1. Protcols for Highly- Dynamic Airborne Networks Egemen 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 Science University of Kansas 1 Presented by Curtis Kelsey

2. Overview Introduction Motivation ANTP AeroTP AeroNP AeroRP AeroGW Simulation Results Conclusions Observations References 2

3. 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

4. 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 4

5. Motivation Integrated Networked Enhanced Telemetry (iNET) program identified a set of needs Predecessors do not serve this domain adequately 5 Link Stability Analysis Airborne network protocols

6. 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. 6 System architecture

7. 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

8. AeroTP 8

9. 9 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

10. AeroNP IP-compatible network protocol Replicates IP services Provides QoS – 4 levels AeroRP packets are classed the highest always C 2 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 10 AeroNP Packet Structure

11. 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 11

12. 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 s d = recorded speed 12

13. AeroGW IP - AeroNP translation TCP/UDP/RTP - AeroTP splicing Gateways are built into TAs and GSs 13

14. AeroGW 14

15. 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 15 AeroTP fully-reliable mode Average goodputAverage delay Cumulative goodput Cumulative overhead Cumulative goodput comparison

16. Simulation Results AeroRP Velocity 1200 m/s Node density 5 to 60 16 AeroRP Results Effect of node density on PDR

17. 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. 17

18. 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 18

19. 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=2348597http://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 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 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. 19

20. Summary Introduction Motivation ANTP AeroTP AeroNP AeroRP AeroGW Simulation Results Conclusions Observations References 20

21. Questions? 21