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991.
992.
在光突发交换试验网络中对TCP的性能进行了实验研究.首先研究了丢包对网络性能的影响,表明突发包丢失将导致TCP吞吐量的快速下降,并且丢包率越高,可用的TCP传输带宽越窄.然后分别详细研究了OBS试验网络中的延时损伤和报文段关联增益,以及对TCP传输性能的影响.最后综合考虑这些因素.实验结果表明,在本OBS试验网络中存在一个不随丢包率变化的最优化突发包组装时间250us使得可用TCP带宽最大化.为了最大限度地提高TCP的传输性能,组包时间应该选择等于或稍大于这个最优值. 相似文献
993.
针对当前输油管道压力监控现状,结合GPRS通信模块MC39i,给出了能够实现远程数据传输并可广泛应用于远程监控系统的设计方案。重点阐述了系统的硬件组成以及基于嵌入式实时操作系统FreeRTOS实现数据传输模块的软件设计;采用基于状态机的结构设计方法实现PPP链路层协议,实现GPRS模块与互连网络的连接;分析和比较了UDP和TCP两种传输层数据传输方式,并给出了基于uIP TCP/IP协议栈实现TCP和UDP传输协议的原理;对UDP协议的传输可靠性进行改进,采用带握手的UDP协议可以较好地满足实时性的可靠性要求,并对数据传输性能进行了测试。 相似文献
994.
智能家居系统如何接入Internet是一个难点问题。在对现有嵌入式系统连入Internet技术分析的基础上,结合嵌入式Internet技术、计算机网络技术、电力线数据通信技术,设计出一种高性价比的电力线载波智能家庭网关系统。最后给出了智能家庭网关系统的应用实例,实现了对智能家电的远程监控。 相似文献
995.
996.
采用RSVP-TE信令协议,对重叠网络模型中的UNI信令进行了研究,并对它作了简单的分析,最后在重叠模型的基础上简要描述了通过UNI接口利用RSVP—TE如何实现客户端与网络端之间路径的建立与删除. 相似文献
997.
In this paper, in-sequence delivery delay of an acknowledged mode radio link control (AM-RLC) protocol in wideband code division
multiple access (W-CDMA) networks is studied. Two special protocol phenomena, duplicated retransmission, and delayed acknowledgment,
are reported. A two-step dependent Markov chain is adopted to model the AM-RLC protocol. The in-sequence delivery is evaluated
by means of an analysis through tracking the transmission status of a specific packet data unit (PDU) and its blocking PDUs.
Analysis results indicate that in-sequence delivery delay is approximately linear with frame error rate. Analysis results
also exhibit that in-sequence delivery delay is highly related to status report interval. Based on this observation, a dynamic
AM-RLC scheme is proposed. The proposed AM-RLC scheme dynamically changes status report interval according to channel status.
Extensive simulations are carried out to verify the effectiveness of the proposed scheme. It is found that the proposed scheme
can reduce status report without penalty to in-sequence delivery delay. 相似文献
998.
The deployment of infrastructure-less ad hoc networks is suffering from the lack of applications in spite of active research
over a decade. This problem can be solved to a certain extent by porting successful legacy Internet applications and protocols
to the ad hoc network domain. Session Initiation Protocol (SIP) is designed to provide the signaling support for multimedia
applications such as Internet telephony, Instant Messaging, Presence etc. SIP relies on the infrastructure of the Internet
and an overlay of centralized SIP servers to enable the SIP endpoints discover each other and establish a session by exchanging
SIP messages. However, such an infrastructure is unavailable in ad hoc networks. In this paper, we propose two approaches
to solve this problem and enable SIP-based session setup in ad hoc networks (i) a loosely coupled approach, where the SIP
endpoint discovery is decoupled from the routing procedure and (ii) a tightly coupled approach, which integrates the endpoint
discovery with a fully distributed cluster based routing protocol that builds a virtual topology for efficient routing. Simulation
experiments show that the tightly coupled approach performs better for (relatively) static multihop wireless networks than
the loosely coupled approach in terms of the latency in SIP session setup. The loosely coupled approach, on the other hand,
generally performs better in networks with random node mobility. The tightly coupled approach, however, has lower control
overhead in both the cases.
This work was partially done while the author was a graduate student in CReWMaN, University of Texas at Arlington.
Dr. Nilanjan Banerjee is a Senior Research Engineer in the Networks Research group at Motorola India Research Labs. He is currently working on
converged network systems. He received his Ph.D. and M.S. in computer science and engineering from University of Texas at
Arlington. He received his B.E. degree in the same discipline from Jadavpur University, India. His research interests include
telecom network architectures and protocols, identity management and network security, mobile and pervasive computing, measures
for performance, modeling and simulation, and optimization in dynamic systems.
Dr Arup Acharya is a Research Staff Member in the Internet Infrastructure and Computing Utilities group at IBM T.J. Watson Research Center
and leads the Advanced Networking micropractice in On-Demand Innovation Services. His current work includes SIP-based services
such as VoIP, Instant Messaging and Presence, and includes customer consulting engagements and providing subject matter expertise
in corporate strategy teams. Presently, he is leading a IBM Research project on scalability and performance of SIP servers
for large workloads. In addition, he also works on different topics in mobile/wireless networking such as mesh networks. He
has published extensively in conferences/journals and has been awarded seven patents. Before joining IBM in 2000, he was with
NEC C&C Research Laboratories, Princeton. He received a B.Tech degree in Computer Science from the Indian Institute of Technology,
Kharagpur and a PhD in Computer Science from Rutgers University in 1995. Further information is available at
Dr. Sajal K. Das is a Professor of Computer Science and Engineering and also the Founding Director of the Center for Research in Wireless
Mobility and Networking (CReWMaN) at the University of Texas at Arlington (UTA). His current research interests include sensor
networks, resource and mobility management in wireless networks, mobile and pervasive computing, wireless multimedia and QoS
provisioning, wireless internet architectures and protocols, grid computing, applied graph theory and game theory. He has
published over 400 research papers in these areas, holds four US patents in wireless internet and mobile networks. He received
Best Paper Awards in IEEE PerCom’06, ACM MobiCom’99, ICOIN’02, ACM MSwiM’00 and ACM/IEEE PADS’97. He is also recipient of
UTA’s Outstanding Faculty Research Award in Computer Science (2001 and 2003), College of Engineering Research Excellence Award
(2003), the University Award for Distinguished record of Research (2005), and UTA Academy of Distinguished Scholars Award
(2006). He serves as the Editor-in-Chief of Pervasive and Mobile Computing journal, and as Associate Editor of IEEE Transactions
on Mobile Computing, ACM/Springer Wireless Networks, IEEE Transactions on Parallel and Distributed Systems. He has served
as General or Program Chair and TPC member of numerous IEEE and ACM conferences. He is a member of IEEE TCCC and TCPP Executive
Committees. 相似文献
999.
结合智能卡管理系统的设计开发,叙述了系统中软硬件之间通信协议的制定、基于组件技术的数据采集及通信功能的实现。通信组件利用面向对象技术,对系统中的软硬件通信协议的细节进行了抽象和封装,提高了软件的开发效率和可靠度。 相似文献
1000.