This paper presents a study of positioning system that provides advanced information services based on Wi-Fi and Bluetooth Low Energy (BLE) technologies. It uses Wi-Fi for rough positioning and BLE for fine positioning. It is designed for use in public transportation system stations and terminals where the conditions are “hostile” or unfavourable due to signal noise produced by the continuous movement of passengers and buses, data collection conducted in the constant presence thereof, multipath fading, non-line of sight (NLOS) conditions, the fact that part of the wireless communication infrastructure has already been deployed and positioned in a way that may not be optimal for positioning purposes, variable humidity conditions, etc. The ultimate goal is to provide a service that may be used to assist people with special needs. We present experimental results based on scene analysis; the main distance metric used was the Euclidean distance but the Mahalanobis distance was also used in one case. The algorithm employed to compare fingerprints was the weighted k-nearest neighbor one. For Wi-Fi, with only three visible access points, accuracy ranged from 3.94 to 4.82 m, and precision from 5.21 to 7.0 m 90% of the time. With respect to BLE, with a low beacon density (1 beacon per 45.7 m²), accuracy ranged from 1.47 to 2.15 m, and precision from 1.81 to 3.58 m 90% of the time. Taking into account the fact that this system is designed to work in real situations in a scenario with high environmental fluctuations, and comparing the results with others obtained in laboratory scenarios, our results are promising and demonstrate that the system would be able to position users with these reasonable values of accuracy and precision.

Communication media have become the primary way of interaction thanks to the discovery and innovation of many new technologies. One of the most widely used communication systems today is video streaming, which is constantly evolving. Such communications are a good alternative to face-to-face meetings, and are therefore very useful for coping with many problems caused by distance. However, they suffer from different issues such as bandwidth limitation, network congestion, energy efficiency, cost, reliability and connectivity. Hence, the quality of service and the quality of experience are considered the two most important issues for this type of communication. This work presents a complete comparative study of two of the most used protocols of video streaming, Real Time Streaming Protocol (RTSP) and the Web Real-Time Communication (WebRTC). In addition, this paper proposes two new mobile applications that implement those protocols in Android whose objective is to know how they are influenced by the aspects that most affect the streaming quality of service, which are the connection establishment time and the stream reception time. The new video streaming applications are also compared with the most popular video streaming applications for Android, and the experimental results of the analysis show that the developed WebRTC implementation improves the performance of the most popular video streaming applications with respect to the stream packet delay.

Smart-locks have become increasingly popular for access to homes and businesses in many countries, because of their ease of use and adaptability. These locks offer a simple and secure alternative to traditional key-based entry, making them an attractive choice for both residential and commercial properties. Nevertheless, it is essential to acknowledge the potential security threats that come with any new technology. The security of smart-locks is particularly critical, as a breach could result in unauthorized entry. Since the smart-locks can connect, there are different ways to check if vulnerabilities can be found easily or on the contrary, if the security level is high. Two of the main ways of checking the security level of this kind of IoT device are the information that can be obtained from the Android application and the security level of the Bluetooth connection. Many vulnerabilities can be found in the Android smart lock management application. This application is very useful to perform all the configurations with such a lock, but if it is not properly implemented and secured, it can provide clues for malicious users to perform unauthorized access to the system. Another security factor is the Bluetooth connection. This ensures that only authorized users have access to the property. In this work, we have analyzed the security level of different parts of smart-locks. In particular, we have analyzed the security of the applications for the most important smart-locks on the market. This study reveals relevant information such as whether the application is obfuscated or not, the encryption algorithm for the Bluetooth connection, or relevant URLs that applications use to connect to the cloud. The security of the Bluetooth connection between the smartphone application and two selected smart-locks was also analyzed. It was demonstrated that if no encryption is used for the Bluetooth connection, the smart-lock is not secure, but if AES encryption is used, the security level is high.

A vehicular ad hoc network (VANET) is a wireless network that provides communications between nearby vehicles. Among the different types of information that can be made available to vehicles through VANETs, road traffic information is the most important one. This work is part of an experimental development of a wireless communication platform oriented to applications that allow improving road efficiency and safety, managing and monitoring road traffic, encouraging cooperative driving, and offering pedestrian services and other added-value uses. The proposed system consists of smartphones, sensors, and Wi-Fi hotspots 2.0, as well as complementary functionalities including access to network infrastructure via 3G, GPRS, and 4G. The developed wireless network prototype allows taking advantage of the potential benefits of VANETs. At the same time, the use of smartphones does not require large money investments either in public or restricted areas. The first implementations with smartphones have been useful to test the behaviour of the proposal in a real environment. We have also implemented a large-scale simulation by using NS-2 simulator. From the obtained data, we have estimated the minimum requirements necessary for the correct working of a VANET and the problems that can happen in case of possible attacks or communication overhead.