We present a discrete time single-server two-level mixed service polling systems with two queue types, one center queue and N normal queues. Two-level means the center queue will be successive served after each normal...We present a discrete time single-server two-level mixed service polling systems with two queue types, one center queue and N normal queues. Two-level means the center queue will be successive served after each normal queue. In the first level, server visits between the center queue and the normal queue. In the second level, normal queues are polled by a cyclic order. Mixed service means the service discipline are exhaustive for center queue, and parallel 1-limited for normal queues. We propose an imbedded Markov chain framework to drive the closed-form expressions for the mean cycle time, mean queue length, and mean waiting time. Numerical examples demonstrate that theoretical and simulation results are identical the new system efficiently differentiates priorities.展开更多
Recently, applications of real-time polling service (rtPS) in IEEE 802.16 wireless networks have gained considerable popularity. These applications generate large amounts of real time traffic in the network and thus m...Recently, applications of real-time polling service (rtPS) in IEEE 802.16 wireless networks have gained considerable popularity. These applications generate large amounts of real time traffic in the network and thus maintaining the quality of service (QoS) such as packet delay requirement in rtPS dominant networks is critical. Existing dimensioning methodology does not consider QoS parameters of rtPS in network dimensioning. Moreover, exhaustive and time-consuming simulations are required to evaluate the performance and QoS of rtPS. To overcome this problem, we propose an improved radio network dimensioning framework which considers QoS parameters of rtPS in network dimensioning. In this framework, an analytical model is developed to evaluate the capacity and performance of rtPS in IEEE 802.16 wireless networks. The proposed framework provides a fast and accurate means of finding the trade-off between system load and packet delay, thus providing network operators with an analytical tool that jointly considers coverage, capacity and QoS requirements for obtaining the minimum number of sites required. The accuracy of the proposed model is validated through simulations.展开更多
为了改善无人机数据链(unmanned aerial vehicle data link,UAV-DL)的吞吐量和平均时延,结合UAV的Markov飞行状态、Gilbert-Elliot信道模型和不同分组网络的优先级,提出了一种基于Gilbert-Elliot信道的UAV数据链多链路轮询策略。该策略...为了改善无人机数据链(unmanned aerial vehicle data link,UAV-DL)的吞吐量和平均时延,结合UAV的Markov飞行状态、Gilbert-Elliot信道模型和不同分组网络的优先级,提出了一种基于Gilbert-Elliot信道的UAV数据链多链路轮询策略。该策略以链路信道状态和不同分组网络的优先级为轮询的最优目标,首先,依据轮询的最优目标完成信息的传输,然后,依据排队过程的概率母函数和基本的排队原理分析了UAV数据链多链路轮询机制的性能。最后通过Opnet仿真了该策略组网条件下的平均时延和吞吐量,结果表明:与其典型的两种轮询方式相比,该方案的平均时延削减了至少30%,组网的吞吐量增加了1.3倍。展开更多
基金Supported by the National Natural Science Foundation of China (No. 61072079)Science Foundation of Yunnan Provincial Department (No. 2011Y117)
文摘We present a discrete time single-server two-level mixed service polling systems with two queue types, one center queue and N normal queues. Two-level means the center queue will be successive served after each normal queue. In the first level, server visits between the center queue and the normal queue. In the second level, normal queues are polled by a cyclic order. Mixed service means the service discipline are exhaustive for center queue, and parallel 1-limited for normal queues. We propose an imbedded Markov chain framework to drive the closed-form expressions for the mean cycle time, mean queue length, and mean waiting time. Numerical examples demonstrate that theoretical and simulation results are identical the new system efficiently differentiates priorities.
文摘Recently, applications of real-time polling service (rtPS) in IEEE 802.16 wireless networks have gained considerable popularity. These applications generate large amounts of real time traffic in the network and thus maintaining the quality of service (QoS) such as packet delay requirement in rtPS dominant networks is critical. Existing dimensioning methodology does not consider QoS parameters of rtPS in network dimensioning. Moreover, exhaustive and time-consuming simulations are required to evaluate the performance and QoS of rtPS. To overcome this problem, we propose an improved radio network dimensioning framework which considers QoS parameters of rtPS in network dimensioning. In this framework, an analytical model is developed to evaluate the capacity and performance of rtPS in IEEE 802.16 wireless networks. The proposed framework provides a fast and accurate means of finding the trade-off between system load and packet delay, thus providing network operators with an analytical tool that jointly considers coverage, capacity and QoS requirements for obtaining the minimum number of sites required. The accuracy of the proposed model is validated through simulations.
文摘为了改善无人机数据链(unmanned aerial vehicle data link,UAV-DL)的吞吐量和平均时延,结合UAV的Markov飞行状态、Gilbert-Elliot信道模型和不同分组网络的优先级,提出了一种基于Gilbert-Elliot信道的UAV数据链多链路轮询策略。该策略以链路信道状态和不同分组网络的优先级为轮询的最优目标,首先,依据轮询的最优目标完成信息的传输,然后,依据排队过程的概率母函数和基本的排队原理分析了UAV数据链多链路轮询机制的性能。最后通过Opnet仿真了该策略组网条件下的平均时延和吞吐量,结果表明:与其典型的两种轮询方式相比,该方案的平均时延削减了至少30%,组网的吞吐量增加了1.3倍。
