protcols for highly- dynamic airborne networks egemen k. Çetinkaya, justin p. rohrer, abdul jabbar,...
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Protcols for Highly-Dynamic Airborne NetworksEgemen K. Çetinkaya, Justin P. Rohrer, Abdul Jabbar, Mohammed J.F. Alenazi, Dongsheng Zhang, Dan S. Broyles, Kamakshi Sirisha Pathapati, Hemanth Narra, Kevin Peters, Santosh Ajith Gogi, and James P.G. Sterbenz
Department of Electrical Engineering and Computer ScienceUniversity of Kansas
1Presented by Curtis Kelsey
Overview• Introduction• Motivation• ANTP• AeroTP• AeroNP• AeroRP• AeroGW
• Simulation Results• Conclusions• Observations• References
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Introduction• Airborne network structure• Predecessors to ANTP• TCP/IP (UDP)
• 40 byte packet overhead• Static routing• Transport assumes stable path• No explicit cross-layer info exchange
• Mobile Ad-Hoc Network (MANET)• Routing relies on non-geographic based
links• Space Communications Protocol
Standards (SCPS-TP)3
Dynamic airborne environment
Introduction• Challenges• Limited power (limits range) • Limited RF-spectrum • Intermittent connectivity• Mobility (Speeds up to Mach 3.5)• Data corruption & loss
• TCP limits• Assumes all loss is congestion• Handshaking connection setup• Slow-start algorithm
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Motivation• Integrated Networked
Enhanced Telemetry (iNET) program identified a set of needs
• Predecessors do not serve this domain adequately
5Link Stability Analysis
Airborne network protocols
ANTP• Consists of 4 protocols• Aeronautical Transport
Protocol (AeroTP)• Aeronautical Network
Protocol (AeroNP)• Aeronautical Routing
Protocol (AeroRP)• Aeronautical Gateway
(AeroGW)• Why? Small contact duration
between two TAs.
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System architecture
AeroTP• Handshake-free connection setup• Transmit peak-rate immediately• Reduced ACK usage; Selective
Negative ACK (SNACK)• Header compression• Relay nodes buffer data for
retransmit• Connection state info memory• Modes• Reliable (fully TCP compatible)• Nearly-reliable• Quasi-reliable• Best-effort connections• Best-effort datagrams (fully UDP
compatible)7
Data Segment Structure
MACK Segment Structure
AeroTP
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• Control messages used for opening/closing connection• ASYN, ASYNACK,AFIN,
AFINACK• Opportunistic connection
establishment• Data & control overlap
State Transition Definitions
Connection Management
State Transition Diagram
AeroNP• IP-compatible network protocol• Replicates IP services• Provides• QoS – 4 levels
• AeroRP packets are classed the highest always• C2 given priority over application data
• Flow control• Implemented by a cross-layering mechanism with the iNET TDMA MAC layer
• Error detection• Corruption Indicator- header error check- cyclic redundancy code (HEC-CRC)
• Congestion Indicator (CI)• Specifies node congestion (defers packets from being forwarded)
• Geological Information• AN geological information (extended header)• Else, basic header
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AeroNP Packet Structure
AeroRP• Geographic routing protocol• Per-hop routing decisions• GS Updates• Additional mechanism for neighbor discovery• AN topology info or link info broadcast to other Ans• GSTopology/GSLink advertisements
• Operation Modes• Ferrying• Buffer• Drop
• Promiscuous• Beacon• Beaconless
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AeroRP• Phase 1• Neighbor discovery
• Active snooping• Beacon mode• GS Updates
• Phase 2• Data forwarding
• Determine next hop from topology table• Use time-to-intercept (TTI) metric• delta d = Euclidean distance• R = common transmission range• sd = recorded speed
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AeroGW• IP - AeroNP translation• TCP/UDP/RTP - AeroTP
splicing• Gateways are built into TAs
and GSs
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Simulation Results• Simulations performed using
ns-3• 1MB of data transmitted• AeroTP• Selective-repeat ARQ used
for reliable mode• FEC used for quasi-reliable
mode
15AeroTP fully-reliable mode
Average goodput Average delay
Cumulative goodput Cumulative overhead
Cumulative goodput comparison
Simulation Results• AeroRP• Velocity 1200 m/s• Node density 5 to 60
16Ae
roRP
Res
ults
Effect of node density on PDR
Conclusions• Existing TCP/IP protocols are not suited for highly-dynamic
airborne networks
• Prediction of link availability provides significant improvements in end-to-end data delivery (AeroRP)
• Further testing required. Planned testing on radio-controlled aircraft.
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Presenter’s Observations• Degradation of redundancy = throughput improvements
• Introduction of spatial cues increases system knowledge/forcast capability
• Cross-layer communication reduces redundancy without reducing information
• Per node burden is increased/ more costly nodes
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References• (Primary Paper) Cetinkaya, E., & Rohrer, J. (2012). Protocols for highly-dynamic airborne
networks. Proceedings of the 18th annual international conference on Mobile computing and networking, 411–413. Retrieved from http://dl.acm.org/citation.cfm?id=2348597
• Narra, H., Cetinkaya, E., & Sterbenz, J. (2012). Performance analysis of AeroRP with ground station advertisements. Proceedings of the first ACM …, 43–47. Retrieved from http://dl.acm.org/ft_gateway.cfm?id=2248337&ftid=1233995&dwn=1&CFID=118936837&CFTOKEN=41922410
• Sterbenz, J., Pathapati, K., Nguyen, T., & Rohrer, J. (2011). Performance Analysis of the AeroTP Transport Protocol for Highly-Dynamic Airborne Telemetry Networks. Retrieved from http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=ADA544743
• J. P. Rohrer, E. Perrins, and J. P. G. Sterbenz. End-to-end disruption-tolerant transport protocol issues and design for airborne telemetry networks. In Proceedings of the International Telemetering Conference (ITC), San Diego, CA, October 2008
• A. Jabbar, E. Perrins, and J. P. G. Sterbenz. A cross-layered protocol architecture for highly-dynamic multihop airborne telemetry networks. In Proceedings of the International Telemetering Conference (ITC), San Diego, CA, October 2008.
• E. K. ¸Cetinkaya and J. P. G. Sterbenz. Aeronautical Gateways: Supporting TCP/IP-based Devices and Applications over Modern Telemetry Networks. In Proceedings of the International Telemetering Conference (ITC), Las Vegas, NV, October 2009.
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Summary• Introduction• Motivation• ANTP• AeroTP• AeroNP• AeroRP• AeroGW
• Simulation Results• Conclusions• Observations• References
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