## 5 Analysis of Recent Smart Campus and University Deployments
### Communications Technologies  
In the past, researchers have used diverse technologies for connecting remote outdoor IoT nodes with smart campus platforms. Note that such technologies may differ a great deal from one scenario to another, as the distance to be covered and the kind obstacles found in the environment (especially, metallic objects [136]), severely condition signal propagation. For instance, in [35], the authors propose the design of an IoT-based smart campus that makes use of BLE and ZigBee for providing short and medium-range communications. Nonetheless, note that ZigBee nodes can act as relays in a ZigBee mesh, so that the exchanged information can reach long distances [137]. WiFi (i.e., the IEEE 802.11 a/b/g/n/ac standards) is another popular technology that has already been suggested for providing indoor connectivity for smart campuses [64]. Bluetooth beacons can be also used in smart campus applications [138; 139], but they usually are restricted to indoor environments, as their outdoor use requires the deployment of dense networks whose management is complicated [140]. Due to the popularity of mobile phones, the main cell phone communications technologies (i.e., 2G/3G/4G) have been suggested for providing smart campus services [141; 142]. 5G technologies are still being deployed worldwide, but their use has already been proposed due to their ability to provide fast communications and reduce response latency in smart campus applications [122]. Despite the good perspectives of 5G for the next decade, nowadays, Low-Power Wide Area Network (LPWAN) technologies are arguably one of the best alternatives for smart campus applications that require low-power and long-distance IoT communications [143]. Some of the most popular LPWAN technologies are SigFox [144], LoRaWAN [145], and NB-IoT [146], existing other emerging technologies like Ingenu Random Phase Multiple Access (RPMA) [147], Weightless-P [148], or NB-Fi [149]. LoRaWAN defines the communication protocol and the system architecture for the network and uses LoRa as the physical layer. Although there are several recent works on the application of LoRa/LoRaWAN to multiple scenarios [150], only a few of them are focused on the deployment of smart campuses services [66; 70; 151; 152; 153]. For example, the authors of [152] analyze the indoor and outdoor performance of LoRaWAN on a French smart campus. In addition, other researchers [153] proposed a smart campus air quality system whose communications were carried out by LoRaWAN nodes. Another example can be found in [70], where the authors make use of a radio planning simulator to determine the optimal location of LoRaWAN nodes that provide smart campus services in outdoor applications. There are also short-distance communications technologies that can be useful in smart campus applications. For instance, ANT+ transceivers are often embedded into chest straps to monitor performance and health in sports. Another example of popular short-distance communications technology is Radio Frequency IDentification (RFID), which is commonly used in university access control and payment systems [28]. Table 2 summarizes the main characteristics of the latest and most popular communications technologies for smart campus applications. Moreover, Table 3 compares the communications technologies of the most relevant smart campus solutions. Such a Table also indicates whether the provided references detail the network planning of the proposed solution and, as it can be observed, only a couple of works give details about it. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Technology** & **Frequency Band** & \begin{tabular}{c} **Typical** \\ **Maximum** \\ **Range** \\ \end{tabular}