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Anti-Jamming Capability for RT-1944/U Radio


OBJECTIVE: The objective is to develop an affordable solution that provides anti-jamming capability to the existing RT1944 Radio used for communication between Littoral Combat Ship (LCS) seaframes and the Unmanned Vehicle s (UVs) that constitute part of the LCS Mission Packages. DESCRIPTION: The Littoral Combat Ship (LCS) Minecountermeasure (MCM) Mission Package (MP) will contain two types of unmanned vehicle to execute its mission: an Unmanned Surface Vehicle (USV) and a semisubmersible USV. The semisubmersible is the Remote Multimission Vehicle (RMMV), a snorkeling USV which is part of the AN/WLD-1 Remote Minehunting System (RMS). The Unmanned Surface Vehicles will be components of the Unmanned Influence Sweep System (UISS). The Multiple Vehicle Communications System (MVCS) provides the LCS MCM MP with the capability to simultaneously communicate with multiple RMMVs and USVs by providing common data link and network communication services. The RT-1944/U radio has been selected for the current MVCS increment for Line of Sight (LOS) communications between the LCS and the RMMV and the Unmanned Influence Sweep UIS USVs. However, the radio lacks an anti-jamming capability, an important MCM MP requirement. Reference (1) provides information about the radio. Under this topic, the Navy seeks retrofit anti-jamming capability onto a radio that wasn"t designed for it from the beginning. The requirement is important because hostile forces can use various radio jamming types such as Continuous Wave (CW) tone, swept CW tone, noise, clone signal, and transmitted pulsed signals to break the communications link to the unmanned vehicles by causing packet loss or preventing the receiver from being able to acquire or process any signals. To counter these types of threats, anti-jamming can be implemented by modifying the radio waveforms and installing directional antennas on the unmanned vehicles and, additionally, by using filters, which are required to allow multiple LCs seaframes to operate in the same area without co-site interference. References (2) and (3) are surveys of jamming and anti-jamming techniques provide useful overview information. The MVCS requirement is that the radio system shall meet all performance specifications when an LCS sea frame and its unmanned vehicles are in a 30 dB Jammer/ Signal (J/S) power density environment, as measured at the antenna plane of reference, and with the jamming signal being a CW tone located at any point in the operating bandwidth of the radio system (2.2 GHz to 2.4 GHz). The performance shall be achieved over a minimum of 270 degrees of azimuth coverage. The objective requirement is when the LCS sea frame and unmanned systems are in a 36 dB J/S power density environment. MVCS has directional antennas on the LCS sea frame but the RMMV and UISS have omni-directional antennas. The innovation required to replace the omni-directional antennas with directional antennas can include developing affordable phased array, null steered antennas for the two unmanned vehicles. A significant part of the innovation is doing anti-jamming in a packet based network. Most of the literature focuses on anti-jamming Global Positioning Satellite (GPS antennas) and assumes availability of a continuous transmitter that provides a signal to interference measurement whenever one is needed. In this case, a new packet needs to arrive in order to get an SNR measurement. Consequently, an antenna adaptation should not interfere with the basic functionality (control and coordination) of the network. The MVCS currently does not have filters for jamming signals that are in the operating band of the RT-1944/U radio system (2.2 GHz to 2.4 GHz). Currently available filter technology provides banks of filters tuned to specific frequencies. These filters are large and expensive. The unmanned vehicles do not have the space for such filters. The innovation needed is an affordable filter tunable to different frequencies and small enough to be used on the unmanned vehicles. Fully addressing the topic objective will likely require a multi-faceted approach. Proposals may address a total solution or components of a total solution; waveform modification; directional antenna; tunable filter. Other solutions that work in conjunction with these components will also be considered. Proposals should include the ant- jamming performance that will be gained from the anti-jamming technique(s) being proposed, and the modifications and additional weight required for the RMMV, UISS, and LCS sea frame. Solutions should be compatible with the requirements of the existing platforms and infrastructure. The Phase I effort will not require access to classified information. If need be, data of the same level of complexity as secured data will be provided to support Phase I work. The Phase II effort will likely require secure access, and the contractor will need to be prepared for personnel and facility certification for secure access. PHASE I: The company will develop concepts for its proposed solution to prevent jamming of the MVCS radio used on LCS platforms, the RMMV, and UISS USV that meet the requirements described above. The company will demonstrate the feasibility of the concepts in meeting Navy needs and will establish that the concepts can be feasibly developed into a useful product for the Navy. The company will establish feasibility by performing an analysis of its design concept against an in band CW tone to determine the anti-jamming performance that the design will provide to the MVCS radio system. The company will also assess the feasibility of integrating the solution into the radio systems on the three platforms in terms of space, weight, and platform modification. The small business will provide a Phase II development plan that will address performance goals, key technical milestones, and technical risk reduction. PHASE II: Based on the results of Phase I and the Phase II development plan, the small business will develop prototypes of its solution for evaluation on the three platforms to determine the solutions ability to meet the MVCS anti-jamming requirement, including the solutions ability t o operate within the total MVCS. The company will use the results to refine the prototype into a formal design suitable for a critical design review. The company will prepare a Phase III development plan to transition the technology to Navy use. PHASE III: If Phase II is successful, the company will be expected to support the Navy in transitioning the technology for MVCS use. The company will support PMS420 procurement, technology upgrades, integration, test, validation, certification, and qualification for implementation. PRIVATE SECTOR COMMERCIAL POTENTIAL/DUAL-USE APPLICATIONS: Anti-jamming technology for wireless networks has applications in police, civil defense, search and rescue, and industrial use wherever critical communications can be intentionally or inadvertently interfered with. REFERENCES: 1. Harris Corporation. Documentation for SeaLancetTM RT-1944/U Radio. Downloaded 15 April 2012. 2. Kandangath, Anil."Jamming Mitigation Techniques for Spread Spectrum Communication Systems." Downloaded 6 May 2012. 3. Mpitziopoulos, Aristides; Gavalas, Damianos; Konstantopoulos, Charalampos; and Pantziou, Grammati,"A Survey on Jamming Attacks and Countermeasures in WSNs."IEEE Communications Surveys & Tutorials, Vol. 11, No. 4, Fourth Quarter 2009. Pages 42-56.
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