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Bandwidth Request

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Eun-chan Park – 1st expert on this subject based on the ideXlab platform

  • TCP-aware bidirectional Bandwidth allocation in IEEE 802.16 networks
    Wireless Networks, 2010
    Co-Authors: Eun-chan Park

    Abstract:

    In this paper, we propose a bidirectional Bandwidth-allocation mechanism to improve TCP performance in the IEEE 802.16 broadband wireless access networks. By coupling the Bandwidth allocation for uplink and downlink connections, the proposed mechanism increases the throughput of the downlink TCP flow and it enhances the efficiency of uplink Bandwidth allocation for the TCP acknowledgment (ACK). According to the IEEE 802.16 standard, when serving a downlink TCP flow, the transmission of the uplink ACK, which is performed over a separate unidirectional connection, incurs additional BandwidthRequest/allocation delay. Thus, it increases the round trip time of the downlink TCP flow and results in the decrease of throughput accordingly. First, we derive an analytical model to investigate the effect of the uplink BandwidthRequest/allocation delay on the downlink TCP throughput. Second, we propose a simple, yet effective, bidirectional Bandwidth-allocation scheme that combines proactive Bandwidth allocation with piggyback Bandwidth Request . The proposed scheme reduces unnecessary BandwidthRequest delay and the relevant signaling overhead due to proactive allocation; meanwhile, it maintains high efficiency of uplink Bandwidth usage by using piggyback Request. Moreover, our proposed scheme is quite simple and practical; it can be simply implemented in the base station without requiring any modification in the subscriber stations or resorting to any cross-layer signaling mechanisms. The simulation results ascertain that the proposed approach significantly increases the downlink TCP throughput and the uplink Bandwidth efficiency.

  • QSHINE – Enhanced Bandwidth Allocation for TCP Flows in WiMAX Networks
    Lecture Notes of the Institute for Computer Sciences Social Informatics and Telecommunications Engineering, 2009
    Co-Authors: Eun-chan Park, Chunyu Hu

    Abstract:

    In this paper, we propose a bidirectional Bandwidth-allocation mechanism to improve TCP performance in the IEEE 802.16 WiMAX networks. According to the IEEE 802.16 standard, when serving a downlink TCP flow, the transmission of the uplink ACK, which is performed over a separate unidirectional connection, incurs additional BandwidthRequest/allocation delay. Thus, it increases the round trip time of the downlink TCP flow and results in the decrease of throughput accordingly. First, we derive an analytical model to investigate the effect of the uplink BandwidthRequest/allocation delay on the downlink TCP throughput. Second, we propose a simple, yet effective, bidirectional Bandwidth-allocation mechanism that couples the Bandwidth allocation for uplink and downlink connections by using either proactive Bandwidth allocation or piggyback Bandwidth Request. The proposed scheme reduces unnecessary BandwidthRequest delay and the relevant signaling overhead due to proactive allocation; meanwhile, it maintains high efficiency of uplink Bandwidth usage by using piggyback Request. Moreover, our proposed scheme is quite simple and practical; it can be simply implemented in the base station without requiring any modification in the subscriber stations or resorting to any cross-layer signaling mechanisms. The simulation results ascertain that the proposed approach significantly increases the downlink TCP throughput and the uplink Bandwidth efficiency.

  • Efficient Uplink Bandwidth Request with Delay Regulation for Real-Time Service in Mobile WiMAX Networks
    IEEE Transactions on Mobile Computing, 2009
    Co-Authors: Eun-chan Park

    Abstract:

    The emerging broadband wireless access technology based on IEEE 802.16 is one of the most promising solutions to provide ubiquitous wireless access to the broadband service at low cost. This paper proposes an efficient uplink Bandwidth Request-allocation algorithm for real-time services in Mobile WiMAX networks based on IEEE 802.16e. In order to minimize Bandwidth wastage without degrading quality of service (QoS), we introduce a notion of target delay and propose dual feedback architecture. The proposed algorithm calculates the amount of Bandwidth Request such that the delay is regulated around the desired level to minimize delay violation and delay jitter for real-time services. Also, it can increase utilization of wireless channel by making use of dual feedback, where the Bandwidth Request is adjusted based on the information about the backlogged amount of traffic in the queue and the rate mismatch between packet arrival and service rates. Due to the target delay and dual feedback, the proposed scheme can control delay and allocate Bandwidth efficiently while satisfying QoS requirement. The stability of the proposed algorithm is analyzed from a control-theoretic viewpoint, and a simple design guideline is derived based on this analysis. By implementing the algorithm in OPNET simulator, its performance is evaluated in terms of queue regulation, optimal Bandwidth allocation, delay controllability, and robustness to traffic characteristics.

Bong Dae Choi – 2nd expert on this subject based on the ideXlab platform

  • delay analysis and optimization of Bandwidth Request under unicast polling in ieee 802 16e over gilbert elliot error channel
    IEICE Transactions on Communications, 2009
    Co-Authors: Eunju Hwang, Frank Roijers, Bong Dae Choi

    Abstract:

    In the centralized polling mode in IEEE 802.16e, a base station (BS) polls mobile stations (MSs) for Bandwidth reservation in one of three polling modes; unicast, multicast, or broadcast pollings. In unicast polling, the BS polls each individual MS to allow to transmit a Bandwidth Request packet. This paper presents an analytical model for the unicast polling of Bandwidth Request in IEEE 802.16e networks over Gilbert-Elliot error channel. We derive the probability distribution for the delay of Bandwidth Requests due to wireless transmission errors and find the loss probability of Request packets due to finite retransmission attempts. By using the delay distribution and the loss probability, we optimize the number of polling slots within a frame and the maximum retransmission number while satisfying QoS on the total loss probability which combines two losses: packet loss due to the excess of maximum retransmission and delay outage loss due to the maximum tolerable delay bound. In addition, we obtain the utilization of polling slots, which is defined as the ratio of the number of polling slots used for the MS’s successful transmission to the total number of polling slots used by the MS over a long run time. Analysis results are shown to well match with simulation results. Numerical results give examples of the optimal number of polling slots within a frame and the optimal maximum retransmission number depending on delay bounds, the number of MSs and the channel conditions. Copyright © 2009 The Institute of Electronics, Information and Communication Engineers.

  • Delay Analysis of Bandwidth Request in Truncated Binary Exponential Backoff Mechanism over Error-Free/Error-Prone Channels in IEEE 802.16e
    2008 16th Interntional Workshop on Quality of Service, 2008
    Co-Authors: Eunju Hwang, Andrey Lyakhov, Bong Dae Choi

    Abstract:

    We investigate the delay of the Bandwidth Request under the truncated binary exponential backoff (TBEB) mechanism in the IEEE 802.16e, considering error-free/error- prone wireless channels. We derive the distribution of delay of Bandwidth Request packets in the TBEB by an analytic method on the assumption of Bernoulli Request arrival process and error-free channel conditions, and extend the analytic results to the error-prone channel condition where the Request transmissions have error with i.i.d. By numerical analysis we can find the optimal number of transmission opportunities for transmitting Bandwidth Requests of the TBEB satisfying QoS on delay bound and loss bound.

  • delay analysis of Bandwidth Request in truncated binary exponential backoff mechanism over error free error prone channels in ieee 802 16e
    International Workshop on Quality of Service, 2008
    Co-Authors: Eunju Hwang, Andrey Lyakhov, Bong Dae Choi

    Abstract:

    We investigate the delay of the Bandwidth Request under the truncated binary exponential backoff (TBEB) mechanism in the IEEE 802.16e, considering error-free/error- prone wireless channels. We derive the distribution of delay of Bandwidth Request packets in the TBEB by an analytic method on the assumption of Bernoulli Request arrival process and error-free channel conditions, and extend the analytic results to the error-prone channel condition where the Request transmissions have error with i.i.d. By numerical analysis we can find the optimal number of transmission opportunities for transmitting Bandwidth Requests of the TBEB satisfying QoS on delay bound and loss bound.

Eunju Hwang – 3rd expert on this subject based on the ideXlab platform

  • delay analysis and optimization of Bandwidth Request under unicast polling in ieee 802 16e over gilbert elliot error channel
    IEICE Transactions on Communications, 2009
    Co-Authors: Eunju Hwang, Frank Roijers, Bong Dae Choi

    Abstract:

    In the centralized polling mode in IEEE 802.16e, a base station (BS) polls mobile stations (MSs) for Bandwidth reservation in one of three polling modes; unicast, multicast, or broadcast pollings. In unicast polling, the BS polls each individual MS to allow to transmit a Bandwidth Request packet. This paper presents an analytical model for the unicast polling of Bandwidth Request in IEEE 802.16e networks over Gilbert-Elliot error channel. We derive the probability distribution for the delay of Bandwidth Requests due to wireless transmission errors and find the loss probability of Request packets due to finite retransmission attempts. By using the delay distribution and the loss probability, we optimize the number of polling slots within a frame and the maximum retransmission number while satisfying QoS on the total loss probability which combines two losses: packet loss due to the excess of maximum retransmission and delay outage loss due to the maximum tolerable delay bound. In addition, we obtain the utilization of polling slots, which is defined as the ratio of the number of polling slots used for the MS’s successful transmission to the total number of polling slots used by the MS over a long run time. Analysis results are shown to well match with simulation results. Numerical results give examples of the optimal number of polling slots within a frame and the optimal maximum retransmission number depending on delay bounds, the number of MSs and the channel conditions. Copyright © 2009 The Institute of Electronics, Information and Communication Engineers.

  • Delay Analysis of Bandwidth Request in Truncated Binary Exponential Backoff Mechanism over Error-Free/Error-Prone Channels in IEEE 802.16e
    2008 16th Interntional Workshop on Quality of Service, 2008
    Co-Authors: Eunju Hwang, Andrey Lyakhov, Bong Dae Choi

    Abstract:

    We investigate the delay of the Bandwidth Request under the truncated binary exponential backoff (TBEB) mechanism in the IEEE 802.16e, considering error-free/error- prone wireless channels. We derive the distribution of delay of Bandwidth Request packets in the TBEB by an analytic method on the assumption of Bernoulli Request arrival process and error-free channel conditions, and extend the analytic results to the error-prone channel condition where the Request transmissions have error with i.i.d. By numerical analysis we can find the optimal number of transmission opportunities for transmitting Bandwidth Requests of the TBEB satisfying QoS on delay bound and loss bound.

  • delay analysis of Bandwidth Request in truncated binary exponential backoff mechanism over error free error prone channels in ieee 802 16e
    International Workshop on Quality of Service, 2008
    Co-Authors: Eunju Hwang, Andrey Lyakhov, Bong Dae Choi

    Abstract:

    We investigate the delay of the Bandwidth Request under the truncated binary exponential backoff (TBEB) mechanism in the IEEE 802.16e, considering error-free/error- prone wireless channels. We derive the distribution of delay of Bandwidth Request packets in the TBEB by an analytic method on the assumption of Bernoulli Request arrival process and error-free channel conditions, and extend the analytic results to the error-prone channel condition where the Request transmissions have error with i.i.d. By numerical analysis we can find the optimal number of transmission opportunities for transmitting Bandwidth Requests of the TBEB satisfying QoS on delay bound and loss bound.