia Broadcasting(DMB) system is developed to offer high quality audio-visual multimedia contents to the uses by the various portable terminals in the mobile environment. Integrated complex reception platform is required to receive multimedia broadcasting services transmitted from various transmission media. In this paper, we present the design and implementation technic for providing the both of terrestrial and satellite DMB services simultaneously using the same hardware platform. The implemented complex receiving terminal to accommodate these DMB services simultaneously need composed of it RF module. it baseband module, it complex control module and the complex de-multiplexer module. The complex control module is designed using uClinux operating system. The complex de-multiplexer, which perform the functions of the address decoder and each DMB stream de-multiplexer, is implemented. with FPGA device. The implemented platform is tested in a real environment and its performance is satisfied with required performance criteria.

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Improved authentication mechanism of the RADIUS protocol in the Internet of Things (사물인터넷 환경에서 RADIUS 프로토콜의 향상된 인증기법)

  • Kim, Young-Se;Han, Keun-hee;Kim, Kee-cheon
    • Journal of Internet of Things and Convergence
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    • v.2 no.1
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    • pp.1-6
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    • 2016
  • The IOT environment, people connected to the network, object, everything such as space (Things) generates data in real time. The information between the object collecting, sharing, are utilized. Currently health care, research in various fields such as smart home has been promoted. Also appeared concepts emphasized all things(IOE) Internet connection between the geographic space and the Internet. Human, while important connections between the objects, such as objects, studies of efficient and secure authentication technologies have been developed. In this paper, we propose a RADIUS (Remote Authentication Dial In User Service) protocol for improved mutual authentication between each object in the IOT environment.

Rotationally Invariant Space-Time Trellis Codes with 4-D Rectangular Constellations for High Data Rate Wireless Communications

  • Sterian, Corneliu Eugen D.;Wang, Cheng-Xiang;Johnsen, Ragnar;Patzold, Matthias
    • Journal of Communications and Networks
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    • v.6 no.3
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    • pp.258-268
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    • 2004
  • We demonstrate rotationally invariant space-time (ST) trellis codes with a 4-D rectangular signal constellation for data transmission over fading channels using two transmit antennas. The rotational invariance is a good property to have that may alleviate the task of the carrier phase tracking circuit in the receiver. The transmitted data stream is segmented into eight bit blocks and quadrature amplitude modulated using a 256 point 4-D signal constellation whose 2-D constituent constellation is a 16 point square constellation doubly partitioned. The 4-D signal constellation is simply the Cartesian product of the 2-D signal constellation with it-self and has 32 subsets. The partition is performed on one side into four subsets A, B, C, and D with increased minimum-squared Euclidian distance, and on the other side into four rings, where each ring includes four points of equal energy. We propose both linear and nonlinear ST trellis codes and perform simulations using an appropriate multiple-input multiple-output (MIMO) channel model. The 4-D ST codes constructed here demonstrate about the same frame error rate (FER) performance as their 2-D counterparts, having however the added value of rotational invariance.

Channel Estimation and Adaptive Channel Coding Technique for Video Transmission (동영상 전송을 위한 채널 예측과 적응적 오류정정 부호화 기법)

  • 송정선;이창우
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.5A
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    • pp.492-501
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    • 2004
  • The performance of mobile communication systems depends on the state of the time-varying multi-path fading channel. To effectively prevent the corruption of video stream and its propagation in spatial and temporal domain, proactive error controls are widely being deployed. Among possible candidates, the rate compatible punctured convolutional (RCPC) code has been widely used for multimedia data, since its rate can be determined flexibly. In this paper, the adaptive channel estimation and the adaptive error correction techniques over the time-varying mobile channel have been proposed. Extensive computer simulations show that the proposed techniques yield the superior performance than the fixed rate system.

A Synchronization Scheme for Hierarchical Video Streams over Heterogeneous Networks

  • Sohn, Yejin;Cho, Minju;Seo, Minjae;Paik, Jongho
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.8
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    • pp.3121-3135
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    • 2015
  • Owing to the increase in consumption of multimedia content and the improvement of device capacity, user demand for high-quality content has increased. However, it is difficult to transport such large amounts of content over the existing broadcasting network with limited bandwidth. To provide high-definition broadcasting, some studies suggest methods of transporting multimedia over heterogeneous networks after encoding content hierarchically. MPEG Media Transport (MMT), standardized by Moving Picture Experts Group (MPEG), is a solution that enables large-volume media transport over heterogeneous networks such as digital broadcasting networks and packet-switched networks. In the case of delivering a scalable encoded video over different networks, synchronization of each stream is an important issue. MMT defines a synchronization scheme, but does not contain sufficient functions to implement it. In this paper, we propose a synchronization scheme for media streams that are encoded hierarchically, divided into layers, and transported over heterogeneous networks. We implement our scheme using MMT and HTTP, and experimented using three encapsulated video streams with different durations. As a result, we show that the proposed scheme can reduce the waiting time to display high-quality video, relative to Dynamic Adaptive Streaming over HTTP-Scalable Video Coding (DASH-SVC) by requesting segments of enhanced layers after calculating the transmission time. Additionally, we find out that the selection of durations have a relation to the characteristics of the video.