Eureka! Institutional Repository

Instilling a sense of security in citizens, preventing and intervening immediately in man-made and natural disasters, managing and restoring the consequences of such disasters, searching for and finding survivors, and ensuring the functional continuity of social structures after such events are core responsibilities of public security personnel. First responders, a particular part of these personnel, concentrate to the fullest extent on fulfilling these responsibilities. One of the most important requirements that directly relates to the perfect operational response of these teams is communication. The uninterrupted, efficient, interoperable, and secure communication of first responders is of major importance and is related to their ability to save lives in the field. The contribution of technology to the issue of communication for these services is crucial, and the standards that have been developed support the corresponding applications. However, given that a global transition to fully broadband technologies is being attempted, an overview of existing technological solutions and those that will be of concern in the near future has been carried out in the context of selecting the best architectures and applications for critical communications. In this paper, an extensive and in-depth literature review of both the technological requirements of critical communications and the protocols and standards that support them was carried out. The existing solutions and their architectures were presented, as well as those that are expected to be of concern in the future. In today's technological environment, and given the official launch of 5G by 2020, the way has been paved for the vision of fully broadband communications, providing all the benefits of Mission Critical Services (MCX), voice, video, and data by qualitatively upgrading the most important Mission Critical Push to Talk (MCPTT) services, which are the communications cell of public safety. The new architectures efficiently integrate a set of innovative technologies related to the Internet of Things (IoT), cloud computing, edge/cloud computing, and artificial intelligence applications and devices, augmented and virtual reality (AR), and machine learning (ML), but also a group of peripheral technology structures such as unmanned aerial systems (UASs) and communications using non-terrestrial wireless networks. The combination of many of these in the implementation of public safety communication networks of any coverage range creates a multitude of challenges and open issues that the scientific community is called upon to address. It appears that the five-year period from 2023 to 2028 will be critical for public safety as it will define how this technological evolution will occur in the networks used by practitioners. At the same time, there is a global trend towards outward-looking services that have traditionally been cautious about open sources on the occasion of security and confidentiality issues. Citizens are encouraged to play an active role and assist services, recognizing the potential of social media, crowdsourcing, and volunteering. In addition, these platforms are seen as a welcoming place to showcase and promote their work to build trust in the institutions they represent. However, it is clear that the road to full broadband requires a substantial contribution from all stakeholders, whether they are government departments, bodies and associations, or organizations and initiatives that are in any way related to the implementation and development of communication standards. At the same time, political will, a unified approach at the national and continental level, and corresponding financial support are essential. It remains to be seen how all these initiatives moving in the same direction will converge for the common good. Finally, an important research on the communication material and software needs of our country's first responders was attempted, with the preparation of an appropriate questionnaire that aspires to certify and prioritize them, in order to form the rationale for the corresponding proposal for our country.