## 2 Related Work  
Although the study of communication capabilities for public safety has been in the scope of several research works, the overall number of these papers in the literature does not reflect the significance of the topic. In [7], the authors surveyed regulatory, standardization, and research activities dealing with wireless communication technologies in the public safety domain, with a particular focus on LMR systems. However, the inability of the traditionally used LMR systems to support modern data applications makes the migration toward standards that support the requirements of broadband services evident [8]. Consequently, the authors in [9] performed a comparative analysis of legacy (i.e., LMR) and emerging (i.e., LTE) technologies for public safety communications. The spectrum allocation for public safety usage across all the frequency bands in the United States and the benefits of LTE-based over LMR-based public safety networks were among the main topics addressed in [9].  
LTE-based public safety networks were also studied in [10; 11]. These works discussed how 4 th Generation (4G) cellular technology promises to provide an evolution path toward broadband capabilities for existing and new public safety networks. As the next step after 4G, the 5 th Generation (5G) standard brings massive improvements and novel capabilities for multiple vertical sectors including the public safety industry [12]. In [13], the authorspresented a 5G solution proposed by the FASTER project for safe and efficient emergency response [14]. This solution was based on 5G nonstandalone (NSA) architecture and ultra-reliable low-latency communications (URLLC). A 5G-based, cloud-enabled, small-cell architecture was also proposed in [15] as part of the 5G ESSENCE project [16]. Cellular technologies are the communication solutions adopted in [10; 11; 12; 13; 14; 15; 16]. However, neither of these works provided an updated summary of the cellular features ratified by 3 GPP to enable the deployment of 4G- and 5G-based public safety networks.  
Other public-safety-related research works focused on the equipment and devices that can be used to assist first responders in public safety operations. The main assistant systems employed in public safety networks and proposed in several works are unmanned aerial vehicles (UAVs) or drones. The authors in [17; 18] showed that public safety communications can benefit from deploying UAVs for providing broadband connectivity and extending network coverage and capacity. The ability to cover unreachable locations was the motivation behind the use of UAVs in a public safety solution for real-time immersive remote monitoring in [19].  
Although the authors in [19; 20] introduced using wearable devices by first responders, the presented use cases were limited to conventional high-end augmented/virtual reality (AR/VR) and low-end Internet of Things (IoT) applications. While AR/VR head-mounted devices were employed in [19] for immersive remote presence, ref. [20] proposed the utilization of IoT sensors and cameras in a collaborative system for disaster management. Other categories of wearables with potentially more applications, such as watch-type devices, are not included among the studied use cases. Therefore, a closer look at the potential role of wearable technology in cellular-enabled public safety networks is not provided in these works. In the scope of this paper, we aim to address the above-identified research gaps in terms of systematizing cellular communication technologies and wearable solutions for next-generation public safety operations.