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Chihwen Chang - One of the best experts on this subject based on the ideXlab platform.

  • gap processing time analysis of stall avoidance schemes for high speed downLink packet access with parallel harq mechanisms
    IEEE Transactions on Mobile Computing, 2006
    Co-Authors: Lichun Wang, Chihwen Chang
    Abstract:

    The parallel multichannel stop-and-wait (SAW) hybrid automatic repeat request (HARQ) mechanism is one of key technologies for high-speed downLink packet access in the wideband code division multiple access system. However, this parallel HARQ mechanism may encounter a serious stall problem, resulting from the error of the negative acknowledgement (NACK) changing to the acknowledgement (ACK) in the Control channel. In the stall situation, the receiver waits for a packet that will be no longer be sent by the transmitter and stops delivering the medium access Control (MAC) layer packets to the upper layer. The stall issue seriously degrades the quality of service for the high-speed mobile terminal owing to the high probability of NACK-to-ACK errors. In this paper, we present an analytical approach to compare three stall avoidance schemes: the timer-based, the window-based, and the indicator-based schemes. To this end, we first propose a new performance metric-gap processing time, which is defined as the duration for a non recoverable gap appearing in the MAC layer reordering buffer until it is recognized. Second, we derive the probability mass functions and the closed-form expressions for the average gap processing time of these three stall avoidance schemes. It will be shown that our analytical results match the simulations well. Further, by analysis, we demonstrate that the indicator-based stall avoidance scheme outperforms the timer-based and the window-based schemes. The developed analytical approaches can help determine a proper number of processes for the parallel SAW HARQ mechanisms. We also show that the analytical formulas can be used to design the number of acceptable fully loaded users for an admission Control policy subject to the gap processing time constraint. In the future, our analysis can facilitate the MAC/Radio Link Control (RLC) cross-layer design because the gap processing time in the MAC layer is closely related to the RLC timeout mechanism and the window size in the RLC retransmission mechanism

  • gap processing time analysis of stall avoidance mechanisms for high speed downLink packet access with parallel harq schemes
    International Conference on Wireless Networks, 2005
    Co-Authors: Lichun Wang, Chihwen Chang
    Abstract:

    The parallel multi-channel stop-and-wait (SAW) hybrid automatic repeat request (HARQ) mechanism is one of key technologies Tor high speed downLink packet access in the wideband code division multiple access system. However, this parallel HARQ mechanism may encounter a serious stall problem, resulted from the error of the negative acknowledgement (NACK) changing to the acknowledgement (ACK) in the Control channel. In the stall situation, the receiver waits for a packet that is no longer sent by the transmitter and stops delivering the medium access Control (MAC) layer packets to the upper layer. The stall issue seriously degrades the quality of service for the high speed mobile terminal owing to the high probability of NACK-to-ACK errors. In this paper, we present an analytical approach to compare three stall avoidance schemes: the timer-based, the window-based, and the indicator-based schemes. To this end, we first define a new performance metric - the gap-processing time - the duration for a nonrecoverable gap appearing in the MAC layer re-ordering buffer until it is recognized. Second, we derive the closed-form expressions for the average gap-processing time of these three stall avoidance schemes. It is shown that our analytical results match the simulations well. Further, by analysis we demonstrate that the indicator-based stall avoidance scheme outperforms the timer-based and the window-based schemes. The developed analytical approaches provide important insight into determining a proper number of processes in the parallel SAW HARQ mechanism when applying the indicator-based stall avoidance scheme. Moreover, our analysis can facilitate the physical/MAC/Radio Link Control cross-layer design because the gap-processing time is closely related to packet error rate in the physical layer, reordering buffer size in the MAC and RLC layer.

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

  • gap processing time analysis of stall avoidance schemes for high speed downLink packet access with parallel harq mechanisms
    IEEE Transactions on Mobile Computing, 2006
    Co-Authors: Lichun Wang, Chihwen Chang
    Abstract:

    The parallel multichannel stop-and-wait (SAW) hybrid automatic repeat request (HARQ) mechanism is one of key technologies for high-speed downLink packet access in the wideband code division multiple access system. However, this parallel HARQ mechanism may encounter a serious stall problem, resulting from the error of the negative acknowledgement (NACK) changing to the acknowledgement (ACK) in the Control channel. In the stall situation, the receiver waits for a packet that will be no longer be sent by the transmitter and stops delivering the medium access Control (MAC) layer packets to the upper layer. The stall issue seriously degrades the quality of service for the high-speed mobile terminal owing to the high probability of NACK-to-ACK errors. In this paper, we present an analytical approach to compare three stall avoidance schemes: the timer-based, the window-based, and the indicator-based schemes. To this end, we first propose a new performance metric-gap processing time, which is defined as the duration for a non recoverable gap appearing in the MAC layer reordering buffer until it is recognized. Second, we derive the probability mass functions and the closed-form expressions for the average gap processing time of these three stall avoidance schemes. It will be shown that our analytical results match the simulations well. Further, by analysis, we demonstrate that the indicator-based stall avoidance scheme outperforms the timer-based and the window-based schemes. The developed analytical approaches can help determine a proper number of processes for the parallel SAW HARQ mechanisms. We also show that the analytical formulas can be used to design the number of acceptable fully loaded users for an admission Control policy subject to the gap processing time constraint. In the future, our analysis can facilitate the MAC/Radio Link Control (RLC) cross-layer design because the gap processing time in the MAC layer is closely related to the RLC timeout mechanism and the window size in the RLC retransmission mechanism

  • gap processing time analysis of stall avoidance mechanisms for high speed downLink packet access with parallel harq schemes
    International Conference on Wireless Networks, 2005
    Co-Authors: Lichun Wang, Chihwen Chang
    Abstract:

    The parallel multi-channel stop-and-wait (SAW) hybrid automatic repeat request (HARQ) mechanism is one of key technologies Tor high speed downLink packet access in the wideband code division multiple access system. However, this parallel HARQ mechanism may encounter a serious stall problem, resulted from the error of the negative acknowledgement (NACK) changing to the acknowledgement (ACK) in the Control channel. In the stall situation, the receiver waits for a packet that is no longer sent by the transmitter and stops delivering the medium access Control (MAC) layer packets to the upper layer. The stall issue seriously degrades the quality of service for the high speed mobile terminal owing to the high probability of NACK-to-ACK errors. In this paper, we present an analytical approach to compare three stall avoidance schemes: the timer-based, the window-based, and the indicator-based schemes. To this end, we first define a new performance metric - the gap-processing time - the duration for a nonrecoverable gap appearing in the MAC layer re-ordering buffer until it is recognized. Second, we derive the closed-form expressions for the average gap-processing time of these three stall avoidance schemes. It is shown that our analytical results match the simulations well. Further, by analysis we demonstrate that the indicator-based stall avoidance scheme outperforms the timer-based and the window-based schemes. The developed analytical approaches provide important insight into determining a proper number of processes in the parallel SAW HARQ mechanism when applying the indicator-based stall avoidance scheme. Moreover, our analysis can facilitate the physical/MAC/Radio Link Control cross-layer design because the gap-processing time is closely related to packet error rate in the physical layer, reordering buffer size in the MAC and RLC layer.

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

  • Performance analysis on the Radio Link Control protocol of UMTS system
    Proceedings IEEE 56th Vehicular Technology Conference, 2026
    Co-Authors: Yi-chiun Chen, E. Gonen, Peijuan Liu
    Abstract:

    Radio Link Control (RLC) is a layer 2 protocol used in the UMTS 3G cellular systems for error recovery and flow Control. It is close to the selective repeat automatic repeat request (SR-ARQ). Different setups of the RLC parameters such as transmit window size, receiving window size, periodic poll timer, poll timer, and poll prohibit timer can have significant impact to the overall RLC performance. The configuration and optimization of RLC parameters are critical to ensure that precious Radio resources are fully utilized. We explore the error rate, the RLC round trip time (RTT), and the TCP flow Control impact to the RLC transmit window size selections. Simulation results are presented to demonstrate how the transmit window size impacts the RLC throughput and delay performance.

B G Evans - One of the best experts on this subject based on the ideXlab platform.

  • performance evaluation of sip based session establishment over satellite umts
    Vehicular Technology Conference, 2003
    Co-Authors: V Y H Kueh, Rahim Tafazolli, B G Evans
    Abstract:

    Session initiation protocol (SIP) has been selected by the third generation partnership project (3GPP) as the official end-to-end IP signalling protocol for establishing multimedia sessions in the IP based universal mobile telecommunication systems (UMTS) network. Since a satellite component has been identified within UMTS, there is a need to support SIP-based session establishment over satellite-UMTS (S-UMTS) as well as to achieve an end-to-end seamless IP-based terrestrial/satellite network integration. This paper aims at evaluating the performance of SIP-based session setup over the S-UMTS, taking into account the larger propagation delay over the satellite as well as the impact of the UMTS Radio interference. It also addresses the issue of incorporating a Link layer retransmission based on the Radio Link Control acknowledgement mode (RLC-AM) mechanisms and examines its implications on the SIP session establishment performance.

Yi-chiun Chen - One of the best experts on this subject based on the ideXlab platform.

  • Performance analysis on the Radio Link Control protocol of UMTS system
    Proceedings IEEE 56th Vehicular Technology Conference, 2026
    Co-Authors: Yi-chiun Chen, E. Gonen, Peijuan Liu
    Abstract:

    Radio Link Control (RLC) is a layer 2 protocol used in the UMTS 3G cellular systems for error recovery and flow Control. It is close to the selective repeat automatic repeat request (SR-ARQ). Different setups of the RLC parameters such as transmit window size, receiving window size, periodic poll timer, poll timer, and poll prohibit timer can have significant impact to the overall RLC performance. The configuration and optimization of RLC parameters are critical to ensure that precious Radio resources are fully utilized. We explore the error rate, the RLC round trip time (RTT), and the TCP flow Control impact to the RLC transmit window size selections. Simulation results are presented to demonstrate how the transmit window size impacts the RLC throughput and delay performance.