The Experts below are selected from a list of 21972 Experts worldwide ranked by ideXlab platform

Wenbo Wang - One of the best experts on this subject based on the ideXlab platform.

  • VTC Spring - A Novel Unequal-Error-Protected STBC Design for Multimedia Transmission
    2011 IEEE 73rd Vehicular Technology Conference (VTC Spring), 2011
    Co-Authors: Yang Liu, Hui Zhao, Bin Zheng, Wenbo Wang
    Abstract:

    A new unequal-error-protected space-time block code (UEP-STBC) is designed in this paper for Multimedia Transmission systems deployed with multiple antennas. Traditionally, a space-time code is designed to support a single information stream aiming to achieve a point on the fundamental rate versus diversity tradeoff curve, while this proposed class of codes has the capability of transmitting different performed symbols from different layers within the same codeword. The UEP-STBC, whose symbols belong to different orthogonal layers without interference, is fit for the systems using scalable video coding (SVC) as the source coding. The design covers the cases of arbitrary number of transmit antennas. The simulation results demonstrate the performance advantage and coverage enhancement of the proposed codes in Multimedia Transmission over conventional codes.

Wang Chun-lei - One of the best experts on this subject based on the ideXlab platform.

  • High-speed Wireless Multimedia Transmission System Based on Wi-Fi
    Computer Engineering, 2011
    Co-Authors: Wang Chun-lei
    Abstract:

    In order to enhance the Transmission rate of the wireless Multimedia Transmission,this paper puts forward a high-speed wireless Multimedia Transmission system based on Wi-Fi.It includes the compare of Wi-Fi with existing wireless Transmission agreement,and selects Ad Hoc network combing with the UDP protocol,by means of seven scene repeated testing.Experimental results show that the average Transmission rate of Wi-Fi goes from 8.02 Mb/s to 12 Mb/s.

Der-jiunn Deng - One of the best experts on this subject based on the ideXlab platform.

  • PSSB: Priority enforced slow-start backoff algorithm for Multimedia Transmission in wireless ad-hoc networks
    Journal of Network and Computer Applications, 2011
    Co-Authors: Der-jiunn Deng
    Abstract:

    The binary exponential backoff (BEB) algorithm is the fundamental access method, which provides collision avoidance in wireless ad-hoc networks. However, BEB algorithm poses several performance issues. For example, the high collision rate problem, unfair channel access and throughput degradation have been several widely known issues. Besides, frames in BEB do not have priorities, making it unsuitable for Multimedia communications. With a little bad luck, a station might have to wait arbitrarily long to send a frame. In this paper, we introduce the priority enforced slow-start backoff algorithm (PSSB) for Multimedia Transmission for wireless ad-hoc networks, which employs a distributed adaptive contention window control mechanism to mitigate intensive collisions in congested scenario and support priority traffic for Multimedia Transmission. Furthermore, the proposed scheme could alleviate the fairness problem in partially connected network topology by employing feedback information from wireless stations. Simulations are conducted to evaluate the performance of the proposed scheme. The results show that the proposed scheme outperforms the BEB algorithm in many aspects in wireless ad hoc networks.

Yang Liu - One of the best experts on this subject based on the ideXlab platform.

  • VTC Spring - A Novel Unequal-Error-Protected STBC Design for Multimedia Transmission
    2011 IEEE 73rd Vehicular Technology Conference (VTC Spring), 2011
    Co-Authors: Yang Liu, Hui Zhao, Bin Zheng, Wenbo Wang
    Abstract:

    A new unequal-error-protected space-time block code (UEP-STBC) is designed in this paper for Multimedia Transmission systems deployed with multiple antennas. Traditionally, a space-time code is designed to support a single information stream aiming to achieve a point on the fundamental rate versus diversity tradeoff curve, while this proposed class of codes has the capability of transmitting different performed symbols from different layers within the same codeword. The UEP-STBC, whose symbols belong to different orthogonal layers without interference, is fit for the systems using scalable video coding (SVC) as the source coding. The design covers the cases of arbitrary number of transmit antennas. The simulation results demonstrate the performance advantage and coverage enhancement of the proposed codes in Multimedia Transmission over conventional codes.

Mihaela Van Der Schaar - One of the best experts on this subject based on the ideXlab platform.

  • mechanism based resource allocation for Multimedia Transmission over spectrum agile wireless networks
    IEEE Journal on Selected Areas in Communications, 2007
    Co-Authors: A R Fattahi, Fangwen Fu, Mihaela Van Der Schaar, Federico Paganini
    Abstract:

    We propose to add a new dimension to existing wireless Multimedia systems by enabling autonomous stations to dynamically compete for communication resources through adjustment of their internal strategies and sharing their private information. We focus on emerging spectrum agile wireless networks, where developing an efficient strategy for managing available communication resources is of high importance. The proposed dynamic resource management approach for wireless Multimedia changes the passive way stations are currently adapting their joint source-channel coding strategies according to available wireless resources. Each wireless station can play the resource management game by adapting its Multimedia Transmission strategy depending on the experienced channel conditions and user requirements. The resource allocation game is coordinated by a network moderator, which deploys mechanism-based resource management to determine the amount of Transmission time to be allocated to various users on different frequency bands such that certain global system metrics are optimized. Subsequently, the moderator charges the various users based on the amount of resources it has allocated to them, in order to discourage them from being dishonest about their resource requirements. We investigate and quantify both the users' and the system performance when different cross-layer strategies, and hence users' levels of smartness, are deployed by wireless stations. Our simulations show that mechanism-based resource management outperforms conventional techniques such as air-fair time and equal time resource allocation in terms of the obtained system utility. They also provide insights that can guide the design of emerging spectrum agile network protocols and applications

  • Cross-Layer Packetization and ReTransmission Strategies for Delay-Sensitive Wireless Multimedia Transmission
    IEEE Transactions on Multimedia, 2007
    Co-Authors: Mihaela Van Der Schaar, Deepak S. Turaga
    Abstract:

    Existing wireless networks provide dynamically varying resources with only limited support for the quality of service required by the bandwidth-intense, loss-tolerant and delay-sensitive Multimedia applications. This variability of resources does not significantly impact delay insensitive data Transmission (e.g., file transfers), but has considerable consequences for Multimedia applications. Recently, the research focus has been to adapt existing algorithms and protocols at the lower layers of the protocol stack to better support Multimedia Transmission applications and conversely, to modify application layer solutions to cope with the varying wireless networks resources. In this paper, we show that significant improvements in wireless Multimedia performance can be obtained by deploying a joint application-layer adaptive packetization and prioritized scheduling and MAC-layer reTransmission strategy. We deploy a state-of-the-art wavelet coder for the compression of the video data that enables on-the-fly adaptation to changing channel conditions and inherent prioritization of the video bitstream. We pose the cross-layer problem as a distortion minimization given delay constraints and derive analytical solutions by modifying existing joint source-channel coding theory aimed at fulfilling rate, rather than delay, constraints. We also propose real-time algorithms that explicitly consider the available information about previously transmitted packets. The obtained results show significant improvements in terms of video quality as opposed to ad-hoc optimizations currently deployed, while the complexity associated with performing this optimization in real time, i.e., at Transmission time, is limited