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Transcript of 1 Grand Challenges in Achieving Dynamic Spectrum Access Preston Marshall preston.marshall @darpa.mil...
1
Grand Challenges in Achieving Dynamic Spectrum Access
Preston Marshallpreston.marshall @darpa.mil
Defense Advanced Research Projects AgencyAdvanced Technology Office
Connectionles
s
Connectionles
s
Networks
Networks
Radio-Isotope Micro-power
SourcesOne of
DARPA’s top 5 programs!
•Defense News, June 3, 2002
One of DARPA’s top 5
programs!
•Defense News, June 3, 2002
Wolfpack
Opinions expressed are those of the authors, and do not represent the position of DARPA, the Department of Defense, or the United States Government
PhotonicPhotonic
AvionicsAvionics
Retro-DirectiveNoise
CorrelatingRadar
RescueRadio
Adapt,Morph,
Proliferate
STORE
FORWARD
FLOODFLOODROUTEROUTE
STORE
FORWARD
FLOODFLOODROUTEROUTE
2006 Technology and Policy for Advanced Spectrum
Exploiting
Exploiting
2
The Next Challenges
• Dynamic Spectrum is on It’s Way to Accomplishment
• Key to Adoption is the Widest Possible Range of Benefit
• Better Spectrum Management is Important, ….– But May not be the Sole or Most Effective Argument
for its Adoption
• Need to Research Network Capability Enabled by Dynamic Spectrum– How Can We Exploit Truly Dynamic Networks?– Understand Physical Layer Bandwidth Sharing– Create (and Tear Down) Topologies Every Second
Why Just Put Dynamic Spectrum in Static Network Concepts?
3
Some Research Topics Enabled by Dynamic Spectrum (Partial)
• Adaptive Topology– Just in Time Connectivity– Don’t Do Topology Discovery – Do Topology Creation
• Non-Linear Effects Mitigation– Look at Total Energy – Not Just One Frequency
• Adaptive Spectral Bandwidth, Modes, ….• Optimization of Networks with No Fixed Bandwidth,
But some Interactions due to Shared Spectrum Resource– …. Oh, and update them every second!
• How Can Dynamic Spectrum and MAC Layer Operation Be Fused– Cooperative and non-Cooperative Channel Sharing
These Topics Have No EquivalentWired IP Metaphor
4
Discussion Points
• Overarching Thrusts of the DARPA Adaptive Networking Programs
• Current Technical Progress in Adaptive Spectrum
• Future Issues with Growth of non-Linear Effects (Front End Linearity)
• Leveraging Adaptive Spectrum to:–Lower Device Cost–Address Dense RF Environments–Create Adaptive Network and Services
5
XYZ.COM
Infrastructureless Networking:How Do I Network Without?
CentralCentralServersServers
CacheServers
KnownTopology
Frequency &Frequency &Network Network PlanningPlanning
Enter SearchIndex Index
ServicesServicesFiber &Wires
Cell Towers UnlimitedUnlimited
EnergyEnergy
6
Technology Implications
Current (Possible) Future
• Extensive Pre-Planning • Self Monitoring and Adaptation
• Fixed Network Structure • Self Forming
• Asymmetric, Hub-Spoke (ex. Cellular, VOIP)
• Peer to Peer
• Separate Network and User Equipment• Security at the Perimeter• Services and Info at Core
• User Equipment is the Network• Distributed Security • Info at Edge
7
How Can We Operate in a Wide Range of Environments, Missions, Densities, …
• Device Adaptation is Key to Needed Technology– Self Organize to Operate Without Infrastructure
• But Leverage Whatever Infrastructure is Available– Locate Unused Radio Spectrum
• While Ensuring no Interference to Other Users• Continuously Measure Environment• Avoid Need for Detailed Pre-planning, Deconfliction, …
– Morph Physical and Media Access Layers• Leverage Multi-path with MIMO• Select Waveforms, bandwidths, Access Control Mechanisms
– Apply Multiple Network Topologies• Optimize Packets, Streams, Multicasts, …
– Adapt Topology to Mission and Opportunities• Opportunistic (instead of Fixed) Topology• Continuously Adjust Topology to Meet Instantaneous Network Needs
• And Do All this at New Levels of Affordability– Essential to Achieving Required Density– Adaptation Can Mitigate Engineering Performance
Compromises and Use Less Costly Devices
8
Some Wireless Networking Research Programs at DARPA
• neXt Generation Communications (XG)– Develop Technology to Sense and Situationally Adapt Spectrum
Usage for a 10 Times Increase in Spectrum Access• Disruption Tolerant Networking
– Extending the Network Framework to Include Storage and Delivery for Episodic Networks• (Leverage Whatever Connectivity is Available)
• MnM Mobile MIMO– Extending Multiple Input/Multiple Output Technology to Mobile
Platforms for a 9 times increase in Throughput• Wireless Network After Next
– Develop the Technology for Dense, Low Node Cost (Under $500) Networks with High QOS
• Connectionless Networking– Dynamically Adapting Network Time Synchronization, Routing,
Energy Strategy to Achieve High Performance at 100th the Energy
9
Some Wireless Networking Research Programs at DARPA (Continued)
• Polarization Rotation Modulation– Encode Information in Polarization to Achieve a 9x More Space
to Space and Space to Ground Bandwidth
• Radio-Isotope Micro Power Sources– Power “Manufactured In” for Life of Device
• Ultra-wideband Networking (NETX)– Close in LPD Communications in Harsh Environments– Very High Accuracy Positioning
• Spatial Optical (Air/Air and Air/Ground)– “Wireless Does Not Always Mean RF!” – Adapting for the Reliability of RF, and Speed of Fiber– Air to Air and Air to Ground Providing for Wireless
Communications at Fiber Speeds (ORCLE)– Passive Optical Tags that provide 100’s of Kilobits/Sec
10
All Spectrum May Be Assigned, But…
…Most Spectrum Is Unused!
XG is Developing the Technology and System Concepts for DoD to Dynamically Access All Available
Spectrum
React
Formulate Best Course of Action
ReactReact
Formulate Best Formulate Best Course of ActionCourse of Action
Adapt
Transition network to new emission plan
AdaptAdapt
Transition Transition network to new network to new emission plan emission plan
Characterize
Rapid waveform determination
CharacterizeCharacterize
Rapid waveform Rapid waveform determinationdetermination
Sense
Real time, Low-power, wideband
monitoring
SenseSense
Real time, LowReal time, Low--power, wideband power, wideband
monitoringmonitoring
AutonomousAutonomousDynamic Dynamic SpectrumSpectrumUtilizationUtilization
DARPA XG Program
Goal: Demonstrate Factor of 10 Increase in Spectrum Access
Maximum Amplitudes
Frequency (MHz)
Am
pli
du
e (
dB
m)
Heavy UseHeavy Use
Sparse UseSparse Use
Heavy UseHeavy Use
Medium UseMedium Use
11
DARPA XG Program Investments
XG PrototypeXG Prototype& Demonstration& Demonstration
Spectrum AwarenessSpectrum Awareness
InterferenceInterferenceEffectsEffectsAssessmentAssessment
BehaviorBehavior
AdaptiveAdaptiveNetworkNetworkOperationOperation
Spectrum Measurements
Sensor Technology Signal Processing Algorithms
Distributed SensingAlgorithms
IEEE 1900IEEE 1900PolicyDescription
Spectrum AdaptiveNetworking
OptimizingStrategies
PolicyReasoning
Capabilityand Affordability
Dynamics
SubnoiseDetection
IncreasedAwarenes
s
PerformanceExperiments
Methodology
Framework &Semantics
EngineeringBasis
Non-InterferingOperation
Tactics
PolicyLanguage
EnforcementImplementation
Assessments
12
Transceiver
SystemStrategy
Reasoner
XG Operation
Select
Opportunities
PolicyReasoner
DevelopOptions Process
Request
Determine
Opportunities
Yes/No or Additional
Constraints
AccreditedPolicy
RF Info Acquisition
Sensing Loop
Policy Engine
RadioPlatform
Me
ss
age
Flo
w
RF ResourceRequest
RF Transmit Plan
13
What We Expect
• Simulation of Early Designs Using Recorded Spectrum Measurements Shows Significant Potential
Data from Lockheed Martin, Raytheon, and Shared Spectrum Company models
90% Spectrum Access at 90% Connectivity
Typical Spectrum Occupancy ~6%
10x increased spectrum access10x increased spectrum access
Multiple XG BandwidthsMultiple XG Bandwidths
14XG 098 v3
Non-Cooperative XG Network
Cooperative XG NetworkHomogenous
XG NetworkUGS
XG Nodes EmulateMultiple Radio Types
XG Policy Administratorand Analyzer
DemonstrationController
Wide Variety of Un-cooperative Nodes
Satelliteback-haulinstrumentation links
Wide Variety ofNon-cooperative Nodes
XG Prototype Developmentand Demonstration Schedule
• Conduct Series of Field Demos– Incrementally Add Performance
• Midterm Demonstration (Demo 3)– 6 Nodes with Core Capabilities– Provide Confidence to Stakeholders
• Final Demonstration – 25 XG Nodes with Advanced Capabilities– Show Capability for Transition
XG 008 v6
Task Name
DemonstrationsCriteria Dev’t1. Two Node2. Five Node3. Technology4. Initial System5. Upgraded System6. Final Configuration7. Final Urban8. Final Test Range
3
78
12
56
4
#1 demonstrates:2 nodesDemo Spectrum PolicyPerformance DetectorRendezvousFrequency Selection
# 6, 7, & 8 Demonstrates All Technologies
#2 adds:6 nodesGroup Behaviors
#3 adds:6 mobile nodesNetwork FunctionsLow Power Detector
#4 adds:Policy EnforcerUltimate Modem
#5 adds:25 mobile nodesEnhanced Detector
Phase
3aPhase 3b Phase 3c
XG 008 v6
Task Name
DemonstrationsCriteria Dev’t1. Two Node2. Six Node3. Technology4. Initial System5. Upgraded System6. Final Configuration7. Final Urban8. Final Test Range
3
78
12
56
4
#1 demonstrates:2 nodesDemo Spectrum PolicyPerformance DetectorRendezvousFrequency Selection
# 6, 7, & 8 Demonstrate All Technologies
#2 adds:6 nodesGroup Behaviors
#3 adds:6 mobile nodesNetwork FunctionsLow Power Detector
#4 adds:Policy EnforcerUltimate Modem
#5 adds:25 mobile nodesEnhanced Detector
Phase
3aPhase 3b Phase 3c
15
Demonstration Objectivesto Show:
• No Harm– Detects Potential Victims Before Causing Harmful
Interference– Disseminates Sensor Data For Spectrum Awareness– Incorporates Automated Spectrum Rule Enforcement
Algorithms
• XG Works– Demonstrates Automated Rendezvous and Frequency
Selection– Enables Node Transitions Between Networks– Conducts Operations With Multiple Cooperative and Non-
Cooperative networks
• Adds Value– Increases Spectrum Access and Communications Capacity– Implements No Setup Networking– Implements Automated Spectrum Rule Updating Algorithms
16
XG Radios (mobile)
NC DoD Radio (fixed)
Equipment Installed in Vans
NC DoD Radio and Test Equipment XG Radio and Test Equipment
Legacy Radio Link
XG Link
17
XG Behaves!!
With XG – Sense and Jump Without XG – Signals Collide
With XG -- Moved Before Interfering
XG halts transmissions when RX link is broken (dropout caused by propagation losses)
Near instantaneous channel reestablishment
Successful channel reestablishment during extended link dropout
18
Speeded Up Transit of XG Past a Set of Non-Cooperative Radios
• Colors are Different Frequencies
• Dots are XG Radios• Triangles are non-
Cooperative Networks• XG’s Always try to be
on Lowest Frequency Possible (Blue)
19
Simple Scenario, With and Without XGMilitary PSC-5 FM Radio Victim
1.E-05
1.E-04
1.E-03
1.E-02
1.E-01
1.E+00
11
:40
:04
11
:40
:14
11
:40
:24
11
:40
:34
11
:40
:44
11
:40
:54
11
:41
:04
11
:41
:14
11
:41
:24
11
:41
:34
11
:41
:44
11
:41
:54
11
:42
:04
11
:42
:14
11
:42
:24
Time
p
0
200
400
600
800
Victim Radio Bit Error Rate Without XG
Scenario Time
Bit
Err
or R
ate
XG Caused Noise
No
de
Se
pa
rati
on
(m
trs
)
1.E-05
1.E-04
1.E-03
1.E-02
1.E-01
1.E+00
12:5
5:05
12:5
5:15
12:5
5:25
12:5
5:35
12:5
5:45
12:5
5:55
12:5
6:05
12:5
6:15
12:5
6:25
12:5
6:35
12:5
6:45
12:5
6:55
12:5
7:05
Time
0
200
400
600
800
Bit Error Rate With XG
Bit
Err
or R
ate
Typical impulsive Environmental Noise
Scenario Time
No
de
Se
pa
rati
on
(m
trs
)XG Node
Interferes within 600 meters
Only Background
Impulsive Noise
20
XG Strategy
• XG is not the universal solution to all problems– Some cases are likely to be too hard to deal with– One hard case does not does not invalidate XG usefulness
• Testing to be focused on identifying and validating– low hanging fruit– candidate spectra that are unsuitable for sharing
• Anticipate incremental adoption on a “Not to Interfere” basis– Military on military (10x greater packing of radios)– Military on shared (Technical framework for sharing)– Opportunistic (Widespread NIB operation)
Not Essential to Establish New Regulatory Framework, either
Nationally or Internationally
Not Essential to Establish New Regulatory Framework, either
Nationally or Internationally
21
Policy Compliant Behavior
• Rejected Notion that General Solution to Adaptive Radio Could be “Just Code”– Almost 200 Sovereignties– Thousands of Bands– Emerging Technologies
• Investing in Computer Science Structure for Policy Reasoning– Reasoning Technologies to Control
Real-Time Process– Declarative Language Expression– Provable Policy Expression and
Implementation • Partitioned Policies into Two
Categories– Policy Enforcement (Permitted
Operation)– Optimizing (Network and Above)
Secretary of State Telecommunications & Public Information
Secretary of State Secretary of State Telecommunications Telecommunications & Public Information& Public Information
Ministry of Communications
Ministry of Ministry of CommunicationsCommunications
Regulatory Authority of
Communications & Posts
Regulatory Regulatory Authority of Authority of
Communications Communications & Posts& Posts
Regulatory Authority of Telecommunications
and Posts
Regulatory Authority of Regulatory Authority of Telecommunications Telecommunications
and Postsand PostsMinistry of Public Works, Transport,
& Water Mgt
Ministry of Public Ministry of Public Works, Transport, Works, Transport,
& Water Mgt& Water Mgt
Department of Trade & Industry
Department Department of Trade & of Trade & IndustryIndustry
Ministry of Science,
Technology, & Innovation
Ministry of Ministry of Science, Science,
Technology, & Technology, & InnovationInnovation
Ministry of Industry,
Employment, & Communications
Ministry of Ministry of Industry, Industry,
Employment, & Employment, & CommunicationsCommunications
Ministry of Transport &
Communications
Ministry of Ministry of Transport & Transport &
CommunicationsCommunications
Ministry of Civil Affairs &
Communications
Ministry of Civil Ministry of Civil Affairs & Affairs &
CommunicationsCommunicationsMinistry of
Economics, Finance, &
Industry
Ministry of Ministry of Economics, Economics, Finance, & Finance, &
IndustryIndustry
Ministry of Transport &
Communications
Ministry of Ministry of Transport & Transport &
CommunicationsCommunications
Ministry of Infrastructure
Ministry of Ministry of InfrastructureInfrastructure
Ministry of Transport, Posts, &
Telecommunications
Ministry of Transport, Ministry of Transport, Posts, & Posts, &
TelecommunicationsTelecommunications
Department of Public
Enterprise
Department Department of Public of Public
EnterpriseEnterprise
Regulatory
Inte
rope
rabi
lity
Device
Network
RegionalNational
• City-Specific Spectrum Policy
• Waveform Mode• Device Duty Cycle
Limits • Network
Admission Hardware Limits
Security
Admission
Routing
Addressing
Transport
Constantly Shifting
Intersection
22
Future Cognitive Components Will Not Come From Just One Source
Spectrum Policy
Country #1Spectrum
PolicyCountry #2
Device Mfr.Device Mfr.ConstraintsConstraints
Network Network ServiceService
#1#1
Network Network ServiceService
#2#2
IndustryStandard A
IndustryStandard BIndustry
Standard C
Enterprise 2 Enterprise 2 PoliciesPolicies
Enterprise 1 Enterprise 1 PoliciesPoliciesSecuritySecurity
ModeMode SecuritySecurityModeMode
InteroperableInteroperableMode # 2Mode # 2
InteroperableInteroperableMode # 4Mode # 4
InteroperableInteroperableMode # 1Mode # 1
InteroperableInteroperableMode # 3Mode # 3
PersistencePersistencePolicyPolicy
TopologyTopologyOptimizingOptimizing
NetworkNetworkOptimizingOptimizing
MultipleDynamically InteractingCognitiveProcesses
Spectrum LeasingPolicy
23
• Anticipate Incremental Adoption on a Not to Interfere Basis (NIB)– Military on Military (10x Greater Packing of Radios)– Coordinated Sharing (Military
with Coordinated Users)– Opportunistic (Widespread
NIB Operation)
• Incremental Rollout Enables Near-Term Deployment as Appliqué Into Existing Systems– Add Protocols and Adaptation
Software to Digital Networking Radios
– Add Spectrum Sensing Algorithms
XG Program – Transition
Not Necessary to Establish New RegulatoryNot Necessary to Establish New RegulatoryFramework, Either Nationally or InternationallyFramework, Either Nationally or Internationally
24
DARPA Tuner Study Conclusion
•Looking at High Density RF Environments– Even With Ultra-High Quality Front Ends,
Inter-Modulation Will Cause 20 dB (100 Times) Increase in Noise for Wideband Front Ends in Contemplated Density
•Narrow Analog Filters Essential to Survival in Typical Military Dense RF Environments– Can Not Throw Linearity at the Problem– Energy Costs of High Linearity
Unacceptable in Battery Devices•Responsive Strategy
– Accelerate High Performance Tuneable Filter Technology
• 100’s of Individual Filter Settings/Octave• DARPA ASP Program
– Do Not try to Survive on Any Given Frequency
– Use Adaptive Spectrum to
Resolve Remaining
In-Filter Conflicts
INPUT SIGNAL
Post-RF Preprocessing
Non-LinearDistortions
Results Shown for 10w, 10dB Gain, IIP3 = 50dBm (Ultra High Quality) LNA w/ Prime Pwr > 12 Watts
Noise Floor Increases 20
dB!
Even Dynamic Spectrum Can Not Help the Radio with 20 db of Intermod!!
Spectrum Appears to Offer Lots of Opportunities
25
Adaptation Is Key• Without Tunable Ultra-High Q
Front End Filters (Unavailable), Reliable Wideband Radio Operation in Dense Spectrum Can Not be Assured– Legacy Narrow and Fixed Band
Radios Could Rely on Fixed Filters
– Can De-conflict Intended Frequencies, but not Non-Linear Products
– Co-Site Like Situations More Common
– Large Energy Costs for Linearization Unacceptable for Many Applications
• Spectrum Adaptation (as in XG) Essential to Move Around Strong Signals Automatically
0
1
2
3
4
5
6
7
8
-20 -10 0 10 20 30Input IP3
Min
imu
m P
os
sib
le T
un
er
Po
we
rBut,… Even 20
dBm of IIP3 requires at least 5
watts of Prime Power (Ideally)
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
-80 -60 -40 -20 0 20 40 60Input IP3
% le
ss 5
dB
Int
erm
od N
oise
Fixed Filter
No Filter
Tunable Filter
Feasible
Region
IIP3 > 20dBm Required to
Avoid 50% of Spectrum
Having 5 dB Intermod Noise
26
DARPA Director’s Vision of Communications Technology Evolution
Dynamic Spectrum Future Networks
Mobile Self-Forming
MEMS/NEMS
Packet Radios
Topology Optimizer
Cognitive Technology
Mobile Networked MIMO Program – MNM
Future Combat System – Comms Program - FCS-C
Global Mobile Program - GLOMO
Small Unit Operations-Situational Awareness System Program– SUO
SAS
Wireless Network after Next Program - WNAN
Control-Based Mobile Ad-Hoc Networking Program - CBMANET
Next Generation Comms Program - XG
Information ProtectionDynamic Quarantine of Computer Based Worm Attacks Program – DQW
Defense Against Cyber Attack in MANETs Program – DCMANET
Key to Infrastructureless Comm Key to Infrastructureless Comm
27
What We Need to Do Next
• Develop the Technology to: – Adapt Network in order to Operate Radios with 20 db Lower
SFDR and Linearity at the Same Performance• Existing Programs Provide toolkit for the Physical Layer, but Have
no Network to Exploit the Opportunities – Scale Understanding to Ultra-Large Mobile Networks– Extend Concept of Packet Networks to Directly Implement
Tactical Broadcast /Streaming Service – Operate Multiple Network Technologies Simultaneously to
Meet Each Mission QOS Need
• Achieve:– 100 Time Reduction in Network Radio Cost ($500 per 4
Channel Radio)– 10 Time Reduction in Network Area Coverage Cost– 1,000 Times Increase in Demonstrated and Objective Network
Scale (100’s to 100,000’s)– Higher Goodput/Throughput Ratio to support
Broadcast/Netted Voice/Video
28
Adaptive Radio Uses All Network Layers to Resolve Issues
MIMOMIMO
BeamBeamFormingForming NullingNulling
TopologyTopologyPlanningPlanning
SpectrumSpectrumPlanningPlanning
DeviceDeviceSpurs, …Spurs, …
RelocateAround
Spur
SpectrumToo Tight
Re-planAcross
Network
Re-planTopology
UnavoidableStrongSignal
NeedMore Range
Each Technology Can Throw “Tough” Situations to other More Suitable Technologies without Impact on User QOS
No Good MIMO Paths
Network-Wide
Radio Device
Link
Move to New Preselector
BandStrongStrong
NeighborNeighborSignalSignal
DynamicDynamicSpectrumSpectrum
Dynamic Spectrum Key to Adaptive
Networking
29
The DARPA WNAN Network & Radio
• Optimizing Layer– “Looks Through” Lower Layers to Make
Globally Optimizing Decisions• Topology Layer
– Makes the Network Topology Achievable by the Radios. Plans Network Around Spectrum, Power, Channel, …
• Network Layer– Multiple, Unique Networks Optimized for
Stream (Voice and Video), Broadcast (GBS-Like) and Packet Services
• MAC Layer– Adaptive Spectrum, MIMO, and
Beamforming Modes• PHY Layer
– Commercial Component-Based– Mitigated H/W Weaknesses – Standard RF Slice Widely Replicated
Global and LocalOptimizing
New WNANTechnology
New WNANTechnology
DynamicSpectrum
(XG)
MIMO(MnM)
COTS-Based Mil Radios
Existing Program Technology
New Program Technology
CBMANET(As
Applicable)
CBMANET(As
Applicable)
MEMS Filters and Sensors (MTO)
30
Hardware Platform
• Single RF Processing Slice Replicated to form 1, 2 and 4 channel MIMO/XG/ Beamforming Capable Radios
• Reverse of Standard ATO Approach– Build Early H/W and Incrementally Add Network
Capability– Have Early Demonstrator of DARPA Philosophy
and Technology
• Approach:– Develop early Prototypes By Leveraging
Available Commercial Chips (TV-Tuners and Others)
• Use Cost Pressure to Force Innovation for Lower Cost/Higher Performance
• Contribution from MTO New Analog Signal Processing (MEMs Filter Program) Essential
Frequency 900 MHz to 6 GHz
Power 36 dBw
SFDR 60 dB
IP3 What it is!
Peak 10 Mbps
Control- Based MANET
NewTechnology
NewTechnology
DynamicSpectrum
(XG)
MIMO(MnM)
COTS Chip Set
GPS Access Interleaved by Connectionless Networking
Digital Post Processing
$ 500 per 4 Channel Node, Spectrally Adaptive, MIMO, Beamforming, Member of Four Simultaneous Subnetworks, Ultra Low Latency
31
Conclusion
• Dynamic Spectrum Technology is: – Maturing– Being Tested and Demonstrated Now!– Being Worked into the Regulatory Process
• Fundamental Physics-based Constraints Limits Effectiveness of Frequency Assignment (Co-channel) Management in Dense RF Environments– May Offer Opportunity for Nearer Term Affordability and
Performance Benefits
• Need to Start Research into how to Best Exploit the Dynamics that Adaptive Spectrum Makes Possible– Not Clear that this is Evolutionary from Current Technology
• Dynamic Spectrum Access is the Key Technology Needed to Enable a New Generation of Low Cost, Adaptive Wireless Network Devices
32
Thank You!
Preston Marshallpreston.marshall @darpa.mil
Defense Advanced Research Projects AgencyAdvanced Technology Office
Connectionles
s
Connectionles
s
Networks
Networks
Radio-Isotope Micro-power
SourcesOne of
DARPA’s top 5 programs!
•Defense News, June 3, 2002
One of DARPA’s top 5
programs!
•Defense News, June 3, 2002
Wolfpack
Opinions expressed are those of the authors, and do not represent the position of DARPA, the Department of Defense, or the United States Government
PhotonicPhotonic
AvionicsAvionics
Retro-DirectiveNoise
CorrelatingRadar
RescueRadio
Adapt,Morph,
Proliferate
STORE
FORWARD
FLOODFLOODROUTEROUTE
STORE
FORWARD
FLOODFLOODROUTEROUTE