Data Mining - Concepts and Techniques.

Data Mining Practical Machine Learning Tools and Techniques

Topology control in a sensor network balances load on sensor nodes and increases network scalability and lifetime. Clustering sensor nodes is an effective topology control approach. We propose a novel distributed clustering approach for long-lived ad hoc sensor networks. Our proposed approach does not make any assumptions about the presence of infrastructure or about node capabilities, other than the availability of multiple power levels in sensor nodes. We present a protocol, HEED (Hybrid Energy-Efficient Distributed clustering), that periodically selects cluster heads according to a hybrid of the node residual energy and a secondary parameter, such as node proximity to its neighbors or node degree. HEED terminates in O(1) iterations, incurs low message overhead, and achieves fairly uniform cluster head distribution across the network. We prove that, with appropriate bounds on node density and intracluster and intercluster transmission ranges, HEED can asymptotically almost surely guarantee connectivity of clustered networks. Simulation results demonstrate that our proposed approach is effective in prolonging the network lifetime and supporting scalable data aggregation.

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HEED: a hybrid, energy-efficient, distributed clustering approach for ad hoc sensor networks

http://cpham.perso.univ-pau.fr/ENSEIGNEMENT/PAU-UPPA/RESA-M2/Clustering-abasi.pdf

A survey on clustering algorithms for wireless sensor networks

Topology Control (TC) is one of the most important techniques used in wireless ad hoc and sensor networks to reduce energy consumption (which is essential to extend the network operational time) and radio interference (with a positive effect on the network traffic carrying capacity). The goal of this technique is to control the topology of the graph representing the communication links between network nodes with the purpose of maintaining some global graph property (e.g., connectivity), while reducing energy consumption and/or interference that are strictly related to the nodes' transmitting range. In this article, we state several problems related to topology control in wireless ad hoc and sensor networks, and we survey state-of-the-art solutions which have been proposed to tackle them. We also outline several directions for further research which we hope will motivate researchers to undertake additional studies in this field.

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Topology Control in Wireless Ad Hoc and Sensor Networks

We investigate the behavior of a new response strategy to TCP Explicit Congestion Notification (ECN) The new strategy is more aggressive in the short term, but preserves TCP long term behavior - without modifying the router ECN marking rate A more aggressive short term behavior gives incentives for hosts to become ECN-compliant ECN serves as an early warning sign in this case Our analysis demonstrates the effectiveness of the new TCP ECN behavior Simulation results with short/long lived FTP, UDP and HTTP connections, multiple bottleneck configurations, and various TCP flavors and parameters, demonstrate higher throughput and reduced oscillations with the new response strategy

On TCP reaction to Explicit Congestion Notification

An explicit rate switch scheme monitors the load at each link and gives feedback to the sources. We define the overload factor as the ratio of the input rate to the available capacity. In this paper, we present four overload based ABR switch schemes which provide MCR guarantees. The switch schemes proposed use the overload factor and other quantities to calculate feedback rates. A dynamic queue control mechanism is used to achieve efficient usage of the link, control queues and, achieve constant queuing delay at steady state. The proposed algorithms are studied and compared using several configurations. The configurations were chosen to test the performance of the algorithms in presence of link bottlenecks, source bottlenecks and transient sources. A comparison of the proposed algorithms based on the simulation results is presented.

Overload Based Explicit Rate Switch Schemes with MCR Guarantees

-Effective network measurement can signi&#64257;cantly improve application performance. One of the main challenges in obtaining network measurements is to achieve high accuracy while consuming few network resources. To address this problem, several inference mechanisms have been proposed. These mechanisms can provide the O(n2 ) end-to-end measurements among n nodes using O(n) measurements, with some loss in accuracy. We construct a measurement request graph where a measurement request issued by an application (e.g., for delay between two nodes) is represented by an edge between the nodes. When the measurement request graph is sparse, an inference mechanism operating over all the nodes (complete inference) incurs unnecessary cost. Given a measurement request graph, our goal is to optimize the number of measurements as well as improve overall accuracy by applying inference only to dense sub-graphs, while taking the other measurements directly. We call this technique partial inference. Previous work only considered static measurement request graphs. However, the measurement request graph can be dynamic when nodes frequently join and leave the network. This paper designs and evaluates a distributed algorithm where each node decides if it should participate in an inference mechanism based on limited information.

/pdf/distributed-partial-inference-under-churn-21nebfc7ay.pdf

Distributed Partial Inference under Churn

Network Functions Virtualization (NFV) has enabled operators to dynamically place and allocate resources for network services to match workload requirements. However, unbounded end-to-end (e2e) latency of Service Function Chains (SFCs) resulting from distributed Virtualized Network Function (VNF) deployments can severely degrade performance. In particular, SFC instantiations with inter-data center links can incur high e2e latencies and Service Level Agreement (SLA) violations. These latencies can trigger timeouts and protocol errors with latency-sensitive operations.Traditional solutions to reduce e2e latency involve physical deployment of service elements in close proximity. These solutions are, however, no longer viable in the NFV era. In this paper, we present our solution that bounds the e2e latency in SFCs and inter-VNF control message exchanges by creating micro-service aggregates based on the affinity between VNFs. Our system, Contain-ed, dynamically creates and manages affinity aggregates using light-weight virtualization technologies like containers, allowing them to be placed in close proximity and hence bounding the e2e latency. We have applied Contain-ed to the Clearwater IP Multimedia Subsystem and built a proof-of-concept. Our results demonstrate that, by utilizing application and protocol specific knowledge, affinity aggregates can effectively bound SFC delays and significantly reduce protocol errors and service disruptions.

Contain-ed: An NFV Micro-Service System for Containing e2e Latency

Routing stability and correctness in the Internet have long been a concern. Despite this, few theoretical frameworks have been proposed to check BGP configurations for convergence and safety. The most popular approach is based on the Stable Paths Problem (SPP) model. Unfortunately, SPP requires enumeration of all possible control-plane paths, which is infeasible in large networks. In this work, we study how to apply algebraic frameworks to the BGP configuration checking problem. We propose an extension of the Stratified Shortest Path Problem (SSPP) model that has a similar expressive power to SPP, but enables more efficient checking of configuration correctness. Our approach remains valid when BGP policies are applied to iBGP sessions - a case which is often overlooked by previous work, although common in today's Internet. While this paper focuses mainly on iBGP problems, our methodology can be extended to eBGP if operators are willing to share their local-preference configurations.

/pdf/reducing-the-complexity-of-bgp-stability-analysis-with-1hzgle6j0e.pdf

Sonia Fahmy

Papers

On TCP reaction to Explicit Congestion Notification

Overload Based Explicit Rate Switch Schemes with MCR Guarantees

Distributed Partial Inference under Churn

Contain-ed: An NFV Micro-Service System for Containing e2e Latency

Reducing the complexity of BGP stability analysis with hybrid combinatorial-algebraic models