## 2 State of the Art  
BLE technology (also known as Bluetooth-Smart) is a type of technology created in 2011 by the Bluetooth Special Interest Group (SIG) [3] with the aim of creating innovative applications in the health, fitness, safety and home entertainment industry. Its use has been common in physical devices such as smart watches, bracelets and all types of everyday appliances. The main difference of the BLE protocol compared with the classical Bluetooth protocol is that BLE can be used to emit the same signal, considerably reducing the energy consumed for this purpose. The main advantage of using BLE over other wireless technologies is that it allows broadcasting content such as a web address. In addition, this type of device has low power consumption, which allows it to operate for months or even years without any interruption with a normal battery. Android and iPhone mobile devices with Bluetooth 4.0 or higher can be used to receive the BLE signal, for instance to display the web content pointed by a beacon. The main disadvantage of this technology is that it currently requires  
Figure 1: Comparison between search terms [2]. an Internet connection. This requirement in many cases is a problem due to the fact that although mobile networks are quite widespread, in many places, they are not available or the connection is so slow that it is practically unusable. BLE technology has gained so much importance that even the largest technology world-renowned companies have opted for it. More specifically, the two biggest companies that have contributed to its development are Google and Apple, proposing their models of Eddystone/AltBeacon/Physical [4] web and iBeacon [5], respectively. Until now, most projects developed by Google with this type of beacon have been based on the location of entities. For example, one of the projects Google proposes on the official Physical Web site is the location and identification of pets. It is also used by many stores to promote their products, offering special prices or discounts on items because advertising in Smart Cities [6] is one of the main objectives in the current use of BLE technology with beacons. Thanks to the wide research and the protocol improvement, a variety of projects that use BLE can be found. The proposed use of this technology goes from the use of drones for the rescue of people [7] to systems for delivering assistance [8] and even to the management of energy consumption in an office [9]. However, the most usual application of this type of device is indoor location [10; 11; 12; 13; 14]. Besides, a project has been proposed to give a solution in underwater environments, providing an underwater location system [15] using beacons. Until now, all aforementioned applications and projects have made use of Bluetooth technology for POIs as a sensor dependent on other technologies, such as an Internet connection, to retrieve the information about the place, as shown in [16; 17]. This is not the case of the proposal described in this work. The current work presents a novel IoT application of the new protocol created by Google in 2016 known as FatBeacon. This protocol can be used to send web content in Hypertext Transfer Markup Language (HTML) format directly from the beacon to users' smartphones, broadcasting the HTML content. This must not be confused with a web address URL. The broadcast includes the JavaScript (JS), Cascade Style Sheet (CSS), images or other HTML resources without needing an Internet connection. The main difference between the new protocol and the classical ones implemented in Bluetooth is that these can only broadcast in URL format, requiring an Internet connection to acquire the content. Because of that, the aim of this work is focused on giving a new kind of guidance system based on the new FatBeacon protocol as a solution in areas where there is no Internet coverage or where Internet connection is practically inaccessible.