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Small robot assured communications in complex RF environments


TECHNOLOGY AREA(S): Electronics 

OBJECTIVE: Develop and demonstrate Radio Frequency (RF)-based communication system for small robots in cluttered, urban, underground, and jammed environments to detect and avoid areas of RF interference. Threshold data rates should support video. 

DESCRIPTION: Soldiers require a portable unmanned ground robot vehicle controlled at a distance of 300 meters or more in urban areas, inside buildings, in subterranean, active jamming environments, and complex RF environments. 1. The built-in radio should be able to operate in line-of-sight (LOS), multi-path environments, or beyond line of site (BLOS) environments. 2. Human weight-carrying limitations limit the total robot’s weight to 25 pounds. The radio equipment weight should not exceed 2 pounds, excluding batteries. 3. Radio equipment and antenna size should permit robot deployment through a 24-inch diameter manhole. 4. The robot will be powered from BB-2590s (2 batteries per robot with a total power available of 270 Watts), the radio will be powered from these batteries, but may have additional or auxiliary power for extended operations or power intensive applications. If the on board batteries are the sole source of supplied power then no more than 50% (135 watts) shall be used by the radio. 5. The robot will send back information in form of video, voice and data. High video resolution is required and low latency because of the mobility of the vehicle. The Army prefers to use video compression according to the H.264 standard and bit rate of at least 2 Megabits per second. 6. The radio should have the following capabilities: a. Multiple Inputs and Multiple Outputs (MIMO) b. Adhoc Mobile Mesh Networking c. Dynamic Spectrum Access d. Spectrum reuse to minimize multi-hop band width penalties e. A minimum of user replaceable frequency modules f. Dynamically adjustable power output based on link strength with the next radio link in the mesh network g. Radio interference mitigation strategies that allow the network to continue to function by reducing effects of jamming / RF interferences such as beamforming and spatial nulling Comparable equipment is available from SILVUSTM as a MIMO enabled radio StreamCasterTM 4200 or 4400 and from Persistent SystemsTM a similar radio, MPU5TM. These radios have many enhanced features but it is not clear if and what type of interference mitigation mechanism they have, one of the main features desired in any new candidate radio for the TARDEC application. The robot radio should meet or exceed these capabilities in similar or smaller size, power consumption and operation in an environment with strong interference signals. In addition, it should be able to either control or generate signals that will allow a controller to change the robot’s route so as to evade interference. Robot users will require training, preferably with a built-in system, or otherwise. Quick and efficient updates, including over a wireless connection, must be available. A minimum of four systems should be able operate within one square kilometer without suffering mutual interference. Three robots at a distance of two feet away from each other should not suffer from interference. The radio frequencies should lie within the Federal frequency bands and equivalent International bands for mobile as well as fixed devices. If the radio detects interference, coming from friend or foe, it should be able to either cancel the interference or dynamically switch frequency to an interference-free band. Multiple frequency bands and dynamic frequency agility should be considered as necessary. Environmental conditions, such as temperature and humidity must be accounted for. The antenna system is an integral part of the radio. When the robot communicates with the soldier, its relative orientation may change. Therefore its antenna sensitivity should be independent of azimuthal orientation. The soldier operator will need a controller with input and display capabilities to control the robot, in essence a handheld radio. This device should weigh no more than 2.5 pounds, including the batteries. Data processing and presentation capabilities may be built into the radios or in attached devices. Any interfaces to attached devices must be non- proprietary, compatible with the widest possible available standards. Robots may fall in enemy hands. A mechanism must be available so that the robot operating system and data can be rendered useless from a remote location. Protection mechanisms against hackers or “insiders” should also be investigated. 

PHASE I: Determine the technical feasibility of the described approach through study, modeling, simulation, or breadboard. Validate analytical predictions of performance of key elements of the proposed solution. Deliverables include a conceptual design of the proposed solution. 

PHASE II: Finalize the design from Phase I. Deliverable is a prototype of the proposed solution based on the Phase I work. Deliverable to be tested in a relevant environment (TRL 6). 

PHASE III: The prototype or its algorithms could be incorporated in military radio systems for small robots. The prototype or its algorithms could also be incorporated in commercial radios. These would be widely applicable to first responders, military, mining, and dense urban area users. 


1: Lee, Won-Yeol, and Ian F. Akyildiz. "Optimal spectrum sensing framework for cognitive radio networks." IEEE Transactions on wireless communications 7.10 (2008).

2:  Chou, Chun-Ting, Hyoil Kim, and Kang G. Shin. "What and how much to gain by spectrum agility?." IEEE Journal on Selected Areas in Communications 25.3 (2007).


4:  K. Grover, A. Lim, and Q. Yang, "Jamming and anti-jamming techniques in wireless networks: A survey," Int. J. Ad Hoc Ubiquitous Comput., vol. 17, no. 4, pp. 197–215, Dec. 2014.

5:  C. Zhou, T. Plass, R. Jacksha and J. A. Waynert, "RF Propagation in Mines and Tunnels: Extensive measurements for vertically, horizontally, and cross-polarized signals in mines and tunnels.," in IEEE Antennas and Propagation Magazine, vol. 57, no. 4, pp. 88-102, Aug. 2015.

6:  Persistent Systems

7:  Silvus Technologies Streamcaster

KEYWORDS: Spectrum, Cognitive Radio, Spectrum Sensing, Dynamic Frequency Selection, Transmit Power Control 


James Wills 

(586) 282-9297 

Dr. Georg Karawas 

(443) 395-7482 

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