The Experts below are selected from a list of 8592 Experts worldwide ranked by ideXlab platform
Tony Q.s. Quek - One of the best experts on this subject based on the ideXlab platform.
-
burstiness aware bandwidth reservation for uplink transmission in tactile internet
International Conference on Communications, 2018Co-Authors: Zhanwei Hou, Changyang She, Tony Q.s. Quek, Branka VuceticAbstract:The tactile internet that will enable human tactile to visual feedback control has drawn significant attentions from both academic and industrial communities. One of the key challenges of tactile internet is how to ensure ultra- reliable and low-latency communications between the local operator and the remote device. Existing studies found that the packet arrival process in tactile internet is very bursty. However, how to design burstiness aware bandwidth reservation for tactile internet is still unclear. To this end, we first apply Neyman-Pearson method to classify the arrival process of each user in high and low traffic states, and then optimize reserved bandwidth for them. The optimal overall bandwidth required to guarantee the latency and reliability requirements is achieved. Classification errors, Queueing Delay violation, and decoding errors are considered for high traffic users. Transmission collisions in random access procedure and decoding errors during retransmission phase are taken into account when users are in low traffic state. Simulation results show that the proposed method can save up to $66.7\%$ of the bandwidth compared with the method that is not aware of burstiness.
-
Cross-Layer Optimization for Ultra-Reliable and Low-Latency Radio Access Networks
IEEE Transactions on Wireless Communications, 2018Co-Authors: Changyang She, Chenyang Yang, Tony Q.s. QuekAbstract:In this paper, we propose a framework for cross-layer optimization to ensure ultra-high reliability and ultra-low latency in radio access networks, where both transmission Delay and Queueing Delay are considered. With short transmission time, the blocklength of channel codes is finite, and the Shannon capacity cannot be used to characterize the maximal achievable rate with given transmission error probability. With randomly arrived packets, some packets may violate the Queueing Delay. Moreover, since the Queueing Delay is shorter than the channel coherence time in typical scenarios, the required transmit power to guarantee the Queueing Delay and transmission error probability will become unbounded even with spatial diversity. To ensure the required quality-of-service (QoS) with finite transmit power, a proactive packet dropping mechanism is introduced. Then, the overall packet loss probability includes transmission error probability, Queueing Delay violation probability, and packet dropping probability. We optimize the packet dropping policy, power allocation policy, and bandwidth allocation policy to minimize the transmit power under the QoS constraint. The optimal solution is obtained, which depends on both channel and queue state information. Simulation and numerical results validate our analysis, and show that setting the three packet loss probabilities as equal causes marginal power loss.
-
Joint Uplink and Downlink Resource Configuration for Ultra-reliable and Low-latency Communications
IEEE Transactions on Communications, 2018Co-Authors: Changyang She, Chenyang Yang, Tony Q.s. QuekAbstract:Supporting ultra-reliable and low-latency communications (URLLC) is one of the major goals for the fifth-generation cellular networks. Since spectrum usage efficiency is always a concern, and large bandwidth is required for ensuring stringent quality-of-service (QoS), we minimize the total bandwidth under the QoS constraints of URLLC. We first propose a packet delivery mechanism for URLLC. To reduce the required bandwidth for ensuring Queueing Delay, we consider a statistical multiplexing Queueing mode, where the packets to be sent to different devices are waiting in one queue at the base station, and broadcast mode is adopted in downlink transmission. In this way, downlink bandwidth is shared among packets of multiple devices. In uplink transmission, different subchannels are allocated to different devices to avoid strong interference. Then, we jointly optimize uplink and downlink bandwidth configuration and Delay components to minimize the total bandwidth required to guarantee the overall packet loss and end-to-end Delay, which includes uplink and downlink transmission Delays, Queueing Delay and backhaul Delay. We propose a two-step method to find the optimal solution. Simulation and numerical results validate our analysis and show remarkable performance gain by jointly optimizing uplink and downlink configuration.
-
cross layer optimization for ultra reliable and low latency radio access networks
arXiv: Information Theory, 2017Co-Authors: Chenyang Yang, Tony Q.s. QuekAbstract:In this paper, we propose a framework for cross-layer optimization to ensure ultra-high reliability and ultra-low latency in radio access networks, where both transmission Delay and Queueing Delay are considered. With short transmission time, the blocklength of channel codes is finite, and the Shannon Capacity cannot be used to characterize the maximal achievable rate with given transmission error probability. With randomly arrived packets, some packets may violate the Queueing Delay. Moreover, since the Queueing Delay is shorter than the channel coherence time in typical scenarios, the required transmit power to guarantee the Queueing Delay and transmission error probability will become unbounded even with spatial diversity. To ensure the required quality-of-service (QoS) with finite transmit power, a proactive packet dropping mechanism is introduced. Then, the overall packet loss probability includes transmission error probability, Queueing Delay violation probability, and packet dropping probability. We optimize the packet dropping policy, power allocation policy, and bandwidth allocation policy to minimize the transmit power under the QoS constraint. The optimal solution is obtained, which depends on both channel and queue state information. Simulation and numerical results validate our analysis, and show that setting packet loss probabilities equal is a near optimal solution.
-
Radio Resource Management for Ultra-Reliable and Low-Latency Communications
IEEE Communications Magazine, 2017Co-Authors: Changyang She, Chenyang Yang, Tony Q.s. QuekAbstract:Supporting ultra-reliable and low-latency communications (URLLC) is one of the major goals in 5G communication systems. Previous studies focus on ensuring end-to-end Delay requirement by reducing transmission Delay and coding Delay, and only consider reliability in data transmission. However, the reliability reflected by overall packet loss also includes other components such as Queueing Delay violation. Moreover, which tools are appropriate to design radio resource allocation under constraints on Delay, reliability, and availability is not well understood. As a result, how to optimize resource allocation for URLLC is still unclear. In this article, we first discuss the Delay and packet loss components in URLLC and the network availability for supporting the quality of service of users. Then we present tools for resource optimization in URLLC. Last, we summarize the major challenges related to resource management for URLLC, and perform a case study.
Changyang She - One of the best experts on this subject based on the ideXlab platform.
-
burstiness aware bandwidth reservation for uplink transmission in tactile internet
International Conference on Communications, 2018Co-Authors: Zhanwei Hou, Changyang She, Tony Q.s. Quek, Branka VuceticAbstract:The tactile internet that will enable human tactile to visual feedback control has drawn significant attentions from both academic and industrial communities. One of the key challenges of tactile internet is how to ensure ultra- reliable and low-latency communications between the local operator and the remote device. Existing studies found that the packet arrival process in tactile internet is very bursty. However, how to design burstiness aware bandwidth reservation for tactile internet is still unclear. To this end, we first apply Neyman-Pearson method to classify the arrival process of each user in high and low traffic states, and then optimize reserved bandwidth for them. The optimal overall bandwidth required to guarantee the latency and reliability requirements is achieved. Classification errors, Queueing Delay violation, and decoding errors are considered for high traffic users. Transmission collisions in random access procedure and decoding errors during retransmission phase are taken into account when users are in low traffic state. Simulation results show that the proposed method can save up to $66.7\%$ of the bandwidth compared with the method that is not aware of burstiness.
-
Cross-Layer Optimization for Ultra-Reliable and Low-Latency Radio Access Networks
IEEE Transactions on Wireless Communications, 2018Co-Authors: Changyang She, Chenyang Yang, Tony Q.s. QuekAbstract:In this paper, we propose a framework for cross-layer optimization to ensure ultra-high reliability and ultra-low latency in radio access networks, where both transmission Delay and Queueing Delay are considered. With short transmission time, the blocklength of channel codes is finite, and the Shannon capacity cannot be used to characterize the maximal achievable rate with given transmission error probability. With randomly arrived packets, some packets may violate the Queueing Delay. Moreover, since the Queueing Delay is shorter than the channel coherence time in typical scenarios, the required transmit power to guarantee the Queueing Delay and transmission error probability will become unbounded even with spatial diversity. To ensure the required quality-of-service (QoS) with finite transmit power, a proactive packet dropping mechanism is introduced. Then, the overall packet loss probability includes transmission error probability, Queueing Delay violation probability, and packet dropping probability. We optimize the packet dropping policy, power allocation policy, and bandwidth allocation policy to minimize the transmit power under the QoS constraint. The optimal solution is obtained, which depends on both channel and queue state information. Simulation and numerical results validate our analysis, and show that setting the three packet loss probabilities as equal causes marginal power loss.
-
Joint Uplink and Downlink Resource Configuration for Ultra-reliable and Low-latency Communications
IEEE Transactions on Communications, 2018Co-Authors: Changyang She, Chenyang Yang, Tony Q.s. QuekAbstract:Supporting ultra-reliable and low-latency communications (URLLC) is one of the major goals for the fifth-generation cellular networks. Since spectrum usage efficiency is always a concern, and large bandwidth is required for ensuring stringent quality-of-service (QoS), we minimize the total bandwidth under the QoS constraints of URLLC. We first propose a packet delivery mechanism for URLLC. To reduce the required bandwidth for ensuring Queueing Delay, we consider a statistical multiplexing Queueing mode, where the packets to be sent to different devices are waiting in one queue at the base station, and broadcast mode is adopted in downlink transmission. In this way, downlink bandwidth is shared among packets of multiple devices. In uplink transmission, different subchannels are allocated to different devices to avoid strong interference. Then, we jointly optimize uplink and downlink bandwidth configuration and Delay components to minimize the total bandwidth required to guarantee the overall packet loss and end-to-end Delay, which includes uplink and downlink transmission Delays, Queueing Delay and backhaul Delay. We propose a two-step method to find the optimal solution. Simulation and numerical results validate our analysis and show remarkable performance gain by jointly optimizing uplink and downlink configuration.
-
Radio Resource Management for Ultra-Reliable and Low-Latency Communications
IEEE Communications Magazine, 2017Co-Authors: Changyang She, Chenyang Yang, Tony Q.s. QuekAbstract:Supporting ultra-reliable and low-latency communications (URLLC) is one of the major goals in 5G communication systems. Previous studies focus on ensuring end-to-end Delay requirement by reducing transmission Delay and coding Delay, and only consider reliability in data transmission. However, the reliability reflected by overall packet loss also includes other components such as Queueing Delay violation. Moreover, which tools are appropriate to design radio resource allocation under constraints on Delay, reliability, and availability is not well understood. As a result, how to optimize resource allocation for URLLC is still unclear. In this article, we first discuss the Delay and packet loss components in URLLC and the network availability for supporting the quality of service of users. Then we present tools for resource optimization in URLLC. Last, we summarize the major challenges related to resource management for URLLC, and perform a case study.
Chenyang Yang - One of the best experts on this subject based on the ideXlab platform.
-
Cross-Layer Optimization for Ultra-Reliable and Low-Latency Radio Access Networks
IEEE Transactions on Wireless Communications, 2018Co-Authors: Changyang She, Chenyang Yang, Tony Q.s. QuekAbstract:In this paper, we propose a framework for cross-layer optimization to ensure ultra-high reliability and ultra-low latency in radio access networks, where both transmission Delay and Queueing Delay are considered. With short transmission time, the blocklength of channel codes is finite, and the Shannon capacity cannot be used to characterize the maximal achievable rate with given transmission error probability. With randomly arrived packets, some packets may violate the Queueing Delay. Moreover, since the Queueing Delay is shorter than the channel coherence time in typical scenarios, the required transmit power to guarantee the Queueing Delay and transmission error probability will become unbounded even with spatial diversity. To ensure the required quality-of-service (QoS) with finite transmit power, a proactive packet dropping mechanism is introduced. Then, the overall packet loss probability includes transmission error probability, Queueing Delay violation probability, and packet dropping probability. We optimize the packet dropping policy, power allocation policy, and bandwidth allocation policy to minimize the transmit power under the QoS constraint. The optimal solution is obtained, which depends on both channel and queue state information. Simulation and numerical results validate our analysis, and show that setting the three packet loss probabilities as equal causes marginal power loss.
-
Joint Uplink and Downlink Resource Configuration for Ultra-reliable and Low-latency Communications
IEEE Transactions on Communications, 2018Co-Authors: Changyang She, Chenyang Yang, Tony Q.s. QuekAbstract:Supporting ultra-reliable and low-latency communications (URLLC) is one of the major goals for the fifth-generation cellular networks. Since spectrum usage efficiency is always a concern, and large bandwidth is required for ensuring stringent quality-of-service (QoS), we minimize the total bandwidth under the QoS constraints of URLLC. We first propose a packet delivery mechanism for URLLC. To reduce the required bandwidth for ensuring Queueing Delay, we consider a statistical multiplexing Queueing mode, where the packets to be sent to different devices are waiting in one queue at the base station, and broadcast mode is adopted in downlink transmission. In this way, downlink bandwidth is shared among packets of multiple devices. In uplink transmission, different subchannels are allocated to different devices to avoid strong interference. Then, we jointly optimize uplink and downlink bandwidth configuration and Delay components to minimize the total bandwidth required to guarantee the overall packet loss and end-to-end Delay, which includes uplink and downlink transmission Delays, Queueing Delay and backhaul Delay. We propose a two-step method to find the optimal solution. Simulation and numerical results validate our analysis and show remarkable performance gain by jointly optimizing uplink and downlink configuration.
-
cross layer optimization for ultra reliable and low latency radio access networks
arXiv: Information Theory, 2017Co-Authors: Chenyang Yang, Tony Q.s. QuekAbstract:In this paper, we propose a framework for cross-layer optimization to ensure ultra-high reliability and ultra-low latency in radio access networks, where both transmission Delay and Queueing Delay are considered. With short transmission time, the blocklength of channel codes is finite, and the Shannon Capacity cannot be used to characterize the maximal achievable rate with given transmission error probability. With randomly arrived packets, some packets may violate the Queueing Delay. Moreover, since the Queueing Delay is shorter than the channel coherence time in typical scenarios, the required transmit power to guarantee the Queueing Delay and transmission error probability will become unbounded even with spatial diversity. To ensure the required quality-of-service (QoS) with finite transmit power, a proactive packet dropping mechanism is introduced. Then, the overall packet loss probability includes transmission error probability, Queueing Delay violation probability, and packet dropping probability. We optimize the packet dropping policy, power allocation policy, and bandwidth allocation policy to minimize the transmit power under the QoS constraint. The optimal solution is obtained, which depends on both channel and queue state information. Simulation and numerical results validate our analysis, and show that setting packet loss probabilities equal is a near optimal solution.
-
Radio Resource Management for Ultra-Reliable and Low-Latency Communications
IEEE Communications Magazine, 2017Co-Authors: Changyang She, Chenyang Yang, Tony Q.s. QuekAbstract:Supporting ultra-reliable and low-latency communications (URLLC) is one of the major goals in 5G communication systems. Previous studies focus on ensuring end-to-end Delay requirement by reducing transmission Delay and coding Delay, and only consider reliability in data transmission. However, the reliability reflected by overall packet loss also includes other components such as Queueing Delay violation. Moreover, which tools are appropriate to design radio resource allocation under constraints on Delay, reliability, and availability is not well understood. As a result, how to optimize resource allocation for URLLC is still unclear. In this article, we first discuss the Delay and packet loss components in URLLC and the network availability for supporting the quality of service of users. Then we present tools for resource optimization in URLLC. Last, we summarize the major challenges related to resource management for URLLC, and perform a case study.
Anthony Ephremides - One of the best experts on this subject based on the ideXlab platform.
-
Joint Queue-Aware and Channel-Aware Delay Optimal Scheduling of Arbitrarily Bursty Traffic Over Multi-State Time-Varying Channels
IEEE Transactions on Communications, 2019Co-Authors: Meng Wang, Wei Chen, Anthony EphremidesAbstract:This paper is motivated by the observation that the average Queueing Delay can be decreased by sacrificing power efficiency in wireless communications. In this sense, we naturally wonder what the minimum Queueing Delay is when the available power is limited and how to achieve the minimum Queueing Delay. To answer these two questions in the scenario where randomly arriving packets are transmitted over multi-state wireless fading channel, a probabilistic cross-layer scheduling policy is proposed in this paper, and characterized by a constrained Markov decision process. Using the steady-state probability of the underlying Markov chain, we are able to derive the mathematical expressions of the concerned metrics, namely, the average Queueing Delay and the average power consumption. To describe the Delay-power tradeoff, we formulate a non-linear programming problem, which, however, is very challenging to solve. By analyzing its structure, this optimization problem can be converted into an equivalent linear programming problem via variable substitution, which allows us to derive the optimal Delay-power tradeoff as well as the optimal scheduling policy. The optimal scheduling policy turns out to be dual-threshold-based, which means transmission decisions should be made based on the optimal thresholds imposed on the queue length and the channel state.
-
a simple derivation of Queueing Delay in a tree network of discrete time queues with deterministic service time
International Symposium on Information Theory, 1994Co-Authors: Eytan Modiano, Jeffrey E Wieselthier, Anthony EphremidesAbstract:We consider a network of discrete-time queues in which the service time is deterministic and the same at each queue. Such a network of queues arises in a data communication network model where data is formatted into fixed-length packets. An important performance index in such networks is Queueing Delay. The model generally used for the analysis of Delay in a large network is based on Kleinrock's(1964) independence assumption, which assumes that the queues at each link behave as independent queues regardless of the interaction of traffic between the different links. This model is reasonably good for systems involving exponential arrivals, a densely connected network and uniform loading among source-destination pairs. Otherwise the model becomes very inaccurate in predicting Delay. >
Meng Wang - One of the best experts on this subject based on the ideXlab platform.
-
Joint Queue-Aware and Channel-Aware Delay Optimal Scheduling of Arbitrarily Bursty Traffic Over Multi-State Time-Varying Channels
IEEE Transactions on Communications, 2019Co-Authors: Meng Wang, Wei Chen, Anthony EphremidesAbstract:This paper is motivated by the observation that the average Queueing Delay can be decreased by sacrificing power efficiency in wireless communications. In this sense, we naturally wonder what the minimum Queueing Delay is when the available power is limited and how to achieve the minimum Queueing Delay. To answer these two questions in the scenario where randomly arriving packets are transmitted over multi-state wireless fading channel, a probabilistic cross-layer scheduling policy is proposed in this paper, and characterized by a constrained Markov decision process. Using the steady-state probability of the underlying Markov chain, we are able to derive the mathematical expressions of the concerned metrics, namely, the average Queueing Delay and the average power consumption. To describe the Delay-power tradeoff, we formulate a non-linear programming problem, which, however, is very challenging to solve. By analyzing its structure, this optimization problem can be converted into an equivalent linear programming problem via variable substitution, which allows us to derive the optimal Delay-power tradeoff as well as the optimal scheduling policy. The optimal scheduling policy turns out to be dual-threshold-based, which means transmission decisions should be made based on the optimal thresholds imposed on the queue length and the channel state.
-
Delay optimal scheduling of arbitrarily bursty traffic over multi state time varying channels
Global Communications Conference, 2016Co-Authors: Meng Wang, Juan Liu, Wei ChenAbstract:An important challenge in the Internet of Things (IoT) is to provide real-time services on low-energy-supply devices. In this paper, we study joint queue-aware and channel-aware scheduling of arbitrarily bursty traffic over multi-state time-varying channels, where the bursty packet arrival in the network layer, the backlogged queue in the data link layer, and the power adaptive transmission with fixed modulation in the physical layer are jointly considered from a cross-layer perspective. To achieve minimum Queueing Delay given a power constraint, a probabilistic cross-layer scheduling policy is proposed, and characterized by a Markov chain model. To describe the Delay-power tradeoff, we formulate a non-linear optimization problem, which however is very challenging to solve. To handle with this issue, we convert the optimization problem into an equivalent Linear Programming (LP) problem, which allows us to obtain the optimal threshold-based scheduling policy with an optimal threshold imposed on the queue length in accordance with each channel state.
-
Delay optimal scheduling of arbitrarily bursty traffic over multi state time varying channels
arXiv: Information Theory, 2016Co-Authors: Meng Wang, Juan Liu, Wei ChenAbstract:In this paper, we study joint queue-aware and channel-aware scheduling of arbitrarily bursty traffic over multi-state time-varying channels, where the bursty packet arrival in the network layer, the backlogged queue in the data link layer, and the power adaptive transmission with fixed modulation in the physical layer are jointly considered from a cross-layer perspective. To achieve minimum Queueing Delay given a power constraint, a probabilistic cross-layer scheduling policy is proposed, and characterized by a Markov chain model. To describe the Delay-power tradeoff, we formulate a non-linear optimization problem, which however is very challenging to solve. To handle with this issue, we convert the optimization problem into an equivalent Linear Programming (LP) problem, which allows us to obtain the optimal threshold-based scheduling policy with an optimal threshold imposed on the queue length in accordance with each channel state.
