# A Systematic Literature Review on Military Software Defined Networks
## 5 Additional Contributions
### Software Defined Radio  
[PERSON] et al. [117] discussed Software Defined Radio, emphasizing the fact that SDR is a major evolution of radio technologies, and a convergence of different pre-existing fields. [PERSON] [118] discussed SDR challenges and opportunities, while [PERSON] et al. [119] presented SDR architecture contributions for next generation space communications. [PERSON] et al. [120] presented a best-effort approach to Data Leakage Prevention (DLP) for inter-organizational Re-configurable Radio Systems (RRS)-based networks. The proposed architecture makes use of data mining techniques, and an efficient \(n\)-dimensional clustering algorithm which has previously been successfully used for real-time anomaly detection in critical infrastructure protection. [PERSON] et al. [121] explored automated, dynamic large-scale radio reconfiguration, through the implementation and characterization of three alternative re-configurable radio designs. These implementations seek to quantify the impacts of implementing large-scale radio re-configuration through SDR application management, enabled by SDR architectures. [PERSON] et al. [122] presented selected research activities at the Air Force Research Laboratory's Space Vehicles Directorate (AFRL/RV), in the arena of software-defined and cognitive radio technology for military space-based applications. Current efforts include development of SDR controlled satellite ground-stations, networked ground station operations for increased efficiency, as well as research into new radio control algorithms and methods of dynamic waveform reconfiguration for satellite applications. [PERSON] et al. [123] focused on ubiquitous wireless network accessibility, and described the necessary research directions for advancing the SDR technology as a facilitator of ubiquitous access. SDR is used in different applications. [PERSON] et al. [124] described a methodology for jamming traditional combat net radios using commercial SDR mounted on unmanned aerial vehicles, while the authors proposed tactics, techniques, and procedures for employing this system within an infantry batttalion. [PERSON] [125] explained recent changes to the JTRS (Joint Tactical Radio System) program, and its new approach to delivering wireless networking capabilities to the warfighter. All JTRS products are based on SDR technologies, in order to enable a more scalable and extensible radio system in comparison to a system composed of dedicated hardware. [PERSON] et al. [126] investigated received signal strength indicator (RSSI) based localization, which attracts a lot of interest because of its simplicity. In order to improve the performance of RSSI based localization, the authors proposed a bias reduction algorithm. [PERSON] et al. [127] described the networking usage requirements for MANET over legacy narrowband tactical waveforms. First, the authors discussed the common characteristics of legacy tactical radio waveforms and the implications of such characteristics for the MANET implementation. Then, an actual MANET implementation over a legacy tactical radio waveform on an SDR is presented with the results of actual field tests. [PERSON] [128] presented a resilient wireless communication architecture based on Moving Target Defense (MTD), and Software Defined Radios (SDRs). The approach achieves resilient operation by randomly changing the runtime characteristics of the wireless communications channels between different wireless nodes, aiming to make it extremely difficult to successfully launching attacks. [PERSON] et al. [129] overviewed the NATO initiative to develop tactical waveform specifications for VHFand UHF communications that are free of intellectual property. These waveforms are for multinational interoperability between NATO nations and coalition users, and can be implemented on SDR platforms in tactical radios. The security architecture has been included in the design from the beginning, and the performance is targeted to be vastly improved over legacy waveforms.