The paper presents a construction of a wireless hybrid data link operates applying two transmission channels using optical radiation (FSO – Free Space Optics) and radio one (RF - Radio Frequency). Based on some parameters (e.g. laser power, optics aperture, photodetector detectivity, signal bandwidth, beam divergence) of the link components, its data range was determined for various operating conditions (visibility and turbulence). Preliminary tests of the link prototype (TRL 6) were carried out at the Military Communication Institute, Poland. The results showed that the use of FSO/RF technology systems can provide the increase in data transmission security, link availability, and immunity to intentional interference. Considering the features of this technology, high applicable potential to military activities was observed.
An important problem that persons responsible for radio communication systems face is how to make these systems immune to jamming. Rapid development of contemporary electronic warfare systems is a reason why that task is difficult to solve without special supporting tools to analyze wave propagation. Currently, an attempt to jam an enemy radio network is a multiphase process for which the most crucially important is collection of information on the enemy radio communication system and then processing it. The results of the analysis enable to estimate efficiency of intended jamming activity and make the decision on emission of jamming signals. The tools that are useful for estimation of the possibility to jam selected radio objects are wave propagation prediction models chosen earlier in the phase of operational and technical analysis. A good example of propagation prediction model of HF waves is the model based on ITU-R P.533-13 recommendation. It is distributed as a free of charge dynamic linked library P533.dll.
The article presents the proposal of implementing the P533.dll library in order to increase the effectiveness of HF radio communication systems jamming. The information in this article may be useful for those who deal with HF radio communication and for those responsible for the operation of electronic warfare systems.
Military wireless communication systems provide services using radio transmission technologies. However, this technology is exposed to modern radio-electronic warfare devices. In some operational scenarios, an application of laser data link (Free Space Optics - FSO) makes it possible to increase data transmission reliability and security. Such capability could be obtain using so-called hybrid FSO/RF communication system. The development of optoelectronic devices (lasers and photodetectors) operated in the spectral range of 8 – 12 μm (Long Wavelength Infrared Radiation - LWIR) enabled to construct a new FSO link. Compared to currently used FSO systems operating in 700-900 nm (NIR) or 1300 – 1550 nm (SWIR) spectral ranges, this link is characterized by less sensitivity to atmospheric phenomena (fog, mists or turbulences) and by greater difficulty of detection. The performed analyses shown that the use of FSO/RF technology systems can provide increase in data transmission security, link availability, secretiveness of operation, and immunity to intentional interference. The paper presents virtues of some wireless communication technologies based on radio, optical and hybrid system configuration. The status of the research on FSO link operated at LWIR wavelength range is also described. This study has been performed in the frame of LasBITer project financed by The Polish National Center of Research and Development. The developed optical data link is a unique device in relation to the FSO technologies available today, because of its operation in LWIR spectrum using quantum cascade lasers and HgCdTe detectors. Scenario of FSO/RF data link works in military operation is also presented.