A Proposed Communication Testbed for Project Jefex-04 and Sutter Iii

Wireless Communications Test Bed: Design and Deployment/Test Plan

Version 2.2

December 4, 2003

This document is in satisfaction of the WiFi Test Bed Phase 1 Contract SC03-034-191 with L-3 ComCept, Contractor Data Requirements List (CDRL) items A001, WiFi Test Bed Design and A002, WiFi Deployment and Checkout Plan

Timothy X Brown Interdisciplinary Telecommunications Electrical and Computer Engineering University of Colorado Boulder, 80309-0530 303-492-1630 [email protected] 1 EXECUTIVE SUMMARY

The L-3 Communications Corporation, ComCept Division, hereinafter referred to as “ComCept”, has engaged the University of Colorado to design, install and operate a wireless communications test bed. This is the final report for Phase I of this project, aimed at the test bed design and deployment/test plan.

This Design and Deployment/Test Plan document applies to Phase 2 of a multi-phased project intended to demonstrate and test Commercial Off The Shelf (COTS) wireless network technology. As Phase 3 is further defined, this document will be updated to address additional activity.

2 TEST BED OVERVIEW AND OJECTIVES

The test bed is being developed at three levels: the capabilities to be demonstrated; the experiments to demonstrate these capabilities; and the architecture that the experiments will be running on. We describe each in turn.

2.1 Capabilities to be demonstrated:

Communication networks between and through aerial vehicles are a mainstay of current battlefield communications. These use specialized radios in designated military radio bands. The aerial vehicles are high-value manned or unmanned vehicles.

This test bed will demonstrate the use of commercial off the shelf (COTS) radios based on low-cost WLAN technology combined with low-cost unmanned aerial vehicles (UAV). The purpose of these experiments is to demonstrate the performance capabilities of these low-cost radios and UAV in two broad scenarios shown in Error: Reference source not found.

NOC Scenario 1 where ad hoc networking with the Scenario 2 where ad hoc networking UAV increases ground node connectivity. between UAVs increases mission range.

Figure 1: Two broad classes of test bed scenarios.

2 2.1.1 Scenario 1: Ground-UAV-Ground In Scenario 1, radios on the ground are mounted in vehicles, carried by personal, or placed at fixed sites. The radios implement a wireless ad hoc (aka mesh) network whereby if a traffic source and destination are not in direct communication range, intermediate nodes will automatically relay the traffic from the source to the destination.

This generally provides good connectivity between ground nodes. When nodes become separated by distance or geography, then the network is disconnected. In these situations, the UAV serves as a communication relay between disconnected nodes on the ground. Ground nodes that are isolated from other ground users can reach each other through the UAV.

This scenario will demonstrate that ad hoc networks working with COTS WLAN radios can provide connectivity to widespread units. It will further demonstrate that low-cost UAVs can extend this connectivity over wider ranges and geography than is possible solely among ground units. It will demonstrate typical performance measures such as network throughput, latency, and availability that would be possible with these networks.

The following table lists the test configurations involved with this scenario. Measures of performance and effectiveness are provided in paragraph 2.1.3.

Test Configurations Ground—Ground Ground—Mobile—Ground Ground—UAV—Ground

The purpose of testing ground-to-ground and ground-mobile-ground communication performance and effectiveness is that it provides a baseline for UAV deployment to be measured against.

2.1.2 Scenario 2: Multiple UAVs In Scenario 2, we focus on an ad hoc network of UAVs. A UAV is on a long-distance mission. Communication range is limited because of power, weight, and volume constraints on the low-cost, light-weight vehicle. Communication range is extended by using intermediate UAVs to relay back to the control center.

The scenario will demonstrate that ad hoc connectivity between UAVs can greatly extend the low-cost, light-weight UAV mission profile. As in the first scenario, the second scenario will demonstrate typical performance measures such as network throughput, latency, and availability that would be possible with these networks.

The following table lists the test configurations involved with this scenario. Measures of performance and effectiveness are provided in paragraph 2.1.3.

3 Test Configurations UAV—UAV Ground—UAV—UAV

Various UAV-Ground configurations will be tested to identify any issues associated with joint coverage and other deployment scenarios.

2.1.3 Measures of Performance and Effectiveness The following table lists the measures of performance and effectiveness associated with scenarios 1 and 2.

Measures of Performance & Effectiveness Data Throughput Latency Packet Loss, Radio Packet Loss, Congestion Jitter Communication Availability Hardware Reliability Network Self-forming & Node-failure Recovery Time Mobility Impact Ease of Deployment/Transportability Remote Connectivity Range Data, Voice, Video, Web Page Communication

The effectiveness of the mesh network protocols will be measured by repeating these experiments with and without the protocols. Without the protocols, means that one or two nodes will be configured as access points and the remaining nodes will use standard 802.11 protocols to connect with the access points.

The effectiveness of voice, video, and web page communication will be a subjective quality of service measure. Data throughput, latency, packet loss, and jitter performance measures will be correlated to subjective quality levels.

4 2.2 Demonstration & Test Experiments In line with the two scenarios, we will perform two sets of experiments. In each of the experiments, packet data traffic will be generated by test sources on the nodes. Three regimes will be tested. In the light-load regime, low data rates will be sent with the purpose of measuring best-case traffic latency. In the medium-load regime, a range of loads will be presented to the network to measure the dependency of latency with loading. In the high-load regime, throughput limits will be measured.

The data obtained will be correlated to the types of service that can be provided under the deployment conditions involved. Service types include file transfer, web page receipt, voice, and video. Phase 3 may be used to demonstrate the actual services.

2.2.1 Experiment 1.1 UAV augmented ground communication In this experiment, we will have up to 8 nodes on the ground participating in an ad hoc network. The ground nodes will be placed so that with ad hoc relaying communication is possible. This experiment will be repeated with and without the UAV to measure its effect on performance.

2.2.2 Experiment 1.2 UAV enabled ground communication In this experiment the nodes will be divided into sub groups which because of range and intervening terrain will not be able to communicate directly. Low, medium, and high load experiments will be performed here also, but, the main goal will be to measure the availability of communication between the nodes with and without a UAV flying overhead.

2.2.3 Experiment 2.1 UAV range experiment This experiment will measure throughput and latency for a single link. The link will be either between a UAV and the ground, or, between two UAVs. The purpose will be to show over what ranges reliable communication is possible in these environments. This will clearly show the maximum bridging range possible with the UAV.

2.2.4 Experiment 2.2 UAV ad hoc communication In this experiment, up to three UAVs will loiter at points along a line away from the test range. The traffic will be between the farthest out UAV and a ground node in the vicinity of the closest UAV. This will show the potential for multiple UAVs to collectively have an extended communication range.

5 2.3 Test Bed Design The test bed will consist of three major components: the communication radio; the UAV platform; and network monitoring. These will be operated at the Table Mountain Antenna Range.

2.3.1 Test Site The Table Mountain National Radio Quiet Zone (NRQZ) is owned by the Department of Commerce and operated by the Institute for Telecommunication Sciences (ITS) approximately 10 miles north of Boulder, CO. The site is 2.5 miles by 1.5 miles on a raised mesa with no permanent radio transmitters in the vicinity. An aerial photo of the site is shown in Figure 1a and a view at ground level on the top of the mesa is shown in Figure 1b. A map of the site is shown in Figure 2.

(a) (b) Figure 1: Views of the Table Mountain National Radio Quiet Zone. Aerial view (a) and ground level view (b).

6 1000’ 300m 1000’ 300m

Public Road Circuit at FS2 Mesa Base

Figure 2: Map of Table Mountain. The grid lines are 1000ft (300m) spacing. FS1 and FS2 are powered fixed site locations. FS1 also has Internet connectivity. The green line highlights a public road circuit around the base of the mesa. Table Mountain has several facilities that make it ideal for our needs. First it is a large 2.5sq mi zone where radio communications is controlled. The top is flat and unobstructed. The facility itself is a mountain obstacle suitable for obstructing users on opposite flanks of the mountain as in Scenario 1 in Error: Reference source not found. It

7 is circled by public roads so that communication to or from the mountain can be easily set up from any direction. The site has buildings that can house equipment and provide AC power. Finally, it has several areas suitable for UAV flight operations (one is labeled in Figure 2).

2.3.2 Communication Radio The goal here is to have a simple robust design that can easily be tested and replicated. The radio is comprised of hardware and software components.

The radio hardware consists of a Soekris 4511 single board computer with 32MB of RAM and 256MB of CF storage connected to an 802.11b WLAN interface card, an RF amplifier with power that can be adjusted between 100mW and 1W, a GPS, and an antenna. These are mounted in a protective housing for the ground-based units, but, will be mounted inside the UAV airframe for the aerial units. The key here is that the radio is constructed of COTS components and only a single design is used for the different configurations. The weight without power supply will be approximately 1 kg. A picture of the ground based unit is shown in Figure 3. The unit in the picture shows the environmental housing containing the antenna and amplifier. The addition of the other components will add about one inch to the height of the radio package.

Figure 3: Radio unit in environmental housing. The dimensions are approximately 8 inches in each direction.

The 802.11b radios will operate on a single radio channel. The additional channels will be utilized for network monitoring. The RF amplifier will allow us to better control range and connectivity in the network. For instance, at lower powers the range will be less and more relay hops will be required for a source to reach its destination. The highest power is the maximum allowed by the FCC. At this level, the maximum range with 802.11b can be tested. The GPS is installed solely for monitoring purposes as described in Section 2.3.4. The antenna will be an integral part of the ground based unit housing, while on the UAVs will be mounted on the airframe. Power will come from several sources. The ground and aerial vehicles will use vehicle power. The fixed units will use AC line

8 power. Personnel units will have battery power. The fixed radios will be mounted on building roofs or low poles. Such locations are distributed throughout the test site. Vehicle mounted radios will be attached to the vehicle roof.

The radio will be controlled by a Linux operating system installed on the single board computer. Standard Linux drivers and interfaces are available for the radio hardware. The ad hoc networking will use a version of the Dynamic Source Routing (DSR) protocols implemented at the University of Colorado. The implementation is very flexible and will be modified for experimentation and monitoring.

2.3.3 UAV The UAV will be a modified version of existing designs developed at the University of Colorado. An example design is show in Figure 4. A CAD drawing for the airframe being developed for this project is shown in Figure 5. The payload bay is the shaded area and the dimensions (19.5x6.5x6.5) are shown in inches. These dimensions are the maximum space and available space is reduced by airframe ribs and tapering towards the tail. The designed performance includes a payload mass of 10lb, flight time of 90min, and cruise speed of 60mph.

Figure 4 Competition UAV similar to the vehicles currently under construction for Phase 2. This electric-powered vehicle carried and deployed a 5-lb payload box and flew with a simulated radome antenna (the white cylinder visible in the photograph above).

9 Figure 5: CAD drawing of the UAV design. The payload bay is the highlighted portion of the diagram.

2.3.4 Network Architecture & Monitoring A key aspect to the test bed will be the ability to monitor and collect data from the UAV and ground nodes. Remote monitoring capabilities will be built into the test bed so that remote observers will be able to monitor test bed performance. The pieces to the monitoring include test range monitoring, backhaul to a monitoring server, and a web based interface for remote users. The network architecture to be used for experimentation and monitoring is shown in Figure 6.

University of Table Mountain Colorado Monitor Ad hoc radio network Server Fixed Fixed Site 1 Mobile Site 2 Fixed Node Fixed Node Node Test Bed Internet Internet Mobile Gateway Node

Wireless Wireless Remote Router Router Monitor

Figure 6: Network Architecture & Monitoring

10 The test range monitoring will consist of additional software loaded on each ad hoc node. This will collect performance statistics with time and location stamps measured from the GPS. This data is periodically sent to a test bed monitoring gateway. The transfer to the gateway will use the underlying ad hoc network.

The total traffic is expected to be small and not significantly impact the network throughput. Though small, for experimental control, we would like to minimize the monitoring traffic use of the ad hoc network. For this purpose, fixed nodes in the network will also be connected via 802.11 wireless router operating on a different frequency. This separate radio is an Avaya Outdoor Router which is COTS equipment for static network wireless interconnectivity. This will facilitate extracting the monitoring data as quickly as possible from the ad hoc network under test and sending it to the test bed gateway outside of the ad hoc network.

The test bed gateway is a standard laptop computer. It will use available networking at the site to backhaul the monitoring data to a server located at the University of Colorado where the data will be collected and processed. Currently the backhaul uses a long distance 802.11 link to the ITS facilities in Boulder. ITS is installing fiber optic connectivity to Table Mountain which will be available with broadband backhaul early in 2004. The monitor server is a standard PC or Sun workstation (depending on server software and monitoring load). It will provide password protected web access to the monitoring data. The web interface will allow remote users to access the data and monitor the location and activity on the site in real time.

2.4 Test bed Equipment: The University of Colorado will provide:  UAV flight operations equipment.  Storage, backup, and distribution of software during development.  Server-class computers for monitor server.  RF test equipment such as Spectrum Analyzers and Signal generators.  Wireless table top test bed for early protocol testing.

ComCept has already provided:  Laptops, and desktops for network gateway and for software development.  Outdoor router equipment for interconnecting fixed sites.  WLAN cards for wireless network.

Remaining Equipment:  11 ad hoc radios, 8 ground based, 3 UAV based.  4 cigarette lighter to 110VAC inverters for vehicle mounted radios and other electronics  2 laptops with large screen for network monitoring.  1 Berkeley Varitronics Yellow Jacket WLAN 802.11b analysis tool for physical and MAC layer debugging.

11  2 Sharp Zaurus SL-5600 Linux based PDAs. Smaller personnel carried nodes.  6 Handheld radios for personnel coordination during testing operations.

2.5 Test Bed Security For the test bed we consider both physical and communication security. The Table Mountain facility is a fenced facility that includes storage and work buildings that can be locked. Equipment such as pole mounted antennas and outdoor routers can be left set up over several days. Portable radios, laptops, and UAV equipment will be stored in on site buildings or carried to and from the site.

To limit access to the wireless communication network, MAC filtering algorithms will be used. The hardware MAC address of every node on the test bed (approximately 20 in total) will be stored on the network devices and only packets that match one of these addresses will be processed. This will prevent casual users from gaining access to the network.

The monitoring server will require a password in order to have access to the remote monitoring facilities.

2.6 Time to Deploy and Teardown An experiment requires the monitoring network to be setup, radios to be mounted and deployed, and the UAVs launched. This section describes this procedure for a general test site.

Installing the monitoring equipment is potentially the most time-consuming portion of the deployment depending on assumptions. For this reason, the monitoring equipment will be setup and tested in the days before experiments. Power should be available at the gateway and each of the monitoring access points. The best case is that the site has a backhaul capability at one point and our equipment can be connected directly to this equipment. Otherwise a wireless backhaul will need to be installed which requires several days of site preparation, antenna mounting, antenna pointing, and configuration. With a ready backhaul, the set up time from arrival to field to remote monitoring availability:  Gateway setup ~ 0.5 hr o Work area designation / setup o Connection to backhaul o Server start and gateway to server communication start / test  Outdoor router install ~ 2 hr per router o Site designation o Outdoor router mount and power connect o Antenna mount, point, and radio connect o Outdoor router radio configuration

12 Multiple outdoor routers can be installed in parallel. If the outdoor routers are installed ahead of time and only need to be turned on and tested, then the monitoring setup time would be less than one hour.

Deploying the radios depends on the mounting configuration.  Fixed radio ~ 0.5 hr per radio o Site designation o Connect to power o Connect to network router o Turn on and test radio and network parameters  Vehicle mounted radio ~ 0.25 hr per radio + moving to test start position o Connect to vehicle power o Mount antenna on vehicle o Turn on and test radio and network parameters  UAV mounted radio ~ 0.25 hr per radio o Coordinate with UAV setup (radio is already mounted and powered) o Turn on and test radio and network parameters  Personnel carried radio ~ 10 min per radio o Check battery charge o Turn on and test radio and network parameters

The radios can be deployed in parallel. A team of two could set up a mixed group of 10 radios in less than two hours.

Launching the UAVs follows the following timeline from arrival to field to UAV launch:  UAV Ground Support ~ 0.5 hr o Grounds inspection o Work Area designation / setup o Launch and Recovery Area designation o Flight Support Equipment setup  Base Station(s) ~ 1 hr * o Aux. Power (generator or local power) o Laptop and Software startup o Radio Modem and Antenna setup  UAV Setup ~ 0.5 hr per UAV * o Payload setup / verification o Assembly o Batteries and Fueling o Weight and Balance check  Pre-Flight ~ 20 min per UAV o Com / Controls check o Aircraft Health and Status check o Flight Plan check / verification  Take-off

13 The total time to launch 3 UAVs would be approximately 3 hours including all setup.

The procedures to teardown would essentially be the reverse of the above procedures. They would be faster across the board and a complete tear down could be done in less than two hours. Packing for shipping via truck would require a half day of padding and boxing of all components. Air shipping would require additional time to separate or purge dangerous items (such as fuel containers) which may require ground shipping.

3 Work Timeline

Test bed development will follow the timeline shown in Error: Reference source not found.

Experiment Design

Site Design

Monitoring

UAV Dress Experiment Rehearsal Report

Radios System Integration & Test Comm. Protocols

Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun 2003 2004

Phase 1 Phase 2 Test Bed Design Platform Design & Build Test Plan Generation Integration, Deployment, Test Figure 8: Test bed component integration timeline.

 December, 2003 o Testing of ad hoc network protocols on CU table top test bed o Range testing using piloted general aviation aircraft o UAV design and construction o Finalize detailed test scenarios o Obtain local/state/federal approvals as required

 January, 2004 o UAV Air frame flight testing

14 o Interference between 802.11 and UAV control/telemetry radio testing o Test site backhaul setup and testing o Monitoring communication design and testing  February, 2004 o UAV-mounted radio tests during flights o UAV to UAV radio communication tests o Monitoring data collection tests at site

 March, 2004 o Ground and air operations coordination at test site o End to end remote monitoring tests o Component-by-component, link-by-link experiment shakedown

 April, 2004 o Integrated test bed and experiment shake down o Final Demonstration

 May, 2004 o Prepare final report o Additional Experiments as needed

 June, 2004 o Submit final report

4 Parallel Background Research

As part of the overall goal of the test bed demonstrations, alternative technologies are being researched and explored. These include alternative WAN, WLAN and radio technologies, alternative UAV airframes and control mechanisms, optionally piloted vehicles (OPV), and various monitoring and test bed suites. We expect when the test bed experiments are completed that we will be able to extrapolate from the test bed experiments to these technology alternatives in order to suggest future directions for this research.

5 Next Steps

This document describes the wireless test bed design and deployment/test plan from a high-level perspective. The schedule for development is aggressive, but, the University of Colorado has the expertise, resources, and commitment to execute in the time given. This document provides broad descriptions of the test bed experiments and we will refine these with precise experimental scripts as we develop the test bed further. As Phase 3 of the project is further defined, this document will be updated accordingly.