Browsing by Subject "Asynchronous transfer mode"
Now showing 1 - 11 of 11
Results Per Page
Sort Options
Item Open Access An approach to manage connectionless services in connection-oriented networks(IEEE, 1996) Abdelatı, Muhammed; Arıkan, ErdalIn this work we propose a pricing scheme which serves as an instrument for managing connectionless services in connection-oriented communication networks. The scheme is able to allocate network bandwidth in a Pareto-optimal way that maximizes the total surplus. The key idea is to decompose the service provision procedure among three separate parties whose interactions are governed by a set of competitive pricing mechanisms.Item Open Access Markov modulated periodic arrival process offered to an ATM multiplexer(IEEE, 1993-11-12) Akar, Nail; Arıkan, ErdalWhen a superposition of on/off sources is offered to a deterministic server, a particular queueing system arises whose analysis has a significant role in ATM based networks. Periodic cell generation during active times is a major feature of these sources. In this paper a new analytical method is provided to solve for this queueing system via an approximation to the transient behavior of the nD/D/1 queue. The solution to the queue length distribution is given in terms of a solution to a linear differential equation with variable coefficients. The technique proposed here has close similarities with the fluid flow approximations and is amenable to extension for more complicated queueing systems with such correlated arrival processes. A numerical example for a packetized voice multiplexer is finally given to demonstrate our results.Item Open Access Markov modulated periodic arrival process offered to an ATM multiplexer(Elsevier BV * North-Holland, 1995-04) Akar, N.; Arıkan, E.When a superposition of on/off sources is offered to a deterministic server, we are faced with a particular queueing system, the analysis of which has a significant role in ATM networks. Periodic cell generation during active times is a major feature of these sources. We provide an analytical approach to solve for this queueing system via an approximation to the transient behavior of the nD/D/1 queue. The solution to the queue length distribution is given in terms of a solution to a linear differential equation with variable coefficients. The technique proposed here has close similarities with the fluid flow approximation and is amenable to extension for more complicated queueing systems with such correlated arrival processes. A numerical example for a packetized voice multiplexer is finally given to demonstrate our results.Item Open Access Matrix-geometric solutions of M/G/1-type Markov chains: A unifying generalized state-space approach(1998) Akar, N.; Oǧuz, N.C.; Sohraby, K.In this paper, we present an algorithmic approach to find the stationary probability distribution of M/G/1-type Markov chains which arise frequently in performance analysis of computer and communication networ ks. The approach unifies finite- and infinite-level Markov chains of this type through a generalized state-space representation for the probability generating function of the stationary solution. When the underlying probability generating matrices are rational, the solution vector for level k, x k, is shown to be in the matrix-geometric form x k+1 = gF k H, k ≥ 0, for the infinite-level case, whereas it takes the modified form x k+1 = g 1F 1 kH 1 + g 2F 2 K-k-1 H 2, 0 ≤ k < K, for the finite-level case. The matrix parameters in the above two expressions can be obtained by decomposing the generalized system into forward and backward subsystems, or, equivalently, by finding bases for certain generalized invariant subspaces of a regular pencil λE - A. We note that the computation of such bases can efficiently be carried out using advanced numerical linear algebra techniques including matrix-sign function iterations with quadratic convergence rates or ordered generalized Schur decomposition. The simplicity of the matrix-geometric form of the solution allows one to obtain various performance measures of interest easily, e.g., overflow probabilities and the moments of the level distribution, which is a significant advantage over conventional recursive methods.Item Open Access Performance analysis of two-level forward error correction for lostcell recovery in ATM networks(IEEE, 1995-04) Oğuz, Nihat Cem; Ayanoğlu, E.The major source of errors in B-ISDN/ATM systems is expected to be buffer overflow during congested conditions, resulting in ATM cell losses which degrade the quality of service. It has been shown by many authors that the performance of the end-to-end system can be made much less sensitive to cell loss by means of forward error correction. This paper discusses the use of a two-level forward error correction scheme for virtual channel and virtual path connections in ATM networks. The scheme exploits simple block coding and code interleaving simultaneously. The simple block, interleaved, and joint coding schemes are studied and analyzed by using a novel and accurate discrete-time analytical method which enables the burstiness of cell losses be captured precisely. Detailed performance calculations, which indicate that it is possible to reduce the cell loss rate by several orders of magnitude over a wide range of network load for various traffic conditions, are discussed, and compared with simulation results. The comparisons show that the method is very accurate for bursty traffic. The advantages of the three coding techniques are quantified for different traffic characteristics and scenarios © Copyright 2009 IEEE - All Rights Reserved.Item Open Access Rerouting for handoffin in a wireless ATM network(1996) Akyol, B.A.; Cox, D.C.Handoff is the procedure by which a user's radio link is transferred between radio ports in the network without an interruption of the user connection. In this article, we discuss how a wireless asynchronous transfer mode (ATM) network may reroute a user connection during a handoff. The authors propose a novel procedure called "Nearest Common Node Rerouting (NCNR)." NCNR is designed to perform the rerouting of user connections due to a handoff event in a fast and efficient manner. The authors conclude by comparing NCNR to other rerouting schemes discussed in the literature.Item Open Access A scheme for handling connectionless services in connection-oriented networks(The Institute of Electronics, Information and Communication Engineers, 1997-10-25) Abdelati, M.; Arikan, E.In this work we propose a pricing scheme which serves as an instrument for managing connectionless services in connection-oriented communication networks. The scheme is able to allocate network bandwidth in a Pareto-optimal way that maximizes the total surplus. The key idea is to decompose the service provision procedure among three separate parties whose interactions are governed by a set of competitive pricing mechanisms.Item Open Access Signaling alternatives in a wireless ATM network(1997) Akyol, B.A.; Cox, D.C.The world of wireless telecommunications is rapidly changing. The capabilities of wireless networks are improving at a steady pace. This paper presents two possible protocols for implementing mobility for wireless users in an asynchronous transfer mode (ATM) network. The vision of the authors is of one "wireless ATM telecommunications network" that is capable of supporting a variety of today's applications with room to grow for advanced applications of the future. We first visit database architectures that can support mobility in a wireless ATM network. We then discuss one of two signaling architecture alternatives, the "overlay signaling," for overlay support of mobile users in the ATM-based wireless telecommunications network. "Overlay signaling" aims at minimizing the modification needed to the existing ATM protocols. We then describe a native "migratory signaling" approach that further integrates wireless and wireline users into one global wireless ATM network at the expense of requiring some modifications to the existing ATM protocols. A performance analysis of the proposed signaling architecture alternatives is also presented. We conclude by pointing out some challenges in merging ATM with wireless telecommunications.Item Open Access A simulation study of two-level forward error correction for lost packet recovery in B-ISDN/ATM(IEEE, 1993) Oğuz, Nihat Cem; Ayanoğlu, E.The major source of errors in B-ISDN/ATM systems is expected to be buffer overflow during congested conditions, resulting in lost packets. A single lost or errored ATM cell will cause retransmission of the entire packet data unit (PDU) that it belongs to. The performance of the end-to-end system can be made much less sensitive to cell loss by means of forward error correction. In this paper, we present the results of a simulation study for an ATM network where forward error correction is performed at both the cell level and the PDU level. The results indicate that (i) cell losses are highly correlated in time, and analytical models ignoring this fact will not yield accurate results, (ii) the correlation of cell losses is similar to burst errors in digital communication, and similar code interleaving techniques should be used, (iii) coding cells and PDUs separately provides this interleaving effect, and this joint code outperforms coding only at the cell level or only at the PDU level in almost all cases simulated.Item Open Access Uniform weighted round robin scheduling algorithms for input queued switches(IEEE, 2001-06) Rai, Idris A.; Alanyalı, MuratThis paper concentrates on obtaining uniform weighted round robin schedules for input queued packet switches. The desired schedules are uniform in the sense that each connection is serviced at regularly spaced time slots, where the spacing is proportional to the inverse of the guaranteed data rate. Suitable applications include ATM networks as well as satellite switched TDMA systems that provide per packet delay guarantees. Three heuristic algorithms are proposed to obtain such schedules under the constraints imposed by the unit speedup of input queued switches. Numerical experiments indicate that the algorithms have remarkable performance in finding uniform schedules.Item Open Access Wireless ATM: limits, challenges, and proposals(Institute of Electrical and Electronics Engineers, 1996) Ayanoglu, E.; Eng, K. Y.; Karol, M. J.Recently, there has been an increased interest in the topic of "wireless ATM." The subject matter raises interest due to the potential combination of two of the hottest topics in communications of the mid-'90s, but at the same time raises a natural question as to its viability, and sometimes even its desirability. In this article the authors survey potential applications of wireless ATM and describe what is usually meant by wireless ATM, why it may make sense, and some of the proposals to build systems based on it. The emphasis in this article is on the physical layer, the data link layer, and the access layer. The authors also present general observations on each of these layers, and some research solutions to these problems. Mobility issues and interoperability with the existing networks are addressed. Finally, the authors list some of the proposals to build wireless ATM systems from the literature.