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NATONATOConsultation, Command and Consultation, Command and

Control AgencyControl Agency

Ad-hoc Networking: Infrastructure-free Ad-hoc Networking: Infrastructure-free Communications for Military OperationsCommunications for Military Operations

Michael Winkler, Marco BartolozziMichael Winkler, Marco Bartolozzi

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Outline of PresentationOutline of Presentation

Motivation for Ad-hoc Networking Motivation for Ad-hoc Networking (M. Winkler)(M. Winkler) Main ConceptsMain Concepts Military RequirementsMilitary Requirements Security IssuesSecurity Issues

Simulation versus Emulation Simulation versus Emulation (M. Bartolozzi)(M. Bartolozzi) The NC3A Prototype NetworkThe NC3A Prototype Network

Set-upSet-up Measurements & ResultsMeasurements & Results

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Motivation for Ad-hoc NetworkingMotivation for Ad-hoc Networking

NATO Network Enabled Capability Feasibility Study: NATO Network Enabled Capability Feasibility Study: “To guarantee the necessary “To guarantee the necessary service availability, service availability, connectivity and agilityconnectivity and agility, the networking and information , the networking and information infrastructure (NII) should exploit the functionality of infrastructure (NII) should exploit the functionality of mobile ad-hoc networks (MANET).”mobile ad-hoc networks (MANET).”

NATO C3 Technical Architecture:NATO C3 Technical Architecture:“Ad-hoc networking is of increasing interest for a “Ad-hoc networking is of increasing interest for a diverse set of diverse set of applications on the battlefield, includingapplications on the battlefield, including distributed sensor and munitions networks and flexible distributed sensor and munitions networks and flexible and rapidly deployed HQ wireless LANsand rapidly deployed HQ wireless LANs.” .”

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Main Ideas of Ad-hoc Networking (1)Main Ideas of Ad-hoc Networking (1)

Multi-hoppingMulti-hopping Communication nodes are relaying traffic for each otherCommunication nodes are relaying traffic for each other Normally based on wireless transmissionsNormally based on wireless transmissions Special-purpose routing, possibly geocast routingSpecial-purpose routing, possibly geocast routing Extension of coverage due to additional nodesExtension of coverage due to additional nodes

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Main Ideas of Ad-hoc Networking (2)Main Ideas of Ad-hoc Networking (2)

Distributed network operationsDistributed network operations No centralized instanceNo centralized instance Network self-organizationNetwork self-organization Self-healing propertiesSelf-healing properties

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Main Ideas of Ad-hoc Networking (3) Main Ideas of Ad-hoc Networking (3)

Infrastructure-free information exchangeInfrastructure-free information exchange Communication is possible where communication devices Communication is possible where communication devices

existexist No need to install any infrastructureNo need to install any infrastructure

Thus achieving overallThus achieving overall High flexibility High flexibility High adaptabilityHigh adaptability Support for static as well as mobile usersSupport for static as well as mobile users

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Specific Military RequirementsSpecific Military Requirements

Rapid deployment capabilityRapid deployment capability Absence of a single point of failureAbsence of a single point of failure Self-healing propertiesSelf-healing properties Encryption capability for classified data transferEncryption capability for classified data transfer Node authenticationNode authentication Secure routingSecure routing Ideally predictable Quality of ServiceIdeally predictable Quality of Service

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Types of Ad-hoc NetworksTypes of Ad-hoc Networks

Mesh NetworksMesh Networks

With many With many interconnection interconnection points with fixed points with fixed infrastructureinfrastructure

Here hybrid Here hybrid architecture architecture using WiMAX using WiMAX & WLAN& WLAN

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Types of Ad-hoc NetworksTypes of Ad-hoc Networks

... besides Mesh Networks:... besides Mesh Networks: Sensor NetworksSensor Networks

Connecting many sensorsConnecting many sensors Power conservation criticalPower conservation critical Very limited computing power and memory sizeVery limited computing power and memory size

Mobile Ad-hoc Networks (MANETs)Mobile Ad-hoc Networks (MANETs) WirelessWireless Supporting mobile usersSupporting mobile users Stand-alone or as extension of fixed infrastructureStand-alone or as extension of fixed infrastructure

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NGO: Non-governmental organizationMANET: Mobile Ad-hoc Network

MANET for Civil Military CooperationMANET for Civil Military Cooperation

Example: Disaster recoveryExample: Disaster recovery Supporting NGOsSupporting NGOs Extending the coverageExtending the coverage

Reach-back to strategic network

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MANET for Civil Military CooperationMANET for Civil Military Cooperation

Example: Disaster recoveryExample: Disaster recovery Supporting NGOsSupporting NGOs Extending the coverageExtending the coverage Need for security measuresNeed for security measures

Reach-back to strategic network

malicious user

NGO: Non-governmental organizationMANET: Mobile Ad-hoc Network

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Security IssuesSecurity Issues

Confidentiality and integrity of data can be ensured by Confidentiality and integrity of data can be ensured by the use of IP encryption devicesthe use of IP encryption devices

Protection of the network Protection of the network availabilityavailability also important also important Possible attacks:Possible attacks:

JammingJamming Routing disruption, e.g. by flooding with routing messagesRouting disruption, e.g. by flooding with routing messages Traffic forwarding attacks, e.g. by setting-up black holeTraffic forwarding attacks, e.g. by setting-up black hole

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Securing Routing Protocols Securing Routing Protocols

Main approach: Add digital signature field to the routed Main approach: Add digital signature field to the routed packetspackets

Proposals for secure routing algorithms exist, Proposals for secure routing algorithms exist, e.g. secure OLSR and secure AODVe.g. secure OLSR and secure AODV

HoweverHowever Key distribution and key updates demandingKey distribution and key updates demanding Increased management trafficIncreased management traffic Problematic to include unknown nodesProblematic to include unknown nodes

Need for further evaluation and practical experienceNeed for further evaluation and practical experience

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Directions for Further ResearchDirections for Further Research

Pervasive resilience & securityPervasive resilience & security Efficient routing algorithmsEfficient routing algorithms Multi-casting and geo-castingMulti-casting and geo-casting Real-time services & end-to-end QoSReal-time services & end-to-end QoS Enhanced scalabilityEnhanced scalability

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Ad-hoc Networking ExperimentationAd-hoc Networking Experimentation

Experimentation on ad-hoc networking has been so far Experimentation on ad-hoc networking has been so far driven by the need to:driven by the need to:Evaluate and compare different ad-hoc routing Evaluate and compare different ad-hoc routing

protocolsprotocols Validate specific operational scenarios Validate specific operational scenarios Encourage progress on the technology itself Encourage progress on the technology itself

It is generally made using two different approaches:It is generally made using two different approaches:SimulationSimulationEmulation Emulation

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Simulation versus EmulationSimulation versus Emulation

Simulation starts from softwareSimulation starts from softwareIt is based on software routines and algorithms that It is based on software routines and algorithms that

replace and resemble the behaviour of the original replace and resemble the behaviour of the original hardware systemhardware system

It aims at:It aims at:Achieving a very high degree of repeatabilityAchieving a very high degree of repeatabilityReducing experimentation costsReducing experimentation costs

Emulation starts from hardwareEmulation starts from hardwareIt is fully or partially made by the same hardware used It is fully or partially made by the same hardware used

in a field deploymentin a field deploymentIt aims at obtaining a good compromise between It aims at obtaining a good compromise between

repeatability and accuracy repeatability and accuracy

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Ad-hoc Experimentation SystemsAd-hoc Experimentation Systems

Simulators:Simulators:NS-2NS-2QualnetQualnetGlomosimGlomosim

Emulated systemsEmulated systemsSarnoffSarnoffEwantEwantOrbitOrbitAPEAPECMUCMU

A

RA = Accuracy (degree of resemblance to real-world experiments)

R = Repeatability (capability to effectively repeat tests under the

same initial conditions)

complex

simple

SARNOFFORBIT

APE CMU

EWANT

real world experiments

NS-2

QUALNET

GLOMOSIM

Emulations

Simulations

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• #4 DELL NOTEBOOKS

• LINUX FEDORA CORE 5

• Kernel 2.6.16-1.2096_FC5

• Senao WLAN PCMCIA cards NL-5354CB+ (802.11g)

• Madwifi-ng v. 0.9.4.5 Atheros driver for FC5

• Static IP addressing

• OLSR v. 0.4.10 routing protocol from olsr.org

• Applications: ping, iperf, ethereal, X-Lite softphone

The NC3A-4F TestbedThe NC3A-4F Testbed

Fieldable

4FFlexible

Fedora Feasible

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Testbed ScenariosTestbed Scenarios

host6

host8

host2

host3

host2 host3 host6 host8

M C

Mesh-to-Chain

Chain-to-Mesh

Mesh Topology

Chain Topology

Changing Topology State-Machine

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Throughput and RTTThroughput and RTT

Mesh topology (1 hop)Mesh topology (1 hop) UDP throughput: 8 Mb/sUDP throughput: 8 Mb/s TCP throughput: 11 Mb/sTCP throughput: 11 Mb/s Round Trip Time: 0,67 msRound Trip Time: 0,67 ms

Chain topology (3 hops)Chain topology (3 hops) UDP throughput: 2,5 Mb/sUDP throughput: 2,5 Mb/s TCP throughput: 650 Kb/sTCP throughput: 650 Kb/s Round Trip Time: 5,5 msRound Trip Time: 5,5 ms

From mesh to chain (1 to 3 hops), RTT increases 10 times,From mesh to chain (1 to 3 hops), RTT increases 10 times,UDP throughput reduces by 70%, TCP throughput reduces UDP throughput reduces by 70%, TCP throughput reduces by 90%;by 90%;→ → SCALABILITY is a crucial issue for ad-hoc networking!SCALABILITY is a crucial issue for ad-hoc networking!

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Test with UDP data transfer and Test with UDP data transfer and changing topologychanging topology

UDP data transfer at 300 UDP data transfer at 300 Kb/s using Iperf Kb/s using Iperf

Topology is changed Topology is changed from mesh to chain using from mesh to chain using a a MAC filteringMAC filtering script script launched from one of the launched from one of the hostshosts

The script uses SSH to The script uses SSH to access other hosts and access other hosts and load / unload access lists load / unload access lists based on MAC addressesbased on MAC addresses

mesh chain mesh

Iperf UDP

SSH TCP

Iperf UDP

bytes

secs

bytes

secs

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VoIP test with high-rate TCP and VoIP test with high-rate TCP and changing topologychanging topology

RTP VoIP

Iperf TCP

mesh chain meshRTP VoIP

SSH TCP

VoIP phone call VoIP phone call established using X-established using X-Lite Softphone (SIP Lite Softphone (SIP protocol)protocol)

TCP data transfer at TCP data transfer at 11 Mb/s using Iperf11 Mb/s using Iperf

Voice quality as Voice quality as perceived by the perceived by the callees was very callees was very good. good. Communication on Communication on both directions was both directions was never interruptednever interrupted

bytes

secs

bytes

secs

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Testbed ConclusionsTestbed Conclusions

The NC3A-4F testbed aimed at proving the functionality of the ad-hoc The NC3A-4F testbed aimed at proving the functionality of the ad-hoc networking technology, using commercial-of-the-shelf hardware and networking technology, using commercial-of-the-shelf hardware and software.software.

UDP and TCP data transfer and Voice over IP communication have been UDP and TCP data transfer and Voice over IP communication have been tested over the NC3A-4F testbed, with satisfactory results overall. tested over the NC3A-4F testbed, with satisfactory results overall.

The tests showed that an increasing number of intermediate hops brings The tests showed that an increasing number of intermediate hops brings significant reduction in terms of overall bandwidth, affecting particularly significant reduction in terms of overall bandwidth, affecting particularly intensive-rate applications. intensive-rate applications.

Low/medium-rate applications such as Voice over IP showed not to be Low/medium-rate applications such as Voice over IP showed not to be significantly affected by multi-hopping.significantly affected by multi-hopping.

Scalability of the ad-hoc networking solution remains a crucial issue that Scalability of the ad-hoc networking solution remains a crucial issue that needs further investigation, in order to provide a consistent feedback on needs further investigation, in order to provide a consistent feedback on how and with which constraints ad-hoc networking can be successfully how and with which constraints ad-hoc networking can be successfully deployed in the theatre.deployed in the theatre.

Contact InformationContact Information

Dr.-Ing. Marco Bartolozzi

Dr.-Ing. Michael Winkler

Telephone +31 (0)70 3743262Michael.Winkler@nc3a.nato.int

NC3A The Hague

Visiting address:

Oude Waalsdorperweg 612597 AK The Hague

Telephone +31 (0)70 3743000Fax +31 (0)70 3743239

Postal address:NATO C3 AgencyP.O. Box 1742501 CD The HagueThe Netherlands

Telephone +31 (0)70 3743465Marco.Bartolozzi@nc3a.nato.int

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Contacting NC3AContacting NC3A

NC3A Brussels

Visiting address:

Bâtiment ZAvenue du Bourget 140B-1110 BrusselsTelephone +32 (0)2 7074111Fax +32 (0)2 7078770

Postal address:NATO C3 AgencyBoulevard Leopold IIIB-1110 Brussels - Belgium

NC3A The Hague

Visiting address:

Oude Waalsdorperweg 612597 AK The Hague

Telephone +31 (0)70 3743000Fax +31 (0)70 3743239

Postal address:NATO C3 AgencyP.O. Box 1742501 CD The HagueThe Netherlands