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61.
LAN Zhou GUO Hong-xiang WU Jian LIN Jin-tong Key Laboratory of OCLT Ministry of Education Beijing University of Posts Telecommunications Beijing P.R. China 《中国邮电高校学报(英文版)》2005,12(2)
1IntroductionOptical Burst Switching (OBS)[1 ~4]provides a feasi-ble paradigm for Internet Protocol (IP) over Wave-length-Division Multiplexing ( WDM) integration[5 ~10],which has been the focus of intense investigation owingtoits flexibilityin utilizingthe terahertz bandwidth of asingle fiber andits capabilitytosupport transparent datatransmissions. However , with the emergence of allkinds of applications such as data ,voice ,the next-gen-eration network must also be designedto provide … 相似文献
62.
A general throughput property of tandem queueing networks with blocking that relates existing decomposition methods to throughput bounds is discussed using the sample path approach. 相似文献
63.
Due to power considerations, it is possible that not all wavelengths available in a fiber can be used at a given time. In this paper, an analytical model is proposed to evaluate the blocking performance of wavelength-routed optical networks with and without wavelength conversion where the usable wavelengths in a fiber is limited to a certain maximum number, referred to as wavelength usage constraint. The effect of the wavelength usage constraint is studied on ring and mesh-torus networks. It is shown that the analytical model closely approximates the simulation results. We also evaluate the performance of the first-fit wavelength assignment algorithm and compare its performance with the random wavelength assignment algorithm through simulation. It is observed that increasing the total number of wavelengths in a fiber is an attractive alternative to wavelength conversion when the number of usable wavelengths in a fiber is maintained the same. 相似文献
64.
TheT(1) theorem with a weak condition on the distribution kernel is proved by using a new method—blocking analysis. It improves
a result of Meyer’s.
Project supported by the National Natural Science Foundation of China (Grant No. 19631080) and the Foundation of Advanced
Research Center, Zhongshan University. 相似文献
65.
Calls arrive at a switch, where they are assigned to any one of the available idle outgoing links. A call is blocked if all the links are busy. A call assigned to an idle link may be immediately lost with a probability which depends on the link. For exponential holding times and an arbitrary arrival process we show that the conditional distribution of the time to reach the blocked state from any state, given the sequence of arrivals, is independent of the policy used to route the calls. Thus the law of overflow traffic is independent of the assignment policy. An explicit formula for the stationary probability that an arriving call sees the node blocked is given for Poisson arrivals. We also give a simple asymptotic formula in this case.Work on this paper was done while the author was at Bellcore and at Berkeley. 相似文献
66.
Spectrum efficiency is a constant challenge in the design of wireless networks. Space-division-multiple-access (SDMA) is a
promising approach to achieve higher spectral efficiency which reuses bandwidth via multiplexing signals based on their spatial
signature. Several different studies have shown that SDMA can effectively improve system capacity in a mobile environment.
In this paper, we present a new Markov chain traffic model for a duplicate-at-last (DL) approach [IEE Proceedings on Communication
146 (1999) 303] in two-fold and three-fold SDMA systems. Simplified blocking probability formulations for two-fold and three-fold
SDMA are also derived. Simulations based on a common method of spatial separation check for channel allocation in SDMA are
presented to evaluate the probability of successfully creating two-fold and three-fold SDMA channels. The simulation, as well
as analytical, results indicate that the SDMA system can reduce the blocking probability of the calls and result in more traffic
loading than a traditional cellular system. The results also show that our simplified approaches not only can reduce the computational
complexity, but can also accurate approximate two-fold and three-fold SDMA performance.
Wen-Jye Huang received the B.S. degree in electrical engineering from Tatung Institute of Technology, Taipei, Taiwan, in 1991, the M.S.
degree in electrical engineering from Ohio University, Athens, OH, in 1997, and the Ph.D. degree in electrical engineering
from The Pennsylvania State University, University Park, PA, in 2001.
Since 2002, he joined the Department of Electrical Engineering, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan, as an assistant
professor. His research activities include smart antenna, SDMA, and MC-CDMA techniques.
John F. Doherty received the B.S. degree (with honors) in engineering science from the College of Staten Island, City University of New York,
in 1982, the M.Eng. degree in electrical engineering from Stevens Institute of Technology, Hoboken, NJ, in 1985, and the Ph.D.
degree in electrical engineering from Rutgers University, New Brunswick, NJ, in 1990. He was an integrated circuit reliability
engineer with IBM, from 1982 to 1984. From 1985 to 1988, he was member of the technical staff at AT&T Bell Laboratories, working
in sonar signal processing.
In 1990, he joined the Electrical and Computer Engineering Department, Iowa State University, Ames, as an assistant professor
and Harpole Entair fellow. He is currently an associate professor of electrical engineering with The Pennsylvania State University,
University Park. His current research activities include interference rejection in wireless communication systems, spatial-division
multiple-access techniques, and radar target detection techniques. He is a former AFOSR summer faculty research fellow at
the Rome Laboratory, Rome, NY, and an Army Research Office Young Investigator. 相似文献
67.
Delay-on-Demand: A Signaling Protocol to Reduce Blocking Probability in Optical Burst-Switching Networks 总被引:2,自引:0,他引:2
Optical burst switching (OBS) is emerging as one promising switching paradigm for the next generation optical networks. To support multiple services in burst-switching networks, the OBS paradigm should support some quality-of-service (QoS) provisioning. A major design issue in such networks is to reduce the blocking probability of the bursts arising due to resource contention at the intermediate core router. In this paper, we propose a signaling protocol which we call ‘Delay-on-Demand’ (OBS-DoD), to reduce blocking probability and support QoS in optical burst-switching networks. The proposed scheme guarantees that at least one of the bursts succeeds depending on its priority, propagation delay from the ingress router, and the burst-size when contention occurs at the core router. For this, we use a control packet to delay, in case of a contention, the transmission of bursts at the ingress router. We compare the performance of our proposal, by simulation, with an earlier proposed scheme, and show that the proposed OBS-DoD outperforms the earlier scheme in reducing the blocking probability. For simulation, we generated bursty traffic using an M/Pareto distribution. 相似文献
68.
Tams Sznyi Antonello Cossidente Andrs Gcs Csaba Mengyn Alessandro Siciliano Zsuzsa Weiner 《组合设计杂志》2005,13(1):25-41
The size of large minimal blocking sets is bounded by the Bruen–Thas upper bound. The bound is sharp when q is a square. Here the bound is improved if q is a non‐square. On the other hand, we present some constructions of reasonably large minimal blocking sets in planes of non‐prime order. The construction can be regarded as a generalization of Buekenhout's construction of unitals. For example, if q is a cube, then our construction gives minimal blocking sets of size q4/3 + 1 or q4/3 + 2. Density results for the spectrum of minimal blocking sets in Galois planes of non‐prime order is also presented. The most attractive case is when q is a square, where we show that there is a minimal blocking set for any size from the interval . © 2004 Wiley Periodicals, Inc. J Combin Designs 13: 25–41, 2005. 相似文献
69.
In this paper we study Markovian queueing networks in which the service and the routing characteristics have a particular
form which leads to a product form stationary distribution for the number of customers in the various queues of the network.
We show that if certain transitions are prohibited due to blocking conditions, then the form of the stationary distribution
is preserved under a certain rerouting protocol. Several examples are presented which illustrate the wide applicability of
the model.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
70.
This paper focuses on the mechanism of Blocking Before Service (BBS), in time-varying many-server queues in tandem. BBS arises in telecommunication networks, production lines and healthcare systems. We model a stochastic tandem network under BBS and develop its corresponding fluid limit, which includes reflection due to jobs lost. Comparing our fluid model against simulation shows that the model is accurate and effective. This gives rise to design/operational insights regarding network throughput, under both BBS and BAS (Blocking After Service). 相似文献