Buffer Management Schemes for Supporting TCP in Gigabit Routers With Per-Flow Queueing

  • Choudhury A.
  • Lakshman T.
  • Stiliadis D.
  • Suter B.

(PREVIOUS TITLE: DESIGN CONSIDERATIONS FOR SUPPORTING TCP WITH PER-FLOW QUEUEING) Recently much research attention has been focused on the use of fair queueing schemes as a means for guaranteeing end-to-end delay bounds. Studies in this context have primarily been for non-feedback-controlled leaky bucket policed traffic. In this paper, we investigate ...

Voice Over ATM Using AAL2 and Bit Dropping: Performance and Call Admission Control

  • Sriram K.
  • Wang Y.

ATM Adaptation Layer 2 (AAL2) has been designed for efficient transport of voice, facsimile (FAX), and voiceband data (VBD) traffic over ATM land-line and wireless networks. The protocol helps achieve low latency and high bandwidth efficiency while applying suitable compression methods on voice/VBD/FAX calls and digital speech interpolation (DSI) on ...

RAKE Receiver Finger Assignment in CDMA Terminals with Fractionally Spaced Multipaths

  • Balachandran K.
  • Chang K.
  • Rege K.

CDMA mobile handsets use a RAKE receiver for pilot assisted demodulation. The RAKE receiver has multiple demodulators, called fingers, which can be used to demodulate distinct multipath components in parallel making it possible to implement diversity reception in the handsets. Typical analyses of the performance of CDMA handsets assume these ...

Pilot Measurement and Synchronization for Wireless Code Division Multiple Access Systems

  • Balachandran K.
  • Chang K.
  • Rege K.

Pilot measurement is a key function of a CDMA mobile terminal. This process is used to detect the presence of multipath components which may be demodulated using a RAKE receiver. The same process is also used to sense strong neighbor pilots so that the mobile may initiate a soft handoff ...

Maintaining Transitive Closure of Graphs in SQL

  • Dong G.
  • Libkin L.
  • Su J.
  • Wong L.

It is common knowledge that relational calculus and even SQL are not expressive enough to express recursive queries such as the transitive closure. In a real database system, one can overcome this problem by storing a graph together with its transitive closure and maintaining the latter whenever updates to the ...

Simultaneous CW Operation of Shared Angular Dispersive Element WDM Lasers

  • Doerr C.
  • Joyner C.
  • Monnard R.
  • Stulz L.

We show that when more than two channels operate continuous-wave simultaneously in shared dispersive element wavelength-division-multiplexing lasers with uniform channel spacing, chi sup ((3)) in the passive shared waveguide can cause spontaneous fluctuations in frequency and power. We propose the simple cure of making the shared waveguide extremely short. We ...

Novel Fabrication of C-Doped Base InGaAs/InP DHBT Structures for High Speed Circuit Applicaitons

  • Burm J.
  • Chen Y.
  • Georgiou G.
  • Geva M.
  • Hamm R.
  • Kopf R.
  • Lang D.
  • Malik R.
  • Ren F.
  • Ryan R.
  • Tate A.

We have fabricated InGaAs/InP based DHBTs for high speed circuit applications. A process involving both wet chemical and ECR plasma etching was developed. Carbon was employed as the p-type dopant of the base layer for excellent device stability. Both the emitter-base and base-collector regions were graded using quaternary InGaAsP alloys. ...

Joint Block-Based Video Source/Channel Coding for Packet-Switched Networks

  • Hinds R.
  • Lim J.
  • Pappas T.

Block-based video coders rely on motion compensated block prediction for more data compression. With the introduction of video coding over packet-switched networks such as the Internet and the resulting packet loss that occurs on congested networks, coding mode selection for each macro-block is significant in determining the overall distortion on ...

Design and Implementation of Triveni: A Process-algebraic API for Threads + Events

  • C. Colby
  • C. Puchol
  • Jagadeesan L.
  • K. Laufer
  • R. Jagadeesan

Current programming practice with threads does not directly support compositional software design. This paper aims to solve this problem and enhance the practice of threads programming with ideas from the theory of concurrency. We present Triveni, a framework and API for integrating threads and events. Design: Triveni is based on ...

Performance and Fluid Simulations of a Novel Shared Buffer Management System

  • Kumaran K.
  • Mitra D.

We consider a switching system which has multiple ports that share a common buffer, in which there is a FIFO logical queue for each port. Each port may support a large number of flows or connections, which are approximately homogeneous in their statistical characteristics, with common QoS requirements in cell ...

Objects and Concurrency in Triveni: A Telecommunication Case Study in Java

  • Colby C.
  • Jagadeesan L.
  • Jagadeesan R.
  • Laufer K.
  • Puchol C.

A key shortcoming in current thread programming models is the lack of support for a notion of abstract behavior, which in a concurrent system is essentially the interaction of the system with its environment. Concretely, let use suppose one is given R, a computer model of a room, that emits ...

Automatically Closing Open Reactive Programs

  • Colby C.
  • Godefroid P.
  • Jagadeesan L.

We study in this paper the problem of analyzing implementations of open systems - systems in which only some of the components are present. We present an algorithm for automatically closing an open concurrent reactive system with its most general environment, i.e., the environment that can provide any input at ...

Embedded Finite Models, Stability Theory, and the Impact of Order

  • Benedikt M.

We show that the expressive power of the relational calculus over finite models embedded in a model M is determined by stability-theoretic properties of M. In particular, we show that if M is stable, then every class of finite structures that can be defined by embedding the structures in M, ...

Workflow Systems: Occasions for Success and Failure

  • Grinter R.

Workflow technologies have created considerabel discussion within the computer supported cooperative work community. ALthough a number of theoretical and empirical warnings about the difficulties of workflow systems have appeared the technologies continue to be built and sold. This paper examines the use of one workflow-like system and outlines three cases ...

The Maximum of a Random Walk and Its Application to Rectangle Packing

  • Coffman E.
  • Flagolet P.
  • Flatto L.
  • Hofri M.

Let S sub o, ..., S sub n be a symmetric random walk that starts at the origin (S sub o = O), and takes steps uniformly distributed on [-1, +1]. We study the large-n behavior of the expected maximum excursion and prove the estimate E max over o<=k<=n S ...

Elastic Bending of a Composite Revisit and Comments on Stoney's Equation

  • Chu S.

Since Stoney derived a simple relationship between the stress of a thin film and the curvature of its substrate for an electrolytically deposited metallic film on a thick substrate plate in 1909, the equation has been widely used by electro-chemists to calculate stresses in electrolytically deposited films. Although the equation ...

Probability of Detection of Residual Echo Based on Magnitude-Squared Coherence Estimate

  • Sui C.

Residual echo is a distorted, partially-canceled, and transient echo of the near-end speech signal returned from the remote network. Previous work [2] has shown that residual echo can be detected and reduced by using a nonlinear processing technique based on frequency coherence. In this paper a mathematical approach to evaluate ...

Interoperation of Copy Avoidance in Network and File I/O

  • Brustoloni J.

Copy avoidance techniques for network I/O often assume that server buffers are ephemeral (i.e., are deallocated as soon as I/O processing completes). Such techniques cannot be used for file I/O, where buffers may need to be cached long-term. Mapped file I/O, however, can easily provide copy avoidance for cached server ...

The Space Complexity of Approximating the Frequency Moments

  • Alon N.
  • Matias Y.

The frequency moments of a sequence containing m, elements of type i, for 1 <- i <- n, are the numbers F sub k = sum from n to i=1 m sup k sub i. We consider the space complexity of randomized algorithms that approximate the numbers F sub k, ...

A Probabilistic Approach to Some Asymptotics in Noiseless Communication

  • Savari S.

Renewal theory is a powerful tool in the analysis of source codes. In this paper, we use renewal theory to obtain some asymptotic properties of finite-state noiseless channels. We discuss the relationship between these results and earlier uses of renewal theory to analyze the Lempel- Ziv codes and the Tunstall ...