# Comprehensive Review of UAV Detection, Security, and Communication Advancements to Prevent Threats
## 1 Introduction  
Technology has advanced, and as a result, the world of today has seen a number of ground-breaking developments. These outcomes have been demonstrated to be more trustworthy, approachable, and economical in our everyday lives. In addition, people now engage with one another in novel ways in their social circles. Additionally, unmanned aerial vehicles (UAVs) are employed for both commercial and private purposes in addition to being heavily utilized in military contexts. The market potential for medium-sized drones has been estimated by the China Unmanned Aerial Vehicle Industry (CUAVI) to reach CNY 80 billion by 2025 [1], whereas the Federal Aviation Administration (FAA) concluded that there are currently 3 million drones flying in the US sky and that number will increase by four times by the end of 2022 [2]. Drone use is increasing because of its value in a variety of jobs, including through the live broadcasting of events, aerial video shoots, the mobility to move packages from one location to another, and simple navigation as shownin Figure 1. These drones are commonly employed for transportation purposes due to their cheap maintenance requirements, ability to take-off and land vertically, ability to hover, and high degree of mobility. These drones are frequently outfitted with computer vision and internet of things (IoT)-like features, particularly for the swarming of drones [3; 4], and they have proven to be an effective choice for surveillance and rescue-related missions [5]. There are, however, a few important elements that are connected to UAV security worries. This collection contains the story of the Iranian military jamming an American drone's control signals [6]; nonetheless, it is still difficult to create a security control module for UAVs that is completely foolproof. Additionally, the first drones were unmanned balloons loaded with explosives that were used to assault Venice in Italy [7]. Later, in 1915, the British troops employed these unmanned balloons for photographic-based surveillance during the renowned Battle of Neuve Chapelle [8]. During this time, cameras were not as advanced; hence, this strategy was suggested to improve visibility [8]. In order to find various terrorists, several of them were also used during the Afghan War [9; 10]. Prior to today, these drones were usually utilized for military operations, but they are now also chosen for the majority of domestic applications, to the point that Amazon began using drones to carry packages in 2014 [11]. They have also been utilized in fields including agriculture [1; 2], for checking building sites [3], and to greatly assist law enforcement organizations with emergency rescue operations. The United States of America started making pilotless aircrafts that could maneuver for roughly a kilometer in the early 1910s. During World War II, the US started developing advanced UAV programs, such as the N2C-2 drone and the OQ-2 communications plane [9], but these endeavors were both expensive and unreliable. In the late 1980s, the US started developing sophisticated drones, and they already have some top-notch micro unmanned aerial vehicles. Drones are also being used in the media business for aerial photography and filmmaking. Drone use is expanding quickly, and at the same time, security and privacy issues have grown more complicated and serious. Figure 1: Security and privacy threats of UAVs. The major goal of this review article is to give readers a comprehensive understanding of the new advancements that have led to the issues surrounding unmanned aerial vehicles (UAVs), including security threats, privacy concerns, and other limits that are important and cannot be disregarded. To give readers a thorough understanding of the subject, the manuscript has been organized into 10 sections. The major goal is to identify these issues and give all scholars access to a single resource that will allow them to fully understand the most recent trends and work to advance their field.