PI: Will Ivancic/GRC Co-PI: Don Sullivan/ARC Real-Time and Store-and-Forward Delivery of Unmanned Airborne Vehicle Sensor Data PI: Will Ivancic/GRC Co-PI: Don Sullivan/ARC 10 Minute Loop of 18 Slides

10 Minute Loop of 18 Slides

10 Minute Loop of 18 Slides

Goals Develop and deploy a mobile communication architecture based on Internet Technologies that will be utilized on the Global Hawk Unmanned Arial Vehicle (UAV) for atmospheric research. Improve the data throughput and utilization of current UAV remote sensing by developing and deploying technologies that enable efficient use of the available communications links. 10 Minute Loop of 18 Slides

Approach Use and/or Develop Standard Store and Forward Disruption Tolerant Networking Technology Implement improvements to the Saratoga transport protocol to include rate-limiting and, if needed, congestion control features Develop a protocol that advertises link properties from an RF modem to an end node 10 Minute Loop of 18 Slides

Missions 10 Minute Loop of 18 Slides

Global Hawk Operational Capability Four Mission Regions, with Arcs of Constant On-Station Times 10 Minute Loop of 18 Slides

GloPac Mission Conducted in support of the Aura Validation Experiment (AVE). Aura is one of the A-train satellites supported by NASA Earth Observation System. Will encompass the entire offshore Pacific region with four to five 30 hour flights. Will fly over the Pacific ocean, from the North Pole to the equator for its first Atmospheric Chemistry experiment. The flights are designed to address various science objectives: Validation and scientific collaboration with NASA earth-monitoring satellite missions, principally the Aura satellite, Observations of stratospheric trace gases in the upper troposphere and lower stratosphere from the mid-latitudes into the tropics, Sampling of polar stratospheric air and the break-up fragments of the air that move into the mid-latitudes, Measurements of dust, smoke, and pollution that cross the Pacific from Asia and Siberia, Measurements of streamers of moist air from the central tropical Pacific that move onto the West Coast of the United States (atmospheric rivers). 10 Minute Loop of 18 Slides

Genesis and Rapid Intensification Processes (GRIP) Better understand how tropical storms form and develop into major hurricanes. Deployment of new remote sensing instruments for wind and temperature that can lead to improved characterization of storm structure and environment. NASA plans to use the DC-8 aircraft and the Global Hawk Unmanned Airborne System (UAS) The spaceborne, suborbital, and airborne observational capabilities of NASA put it in a unique position to assist the hurricane research community in addressing shortcomings in the current state of the science. 10 Minute Loop of 18 Slides

Mobile Communications Architectures 10 Minute Loop of 18 Slides

GloPac Communication Network Reconnected around +/- 70 Degrees Latitude Disconnection Over the North Pole GE 23 Store Forward 3 Mbps Bidirectional Link NASA Dryden L3-Com Ku-Band Transportable Terminal 10 Minute Loop of 18 Slides

GRIP Communication Network Ku Band Satellite - A Ku Band Satellite - B > 3 Mbps Bidirectional Link NASA Dryden Disconnection During Satellite Handover Due to Repointing L3-Com Ku-Band Terminal 10 Minute Loop of 18 Slides

Future Communication Network Ku Band Satellite Disconnection During Handover Between Service Providers NASA Dryden Service Provider A Service Provider B Internet 10 Minute Loop of 18 Slides

Why Store and Forward Global Hawk has large periods of disconnection from the network and needs to store data during disconnection and transmit data during times of connectivity Store and forward can break control loops Allows for link by link transport protocol optimization. NASA Dryden Control Loop 10 Minute Loop of 18 Slides

Layer-2 Triggers 10 Minute Loop of 18 Slides

Smart Modems Modem's transmitting and receiving link rates can be varied over time due to the following: Adaptive coding Changes in Modulation to suit the channel characteristics. Changes in transmission rate to suit the channel characteristics Rate mismatch between RF link and local area network. Serial connections are less of a problem as clocks can be controlled by modem (at least the receiving clock) Ethernet connections are becoming standard and result in rate mismatch between the LAN interface and the RF link. RF 3 Mbps Ethernet 100 Mbps Ethernet 1 Gbps Application Modem 10 Minute Loop of 18 Slides

Issue / Problem In order to condition traffic and get the most out of the RF link, applications need to know the modem's link status (e.g. Link Up/Down, Link Unreliable, Data Rates). Figure 1 corresponds to existing commercial imaging satellites Figure 2 is more generic A standard method is needed for applications to understand the down stream modem’s RF link status and adjust that application traffic pattern accordingly. Modem RF 3 Mbps Serial Link Application Figure 1 Modem RF 3 Mbps Ethernet 100 Mbps 1 Gbps Application Figure 2 10 Minute Loop of 18 Slides

Solution Develop a standard protocol that provides link status conditions Should be able to provide wide area network (WAN) radio reachback link status to applications that may be multiple hops away. Uses Applications can adjust to link state Route Optimization Useful for multi-homed systems RF 256 kbps Modem Ethernet 100 Mbps Application RF 3 Mbps Modem 10 Minute Loop of 18 Slides