A Systematic Literature Review on Military Software Defined Networks <s> Software Defined Radio <s> The Wireless World Research Forum (WWRF) work area on Emerging Technologies pursues the identification of technologies furthering the evolution of future wireless communication systems. Within this exercise, the progression of telecommunications in the next decade is characterised as the convergence towards an IP-based core network providing ubiquitous seamless wireless access in an hierarchical and hybrid self-organising network environment. Whereby, the various radio access systems and the IP based core network will handle interworking, mobility management, and roaming. The key to facilitate this convergence on the access side are Reconfigurable Software Defined Radio (SDR) equipments. Subscribers and users will greatly benefit from this federated telecommunication environment, but only, if they are equipped with a single integrated reconfigurable multi-mode multi-band terminal. Such terminals have to operate in either several or even all the different access environments available and they have to support the whole range of applications that are usually accessible on devices specific for the single access technology in the heterogeneous network environment. This article outlines and describes the SDR Research issues identified in workarea 3 of WWRF (New Communication Environment and Heterogeneous Networks), it focuses and describes the three major research directions followed: High Level System Requirements, SDR Hardware Architecture and System and Software Architectures for Reconfigurable communication systems. <s> BIB001 </s> A Systematic Literature Review on Military Software Defined Networks <s> Software Defined Radio <s> The Joint Tactical Radio System (JTRS) is one of the Department of Defense's (DoD) core transformational programs. The Joint Program Executive Office (JPEO) JTRS manages the acquisition of this critical new capability. The mission of the JPEO JTRS is to develop and produce a family of interoperable, affordable software defined radios at moderate risk which provide secure, wireless networking communications capabilities for Joint forces. This paper will explain recent changes to the JTRS program and its new approach to delivering wireless networking capabilities to the warfighter. <s> BIB002 </s> A Systematic Literature Review on Military Software Defined Networks <s> Software Defined Radio <s> Mobile Ad Hoc Networking (MANET) is a key technology enabler in the tactical communication domain for the Network Centric Warfare.[1] A self-forming, self-healing, infrastructure-less network consisting of mobile nodes is very attractive for beyond line of sight (BLOS) voice and data range extension as well as tactical networking applications in general. Current research and development mostly focus on implementing MANET over new wideband data waveforms. However, a large number of currently fielded tactical radios and the next generation software defined radios (SDR) support various legacy tactical radio waveforms. A mobile ad hoc network over such legacy tactical radio links not only provides war fighters mission critical networking applications such as Situational Awareness and short payload messaging, the MANET nodes can also support voice and legacy data interoperation with the existing fielded legacy radios. Furthermore, the small spectrum footprint of current narrowband tactical radio waveforms can be complementary to the new wideband data waveforms for providing networking access in a spectrum constrained environment. This paper first describes the networking usage requirements for MANET over legacy narrowband tactical waveforms. Next, the common characteristics of legacy tactical radio waveforms and the implications of such characteristics for the MANET implementation are discussed. Then an actual MANET implementation over a legacy tactical radio waveform on a SDR is presented with the results of actual field tests. Finally, several improvements to this implementation are proposed. <s> BIB003 </s> A Systematic Literature Review on Military Software Defined Networks <s> Software Defined Radio <s> Software Defined Radio (SDR) may provide flexible, upgradeable and longer lifetime radio equipment for the military and for civilian wireless communications infrastructure. SDR may also provide more flexible and possibly cheaper multi-standard-terminals for end users. It is also important as a convenient base technology for the future context-sensitive, adaptive and learning radio units referred to as cognitive radios. SDR also poses many challenges, however, some of them causing SDR to evolve slower than otherwise anticipated. Transceiver development challenges include size, weight and power issues such as the required computing capacity, but also SW architectural challenges such as waveform application portability. SDR has demanding implications for regulators, security organizations and business developers. <s> BIB004 </s> A Systematic Literature Review on Military Software Defined Networks <s> Software Defined Radio <s> Abstract : Modern concepts of operations for multinational operations within NATO and partners require air-interface interoperability for VHF and UHF tactical communications. This contrasts with the historical approach to interoperability of using wired gateways at the higher network levels. As a result of the historical trends, national combat-net radios (CNR) have been procured from industry conforming to proprietary specifications. This has made it difficult to achieve interoperability in recent deployments, and has been a barrier to implementing modern operational concepts. A Modern waveform providing interoperability for VHF and UHF tactical communications is under development by NATO, and this emerging standardized waveform specification is, importantly, free of intellectual property restrictions. This networking waveform is tailored for vehicle, manpack, and tank communications, for mobile ground-to-ground links, and ground-to-helicopter for rotary-air support links, providing long range secure tactical MANET supporting voice and data communications beyond 10 s of kilometres distance. In the future soldiers are expected to carry small radios with soldier systems waveforms, offering broadband WiFi-like MANET services, and covering only hundreds of meters. So it should be clear that the new VHF/UHF standardization agreements (STANAGs) offer complementary capabilities to those promised in upcoming soldier radios. <s> BIB005 </s> A Systematic Literature Review on Military Software Defined Networks <s> Software Defined Radio <s> Abstract : The NATO Research and Technology Organization (RTO) / Information Systems Technology (IST) Research Task Group (RTG) on Software Defined Radio (SDR), works on the issues concerning SCA based implementations of waveforms on SDRs. This paper gives a review of the motivation, workflow and results of this international working group. With a potential target of building a Waveform Library in the future, it is important that all the partner nations collaborate and work together. In our contribution, we present some of the important results achieved by national research labs in Germany (FKIE), Turkey (TUBITAK), and Norway (FFI) during the tenure of this Group. Firstly, we present the SCA-based implementation results of STANAG 4285 waveform and the effect of increasing the granularity of the SCA waveform application on the system overhead. After that, we show the portability approach taken to port a waveform between different Operating Environments (OEs) and platforms. The portability efforts between the partner nations are also presented. Finally, the interoperability results show how a waveform running on two different OEs of different partner nations is still able to exchange data. <s> BIB006 </s> A Systematic Literature Review on Military Software Defined Networks <s> Software Defined Radio <s> Establishing radio communication between military commanders, soldiers and law enforcement officers is an important enabling capability to facilitate interoperability. The Joint Tactical Radio System (JTRS) program is enabling communications within the military by implementing different military radio waveforms on software defined radio (SDR) platforms. It is logical to include a Project 25 (P25) public safety waveform in the JTRS waveform portfolio. This paper describes the rapid development of a P25 waveform on a surrogate JTRS SDR platform. The development process and methodology, which starts from a platform agnostic executable waveform model in Matlab, through an intermediate implementation using open tools on generic platforms, to the final platform-specific implementation, is introduced and discussed. This paper shows that adopting this methodology can speed up waveform development and porting. Furthermore, this paper presents the design and implementation of a three way voice bridge among P25, the future multiband multiwaveform modular tactical radio (FM3TR), and voice over Internet Protocol (VoIP), with software communication architecture (SCA) compliant implementation for both the P25 and FM3TR waveforms. This paper shows that critical issues such as interoperability can be tackled efficiently by leveraging SDR and SCA. <s> BIB007 </s> A Systematic Literature Review on Military Software Defined Networks <s> Software Defined Radio <s> The task of improving the effectiveness of public safety communications has become a main priority for governments. This is partly motivated by the increased risk of natural disasters such as flooding, earthquakes, and fires, and partly due to the risks and consequent impact of terrorist attacks. This article focuses on the experience from the European Commission Seventh Framework Programme project known as EULER, which seeks to demonstrate the benefits of software defined radio technology to support the resolution of natural disasters of significant stature, which require the participation of different public safety and military organizations, potentially of different nations. In such scenarios, the presence of interoperability barriers in the disaster area is a major challenge because different organizations may use different wireless communication systems. In this context, the main aspect investigated in EULER is the definition of a common waveform that respects the software communications architecture constraints, and guarantees maximum portability across SDR platforms. This article discusses a range of issues that have been identified thus far within the EULER project; in particular, the perceived pan-European interoperability needs of public safety, and coordination with military devices and networks. Aspects of interoperability are also extended to the three dimensions of platform, waveform, and information assurance. <s> BIB008 </s> A Systematic Literature Review on Military Software Defined Networks <s> Software Defined Radio <s> Reconfigurable Radio Systems (RRS), based on Software Defined Radio (SDR) and Mobile Ad-hoc Network (MANET) technologies, offer considerable advantages for military operations, such as increased network survivability and interoperability. The RRS-based Common Tactical Radio System (GTRS), currently in development by the Swedish Armed Forces, is designed for use in diverse geographical settings and for purposes varying from international combat missions to national contingency operations. However, protecting these networks from attacks and safeguarding the carried information against leaks is an ongoing research challenge, especially in combined scenarios where tactical data may flow across organizational boundaries. This paper presents a best-effort approach to Data Leakage Prevention (DLP) for inter-organizational 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. The DLP architecture is developed as an extension to the GTRS system, modeled and simulated in OPNET™ Modeler. Our results show that common data leaks can be efficiently identified by the proposed scheme, while keeping the important false positive rate at a very low level. <s> BIB009 </s> A Systematic Literature Review on Military Software Defined Networks <s> Software Defined Radio <s> The future airborne network (AN) is envisioned as an IP-based hierarchical network with heterogeneous nodes and waveforms. Due to its highly dynamic nature and bandwidth constraints, new AN technologies are needed to provide reliable network operations with similar levels of mission support as that in terrestrial networks. This paper identifies challenges in designing and evaluating AN technologies and also describes an on-going effort on developing a realistic wireless testing and performance evaluation framework for AN testing and evaluation. A set of use cases are presented to illustrate how the framework can be used to evaluate new architecture and protocols in AN environments. <s> BIB010 </s> A Systematic Literature Review on Military Software Defined Networks <s> Software Defined Radio <s> Abstract In this paper, Received Signal Strength Indicator (RSSI) based localization, which attracts many interests because of its simplicity, is investigated. However, the accuracy of RSSI based localization is low because RSSI measurements are easily susceptible to human presence, multi-path effect, fading and even the change of temperature. In order to improve the performance of RSSI based localization, we propose a bias reduction algorithm. Another important contribution of this paper is that, instead of proving the effectiveness of the algorithm through simulation, a RSSI based localization system is developed using reconfigurable Software Defined Radios (SDRs) to verify the algorithm in practice. The results obtained from real-world experiments demonstrate that the proposed bias reduction algorithm can reduce the bias effectively, thus greatly enhancing the localization accuracy of the system. <s> BIB011 </s> A Systematic Literature Review on Military Software Defined Networks <s> Software Defined Radio <s> The long-term evolution (LTE) is the newly adopted technology to offer enhanced capacity and coverage for current mobility networks, which experience a constant traffic increase and skyrocketing bandwidth demands. This new cellular communication system, built upon a redesigned physical layer and based on an orthogonal frequency division multiple access (OFDMA) modulation, features robust performance in challenging multipath environments and substantially improves the performance of the wireless channel in terms of bits per second per Hertz (bps/Hz). Nevertheless, as all wireless systems, LTE is vulnerable to radio jamming attacks. Such threats have security implications especially in the case of next-generation emergency response communication systems based on LTE technologies. This proof of concept paper overviews a series of new effective attacks (smart jamming) that extend the range and effectiveness of basic radio jamming. Based on these new threats, a series of new potential security research directions are introduced, aiming to enhance the resiliency of LTE networks against such attacks. A spread-spectrum modulation of the main downlink broadcast channels is combined with a scrambling of the radio resource allocation of the uplink control channels and an advanced system information message encryption scheme. Despite the challenging implementation on commercial networks, which would require inclusion of these solutions in future releases of the LTE standard, the security solutions could strongly enhance the security of LTE-based national emergency response communication systems. <s> BIB012 </s> A Systematic Literature Review on Military Software Defined Networks <s> Software Defined Radio <s> The novel software defined radio (SDR) technology allows taking the next step in the evolution of military tactical communications. SDRs allow military radio operators to change waveforms on-the-fly according to the mission needs. On the one hand, new wideband networking waveforms will offer new services like high data throughputs and mobile ad-hoc networking capabilities. On the other hand, legacy waveforms will ensure interoperability to legacy equipment in missions where both types of radios are deployed at the same time. In this article, we analyze if an added value can be provided to the operators at SDRs hosting an `enhanced' legacy waveform. This enhancement shall be introduced such that interoperability to the legacy equipment is still guaranteed. The modern concept of hierarchical modulation allows fulfilling this side constraint. While the legacy waveform acts as base-layer, some enhancement-layers offer extra bit budget to transmit additional information. This spare bit budget can be exploited to increase the data rate (i.e. throughput), the error robustness (and with this communication range), or both. <s> BIB013 </s> A Systematic Literature Review on Military Software Defined Networks <s> Software Defined Radio <s> In this article, we deal with software radio in an original manner, emphasizing the fact that software radio is a major evolution of radio technologies and a convergence of different pre-existing fields. Joseph Mitola deserves credit for formalizing and conceptualizing this evolution. We do not define software radio. Rather, we look at software radio from different perspectives. New equipments include more and more software radio “capacities,” that is, they can be reconfigured thanks to software. Certain former analog functionalities are now performed digitally. We think that the timeframe during which software radio is advantageous, compared to a velcro1 approach for multi-standard terminals, is probably over. However, software radio has taken concrete form in the military field. We show that software radio is used de facto in all equipment and products because of the technological progress to which it has led. Software radio’s legacy indeed is that it has been and still is a catalyst for wireless innovation. We conclude by showing that software radio will be used to its full potential when it is the support technology for other more complex fields such as cognitive radio. <s> BIB014 </s> A Systematic Literature Review on Military Software Defined Networks <s> Software Defined Radio <s> Space communications architecture concepts, comprising the elements of the system, the interactions among them, and the principles that govern their development, are essential factors in developing National Aeronautics and Space Administration (NASA) future exploration and science missions. Accordingly, vital architectural attributes encompass flexibility, the extensibility to insert future capabilities, and to enable evolution to provide interoperability with other current and future systems. Space communications architectures and technologies for this century must satisfy a growing set of requirements, including those for Earth sensing, collaborative observation missions, robotic scientific missions, human missions for exploration of the Moon and Mars where surface activities require supporting communications, and in-space observatories for observing the earth, as well as other star systems and the universe. An advanced, integrated, communications infrastructure will enable the reliable, multipoint, high-data-rate capabilities needed on demand to provide continuous, maximum coverage for areas of concentrated activity. Importantly, the cost/value proposition of the future architecture must be an integral part of its design; an affordable and sustainable architecture is indispensable within anticipated future budget environments. <s> BIB015 </s> A Systematic Literature Review on Military Software Defined Networks <s> Software Defined Radio <s> Military wireless networks used for tactical communication are classified as MANETS. These are dynamic, infrastructureless networks that are well suited for Line of Sight (LOS) as well as Beyond-Line of sight (BLOS) communication. This research work benchmarks the performance of the routing protocol implemented for a high data rate (up to 6Mbps) Lband waveform against the famous AODV routing protocol for wireless networks. Similarity in design of the SDR routing protocol to AODV is the reason for benchmarking against AODV. This paper will first explain about the software defined radios (SDR) followed by the different routing protocols for MANET. Based on the selection of a particular routing protocol different performance parameters that are Packet delivery ratio, Packet Loss, Routing overhead and Throughput have been calculated. Finally, based on the simulated results a conclusion has been drawn to improve the performance of SDR. <s> BIB016 </s> A Systematic Literature Review on Military Software Defined Networks <s> Software Defined Radio <s> Reliable and secure wireless communications is fundamental to connectivity between smarter gadgets and people. This is much more true in defence applications with its unique requirements and challenges. Broadly the data link requirements in defence applications are seen under two categories. One, robust fool-proof zero downtime data links for telemetry, command and control. Second, broad band data links for data streaming and high bandwidth information exchanges. The data link platforms offered for these applications must therefore address the need to quickly prototype waveforms, be easy for field and use-case tests, support quick means for security layer add-ons and easily be amenable to technology adoption, ruggedization and deployment. This paper describes some of the challenges of design and prototyping for defence applications and presents how agile systems built with the right choice of design partition and architecture choices with hardware, software and waveforms can be cognizant of the challenges of the defence applications and illustrates few example cases with simulations and real field deployment trials. It is envisaged that the Agile Cognizant Transceiver (ACT) platform built, helps faster prototyping of defence systems and paves the way for faster product induction cycles in defence automation. <s> BIB017 </s> A Systematic Literature Review on Military Software Defined Networks <s> Software Defined Radio <s> Providing "connectivity from the sky" is the new innovative trend in wireless communications. High and low altitude platforms, drones, aircrafts, and airships are being considered as candidates for deploying wireless communications complementing the terrestrial communication infrastructure. In this article we report the detailed account of the design and implementation challenges of an aerial network consisting of LTE-Advanced (LTE-A) base stations. In particular, we review achievements and innovations harnessed by an aerial network composed of Helikite platforms. Helikites can be raised in the sky to bring Internet access during special events and in the aftermath of an emergency. The trial phase of the system mounting LTE-A technology onboard Helikites to serve users on the ground yielded very encouraging results, and showed that such a system could offer a longer lasting solution, provided that inefficiency in powering the radio frequency equipment in the Helikite can be overcome. <s> BIB018 </s> A Systematic Literature Review on Military Software Defined Networks <s> Software Defined Radio <s> Fourth generation LTE has been selected by U.S. federal and EU authorities to be the technology for public safety networks that would allow first responders to seamlessly communicate between agencies and across geographical locations in tactical and emergency scenarios. From Release 11 on, 3GPP has been developing and specifying dedicated nationwide public safety broadband networks that will be scalable, robust, and resilient, and can address the specific communication needs of emergency services. In this realm, the requirements and scenarios for isolated E-UTRAN with no or limited backhaul access to the core network are still in progress. In this article, we survey possible public safety use cases with the induced network topologies, discuss the current status of the 3GPP standards, and highlight future challenges. We further elaborate on the need to support mobile backhauling in moving-cell scenarios and describe two LTEbased solutions to enable dynamic meshing among the base stations. <s> BIB019 </s> A Systematic Literature Review on Military Software Defined Networks <s> Software Defined Radio <s> Underwater Acoustic Networks (UANs) are widely used in various applications such as climate change monitoring, pollution control and tracking, tactical surveillance and offshore exploration. However, limited consideration is given to the security of such networks, despite the fact that the unique characteristics of UANs make these networks vulnerable to various malicious attacks. In this paper, we address future aspects of how to improve security in UANs. We start by reviewing and discussing the state-of-the-art security threats for underwater networks along with their existing solutions. We then identify the open research issues and challenges in the design of secure protocols for communication in UANs. We propose innovative approaches based on node cooperation, cross-layering, software-defined cognitive networking and context-aware communication in order to effectively provision new or strengthen existing security frameworks in UANs. By using these approaches, we address the problem of detecting malicious behaviours and rogue nodes in order to address the major security issues in UANs. We also investigate the use of a covert channel based detection mechanism which needs to be considered when monitoring or deploying UANs at sea. We believe that the issues raised and future possible solution approaches proposed in this paper will greatly help the researchers contributing towards fortifying security in an inherently in-secure UAN. <s> BIB020 </s> A Systematic Literature Review on Military Software Defined Networks <s> Software Defined Radio <s> In cellular networks, the locations of the radio access network (RAN) elements are determined mainly based on the long-term traffic behaviour. However, when the random and hard-to-predict spatio-temporal distribution of the traffic (load,demand) does not fully match the fixed locations of the RAN elements (supply), some performance degradation becomes inevitable. The concept of multi-tier cells (heterogeneous networks, HetNets) has been introduced in 4G networks to alleviate this mismatch. However, as the traffic distribution deviates more and more from the long-term average, even the HetNet architecture will have difficulty in coping up with the erratic supply-demand mismatch, unless the RAN is grossly over-engineered (which is a financially non-viable solution). In this article, we study the opportunistic utilization of low-altitude unmanned aerial platforms equipped with base stations (BSs), i.e., drone-BSs, in 5G networks. In particular, we envisage a multi-tier drone-cell network complementing the terrestrial HetNets. The variety of equipment, and non-rigid placement options allow utilizing multitier drone-cell networks to serve diversified demands. Hence, drone-cells bring the supply to where the demand is, which sets new frontiers for the heterogeneity in 5G networks. We investigate the advancements promised by drone-cells, and discuss the challenges associated with their operation and management. We propose a drone-cell management framework (DMF) benefiting from the synergy among software defined networking (SDN), network functions virtualization (NFV), and cloud-computing. We demonstrate DMF mechanisms via a case study, and numerically show that it can reduce the cost of utilizing drone-cells in multitenancy cellular networks. <s> BIB021 </s> A Systematic Literature Review on Military Software Defined Networks <s> Software Defined Radio <s> This paper describes a methodology for jamming traditional combat net radios using commercial software-defined radios mounted on unmanned aerial vehicles. The paper demonstrates the technical feasibility of this method given size, weight, and power constraints. We propose tactics, techniques, and procedures for employing this system as a means of electronic fires organic to an infantry battalion. We demonstrate a tactical scenario to show the potential utility of this system. Finally, acquisition cost considerations are covered. <s> BIB022 </s> A Systematic Literature Review on Military Software Defined Networks <s> Software Defined Radio <s> As the use of wireless technologies increases significantly due to ease of deployment, cost-effectiveness and the increase in bandwidth, there is a critical need to make the wireless communications secure, and resilient to attacks or faults (malicious or natural). Wireless communications are inherently prone to cyberattacks due to the open access to the medium. While current wireless protocols have addressed the privacy issues, they have failed to provide effective solutions against denial of service attacks, session hijacking and jamming attacks.In this paper, we present a resilient wireless communication architecture based on Moving Target Defense, and Software Defined Radios (SDRs). The approach achieves its resilient operations by randomly changing the runtime characteristics of the wireless communications channels between different wireless nodes to make it extremely difficult to succeed in launching attacks. The runtime characteristics that can be changed include packet size, network address, modulation type, and the operating frequency of the channel. In addition, the lifespan for each configuration will be random. To reduce the overhead in switching between two consecutive configurations, we use two radio channels that are selected at random from a finite set of potential channels, one will be designated as an active channel while the second acts as a standby channel. This will harden the wireless communications attacks because the attackers have no clue on what channels are currently being used to exploit existing vulnerability and launch an attack. The experimental results and evaluation show that our approach can tolerate a wide range of attacks (Jamming, DOS and session attacks) against wireless networks. <s> BIB023 </s> A Systematic Literature Review on Military Software Defined Networks <s> Software Defined Radio <s> Wireless networks with their ubiquitous applications have become an indispensable part of our daily lives. Wireless networks demand more and more spectral resources to support the ever increasing numbers of users. According to network engineers, the current spectrum crunch can be addressed with the introduction of cognitive radio networks (CRNs). In half-duplex (HD) CRNs, the secondary users (SUs) can either only sense the spectrum or transmit at a given time. This HD operation limits the SU throughput, because the SUs cannot transmit during the spectrum sensing. However, with the advances in self-interference suppression (SIS), full-duplex (FD) CRNs allow for simultaneous spectrum sensing and transmission on a given channel. This FD operation increases the throughput and reduces collisions as compared with HD-CRNs. In this paper, we present a comprehensive survey of FD-CRN communications. We cover the supporting network architectures and the various transmit and receive antenna designs. We classify the different SIS approaches in FD-CRNs. We survey the spectrum sensing approaches and security requirements for FD-CRNs. We also survey major advances in FD medium access control protocols as well as open issues, challenges, and future research directions to support the FD operation in CRNs. <s> BIB024 </s> A Systematic Literature Review on Military Software Defined Networks <s> Software Defined Radio <s> There has been recently a growing trend of using live video feeds in mission-critical applications. Real-time video streaming from the front-end personnel or mobile agents is believed to substantially improve the situational awareness in mission-critical operations, such as disaster relief, law enforcement, and emergency response. Mobile ad hoc networks (MANETs) are a natural contender in such contexts. However, classical MANET routing schemes fall short in terms of scalability, bandwidth, and latency; all the three metrics being quite essential for mission-critical applications. As such, autonomous cooperative routing (ACR) has gained traction as the most viable MANET proposition. Nonetheless, ACR is also associated with a few implementation challenges. If they go unaddressed, will deem ACR practically useless. In this paper, efficient and low-complexity remedies to those issues are presented, analyzed, and validated. The validation is based on field experiments carried out using software-defined radio platforms. Compared with the classical MANET routing schemes, ACR was shown to offer up to two times better throughput, more than four times reduction in end-to-end latency, while observing a given target of transport rate normalized to energy consumption. <s> BIB025
Moy et al. BIB014 discussed Software Defined Radio, emphasizing the fact that SDR is a major evolution of radio technologies, and a convergence of different pre-existing fields. Ulversoy BIB004 discussed SDR challenges and opportunities, while Kacpura et al. BIB015 presented SDR architecture contributions for next generation space communications. Sigholm et al. BIB009 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. Cormier et al.  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. Androlewicz et al.  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. Moessner et al. BIB001 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. Noble et al. BIB022 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 battalion. North BIB002 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. Wei et al. BIB011 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. Wang et al. BIB003 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. Almoualem BIB023 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. Enrico et al. BIB005 overviewed the NATO initiative to develop tactical waveform specifications for VHF and 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. Other research efforts of SDR are presented in BIB006 BIB012 BIB016 BIB017 BIB010  . Kaur et al. BIB016 discussed SDR and different routing protocols for MANET. The MANET Reactive protocol (i.e., AODV) is implemented for SDR by using CSMA/CA, with some modifications. Singh et al. BIB006 provided a review of the motivation, workflow and results of the NATO Research and Technology Organization (RTO)/Information Systems Technology (IST) Research Task Group (RTG) on SDR, which works on the issues concerning Software Communications Architecture (SCA) based implementations of waveforms on SDRs. The authors presented the SCA-based implementation results of STANAG 4285 waveform, and the effect of increasing the granularity of the SCA waveform application on the system overhead. Mahasamudram et al. BIB017 envisioned that the Agile Cognizant Transceiver (ACT) platform built helps faster prototyping of defence systems and paves the way for faster product induction cycles in defence automation. ACT is a complete indigenous solution developed with SDR, in order to support wide band requirements and multi technology waveforms. Moura et al.  presented case studies of attacks aimed at tactical SDR, based on a classification with the most common sources of vulnerabilities, classes of attacks, and types of intrusions that military radio sets may suffer. The authors also described how attack mitigation strategies can impact the development of SDR infrastructures. Amjad et al. BIB024 presented a comprehensive survey of full-duplex (FD)-cognitive radio networks (CRNs) communication. The authors covered the supporting network architectures and the various antenna designs. The authors also surveyed major advances in full-duplex medium access protocol (FD-MAC) protocols as well as open issues, challenges, and future research directions to support the FD operation in CRNs. Chandrasekharan et al. BIB018 reported the detailed account of the design and implementation challenges of an aerial network consisting of LTE-Advanced (LTE-A) base stations. In particular, the authors reviewed achievements and innovations harnessed by an aerial network composed of Helikite platforms. Helikites can be raised in the sky, while they carry battery, antenna, and RRH (Remote Radio Head) equipment to bring Internet access during special events and in the aftermath of an emergency. Cao et al. BIB007 described the rapid development of a P25 waveform on a surrogate Joint Tactical Radio System (JTRS) SDR platform. The JTRS program is enabling communications within the military, by implementing different military radio waveforms on SDR platforms. Furthermore, the authors presented the design and implementation of a three way voice bridge among P25, the future multiband multiwaveform modular tactical radio (FM3TR), and Voice over Internet Protocol (VoIP), with software communication architecture (SCA) compliant implementation for both the P25 and FM3TR waveforms. Favraud et al. BIB019 surveyed possible public safety use cases with the induced network topologies, discussed the current status of the 3GPP standards, and highlighted future challenges. The authors further elaborated on the need to support mobile backhauling in moving-cell scenarios, and describe two LTE-based solutions to enable dynamic meshing among the base stations. Lal et al. BIB020 surveyed the existing security attacks along with their state-of-the-art countermeasures and respective limitations. The authors also proposed new security paradigms for detecting and counteracting malicious activities, both from a generic perspective and within specific scenarios in Underwater Acoustic Networks (UANs). The main research challenges related to the cooperation of mobile and static nodes in a distributed and ad hoc way have been addressed, together with the investigation of multi-metric accurate reputation systems, secure deployment and adaptive monitoring techniques. Baldini et al. BIB008 discussed a range of issues that have been identified thus far within the European Commission Seventh Framework Programme project known as EULER, which seeks to demonstrate the benefits of software defined radio technology to support the resolution of natural disasters of significant stature. In particular, the perceived pan-European interoperability of public safety, and coordination with military devices and networks. Aspects of interoperability are also extended to the three dimensions of platform, waveform, and information assurance. Adrat et al. BIB013 analyzed if an added value can be provided to the operators, by SDRs hosting an "enhanced" legacy waveform, where this is introduced in a way that guarantees the interoperability with the legacy equipment. While the legacy waveform acts as base-layer, some enhancement-layers offer an extra budget for the transmission of additional information. This spare budget can be exploited in order to increase the data rate (i.e., throughput), the error robustness (and with this communication range), or both. Bader et al. BIB025 presented mobile ad hoc networks in latency-and bandwidth-demanding mission-critical applications, while the authors analyzed and validated efficient and low-complexity remedies to those issues, and validated their results based on field experiments carried out using SDR platforms. Compared with the classical Mobile ad hoc network (MANET) routing schemes, autonomous cooperative routing (ACR) was shown to offer up to two times better throughput and more than four times reduction in end-to-end latency. Finally, Bor-Yaliniz et al. BIB021 studied the opportunistic utilization of low-altitude unmanned aerial platforms equipped with base stations (i.e., drone-BSs) in future wireless networks. In particular, the authors envisioned a multi-tier drone-cell network complementing the terrestrial HetNets. Furthermore, they investigated the advancements promised by drone-cells, and discussed the challenges associated with their operation and management.