已为您找到该学者9条结果 成果回收站
【期刊论文】A Game Approach for Multi-Channel Allocation in Multi-Hop Wireless Networks
王新兵, Lin Gao, Xinbing Wang
,-0001,():
-1年11月30日
Channel allocation was extensively investigated in the framework of cellular networks, but it was rarely studied in the wireless ad-hoc networks, especially in the multi-hop ad-hoc networks. In this paper, we study the competitive multi-radio channel allocation problem in multi-hop wireless networks in detail. We model the channel allocation problem as a static cooperative game, in which some players collaborate to achieve high date rate. We propose the min-max coalition-proof Nash equilibrium (MMCPNE) channel allocation scheme in the game, which aims to max the achieved date rates of communication links. We analyze the existence of MMCPNE and prove the necessary conditions for MMCPNE. Furthermore, we propose several algorithms that enable the selfish players to converge to MMCPNE. Simulation results show that MMCPNE outperforms CPNE and NE schemes in terms of achieved data rates of the multi-hop links due to cooperation gain.
Multi-Radio, Channel Allocation, Game Theory, Nash Equilibria
-
36浏览
-
0点赞
-
0收藏
-
0分享
-
413下载
-
0
-
引用
【期刊论文】Achieving 100% Throughput in TCP/AQM under Aggressive Packet Marking with Small Buffer
王新兵, Do Young Eun, Xinbing Wang
,-0001,():
-1年11月30日
We consider a TCP/AQM system with large link capacity (NC) shared by many flows. The traditional rule-of-thumb suggests that the buffer size be chosen in proportion to the number of flows (N) for full link utilization, while recent research outcomes show that O( √N) buffer sizing is sufficient for high utilization and O(1) buffer sizing makes the system stable at the cost of reduced link utilization. In this paper, we consider a system where the AQM is scaled as O(Nα) with a buffer of size O(Nβ) (0 < α < β < 0.5). By capturing randomness both in packet arrivals and in packet markings, we develop a doubly-stochastic model for a TCP/AQM system with many flows. We prove that, under such a scale, the system always performs well in the sense that the link utilization goes to 100% and the loss ratio decreases to zero as the system size N increases. Our results assert that the system enjoys benefit of largeness with no tradeoff between full link utilization, zero packet loss, and small buffer size, at least asymptotically. This is in stark contrast to existing results showing that there always exists a tradeoff between full link utilization and the required buffer size. Extensive ns-2 simulation results under various configurations also confirm our theoretical findings. Our study illustrates that blind application of fluid modeling may result in strange results and exemplifies the importance of choosing a right modeling approach for different scaling regimes.
-
46浏览
-
0点赞
-
0收藏
-
0分享
-
127下载
-
0
-
引用
王新兵, Xinbing Wang, Do Young Eun, Wenye Wang
IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS, VOL.6, NO.9, SEPTEMBER 2007,-0001,():
-1年11月30日
Traditional Call Admission Control (CAC) schemes only consider call-level performance and are mainly designed for circuit-switched wireless network. Since future wireless communications will become packet-switched systems, the packet-level features could be explored to improve the system performance. This is especially true when the TCP-type of elastic applications are running over such packet-switched wireless networks, as the elasticity of TCP applications has more tolerance toward the throughput/delay variation than non-elastic traffic does. In order to efficiently utilize the system resource from an admission control perspective, we propose a TCP-aware CAC scheme to regulate the packet-level dynamics of TCP flows. We analyze the system performance under realistic scenarios in which (i) the call holding time for non-elastic traffic like voice is independent of system states and (ii) the call holding time for TCP type of traffic depends on the system state, i. e., on the TCP flow’s transmission rate. Extensive simulations are presented under different scenarios to show that the proposed scheme can effectively improve the system performance in terms of call blocking probability, call-level throughput (call/min) and link utilization, in accordance with our theoretical results.
Admission control, wireless networks, TCP
-
40浏览
-
0点赞
-
0收藏
-
0分享
-
103下载
-
0
-
引用
【期刊论文】Improve throughput of TCP-Vegas in multihop ad hoc networks
王新兵, Lianghui Ding, Xinbing Wang, Youyun Xu, , Wenjun Zhang
Computer Communications xxx (2008) xxx–xxx,-0001,():
-1年11月30日
Performance of TCP-Vegas is not satisfactory in multihop ad hoc networks over IEEE 802.11 MAC protocol. We analyze the problem with a unified network model and a TCP source window model. We observe that Vegas cannot maintain the optimal window with maximum average throughput when the network capacity is smaller than the reset slow start threshold of Vegas. The aggregate throughput of all traffics decreases as the load of network increases. The main reasons lie in Vegas’s large minimum congestion window, large reset slow start threshold and aggressive window increase policy. All of them induce overload of the network, which cause packet losses at MAC layer and over-reaction at routing layer. These in return result in the breakup of end-to-end connections and reduce the throughput. To fix these problems, we propose a modified TCP protocol based on TCP-Vegas for multihop ad hoc networks, called Vegas-W. We extend congestion window to fraction with a rate control timer under the TCP sending process. Probing mechanisms of legacy TCP-Vegas in both slow start and congestion avoidance phases are changed to increase congestion window after receiving more than one ACK. Furthermore, we update slow start threshold by tracking stable window. We evaluate the performance of Vegas-W through ns-2. Extensive simulation results show that Vegas-W can improve the throughput up to 87% over legacy TCP-Vegas over a variety of topologies including chain, grid, star, dumbbell and hammer, etc.
TCP, Vegas, Throughput, Ad hoc, DSR, 802., 11
-
71浏览
-
0点赞
-
0收藏
-
0分享
-
294下载
-
0
-
引用
【期刊论文】VoIP over IEEE 802.11 WLANs and Effective Admission Control by Adapting Transmitting Interval
王新兵, Zhuo Chen, Lingyun Wang, Xinbing Wang, Hsiao-Hwa Chen
,-0001,():
-1年11月30日
-
49浏览
-
0点赞
-
0收藏
-
0分享
-
159下载
-
0
-
引用