Massachusetts Institute of Technology

Displaying 161-200 of 443 results

  • White Papers // Jan 2011

    Targeting The Poor: Evidence From A Field Experiment In Indonesia

    This paper reports an experiment in 640 Indonesian villages that investigated three approaches to targeting the poor: Proxy-Means Tests (PMT), where a census of assets is used to predict consumption; community targeting, where villagers rank everyone from richest to poorest; and a hybrid. Defining poverty based on PPP$2 per-capita consumption,...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    The Portuguese High Speed Rail Network; Relating Financing To Strategic And Operating Issues

    This paper describes the implementation of the Portuguese High Speed Rail (HSR) Network. The business model developed by RAVE for the PPP's related with the HSR infrastructure is described and discussed. Following a recently awarded research project (EXPRESS) aimed at studying the strategic aspects related with the implementation of HSR...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Frequency Estimation of Internet Packet Streams With Limited Space

    The authors consider a router on the Internet analyzing the statistical properties of a TCP/IP packet stream. A fundamental difficulty with measuring traffic behavior on the Internet is that there is simply too much data to be recorded for later analysis, on the order of gigabytes a second. As a...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Performance of Multihop Wireless Networks: Shortest Path Is Not Enough

    Existing wireless ad hoc routing protocols typically find routes with the minimum hop-count. This paper presents experimental evidence from two wireless test-beds which shows that there are usually multiple minimum hop-count paths, many of which have poor throughput. As a result, minimum-hop-count routing often chooses routes that have significantly less...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Peering Peer-To-Peer Providers

    The early peer-to-peer applications eschewed commercial arrangements and instead established a grass-roots model in which the collection of end-users provided their own distributed computational infrastructure. While this cooperative end-user approach works well in many application settings, it does not provide a sufficiently stable platform for certain peer-to-peer applications (e.g., DHTs...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Geographic Routing Without Planarization

    The authors present a new geographic routing algorithm, the Greedy Distributed Spanning Tree Routing (GDSTR), that finds shorter routes and generates less maintenance traffic than previous algorithms. While geographic routing potentially scales well, it faces the problem of what to do at local dead ends where greedy forwarding fails. Existing...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Pastwatch: A Distributed Version Control System

    Pastwatch is a version control system that acts like a traditional client-server system when users are connected to the network; users can see each other's changes immediately after the changes are committed. When a user is not connected, Pastwatch also allows users to read revisions from the repository, commit new...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Proactive Replication for Data Durability

    Many wide area storage systems replicate data for durability. A common way of maintaining the replicas is to detect node failures and respond by creating additional copies of objects that were stored on failed nodes and hence suffered a loss of redundancy. Reactive techniques can minimize total bytes sent since...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    F2F: Reliable Storage in Open Networks

    A major hurdle to deploying a distributed storage infrastructure in peer-to-peer systems is storing data reliably using nodes that have little incentive to remain in the system. The authors argue that a node should choose its neighbors (The nodes with which it shares resources) based on existing social relationships instead...

    Provided By Massachusetts Institute of Technology

  • White Papers // Dec 2010

    Demonstration of Multi-Robot Search and Secure

    The authors consider the search and secure problem, where intruders are to be detected in a bounded area without allowing them to escape. The problem is tackled by representing the area to be searched as a traversability graph, which is reduced to a tree graph by placing stationary robots to...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Dec 2010

    Mathematics, Common Sense, And Good Luck: My Life And Careers

    Don't expect to glean any market tips or trading secrets from the author, who steadfastly refuses to disclose the method behind his remarkable record in investing. Instead, listen to this mathematician, hedge fund manager and philanthropist sum up a remarkably varied and rich career, and offer some "Guiding principles" distilled...

    Provided By Massachusetts Institute of Technology

  • White Papers // Dec 2010

    Heracles: Fully Synthesizable Parameterized MIPS-Based Multicore System

    Heracles is an open-source complete multicore system written in Verilog. It is fully parameterized and can be reconfigured and synthesized into different topologies and sizes. Each processing node has a 7-stage pipeline, fully bypassed, microprocessor running the MIPS-III ISA, a 4-stage input-buffer, virtual-channel router, and a local variable-size shared memory....

    Provided By Massachusetts Institute of Technology

  • Webcasts // Dec 2010

    Perceptive Mobile Robots Working Safely Alongside Humans

    Although we are still far from the moment of singularity, or even Star Wars 'Droids, we can anticipate robot colleagues in the near future, believes by the author. The author is developing 'Situationally aware' machines to help out humans in those "Unstructured environments?where we live, work and recreate."

    Provided By Massachusetts Institute of Technology

  • Webcasts // Dec 2010

    Relaunching Growth In Europe

    The presenter finds it difficult to witness the calamitous decline of Spain, a nation he led to robust economic health as prime minister from 1996 to 2004. The gains during his administration have vanished following the international financial crisis. But the economic misfortunes of Spain and other European nations are...

    Provided By Massachusetts Institute of Technology

  • White Papers // Dec 2010

    Compressive Sensing Over Networks

    In this paper, the authors demonstrate some applications of compressive sensing over networks. They make a connection between compressive sensing and traditional information theoretic techniques in source coding and channel coding. The results provide an explicit trade-off between the rate and the decoding complexity. The key difference of compressive sensing...

    Provided By Massachusetts Institute of Technology

  • White Papers // Dec 2010

    Price Of Airline Frequency Competition

    Frequency competition influences capacity allocation decisions in airline markets and has important implications to airline profitability and airport congestion. Market share of a competing airline is a function of its frequency share and the relationship between the two is pivotal for understanding the impacts of frequency competition on airline business....

    Provided By Massachusetts Institute of Technology

  • White Papers // Nov 2010

    Scalable Directoryless Shared Memory Coherence Using Execution Migration

    The authors introduce the concept of deadlock-free migration-based coherent shared memory to the NUCA family of architectures. Migration-based architectures move threads among cores to guarantee sequential semantics in large multicores. Using an Execution Migration (EM) architecture, the authors achieve performance comparable to directory-based architectures without using directories: avoiding automatic data...

    Provided By Massachusetts Institute of Technology

  • White Papers // Nov 2010

    How to Tell if Your Cloud Files Are Vulnerable to Drive Crashes

    This paper presents a new challenge - verifying that a remote server is storing a file in a fault-tolerant manner, i.e., such that it can survive hard-drive failures. The authors describe an approach called the Remote Assessment of Fault Tolerance (RAFT). The key technique in a RAFT is to measure...

    Provided By Massachusetts Institute of Technology

  • White Papers // Nov 2010

    "Whither Industrial Relations: Does It Have A Future In Post-Industrial Society"

    Industrial relations are in trouble. It is in trouble both as a set of institutions and practices, linked to trade unions and collective bargaining and as a scholarly endeavor. The title of talk here, which the author was obliged to provide long in advance, is essentially a place holder for...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Nov 2010

    Communications In Slow-Moving Crises

    What's a journalist to do when a major story must be coaxed reluctantly into public view, or emerges on what seems like a geological time scale? These panelists discuss how to approach slowly evolving but urgent stories at a time when news coverage has shifted inexorably from print and its...

    Provided By Massachusetts Institute of Technology

  • White Papers // Nov 2010

    Whither Industrial Relations: Does It Have A Future In Post-Industrial Society

    Industrial relations are in trouble. It is in trouble both as a set of institutions and practices, linked to trade unions and collective bargaining and as a scholarly endeavor. The title of talk here, which the author was obliged to provide long in advance, is essentially a place holder for...

    Provided By Massachusetts Institute of Technology

  • White Papers // Nov 2010

    Algebraic Watchdog: Mitigating Misbehavior in Wireless Network Coding

    The authors propose a secure scheme for wireless network coding, called the algebraic watchdog. By enabling nodes to detect malicious behaviors probabilistically and use overheard messages to police their downstream neighbors locally, the algebraic watchdog delivers a secure global self-checking network. Unlike traditional Byzantine detection protocols which are receiver based,...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Nov 2010

    The Financial Crisis, The Recession, And The American Political Economy: A Systemic Perspective

    The author shows how useful a varied background in math, political science and business can be, as he dissects the complexities and recent crisis of the U.S. financial system. In a lecture that distills many of the arguments of his recent film, Inside Job, the author conveys dispassionately yet persuasively...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Nov 2010

    The Future Is Gray, Small & Female: Disruptive Demographics And Transportation Tomorrow

    If the prospect of aging and infirmity seems remote, you could use some time with AGNES (Age Gain Now Empathy System), a wearable apparatus that approximates "What it feels like to be a 75-year-old woman."

    Provided By Massachusetts Institute of Technology

  • White Papers // Nov 2010

    Mixed Context and Privacy

    Users engaging Online Service Providers (OSPs) such as Google, Amazon, and Facebook encounter environments architected by a single actor (the OSP), but comprised of content and executable elements potentially provided by multiple actors. For the ten OSPs analyzed, privacy policies only cover content provided directly by the OSP. Content provided...

    Provided By Massachusetts Institute of Technology

  • White Papers // Oct 2010

    Consistent and Efficient Reconstruction of Latent Tree Models

    The authors study the problem of learning a latent tree graphical model where samples are available only from a subset of variables. They propose two consistent and computationally efficient algorithms for learning minimal latent trees, that is, trees without any redundant hidden nodes. Their first algorithm, recursive grouping, builds the...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Oct 2010

    Negotiating The Gulf Disaster

    The Gulf Oil spill hurt many individuals and businesses, and there is broad agreement that they deserve compensation. But working out the nuances of damage payment is no simple matter, as the presenter describes in conversation with an MIT Museum audience.

    Provided By Massachusetts Institute of Technology

  • Webcasts // Oct 2010

    Toward Efficient Airport Operations

    Few of us would elect to spend countless hours at the airport watching planes arrive, depart and sit at gates. But what constitutes a punishment for some actually energizes the presenter, whose research focuses on improving airport operations. Her goal is to make air travel more efficient, robust and green.

    Provided By Massachusetts Institute of Technology

  • White Papers // Oct 2010

    A Simple Message-Passing Algorithm for Compressed Sensing

    Recovery of a vector x from measurements of the form y = Ax has been of central interest in the compressed sensing literature. When restricted to binary vectors, this has been of interest in the context of binary linear error-correcting codes. In essence, both desire a matrix A and an...

    Provided By Massachusetts Institute of Technology

  • White Papers // Oct 2010

    Using DVB-S2 Over Asymmetric Heterogeneous Optical to Radio Frequency Satellite Links

    The DVB-S2 coding standard has seen widespread use in many Radio Frequency (RF) communications applications. The availability of Commercial-Off-The-Shelf (COTS) Intellectual Property (IP) that can be used to rapidly prototype and field communications systems makes this well-performing, standards-based approach to Forward Error Correction (FEC) coding extremely attractive. In this paper,...

    Provided By Massachusetts Institute of Technology

  • White Papers // Oct 2010

    On the Role of Queue Length Information in Network Control

    In this paper, the authors study the role played by queue length information in the operation of flow control and server allocation policies. They first consider a simple model of a single server queue with congestion-based flow control. The input rate at any instant is decided by a flow control...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Oct 2010

    Humanities In The Digital Age

    Reports of the demise of the humanities are exaggerated, suggest these panelists, but there may be reason to fear its loss of relevance. Three scholars whose work touches a variety of disciplines and with wide knowledge of the worlds of academia and publishing ponder the meaning and mission of the...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Oct 2010

    Open Payment, A New Approach To Public Transportation Fare Collection

    Soon, a ticket to ride won't require paper coupons, tokens, human vendors, or even Boston's CharlieCard. Urban transit is abandoning a century old payment system for sophisticated digital payment technology, says the author. The author has been toiling for a decade on technology and methods that will enable transit industry...

    Provided By Massachusetts Institute of Technology

  • White Papers // Oct 2010

    Survivable Network Design Problems in Wireless Networks

    Survivable network design is an important suite of algorithmic problems where the goal is to select a minimum cost network subject to the constraint that some desired connectivity property has to be satisfied by the network. Traditionally, these problems have been studied in a model where individual edges (and sometimes...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Oct 2010

    The Art Of Science Communication

    You wouldn't know that the moderator felt nervous in advance of addressing this audience of neuroscientists. In his trademark style, moderator chats up the crowd like an old friend, sharing anecdotes involving one of his great pursuits: "I love to talk to scientists," moderator says.

    Provided By Massachusetts Institute of Technology

  • White Papers // Oct 2010

    Dynamic Pricing Through Sampling Based Optimization

    In this paper the authors develop an approach to dynamic pricing that combines ideas from data-driven and robust optimization to address the uncertain and dynamic aspects of the problem. In this setting, a firm offers multiple products to be sold over a fixed discrete time horizon. Each product sold consumes...

    Provided By Massachusetts Institute of Technology

  • White Papers // Oct 2010

    Post-2008 Crisis In Labor Standards: Prospects For Labor Regulation Around The World

    Over the course of the last thirty years, government policy has been increasingly dominated by neoclassical economic thought and neoliberal public policies. This has been especially true in the United States, but the trends are evident in one way or another in every part of the world. They reflect in...

    Provided By Massachusetts Institute of Technology

  • White Papers // Oct 2010

    SEEC: A Framework for Self-aware Computing

    As the complexity of computing systems increases, application programmers must be experts in their application domain and have the systems knowledge required to address the problems that arise from parallelism, power, energy, and reliability concerns. One approach to relieving this burden is to make use of self-aware computing systems, which...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Oct 2010

    From Experimental Physics To Internet Entrepreneurship: One Scientist?s Journey

    Few better personify the vitality and ambition fueling China's economic surge than the author. In this energetic and revelatory talk, the author relates his personal evolution from MIT physicist to leading Chinese entrepreneur. An industrious student from a poor family, the author was one of the fortunate few in his...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Oct 2010

    Engineering Smarter Drivers

    While automakers market increasingly intelligent cars, they may be missing the point. No matter how sophisticated the vehicle's brain, suggests by the author, the smartest element on the road is still the human driver. In search of safe, responsive vehicles, designers should not think of separate components - machine and...

    Provided By Massachusetts Institute of Technology

  • White Papers // May 2010

    From Relational Specifications to Logic Programs

    This paper presents a compiler from expressive, relational specifications to logic programs. Specifically, the compiler translates the Imperative Alloy specification language to Prolog. Imperative Alloy is a declarative, relational specification language based on first-order logic and extended with imperative constructs; Alloy specifications are traditionally not executable. In spite of this...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    No Bits Left Behind

    One of the key tenets of database system design is making efficient use of storage and memory resources. However, existing database system implementations are actually extremely wasteful of such resources; for example, most systems leave a great deal of empty space in tuples, index pages, and data pages, and spend...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Securing the Borealis Data Stream Engine

    As Data Stream Management Systems (DSMSs) become more and more popular, there is an increasing need to protect such systems from adversaries. In this paper the authors present an approach to secure DSMSs. They propose a general security framework and an access control model to secure DSMSs. The authors implement...

    Provided By Massachusetts Institute of Technology

  • White Papers // Dec 2010

    Demonstration of Multi-Robot Search and Secure

    The authors consider the search and secure problem, where intruders are to be detected in a bounded area without allowing them to escape. The problem is tackled by representing the area to be searched as a traversability graph, which is reduced to a tree graph by placing stationary robots to...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Apr 2011

    Technology: Do Kids Need More or Less?

    The ultimate questions for this Sandbox 2011 panel, posed by the presenter, are "Where is technology not working? When is technology not the answer?" That's a bold agenda for a panel of children's media creators and a roomful of other producers in the industry, from Sesame Workshop, WGBH, 360 Kid,...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Apr 2011

    Learning 3.0: Why Technology Belongs in Every Classroom

    The Obama Administration's recently unveiled plan for transforming American education through technology does not envision "Plugging kids in and making them smarter," declares the presenter. Instead, it focuses on leveraging aspects of digital technology "To create way more compelling environments in schools," and to address educational inequities and the larger...

    Provided By Massachusetts Institute of Technology

  • White Papers // May 2011

    On the Geometry of Wireless Network Multicast in 2-D

    The authors provide a geometric solution to the problem of optimal relay positioning to maximize the multicast rate for low-SNR networks. The network they consider consists of a single source, multiple receivers and the only intermediate and locatable node as the relay. They construct network the hypergraph of the system...

    Provided By Massachusetts Institute of Technology

  • White Papers // May 2011

    History, Expectations, And Leadership In Evolution Of Cooperation

    The authors study the evolution of the social norm of "Cooperation" in a dynamic environment. Each agent lives for two periods and interacts with agents from the previous and next generations via a coordination game. "History" matters because agents only receive noisy information about the play of the previous generation...

    Provided By Massachusetts Institute of Technology

  • White Papers // Sep 2010

    Opinion Fluctuations And Disagreement In Social Networks

    The authors study a stochastic gossip model of continuous opinion dynamics in a society consisting of two types of agents: regular agents, who update their beliefs according to information that they receive from their social neighbors; and stubborn agents, who never update their opinions and might represent leaders, political parties...

    Provided By Massachusetts Institute of Technology

  • White Papers // Aug 2009

    Automatically Patching Errors in Deployed Software

    The authors present ClearView, a system for automatically patching errors in deployed software. ClearView works on stripped Windows x86 binaries without any need for source code, debugging information, or other external information, and without human intervention. ClearView observes normal executions to learn invariants that characterize the application's normal behavior, uses...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2010

    Dos and Don'ts of Client Authentication on the Web

    Client authentication has been a continuous source of problems on the web. Although many well-studied techniques exist for authentication, websites continue to use extremely weak authentication schemes, especially in non-enterprise environments such as store fronts. These weaknesses often result from careless use of authenticators within Web cookies. Of the twenty-seven...

    Provided By Massachusetts Institute of Technology

  • White Papers // Nov 2009

    Collections, Cardinalities, and Relations

    Logics that involve collections (sets, multisets), and cardinality constraints are useful for reasoning about unbounded data structures and concurrent processes. To make such logics more useful in verification this paper extends them with the ability to compute direct and inverse relation and function images. The authors establish decidability and complexity...

    Provided By Massachusetts Institute of Technology

  • White Papers // Dec 2009

    Breaking and Making Quantum Money: Toward a New Quantum Cryptographic Protocol

    Public-key quantum money is a cryptographic protocol in which a bank can create quantum states which anyone can verify, but no one except possibly the bank can clone or forge. There are no secure public-key quantum money schemes in the literature; as the authors show in this paper, the only...

    Provided By Massachusetts Institute of Technology

  • White Papers // Dec 2009

    Proof-Carrying Data and Hearsay Arguments From Signature Cards

    Design of secure systems can often be expressed as ensuring that some property is maintained at every step of a distributed computation among mutually-untrusting parties. Special cases include integrity of programs running on untrusted platforms, various forms of confidentiality and side-channel resilience, and domain-specific invariants. The authors propose a new...

    Provided By Massachusetts Institute of Technology

  • White Papers // Dec 2009

    Cache Replacement Policies for Multicore Processors

    Almost all of the modern computers use multiple cores, and the number of cores is expected to increase as hardware prices go down, and Moore's law fails to hold. Most of the theoretical algorithmic work so far has focused on the setting where multiple cores are performing the same task....

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Middleboxes No Longer Considered Harmful

    Intermediate network elements, such as Network Address Translators (NATs), firewalls, and transparent caches are now commonplace. The usual reaction in the network architecture community to these so-called middleboxes is a combination of scorn (because they violate important architectural principles) and dismay (because these violations make the Internet less flexible). While...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jun 2010

    Detecting Evolving Patterns of Self-Organizing Networks by Flow Hierarchy Measurement

    Hierarchies occur widely in evolving self-organizing ecological, biological, technological and social networks, but detecting and comparing hierarchies is difficult. Here the authors present a metric and technique to quantitatively assess the extent to which self-organizing directed networks exhibit a flow hierarchy. Flow hierarchy is a commonly observed but theoretically overlooked...

    Provided By Massachusetts Institute of Technology

  • White Papers // Apr 2010

    Arguments for an Information-Centric Internetworking Architecture

    The current Internet architecture focuses on communicating entities, largely leaving aside the information to be exchanged among them. However, trends in communication scenarios show that WHAT is being exchanged becoming more important than WHO are exchanging information. Van Jacobson describes this as moving from interconnecting machines to interconnecting information. Any...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    How to Construct a Correct and Scalable IBGP Configuration

    The Internet's current interdomain routing protocol, BGP (Border Gateway Protocol), has two modes of operation: eBGP (external BGP), used to exchange routing information between autonomous systems, and iBGP (internal BGP), used to propagate that information within an Autonomous System (AS). In a "Full mesh" iBGP configuration, every router has a...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jun 2009

    Wishbone: Profile-Based Partitioning for Sensornet Applications

    The ability to partition sensor network application code across sensor nodes and backend servers is important for running complex, data-intensive applications on sensor platforms that have CPU, energy, and bandwidth limitations. This paper presents Wishbone, a system that takes a dataflow graph of operators and produces an optimal partitioning. With...

    Provided By Massachusetts Institute of Technology

  • White Papers // Oct 2009

    Genetic Variation In Financial Decision Making

    Individuals differ in how they compose their investment portfolios, yet empirical models of portfolio risk typically only account for a small portion of the cross-sectional variance. This paper asks if genetic variation can explain some of these individual differences. Following a major pension reform Swedish adult had to compose a...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Energy-Efficient Dynamic Source Routing in Ad-Hoc Wireless Networks

    The authors present Span-DSR and DSR-PSM, two power-saving algorithms designed for ad-hoc wireless networks using source routing. Span-DSR reduces power consumption and has desirable fairness properties, while maintaining a connected backbone of nodes to route packets. Span-DSR's power saving protocol increases system lifetime by a factor of two better than...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Network-Wide BGP Route Prediction for Traffic Engineering

    The Internet consists of about 13,000 Autonomous Systems (AS's) that exchange routing information using the Border Gateway Protocol (BGP). The operators of each AS must have control over the flow of traffic through their network and between neighboring AS's. However, BGP is a complicated, policy-based protocol that does not include...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jun 2010

    Physical Layer-Aware Wireless Link Layer Protocols

    With wireless devices becoming ubiquitous, the problem of designing high performance and reliable wireless networks is of great importance today. Wireless links are characterized by a rapidly varying channel, requiring transmitters to dynamically adapt their transmit bit rate. The broadcast nature of radio also necessitates the use of medium access...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Scheduling for Small Delay in Multi-Rate Multi-Channel Wireless Networks

    This paper considers the problem of designing scheduling algorithms for multi-channel (e.g., OFDM-based) wireless downlink systems. The authors show that the Server-Side Greedy (SSG) rule introduced in earlier papers for ON-OFF channels performs well even for more general channel models. The key contribution in this paper is the development of...

    Provided By Massachusetts Institute of Technology

  • White Papers // May 2009

    Spectrum Pooling for Next Generation Public Safety Radio Systems

    The Dynamic Spectrum Access (DSA) research and development community is maturing technologies that will enable radios to share RF spectrum much more intensively. Adoption of DSA technologies by the public safety community can better align systems with the future of wireless services more generally and can contribute to making next...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Queue Length Asymptotics for Generalized Max-Weight Scheduling in the Presence of Heavy-Tailed Traffic

    Traditionally, traffic in telecommunication networks has been modeled using Poisson and Markov-modulated processes. These simple traffic models exhibit 'Local randomness', in the sense that much of the variability occurs in short time scales, and only an average behavior is perceived at longer time scales. With the spectacular growth of packet-switched...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    A Robust Optimization Approach to Backup Network Design With Random Failures

    This paper presents a scheme in which a dedicated backup network is designed to provide protection from random link failures. Upon a link failure in the primary network, traffic is rerouted through a preplanned path in the backup network. The authors introduce a novel approach for dealing with random link...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    A State Action Frequency Approach to Throughput Maximization Over Uncertain Wireless Channels

    The authors consider scheduling over a wireless system, where the channel state information is not available a priori to the scheduler, but can be inferred from the past. Specifically, the wireless system is modeled as a network of parallel queues. They assume that the channel state of each queue evolves...

    Provided By Massachusetts Institute of Technology

  • White Papers // Sep 2010

    Throughput Optimal Scheduling in the Presence of Heavy-Tailed Traffic

    The authors investigate the tail behavior of the steady-state queue occupancies under throughput optimal scheduling in the presence of heavy-tailed traffic. They consider a system consisting of two parallel queues, served by a single server. One of the queues receives traffic that is heavy-tailed (the "Heavy queue"), and the other...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Delay in Random Access Wireless Networks With Controlled Mobility

    This paper considers dynamic wireless networks where messages arriving randomly (in time and space) are collected by a mobile receiver. The messages are transmitted to the mobile receiver according to a random access scheme and the receiver dynamically adjusts its position in order to receive these messages in the least...

    Provided By Massachusetts Institute of Technology

  • White Papers // Mar 2010

    Whanau: A Sybil-Proof Distributed Hash Table

    Decentralized systems on the Internet are vulnerable to the "Sybil attack", in which an adversary creates numerous false identities to influence the system's behavior. This problem is particularly pernicious when the system is responsible for routing messages amongst nodes, as in the Distributed Hash Tables (DHT) which underlie many peer-to-peer...

    Provided By Massachusetts Institute of Technology

  • White Papers // Apr 2010

    Robust Routing for Local Area Optical Access Networks

    One approach to providing the benefits of the high data rates afforded by optics is to attempt to implement traditional electronic and electro-optic approaches using optical technologies. In electronics, operations such as buffering, adding packets and dropping packets, or merging packet streams, are done with ease. In optics, however, buffering...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    An Empirical Study of "Bogo" Route Advertisements

    An important factor in the robustness of the inter-domain routing system is whether the routers in Autonomous Systems (ASes) filter routes for "Bogon" address space - i.e., private address space and address space that has not been allocated by the Internet Assigned Numbers Authority (IANA). This paper presents an empirical...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Detecting BGP Configuration Faults With Static Analysis

    The Internet is composed of many independent Autonomous Systems (ASes) that exchange reachability information to destinations using the Border Gateway Protocol (BGP). Network operators in each AS configure BGP routers to control the routes that are learned, selected, and announced to other routers. Faults in BGP configuration can cause forwarding...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Guidelines for Interdomain Traffic Engineering

    Network operators must have control over the flow of traffic into, out of, and across their networks. However, the Border Gateway Protocol (BGP) does not facilitate common traffic engineering tasks, such as balancing load across multiple links to a neighboring AS or directing traffic to a different neighbor. Solving these...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Practical Verification Techniques for Wide-Area Routing

    Protocol and system designers use verification techniques to analyze a system's correctness properties. Network operators need verification techniques to ensure the "Correct" operation of BGP. BGP's distributed dependencies cause small configuration mistakes or oversights to spur complex errors, which sometimes have devastating effects on global connectivity. These errors are often...

    Provided By Massachusetts Institute of Technology

  • White Papers // Nov 2009

    Design and Performance of Multipath MIN Architecture

    In this paper, the authors discuss the use of multipath Multistage Interconnection Networks (MINs) in the design of a fault-tolerant parallel computer. Multipath networks have multiple paths between any input and any output. In particular, they examine networks with either the property of expansion or maximal-fanout. The authors present a...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    The Click Modular Router

    Click is a new software architecture for building flexible and configurable routers. A Click router is assembled from packet processing modules called elements. Individual elements implement simple router functions like packet classification, queuing, scheduling, and interfacing with network devices. A router configuration is a directed graph with elements at the...

    Provided By Massachusetts Institute of Technology

  • White Papers // Feb 2010

    Wealth Accumulation And Factors Accounting For Success

    The authors use detailed income, balance sheet, and cash flow statements constructed for households in a long monthly panel in an emerging market economy, and some recent contributions in economic theory, to document and better understand the factors underlying success in achieving upward mobility in the distribution of net worth....

    Provided By Massachusetts Institute of Technology