Organizing Multicast Receivers Deterministically According to Packet-Loss Correlation

  • Garcia-Luna-Aceves J.
  • Levine B.
  • Paul S.

The ability to trace multicast paths is currently available in the Internet by means of IGMP MTRACE packets. We introduce Tracer, the first protocol that organizes the receivers of a multicast group deterministically while maintaining exact packet-loss correlation for local error recovery, and without requiring any changes to existing multicast ...

Resource Allocation in Multicast Trees

  • Kodialam M.
  • Low S.

Mechanisms have been designed to perform resource reservation in a multicast tree in order to provide quality of service. In this paper, we consider how to allocate bandwidth in a multicast tree so as to optimize some global measure of performance. In our model each receiver has a budget to ...

Chip-Level Verification for Parasitic Coupling Effects in Deep-Submicron Digital Designs

  • Chadha R.
  • Chang F.
  • Feldmann P.
  • Ye L.

Interconnect parasitics are playing a dominant role in determining chip performance and functionality in deep-submicron designs. This problem is compounded by increasing chip frequencies and design complexity. As parasitic coupling capacitances are a significant portion of total capacitance in deep-submicron designs, verification of both performance and functionality assumes greater importance. ...

Modeling Mobile IP in Mobile UNITY

  • Mccann P.
  • Roman G.

With recent advances in wireless communication technology, mobile computing is an increasingly important area of research. A mobile system is one where independently executing components may migrate through some space during the course of the computation, and when the pattern of connectivity among the components changes as they move in ...

Physics and the Communications Industry

  • Brinkman W.
  • Lang D.

This review explores the relationship between physics and communications over the past 125 years. We find that four eras of major change in communications technology can be traced to the corresponding major discoveries of physics that directly influenced the communications industry. The four major eras of physics we explore are ...

Nonmonotonic Behavior in Hard-Core and Widom-Rowlinson Models

  • Brightwell G.
  • Haggstrom O.
  • Winkler P.

We give two examples of nonmonotonic behavior in symmetric systems, exhibiting more than one critical point at which spontaneous symmetry-breaking appears or disappears. The two systems are the hard-care model and the Widom-Rowlinson model, and both examples take place on a variation of the Cayley tree (Bethe lattice) devised by ...

Gibbs Measures and Dismantlable Graphs

  • Brightwell G.
  • Winkler P.

We model physical systems with "hard constraints" by the space hom (G,H) of homomorphisms from a locally finite graph G to a fixed finite constraint graph H. Two homomorphisms are deemed to be adjacent if they differ on a single site of G. We investigate what appears to be a ...

Information Rich Glyphs for Software Management Data

  • Chuah M.
  • Eick S.

Perhaps the most challenging engineering task in modern times involves the construction of large software systems. Managing large software projects requires the tracking and scheduling of many resources and understanding complex tradeoffs. To help with this task, we have developed three high-dimensional glyphs for viewing software project management data. The ...

Robust Dynamic Admission Control for Unified Cell and Call QoS in Statistical Multiplexers

  • Mitra D.
  • Reiman M.
  • Wang J.

The design of connection admission control (CAC) for a simple Markovian model of a multiservice statistical multiplexer is considered. The paper begins by laying the foundation through several fundamental analytic concepts, such as a Semi-Markov Decision Process formulation of the design problem and time scale decomposition, before progressively leading up ...

Virtual Partitioning for Robust Resource Sharing: Computational Techniques for Heterogeneous Traffic

  • Borst S.
  • Mitra D.

We consider Virtual Partitioning (VP), a scheme for sharing a resource among several traffic classes in an efficient, fair, and robust manner. In the preliminary design stage, each traffic class is allocated a nominal capacity, which is based on expected offered traffic and required quality-of-service. During operatings, if the current ...

An Objective Technique for Evaluating Doubletalk Detectors in Acoustic Echo Cancelers

  • Benesty J.
  • Cho J.
  • Morgan D.

Echo cancelers commonly employ a doubletalk detector (DTD), which is essential to keep the adaptive filter from diverging in the presence of near-end speech and other disruptive noise. There have been numerous algorithms to detect doubletalk in an acoustic echo canceler (AEC). In these applications, typically, the threshold is chosen ...

Validating Requirements for Fault Tolerant Systems using Model Checking

  • Holzmann G.

Model checking is shown to be an effective tool in validating the behavior of a fault tolerant embedded spacecraft controller. The case study presented here shows that by judiciously abstracting away extraneous complexity, the state space of the model could be exhaustively searched allowing critical functional requirements to be validated ...

Correlated Shadow-Fading in Wireless Networks and Its Effect on Call Dropping

  • Borst S.
  • Golowich S.
  • Kumaran K.

We discuss a statistical model to generate correlated shadow-fading patterns for wireless systems in the absence of detailed propagation and landscape information. The currently available autocorrelation models result in anomalous effects that depend on traffic density and mobility as they propose independent random processes for each mobile. Our approach involves ...

Does Code Decay? Assessing the Evidence from Change Management Data

  • Eick S.
  • Graves T.
  • Karr A.
  • Marron J.
  • Mockus A.

A central feature of the evolution of large software systems is that change--which is necessary to add new functionality, accommodate new hardware and repair faults--becomes increasingly difficult over time. In this paper, we approach this phenomenon, which we term code decay, scientifically and statistically. We define code decay, and propose ...

A New Class of Doubletalk Detectors Based on Cross-Correlation

  • Benesty J.
  • Cho J.
  • Morgan D.

A doubletalk detector (DTD) is used with an echo canceler to sense when far-end speech is corrupted by near-end speech. Its role is to freeze the adaptation of the model filter when near-end speech is present, in order to avoid divergence of the adaptive algorithm. Several authors have proposed to ...

Image and Video Coding

  • Girod B.
  • Gray R.
  • Kovacevic J.
  • Vetterli M.

Due to the vast amount of data associated with images and video, compression is a key technology for their transmission and storage. The availability and demand for images and video continue to outpace increases in network capacity. Hence, the importance of compression is not likely to diminish, in spite of ...

Fundamental Limit on "Interaction Free" Measurements

  • Platzman P.
  • Simon S.

In "interaction free"measurements, one typically wants to detect the presence of an object without touching it with even a single photon. One often imagines a bomb whose trigger is an extremely sensitive measuring device whose presence we would like to detect without triggering it. We point out that all such ...

Wavelet Families of Increasing Order in Arbitrary Dimensions

  • Kovacevic J.
  • Sweldens W.

We build compactly supported biorthogonal wavelets and perfect reconstruction filter banks for any lattice in any dimension with any number of primal and dual vanishing moments. The resulting scaling functions are interpolating. Our construction relies on the lifting scheme and inherits all of its advantages: fast transform, in-place calculation, and ...

Detection and Recovery Techniques for Database Corruption

  • Bohannon P.
  • Rastogi R.
  • Sadarshan S.
  • Seshadri S.
  • Silberschatz A.

(PREVIOUS TITLE: Detecting and Recovering from Data Corruption) Increasingly, for extensibility and performance, special purpose application code is being integrated with database system code. Such application code has direct access to the database system buffers, and as a result, the danger of these applications causing data corruption due to inadvertent ...

Performance Issues in VC-Merge Capable Switches for Multiprotocol Label Switching

  • Elwalid A.
  • Widjaja I.

(PREVIOUS TITLE: PERFORMANCE ISSUES IN VC-MERGE CAPABLE SWITCHES FOR IP OVER ATM NETWORKS) A VC-merge capable ATM switch is one of the most promising solutions to eliminating forwarding bottleneck in the Internet. VC merging allows many routes to be mapped to the same VC label, thereby providing a scalable mapping ...