scispace - formally typeset
Search or ask a question
Institution

AT&T Labs

Company
About: AT&T Labs is a based out in . It is known for research contribution in the topics: Network packet & The Internet. The organization has 1879 authors who have published 5595 publications receiving 483151 citations.


Papers
More filters
Posted Content
TL;DR: In this paper, the problem of joint task offloading and resource allocation in a MEC enabled multi-cell wireless network is considered, where each base station (BS) is equipped with a mobile edge computing server that can assist mobile users in executing computation-intensive tasks via offloading.
Abstract: Mobile-Edge Computing (MEC) is an emerging paradigm that provides a capillary distribution of cloud computing capabilities to the edge of the wireless access network, enabling rich services and applications in close proximity to the end users. In this article, a MEC enabled multi-cell wireless network is considered where each Base Station (BS) is equipped with a MEC server that can assist mobile users in executing computation-intensive tasks via task offloading. The problem of Joint Task Offloading and Resource Allocation (JTORA) is studied in order to maximize the users' task offloading gains, which is measured by the reduction in task completion time and energy consumption. The considered problem is formulated as a Mixed Integer Non-linear Program (MINLP) that involves jointly optimizing the task offloading decision, uplink transmission power of mobile users, and computing resource allocation at the MEC servers. Due to the NP-hardness of this problem, solving for optimal solution is difficult and impractical for a large-scale network. To overcome this drawback, our approach is to decompose the original problem into (i) a Resource Allocation (RA) problem with fixed task offloading decision and (ii) a Task Offloading (TO) problem that optimizes the optimal-value function corresponding to the RA problem. We address the RA problem using convex and quasi-convex optimization techniques, and propose a novel heuristic algorithm to the TO problem that achieves a suboptimal solution in polynomial time. Numerical simulation results show that our algorithm performs closely to the optimal solution and that it significantly improves the users' offloading utility over traditional approaches.

266 citations

Proceedings ArticleDOI
19 Oct 2005
TL;DR: A new dynamic anomography algorithm is introduced, which effectively tracks routing and traffic change, so as to alert with high fidelity on intrinsic changes in network-level traffic, yet not on internal routing changes, an additional benefit of dynamicanomography is that it is robust to missing data, an important operational reality.
Abstract: Anomaly detection is a first and important step needed to respond to unexpected problems and to assure high performance and security in IP networks. We introduce a framework and a powerful class of algorithms for network anomography, the problem of inferring network-level anomalies from widely available data aggregates. The framework contains novel algorithms, as well as a recently published approach based on Principal Component Analysis (PCA). Moreover, owing to its clear separation of inference and anomaly detection, the framework opens the door to the creation of whole families of new algorithms. We introduce several such algorithms here, based on ARIMA modeling, the Fourier transform, Wavelets, and Principal Component Analysis. We introduce a new dynamic anomography algorithm, which effectively tracks routing and traffic change, so as to alert with high fidelity on intrinsic changes in network-level traffic, yet not on internal routing changes. An additional benefit of dynamic anomography is that it is robust to missing data, an important operational reality. To the best of our knowledge, this is the first anomography algorithm that can handle routing changes and missing data. To evaluate these algorithms, we used several months of traffic data collected from the Abilene network and from a large Tier-1 ISP network. To compare performance, we use the methodology put forward earlier for the Abilene data set. The findings are encouraging. Among the new algorithms introduced here, we see: high accuracy in detection (few false negatives and few false positives), and high robustness (little performance degradation in the presence of measurement noise, missing data and routing changes).

265 citations

Journal ArticleDOI
TL;DR: End-to-end measurements of multicast traffic can be used to infer the packet delay distribution and utilization on each link of a logical multicast tree and is evaluated through simulation to establish desirable statistical properties of the estimator, namely consistency and asymptotic normality.
Abstract: Packet delay greatly influences the overall performance of network applications. It is therefore important to identify causes and locations of delay performance degradation within a network. Existing techniques, largely based on end-to-end delay measurements of unicast traffic, are well suited to monitor and characterize the behavior of particular end-to-end paths. Within these approaches, however, it is not clear how to apportion the variable component of end-to-end delay as queueing delay at each link along a path. Moreover, there are issues of scalability for large networks. In this paper, we show how end-to-end measurements of multicast traffic can be used to infer the packet delay distribution and utilization on each link of a logical multicast tree. The idea, recently introduced in Caceres et al. (1999), is to exploit the inherent correlation between multicast observations to infer performance of paths between branch points in a tree spanning a multicast source and its receivers. The method does not depend on cooperation from intervening network elements; because of the bandwidth efficiency of multicast traffic, it is suitable for large-scale measurements of both end-to-end and internal network dynamics. We establish desirable statistical properties of the estimator, namely consistency and asymptotic normality. We evaluate the estimator through simulation and observe that it is robust with respect to moderate violations of the underlying model.

264 citations

Journal ArticleDOI
David Kormann1, Aviel D. Rubin1
01 Jun 2000
TL;DR: The Passport single signon protocol is examined, several risks and attacks are identified, and a flaw that was discovered in the interaction of Passport and Netscape browsers that leaves a user logged in while informing him that he has successfully logged in.
Abstract: Passport is a protocol that enables users to sign onto many different merchants' Web pages by authenticating themselves only once to a common server. This is important because users tend to pick poor (guessable) user names and passwords and to repeat them at different sites. Passport is notable as it is being very widely deployed by Microsoft. At the time of this writing, Passport boasts 40 million consumers and more than 400 authentications per second on average. We examine the Passport single signon protocol, and identify several risks and attacks. We discuss a flaw that we discovered in the interaction of Passport and Netscape browsers that leaves a user logged in while informing him that he has successfully logged out. Finally, we suggest several areas of improvement.

264 citations

Proceedings ArticleDOI
Mihai Patrascu1, Ryan Williams2
17 Jan 2010
TL;DR: Reductions from the problem of determining the satisfiability of Boolean CNF formulas (CNF-SAT) to several natural algorithmic problems are described, showing that attaining any of the following bounds would improve the state of the art in algorithms for SAT.
Abstract: We describe reductions from the problem of determining the satisfiability of Boolean CNF formulas (CNF-SAT) to several natural algorithmic problems. We show that attaining any of the following bounds would improve the state of the art in algorithms for SAT:• an O(nk-e) algorithm for k-Dominating Set, for any k ≥ 3,• a (computationally efficient) protocol for 3-party set disjointness with o(m) bits of communication,• an n°(d) algorithm for d-SUM,• an O(n5-e) algorithm for 2-SAT formulas with m = n1+0(1) clauses, where two clauses may have unrestricted length, and• an O((n + m)k-e) algorithm for HornSat with k unrestricted length clauses.One may interpret our reductions as new attacks on the complexity of SAT, or sharp lower bounds conditional on exponential hardness of SAT.

263 citations


Authors

Showing all 1881 results

NameH-indexPapersCitations
Yoshua Bengio2021033420313
Scott Shenker150454118017
Paul Shala Henry13731835971
Peter Stone130122979713
Yann LeCun121369171211
Louis E. Brus11334763052
Jennifer Rexford10239445277
Andreas F. Molisch9677747530
Vern Paxson9326748382
Lorrie Faith Cranor9232628728
Ward Whitt8942429938
Lawrence R. Rabiner8837870445
Thomas E. Graedel8634827860
William W. Cohen8538431495
Michael K. Reiter8438030267
Network Information
Related Institutions (5)
Microsoft
86.9K papers, 4.1M citations

94% related

Google
39.8K papers, 2.1M citations

91% related

Hewlett-Packard
59.8K papers, 1.4M citations

89% related

Bell Labs
59.8K papers, 3.1M citations

88% related

Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
20225
202133
202069
201971
2018100
201791