Technical report (public abstract)

SWING project has been developed with the objective of ECI (European Critical Infrastructure) protection against the threats or terrorist attacks aimed to inhibit their communications possibility. The case of maritime governmental agencies was taken in consideration. Terrorist attacks, able to put out of order for a long period the Internet connections capabilities, expose the maritime governmental agencies te elevated risks of vulnerability. In fact nowadays essential information is transferred by means of Internet both for management and control. Even if the Internet is on the overall robust, not dependent upon a single machine or cable, it can however be object of terroristic attack. In the above described project results we have shown that it is possible to operate a prototype of a HF-VHF radio connection system, to replace broad-band communications in case of threat and/or terroristic attack on the internet based communication. In more detail we have shown that in the extreme case of complete failure of the broadband communication a minimum flux of essential information for the management and control in case of wide scale terrorist attacks able to render Internet links useless over the Mediterranean region can be maintained.

The SWING project had 19 activities as reported in table 0.1. This final report of the whole project reports on the accomplishment of these objectives and namely

  1. Particular critical infrastructure and the study Internet communications criticality of the maritime governmental agencies, were identified and recognized;
  2. All the requirements necessary for the management, and survival of the HF radio network, were considered and valuated with the radio electric quantities in transmission/reception, modulation, and other techniques to transfer data packets and voice communication;
  3. Internet communications criticality was studied and a methodology to alert HF network system of the maritime governmental agencies by monitoring and checking the Internet traffic and identifying the local or regional Internet failures, was developed;
  4. Communication software and hardware tools supporting reliable and interoperable Short Wave radio communication techniques for the maritime governmental agencies protection, proposing a solution of the HF network architecture in order to avoid data packets collisions and communication conflicts, was developed;
  5. A frequency management and a link optimization system, taking into account the special characteristics of the ionospheric channel and radio interfering frequencies was developed;
  6. A radio-communication architecture for a distributed South European short wave radio network and to realize a 4 TX/RX terminals of HF stations, was designed;
  7. A SVP and a DSVF able to run in every TX/RX terminal was finally designed.

The aim of SWING has been to demonstrate that an high survival HF radio network (data/voice) can real time support communications among ECIs and CGAs, maintaining the minimum flux of essential information, for the management and control in case of wide scale terrorist attacks able to render Internet links useless over the Mediterranean region. The idea SWING was conceived thinking the role of Internet in communication. Internet has been defined as a massive “network of networks” that consists of millions of private, public including critical infrastructures linked by a broad band network to serve billions of users worldwide. Internet carries a vast amount of information resources and services, including the information to support critical Infrastructure. On the other hand, threats, vulnerabilities and risks have grown exponentially with the proliferation of use and dependence on the Internet communications. SWING activities focused the interest towards data/information exchange among maritime infrastructure identified as ECIs and the relative controlling agencies CGAs utilizing Internet broadband communication. In such a context it was easy to envisage the potential risk of wide scale terroristic attacks paralyzing broadband communications for relevant periods. Therefore, in order to prevent the potential black out of vital or priority information exchanges supporting critical infrastructures in such a catastrophic event, SWING project has been identified as a suitable solution. SWING is an emergency back-up system easily deployable in the selected ECIs and CGAs. Such a system is studied in some details including a SVP and DSVF supervisors able to manage and control the main requirements for the critical information exchange. All aspects concerning HF network communication both in physical and logical point of view were studied and the best solutions were proposed. In each SWING node equipped with workstation/server, the SVP-DSVF is active managing the network terminal by checking the Internet functionalities, activating/deactivating the HF back-up network in case of Internet failures. SVP-DSVF also manages all the logical and physical layers of the HF communications and selects the optimal frequencies for reliable communication link. Finally to demonstrate the feasibility of SWING project, the most advanced and inexpensive technology available in the market was used to realize 4 RX/TX terminals. In the prototype the Universal Software Radio Peripheral is the core reconfigurable hardware. It allows general purpose computers (or workstation) to control both the network requirements and the reconfigurable hardware using an high bandwidth Gigabit Ethernet bus. It is possible to perform all of the operations like waveform generation and baseband processing such as filtering and modulation and demodulation, high-speed digital up and down conversion from baseband to IF using the on board FPGA. In spite of the HF band limitations, low data throughput, essential information can be safely exchanged without requiring expensive technologies or cabling connections between the critical infrastructure considered in SWING project.

Aim of this Document is the identification and designation of the European Critical Infrastructures (ECIs) and Controlling Governmental Agencies (CGAs) on the basis of the deliberated by the Council Directive of the European Union. In fact the Council established, by the Directive 2008/114/EC of 8 December 2008, the requirements for the identification and designation of European critical infrastructures and the assessment of the need to improve their protection. In fact the Directive 2008/114/EC European Council identify two possible sectors: transport and energy. In the ambit of SWING project the ECI we designed are the Mediterranean ports of Palermo (Italy), Pireo (Greece) and Barcelona (Spain). In the hypothesis on which the three ECIs that are constantly connected exchanging sensitive information by means of Internet connection a HF network has to partially accomplish such a task. We analyzed some well known internet criticalities examining some above mentioned scientific reports the main causes of weakness either in the computers and in the networks with special reference to the Internet. On the basis of what we obtained (interview with Costal Guard Operative Room) it had been possible to individuate the sensitive information to be transferred by Internet. In this technical report the criticality of the Internet and possible failure like in the case of denial of service (DoS) or other not better identified cases. Subsequently as described in the technical reports N.6, N.7 and N.8 the problems concerning the HF radio network have been studied in order to replace the Internet with the HF radio links.

Aim of this document is to define a physical/logical topology of a HF communication network connecting ECIs and CGAs. We have analyzed the existing techniques, focusing on those architectures considered useful for the future SWING system development. The main goal is to provide a minimum flux of essential information in case of a terrorist attack that may put out of order the Internet connection between some CGAs and their controlled ECIs. MAC requirements and physical layer requirements have been thoroughly discussed. In order to meet the MAC requirements, three different schemes have been investigated: a contention free strategy, a contention based approach and a mixed solution. Among them, the last scheme (mixed solution) seems to be the most appropriate for the SWING system. Specifically, for communications between ECIs and their home CGA the access could be managed through a contention free token protocol (HFTP) enabling the radio terminal to transmit when it holds the token. The choice of this technique is motivated by its ability to efficiently manage the access of multiple ECIs to the HF channel in case of an internet failure over a huge area. For communications between CGAs a contention based protocol (DCHF) is suggested, according to which the transmitting radio terminal must sense the channel before sending its data. Such technique is suited for light traffic networks and fits well with the inter CGAs communication scenario. Due to the specific topology of the SWING system, a dedicated network layer seems unnecessary. The data link is characterized by higher rates and less stringent delay requirements as compared to the voice link. In such a case, the ARQ protocol is used for error-free packet delivery and the autobaud capability is suggested to continuously adapt the data throughput to the prevailing channel conditions. The transmission bandwidth of nearly 100 kHz provides the system with a high degree of frequency diversity, which can be exploited to further increase the reliability of the data link. The modulation parameters provided by the preliminary system design have been employed for the link budget analysis. In doing so we have assumed a worst-case scenario for ionospheric propagation. The EIRP values are given for the HF link between the CGA in Rome and the relative ECIs. The main constraints are dictated by ionospheric conditions and by the environmental noise. Since the technological features of the antenna limit the minimum value of the operative frequency which can be used to establish the HF link, a frequency management system seems necessary for the SWING network.

In order to estimate and characterize the minimum amount of information necessary for the survival of the CIs communication we have simulated scenarios representing the situation around the CG maritime traffic. In this technical report we have determined the European Critical Infrastructures (ECIs) and Controlling Governmental Agencies (CGAs) individuated in the Italian Ministry of Infrastructure and Transport. We have chosen the transport sector and, in particular, the sea transport. In the frame of the SWING project the Coast Guard has been identified as ECI and the General Command as CGA, both under the control of the Ministry of Infrastructures and Transport. We have also studied the organization of these infrastructures in Italy, Spain and Greece and we have realized that all the CGs have approximately the same functions. For what concerns Spain and Greece CGs, we have obtained information on the organization, functions and activities by visiting the respective websites. Whereas for what concerns the CGA, the General Command in Rome has been contacted for an interview. A series of questions have been formulated and their answers reported. We have simulated three Coast Guards in the three Mediterranean ports of Pireo, Palermo and Barcellona (ECIs) and only one CGA located in Rome in the Comando Generale (CDO), that manages and controls all the three Cost Guards. In our simulated scenario concerning the maritime traffic we referred to an AIS system able to control the vessels in a particular area controlled by AIS-VTS stations by means of VHF transponders. The information is up-linked directly by AIS-VTS system in the Operative Room of the CDO. Each vessel contacted by the AIS-VTS contributes approximately with a kbit of data. These amount of information must be elaborated and transferred to the CGs because they are mainly interested in the traffic in their maritime area and other information concerning the safety of the infrastructure. These essential data/voice communications are necessary for management and control of ECIs and reduced data flow is necessary for the HF back-up network, avoiding to waste precious time. Even if the HF network system has scarce efficiency, it is the only way to communicate relatively short messages, necessary for infrastructures awareness, preparedness and protection, between OR-CDO and CGs at long distances, at any time and any condition.

In this report the procedures for the operative supervision of the network architecture have been illustrated. The system requirements of a high-survival radio network, operating in the HF band to provide a minimum flux of information for management and control of the ECIs and CGAs are here examined. It is considered the case of a terrorist attack that may put out of order the Internet connection between considered critical infrastructures. The procedure for the operative supervision of the HF back-up network involves a series of passages including, as first step, the “warm” stand-by condition of HF back-up network and, secondly, the hierarchic of Distributed Supervision Function (DSVF) program enabling, in the proper order, all the operations necessary to put on the network and to return to the “wait” state. Following the procedure DSVF the terminal points equipped by PCs where the program resides evaluate the physical and logical information of the network position of the CGA or ECI, including a priority list of the infrastructures to be alerted. The relevant point concerns the possible employment of the same frequency in each terminal of the HF network. It is worthy to note that when the supervision system triggers the back-up network all the TX/RX points located in the ECIs or CGAs must communicate with the same initial frequency and eventually exploit other frequencies given by the planned procedures, according to degradation of the propagation in the disturbed channels. Of course, in such a condition the transmission of data-packets already described in [6] are considered essential. Eventually a redundant process when the propagation is not optimal [7] could be necessary. Since the whole network (or part of it) is always tuned at the same frequency, it has to change in time according to the propagation condition even in the stand-by state. When the network has to be enabled to avoid collisions in the data packets independently on the mode and type of data, the contention based technique seems promising in short link turnaround time. On the contrary for long turnaround time a contention free approach can be employed. In the DSVF operation, one of the important point concerns the criteria of warning alert and the procedures to activate and to deactivate the back-up network. In the previous report [1] these criteria have been extensively analyzed. Description of some Internet failure scenarios are considered among a large variety of possible situations. In fact this report deals with two main Internet failure scenarios: a most reasonable scenario and worst case analysis. The other cases fall between these two extremes. In the first case the HF link between the CGA and the ECI overcomes the problem locally and the whole network utilizes the broad band communication. A different case is when the attack involves more ECIs and CGAs. Here the HF network will be activate and the Internet connection will be completely ignored but not disconnected. In both cases a system for the supervision of the Internet links checks systematically if the informatics attack is finished. The constant control of the Internet is necessary in order to establish if and when to activate the HF back-up network. At the end it has been described the condition in which the Internet becomes available again, the HF back-up network nodes/links must be deactivated and the Internet links reactivated.

Aim of this Document is to show the state of the art of the existing architectures of HF communication from the network point of view. We have analyzed the existing techniques, focusing on those architectures considered useful for the future SWING system development. The organization of the document in three main sections has been achieved in order to comply with the three layer of the ISO OSI model of our interest: data, network and application.

Due to the nature of SWING system, layer 2 techniques are mostly described from the MAC point of view, even though examples of data management techniques are described in Section 2. Indeed, standards like STANAG 5066 and STANG 4538 are focused on the definition of rules for data packet handling. More interesting to our purpose are the several MAC techniques defined for HF communication. This deliverable is focused on two peculiar protocols, HFTP (High Frequency Token Protocol) and DCHF (Distributed Coordination for High Frequency radio). The analytical comparison between these techniques shown in Section 3 would be useful for the definition of SWING system requirements.

Regarding the Network Layer, we illustrated how HF networks are often fully connected. However, the HF channel can be an unreliable propagation medium, with significant packet loss rates and other environmental effects, leading to intermittent link outages and even network partitions. Although an exhaustive range of routing techniques designed for HF communications is not available in the open literature, we focused our analysis on two specific protocols: the Optimized Link State Routing (OLSR) protocol (an optimization of the classical link state routing algorithm) and the Wireless Address Resolution and Routing Protocol (WARRP) (an integrated address resolution and routing functionality). An analysis of these two protocols has been shown under several traffic conditions.

Finally, some typical applications for HF network have been discussed. Among them, we chose those considered most likely applicable in the foreseen SWING network.

This document illustrates existing architectures for High-Frequency (HF) communication systems. Since HF transmissions are mainly used for long distance tactical communications, the discussion will be focused on several recent military standards developed from the early 1990’s by the North Atlantic Treaty Organization (NATO) and the United States Department of Defense (US-DoD). The attention is mainly concentrated on the physical layer (PHY) specifications, which provides details about the baseband signal processing leading from the information bits stream to the waveform that is launched over the air.

After discussing the propagation mechanisms in the HF band, the main parameters of the HF channel are provided in terms of delay spread and Doppler rate for either good, moderate and poor channel conditions. The component parts of an HF waveform are subsequently illustrated, including the adopted modulation formats, the synchronization methods as well as coding and interleaving schemes. The concept of serial-tone and parallel-tone waveforms is also introduced, illustrating their relative advantages or disadvantages under several operating conditions. A comprehensive overview of serial-tone HF standards is presented for both second generation (2G) and third generation (3G) waveforms. Finally, a couple of parallel-tone modems for HF communications are described with some detail.

The aim of this research activity is to illustrate the technical requirements of a high-survival radio network operating in the high-frequency (HF) band in the South Europe and Mediterranean area. The network will be called SWING and its aim will be that of providing a minimum flux of essential information in case a wide scale terrorist attack puts out of order the Internet connections between some European Critical Infrastructures (ECIs) and their Controlling Governmental Agencies (CGAs). The Medium Access Control (MAC) and Physical (PHY) layer aspects that are required to provide a reliable, secure and robust high survival radio network serving as a back-up communication system will be thoroughly discussed. In particular, three different MAC layer schemes will be investigated and compared: a contention free strategy, a contention based approach and a mixed solution. Among them, the last scheme will be shown to be the most appropriate for the SWING system. Specifically, for communications between ECIs and their home CGA the access will be managed through a contention free token protocol enabling the radio terminal to transmit when it holds the token. The choice of this technique will be motivated by its ability to efficiently manage the access of multiple ECIs to the HF channel in case of the Internet failure over a huge area. For communications between CGAs, a contention based protocol will be proposed, according to which the transmitting radio terminal must sense the channel before sending its data. Regarding the PHY layer specifications, this document will start arguing that reliable interactive communications in the HF frequency range calls for some form of frequency diversity, which can be achieved by using a transmission bandwidth adequately larger than the channel coherence bandwidth. In such a case, the delay spread is expected to span over many signalling periods, thereby producing significant inter-symbol interference. As is known, the latter can be easily handled by a multitone modem operating in the frequency domain with much less complexity than a serial-tone waveform employing a time-domain equalizer. For all these reasons, Orthgonal Frequency-Division Multiplexing (OFDM) will be selected as the air-interface of the SWING network thanks to its advantages in terms of resilience to multipath distortions and the possibility of exploiting the inherent frequency diversity offered by the propagation channel. A preliminary design will be provided for both the voice and data links. The modulation parameters provided by the preliminary system design will be then employed for the link budget analysis. In doing so, a worst-case scenario for ionospheric propagation will be considered.

In this report we have presented the physical layer and MAC layer design of the SWING highsurvival radio network operating in the HF band. As a first step, we have derived the main channel parameters characterizing the ionospheric links connecting the CGA located in Rome with the corresponding ECIs in Barcelona, Cefalù and the Pireo region. Simulation results indicate that in any considered situation the delay spread is less than 0.3 ms, while the sum of the Doppler shift and Doppler spread does not exceed 0.3 Hz. These figures reveal that the channel over which the SWING network is called to operate can be categorized as a rather good HF propagation environment which should not present any insurmountable challenge to the system designer.

Regarding the physical layer design, a distinction is made between voice applications and data transmissions. In any case, the signal bandwidth is chosen larger than the classical 3 kHz analogue voice channel so as to provide the system with an adequate frequency diversity gain. In order to easily cope with the multipath distortions introduced by the HF channel, the multicarrier technology in the form of OFDM is adopted as an air interface. This allows the use of a wide transmission bandwidth without requiring computationally expensive time-domain equalizer structures characterized by a large number of tap coefficients.

The key requirements of the SWING voice link are dictated by the interactivity property of this service and from the specifications of commercial vocoders. In practice, the maximum accepted delay cannot exceed 120 ms, while the bit-error rate should be kept below 10-2. In such a case, the transmission bandwidth is fixed to 9600 Hz and a 4-QAM constellation is employed without any possibility of adapting the constellation size to the prevailing channel conditions. In each OFDM block, one pilot tone is inserted every four information bearing subcarriers in order to provide accurate channel state information even in the presence of severe multipath distortions. The industry standard rate 1/2 convolutional code is adopted in conjunction with bit interleaved coded modulation so as to ensure a reliable link between CGAs and ECIs. This way, an error rate of 10-2 is achieved at an SNR value of 13 dB. To further increase the link reliability, there is also an option to transmit two copies of the encoded bits over distinct subbands using a sort of repetition coding with rate 1/2. Simulation results indicate that an SNR gain of approximately 2 dB can be achieved by adopting this strategy.

Compared to the voice link, data transmission poses less stringent requirements in terms of latency, but demands for higher rates. In such a case, the transmission bandwidth is increased to approximately 100 kHz and an ARQ protocol is used for error-free packet delivery. Furthermore, an autobaud capability is adopted to continuously adapt the data throughput to the measured channel quality. As for the voice link, multiple copies of the same coded bits can be transmitted over different subbands in order to increase the link reliability. This results into six different transmissions modes, with each mode being characterized by the constellation order and the repetition factor taking values in the set {1,2,4,8}. This way, the data throughput can be traded against link reliability according to the actual channel quality.

In order to provide a complete design of the SWING system, we have also investigated the requirements related to network layer operations. In previous reports we highlighted that end-to-end communications in the SWING scenario are most of the times confined to single-hop communications, i.e., from ECIs to CGAs or among CGAs. Such consideration led us to focus our research activity on MAC layer aspects, which are crucial to allow possible concurrent transmissions in the system. For this purpose, we have analysed the network behaviour for both digital voice and data transmissions considering two different MAC schemes: a contention based technique (DCHF) and a contention free mechanism (HFTP). Both techniques have been tested through a mathematical model in order to assess their performance in terms of average latency, channel utilization and saturation throughput. In doing so, we made the following assumptions, which lead to a modelization of DCHF and Token-Passing nodes as M/G/1 queueing systems:

  • the network consists of N nodes, with each node having a mean packet arrival rate of λ packets per second;
  • packets arriving at a node are buffered in a FIFO queue and serviced one at a time;
  • the packet inter-arrival times are exponentially distributed;
  • the mean service rate of the channel is μ packets per second;
  • the service time distribution is general.

After defining the mathematical model, we have performed some tests under different operating conditions. In particular, we considered the two mentioned data types for two different transmission modes (different bit rate and data packet dimension). The results provided by the simulation tests can be summarized as follows:

  • in case of a short link turnaround time, independently of the mode and type of data managed, the contention based technique DCHF shows better performance with respect to the contention free mechanism. Such behaviour is a consequence of the introduction of an overhead in the token management which is heavier than the double handshake mechanism used for DCHF connection establishment, despite of the possibility of collisions introduced by the latter. This fact results into a worse behaviour of HFTP either in terms of latency, channel utilization and saturation throughput (more visible in case of transmission of large data packets).
  • in case of a long turnaround time, the HFTP exhibits improved performance than DCHF. The main reason for such a behavior lies in the different weight of the double handshake in DCHF, that causes a double turnaround, with respect to the token overhead, which is able to generate a single turnaround per passage/transmission.

Finally, since in HF communications the realization of a network with a long turnaround time is more feasible, we may conclude that a medium access control technique without contention based on a token protocol seems to be a suitable solution for the implementation of the SWING network. Clearly, the use of a token-based mechanism to avoid contention might affect the delay in case of a single node transmission. However, bearing in mind the hypothetical topology of the SWING network, our results are supported by the following consideration: an internet failure caused by a terrorist attack will unlikely involve a single ECI and, rather, it will probably cause the contemporary access of several nodes to the SWING network.

In this report we have illustrated the criteria of early warning alert and procedures to activate the back-up network for a high-survival radio network operating in the HF band.

The early warning process has been analysed by a general overview of the possible scenarios of the backbone HF radio network assuming two different potential terroristic attacks.

Some intrinsic requirements and characteristics of the SWING system have been accounted for: simplicity, resilience and scalability. The main Internet supervision methods available in the technical literature and able to detect the occurrence of a network fault have been illustrated.

Finally a typical scenario in which the broadband Internet becomes available again has been discussed presenting the procedure by which the SWING HF links are deactivated and the broadband Internet links are reactivated.

The complete process required for the activation of the HF back-up network after a warning alert event has been analysed assuming a realistic network configuration and two different potential terroristic attacks. In this case the time needed to guarantee a safe basic internet connection via SWING to the node under attack has been simulated in less than 10 minutes from the triggering event. However notice that the effective time required for a complete SWING activation/ deactivation will depend on the event sequence of the terroristic attack and on the complexity of the effective physical topology of the SWING network.

For many decades of the 20th century the HF electromagnetic spectrum of 3-30 MHz was the principal waveband for long distance radio communications and represented an important tool for applied science and for radio users, now still widely used around the world for important purposes including radio frequencies dedicated to emergency services, strategic implementations, and radio services.

Considering that the reflecting layers of the ionosphere are subject to solar-terrestrial interactions and disturbed conditions, the variability of its condition plays an important role for the performance of radio communications and for the choosing of the best radio frequency to use.

The basic principles of ionospheric radio propagation for HF communication and the ionospheric long term prediction methods as well as the ionospheric now casting and forecasting methods widely available on line are here shortly described.

The monthly prediction of the hourly HF set of frequencies over the N radio links given by the network, based on the available ionospheric models and methods and the daily forecasting and now casting of the hourly HF set of frequencies based on the Mediterranean ionospheric measurements for the frequency plan for the example month April 2013 are here presented.

Finally concluding remarks and considerations the frequency management are reported in the conclusions.

In this report the procedures for the possible way to exploit ground wave propagation have been considered. Ground wave propagation can be a reliable way to establish HF links if the frequency remains in the lower part of the range and the distance between the station points remain below 100-200 km. When the frequency and distance increase for the different reasons above explained the various mode of ground wave propagation are no more practicable. Along the LOS of 100-110 km, it results a simple and reliable way to communicate by means of the radio wave both with direct or reflected ray. Greater distances require more power in transmission and for “over the horizon” links the propagation can be done only in surface wave mode. Unfortunately the attenuation became not sustainable while the frequency or the distance increases. Even if this is a continuous process the received power dramatically decreases. In SWING context there are favorable employment conditions of the three described propagation modes.

In this report the procedures for the frequency management and link optimization have been considered. To realize the whole process two tasks are necessary. The first task can be afforded in two main passages, while the last task concerns the data throughput and channel’s quality, evaluable in terms of BER. In Distributed Supervision Function (DSVF) the program for frequency management and link optimization (that contains all the input for long term frequency management) runs. Long term frequency management or frequency forecast is an essential requirement to establish a series of radio links (point-to point) both for transmission and reception in the operating range of frequency from the LUF to the MUF starting in the planned geometric constraints. This task is also necessary to evaluate the transmitting power (Pt), modulation, polarization and the minimum SNR at the receiving point. These are also important for the type of the employed antennas and Low Noise Amplifier (LNA), selection filters, etc. in the receiving devices. Hence, the frequency forecast step to calculate these operating parameters is necessary to plan long term operations. To predict the reflectivity status of the ionospheric layers in those points where the reflection occurs, the ionospheric typical characteristics can be used. For short distances (less than 200-300 km) ground wave propagation [5] can replace sky wave radio link. In this report frequency now casting, or short term forecasting, has also been highlighted. Therefore, the hourly monthly median values are corrected by using methods that introduces new physical inputs or by using real time measurements. These are valid both for LUF and MUF. The first one takes into account also the ionospheric disturbances that strongly affects the radio signal especially in the lower part of the usable range under some particular low ionospheric region disturbances, while the latter can be greatly affected by the higher ionospheric regions. Because other causes can interact with the established radio links, it is useful to adjust the frequencies employed in order to optimize the flux of information evaluating the BER. Link optimization generally concerns the evaluation of both data transfer velocity and BER. Sudden ionospheric disturbances as well as frequency interference on the channel can affect the signal and disrupt the data transfer. To overcome this problems SWING system implements a kind of channel evaluator constituted by the USRP devices. USRP in frequency management system acts itself as a spectrum analyzer estimating from the SNR the channel quality.

In this TR, professional profiles of operators able to maintain and operate with SWING system have been identified. These profiles have been justified by the breakdown of SWING system in FUs concerning the management of the technological devices and software programs. Hence the professional profile identification of the operators able to maintain and operate with the high survival HF network realized in the SWING project has been analyzed from this point of view. The methodology adopted was to examine accurately the FUs of the SWING system in the necessary details. Mainly to maintain and operate with a system like SWING the following sections (based on a SWING system program's hierarchy) have been defined: Supervision Program, Internet Control, User Interface and Control Frequency Management. To manage, maintain, operate and update SWING system four main reference professional figures have been defined. Related to the first task, i.e. Supervision Program, a skilled professional manager having a good knowledge in complex systems is required. The key person could be a Senior Engineer with deep knowledge in SWING system, in R&D and HF data transmission and communication. This is a key person that has to coordinate the other three engineers. For the Internet Control program manager a skilled engineer having technical expertise in SWING system and Internet communications is required. To manage the technological apparatus in the User Interface the appropriate and suited figure is an electronic engineer. While for the Control Frequency Management, the most suited figure is an Informatics Engineer also having knowledge in physics and ionospheric propagation.

The aim of this report has been the dissemination of ideas, procedures, and spreading the best practices and behaviours in the communication aspects among ECIs and CGAs and the protection in case of terroristic attack on the wide band network. SWING project deals with a research and application of an high survival HF network able to maintain a minimum essential data flux for ECIs and CGAs communication even in critical condition of the large band Internet failures.

As previously described, this activity has been done through seminars, conferences at the presence of public authorities Maritime and Government Authorities held during the project at the Istituto Nazionale di Geofisica e Vulcanologia- Rome, Italy and Observatory of Ebre Roquetes, Spain. In these occasions SWING organization prepared and distributed paper documents and pen-drives containing all the informative documents: events, brochures, summaries, technical reports etc.. In the EO meeting, it was mainly highlighted the technologic aspect during the seminary and, later in a demo showing, the experiment of transmissionreception of three HF stations.

Concerning the website http://swing.rm.ingv.it/, the essential information and both SWING’s and EU’s logos were reported. Home page contains information about the project; the list of the partners with some useful details; the relevant events (i.e. meetings, seminars) chronologically ordered with details and documents (i.e. agenda, presentations); all the EU docs and reserved documents visible only for the registered users; lists of some useful web links related to the project; the page configured to send; the search component allows the search of pages using a simple text string. Reserved Area: only registered users can access this area of the website using the form on the left column. Note that a registered user can access mainly at the reserved documents (i.e. deliverables) and other material not publicly available.

In this report, the courses and conferences for professional training in the framework of SWING project have been presented. The activities of SWING for professional training were performed through 4-days course and 1-day seminar, held in Rome at Istituto Nazionale di Geofisica e Vulcanologia. The professional training courses were addressed to the interested public operators belonging to Maritime and Government Authorities. In the tutorial activities above mentioned the principal lines of the project have been highlighted. Within this choice all the considered objectives proposed by CIPS program were analytically presented and discussed. It was explained that SWING project identified as potential application in high survival HF radio communication to support ECIs and CGAs devoted to the protection of the harbours and of the relative public authorities devoted to the management and vessel’s traffic control. To this aim SWING took into consideration the two systems Automatic Identification System (AIS) and Vessel Traffic Service (VTS). All these information derived from an interview with authorities involved in the maritime protection it selves with an exchange of information between the Maritime Authorities and SWING staff . A first informative contact was with Italian Maritime Authority both to explain SWING project finalities and to obtain information concerning the organization of “Comando Generale della Marina Militare”, also visiting the Operative Room of the Coast Guard in Via dell’Arte, Rome (Italy). Following a series of questions and notions useful for the project were obtained. In the reference there are reported the internal technical reports issued in SWING project.

This document contains a synthesis of the activities of SWING project to be presented to the chosen maritime authorities. This informative document is a survey of the main subjects dealt during the two-years project. The context in which the project has been developed is the protection of the maritime governmental agencies against the trheats or terrorist attacks. In fact, the potential risk of wide scale terrorist attacks able to put out of order, for a long period, the internet connections capabilities exposes the the maritime governmental agencies in a stage of vulnerability because of some essential information are transferred by means of internet both for management and control. This is particularly important in South Europe and the Mediterranean area. Recently this region has become the critical southern border of the EU more exposed to the cyber threat because the geographical disposition of critical infrastructures does not allow internet connectivity as efficient and reliable as in other north European countries. Then the present electronic dependence of the maritime governmental agencies, based on data/information exchange through internet, requires an alternative and independent high survival as back-up system of communication. The aim of SWING has been to study a high survival HF radio network (data/voice) to real time support of the maritime governmental agencies communications, maintaining the minimum flux of essential information for the management and control in case of wide scale terrorist attacks able to render internet links useless over the Mediterranean region. This will increase the awareness and protection of the maritime governmental agencies operators in the extreme case of the complete broadband failure of the communication.
To address what above exposed SWING achieved the following objectives:

  1. to identify the particular critical infrastructure and to study internet communications criticality of the maritime governmental agencies;
  2. to analyze the requirements necessary to management and control to propose a high survival HF radio network, evaluating the radio electric quantities in transmission/reception, modulation, and other techniques to transfer data packets and voice communication;
  3. to study Internet communications criticality and propose a methodology to alert HF network system of the maritime governmental agencies, monitoring and checking the internet traffic and individuate the local or regional Internet failures;
  4. to develop a communication software and hardware tools supporting reliable and interoperable Short Wave radio communication techniques for the maritime governmental agencies protection, proposing solution of the HF network architecture in order to avoid data packets collisions and communication conflicts (MAC, token protocol etc);
  5. to propose a frequency management and link optimization system taking into account the special characteristics of the ionospheric channel and interfering radio HFs;
  6. to design a radio-communication architecture for a distributed South European short wave radio network and realize a 4 RX/TX terminals of HF stations;
  7. to describe a general supervision program and a distributed supervision function able to run in every TX/RX terminal, determine the criteria for early warning alerts recognizing Internet interruption, and able to activate the procedures of HF network back-up in case of threat or attack, to maintain control over ECIs keeping them linked even in critical conditions, to evaluate the particular characteristics of the ionospheric channel in order to establish a suitable control system for the HFs selection, to prepare data packets containing the necessary information transfering the minimal amount of necessary information, to check the errors and the communications handshaking, to deactivate the HF network points, to communicate the stage when Internet is again available.

In this report a practical realization of a demonstrator constituted by 4-terminals HF network has been discussed. After a brief overview of the technologies currently in use in HF band, a detailed description of the SWING network has been given focusing on the main network components (e.g. transmitter and receiver architecture and antenna system).
The design and the realization of the demonstrator took advantage from the most advanced technology available in the market i.e. the software defined radio. The Universal Software Radio Peripheral (USRP) employed is a reconfigurable hardware peripheral that allows general purpose computers to control using a high bandwidth Gigabit Ethernet bus. It was possible to perform all of the operations like waveform generation and baseband processing such as filtering and modulation and demodulation. USRP also performs high-speed digital up and down conversion from baseband to IF using the on board FPGA.

The demonstrator activity has been divided in the following two experiments:

  1. Chirp experiment The chirp system was basically intended to study the background noise in the transmitter and receiver locations. The ionospheric prediction result was used to decide the spectrum sensing range. The identified local noise band using spectral sensing within the frequency range of the ionospheric forecast must be avoided for establishing the radio link. The noise bands at the receiver location must not be used for the radio link because the detection probability of the receiver is very low or zero in those bands. The noise bands at the transmitting location cannot be used for the radio link in order to avoid interference with other radio communications in the area. This chirp system was also used for the study of the ground wave and the sky wave propagation.

  2. PSK experiment This demonstrator regards a possible theoretical and practical implementation of a HF communication link wherein a PSK modulation is used to modulate the data to be transmitted. A reduced scenario has been considered because of the large complexity in modelling of a HF network with more than two terminals. The scenario specifications are: - Point to point connection type; - Single carrier frequency; - PSK modulation type.

During the experiment, the USRP hardware and LabVIEW software have been used; the first represents a low cost and extremely flexible solution for SDR application, while the second represents a general purpose software for data processing and instruments control. The functionality of this system has been experimentally demonstrated in a closed-loop configuration. Moreover the effect of additive white Gaussian noise has been evaluated by using a set of different signal to noise ratio.