OLSRp: Predicting Control Information to Achieve Scalability in OLSR Ad Hoc Networks

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OLSRp: Predicting Control Information to Achieve Scalability in OLSR Ad Hoc Networks Esunly Medina ф Roc Meseguer ф Carlos Molina λ Dolors Royo ф Santander (SPAIN) - September 22-24, 2010 ф Dept. Arquitectura de Computadors Universitat Politècnica de Catalunya Barcelona, Spain {esunlyma, meseguer, dolors}@ac.upc.edu λ Dept. Enginyeria Informàtica i Matemàtiques Universitat Rovira i Virgili Tarragona, Spain [email protected]

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Santander (SPAIN) - September 22-24, 2010. OLSRp: Predicting Control Information to Achieve Scalability in OLSR Ad Hoc Networks. Esunly Medina ф Roc Meseguer ф Carlos Molina λ Dolors Royo ф. ф Dept. Arquitectura de Computadors Universitat Politècnica de Catalunya Barcelona, Spain - PowerPoint PPT Presentation

Transcript of OLSRp: Predicting Control Information to Achieve Scalability in OLSR Ad Hoc Networks

  • OLSRp: Predicting Control Information to Achieve Scalability in OLSR Ad Hoc NetworksEsunly Medina Roc Meseguer Carlos Molina Dolors Royo

    Santander (SPAIN) - September 22-24, 2010 Dept. Arquitectura de ComputadorsUniversitat Politcnica de Catalunya Barcelona, Spain {esunlyma, meseguer, dolors}@ac.upc.edu Dept. Enginyeria Informtica i MatemtiquesUniversitat Rovira i VirgiliTarragona, Spain [email protected]

  • MotivationPotentialityOLSRpConclusions & Future WorkOLSROutline

  • Motivation

  • Ad-hoc networks:Need for maintaining network topologyControl messages consume network resourcesProactive link state routing protocols:

    Each node has a topology mapPeriodically broadcast routing information to neighbors

    Motivation but when the number of nodes is high

  • can overload the network!!!

  • OLSROLSR: Control Traffic and EnergyTraffic and energy do NOT scale !!!OLSR is one of the most intensive energy-consumers

  • can we increase scalability of routing protocols for ad-hoc networks?

  • Data per query Queries per second constantFor routing protocols:D = Size of packetsQ = Number of packets per second sent to the network

    We focus on Q:Reducing transmitted packetsWithout adding complexity to network management

    HOW?OLSRDQ principlePREDICTING MESSAGES !!!!

  • Called OLSRpPredicts duplicated topology-update messagesReduce messages transmitted through the network Saves computational processing and energyIndependent of the OLSR configuration Self-adapts to network changes. We propose a mechanism for increasing scalability of ad-hoc networksbased on link state proactive routing protocols

  • Potentiality

  • NS-2 & NS-3

    Grid topology, D = 100, 200, 500 m

    802.11b Wi-Fi cards, Tx rate 1Mbps

    Node mobility:Static, 0.1, 1, 5, 10 m/sFriis Propagation Model

    ICMP traffic

    OLSR control messages:HELLO=2sTC=5sOLSRExperimental Setup

  • OLSRTC vs HELLO

    OLSR: Messages distributionRatio of TC messages is significant for low density of nodes

  • OLSRControl Information RepetitionNumber of nodes does not affect repetition

  • Density of nodes slightly affects repetitionOLSRControl Information Repetition

  • Repetition is mainly affected by mobilityOLSRControl Information Repetition

  • OLSRControl Information RepetitionRepetition still being significant for high node speeds

  • OLSRp

  • Prevent MPRs from transmitting duplicated TC throughout the network:

    OLSROLSRp: Basis

    Last-value predictor placed in every node of the network

    MPRs predicts when they have a new TC to transmit

    The other network nodes predict and reuse the same TC

    100% accuracy: If predicted TC new TC MPR sends the new TC

    HELLO messages for validation

    The topology have changed and the new TC must be sentThe MPR is inactive and we must deactivate the predictor

  • TCWifi TCOLSRif MPR: TCOLSR TCWifiOLSROLSRp: Layersif (TC[n]=TC[n-1]): TCOLSRp TCOLSRelse: TCWifi TCOLSRif MPR if(TC[n]=TC[n-1]): TCOLSRpelse: TCOLSR TCWifi

  • OLSROLSRp: Basis

    Each node keeps a table whose dimensions depends on the number of nodes Each entry records info about a specific node:

    The nodes @IP

    The list of @IP of the MPRs (O.A.) that announce the node in their TCs and the current state of the node (A or I). (HELLO messages received).

    A predictor state indicator for MPR nodes (On or Off):

    On when at least one of the TC that contains information about the MPR is active

    Off when the node is inactive in all the announcing TC messages (new TC message will be sent)

  • OLSROLSRp: ExampleBB

  • OLSROLSRp: ExampleBBNODE D TABLE

  • OLSROLSRp: ExampleBBNODE D TABLEX

  • OLSROLSRp: ExampleBBNODE D TABLEX

  • OLSROLSRp: ExampleBBNODE D TABLEX

  • Reduction in:Control trafficOLSROLSRp: Benefits

  • OLSROLSRp: Some Results

  • Conclusions & Future Work

  • OLSRConclusions & Future WorkConclusions:OLSRp has similar performance than standard OLSRCan dynamically self-adapt to topology changesReduces network congestionSaves computer processing and energy consumption

    Future Work:Further evaluation of OLSRp performanceAssessment in real-world testbedsApplication in other routing protocols

  • Questions?OLSRp: Predicting Control Information to Achieve Scalability in OLSR Ad Hoc Networks Santander (SPAIN) - September 22-24, 2010

    ****A link-state routing protocol is one of the two main classes of routing protocols used in packet switching networks for computer communications, the other major class being the distance-vector routing protocol. Examples of link-state routing protocols include OSPF and IS-IS.

    The link-state protocol is performed by every switching node in the network (i.e. nodes that are prepared to forward packets; in the Internet, these are called routers). The basic concept of link-state routing is that every node constructs a map of the connectivity to the network, in the form of a graph, showing which nodes are connected to which other nodes. Each node then independently calculates the next best logical path from it to every possible destination in the network. The collection of best paths will then form the node's routing table.This contrasts with distance-vector routing protocols, which works by having each node share its routing table with its neighbors. In a link-state protocol the only information passed between nodes is connectivity related.Link state algorithms are sometimes characterized by the Each router tells the world about its neighbors.

    Link.State y Vector Distance pueden ser PROACTIVOS o REACTIVOS

    Pro-active (table-driven) routingThis type of protocols maintains fresh lists of destinations and their routes by periodically distributing routing tables throughout the network. The main disadvantages of such algorithms are: 1. Respective amount of data for maintenance. 2. Slow reaction on restructuring and failures.

    This type of protocols finds a route on demand by flooding the network with Route Request packets. The main disadvantages of such algorithms are: 1. High latency time in route finding. 2. Excessive flooding can lead to network clogging.

    **Problemes oberts en xarxes ad hoc: (1) hetegeneitat (2) seguritat (3) escalabilitat (4) consum d'energiaProtocolo de routing no es un problema**We propose a mechanism for increasing scalability of link state proactive routing protocols for ad-hoc networks.*****************OLSRp considerably reduces the overall cost involved in the transmission/reception and packing/unpacking processes. The cost in energy and processing time is higher than the additional cost introduced by the implementation of the OLSRp mechanism (it is widely known that a single packet transmission consumes the same energy as the execution of millions of instructions).*****