Interoperability is a functionality that facilitates integration amongst disparate devices and systems used by applications. Integration, inter-operability, middleware, and standardization are some of the synonyms or solutions of interoperability. As such, interoperability facilitates timely, efficient, and effective completion of applications, in addition to finding new, smarter, and more adaptive services. Smart cities, like many other environments and applications, suffer from the lack of interoperability, which makes their processing very challenging. The lack of interoperability also leads to ineffectiveness, which is highly undesirable for applications that deal with emergencies or have exceptional requirements. In particular, interoperability is highly desirable in heterogeneous systems. This research presents a comprehensive review of the available methods and ways to deal with the issues related to interoperability. In addition, the article provides a classification of the available solutions to overcome the lack of interoperability. Various methods which claim to provide interoperability, are sorted out according to the domains and context in which they appear. This research has identified the advantages and limitations of the available methods for facilitating interoperability. A comprehensive framework for dealing with Interoperability in different domains is proposed. This framework provides a hybrid approach for dealing with interoperability, which could be regarded as a comprehensive and reliable solution when dealing with smart cities.

Thousands of people have lost their lives in stampedes and other crowd related disasters in recent years. Most of these fatalities seem to have been caused by poor control and management of crowds, which is discussed in this article. An efficient and effective crowd management system must also have a plan to deal with the ongoing threat of terrorism and outbreak of various kinds of communicable diseases. In this article, we present a framework of a Crowd Control and Health Management System specially designed to prevent and manage stampedes and other disasters. The system has two subsystems; one for dealing with the management of stampedes and other disasters and the other with healthcare management. As part of the proposed system, an algorithm for an early detection of stampedes, with proof and simulation of implementation, is provided. As part of the healthcare management subsystem, we integrate several mobile applications and develop four of them dealing with relief issues, blood donations, complaints and alerts, and utilizing mobile phones as a sensor device. Our system makes use of various kinds of wireless, mobile, and other technologies and tools including Fog Computing, Smart Phones, Smart Digital Street, IP‐Cameras, Radio Frequency Identification (RFID), Voice Alarm, Light Alarm, and Global Positioning System (GPS). We compare merits and effectiveness of RFID and Wireless Sensor Networks (WSNs), as well as those of Cloud and Fog with a view of using them as part of the proposed framework. We also discuss applications of our systems in real‐life cases of Hajj, an annual pilgrimage of millions of people to Mecca, and Kumbh Mela, a periodic gathering of tens of millions of people in India, both of which have accounted for the majority of fatalities in stampedes and other disasters.

Preservation of privacy of users’ personal data has always been a critical issue to deal with. This issue in the Internet of Things (IoT), which facilitates millions of applications, has become even more challenging. Currently, several approaches and methods are available to safeguard privacy but each of them suffers from one or more anomalies. In particular, Trusted Third-Party approach relies on the trust of a third-party server, Cooperation needs the trust of other peers, Obfuscation is known to return inaccurate results, and Dummy generates too much overhead. Moreover, these and most of the other well-known approaches deal only with specific types of applications linked to the location-based services. In this paper, we present two new methods, namely: Blind Third Party (BTP) and Blind Peers ( $B_{L}P$ ), and combine them to form a new one to be known as the Blind Approach ( $B_{L}A$ ). With the help of simulation results we shall demonstrate the effectiveness and superiority of $B_{L}A$ over the other available methods. The simulation results also exhibit that $B_{L}A$ is free from all the existing problems of the other approaches. However, $B_{L}A$ causes a slight increase in the average (response) time, which we consider to be a minor issue. We shall also discuss the capability and superiority of the Blind Approach in the cases of E-health, Smart Transportation, and Smart Home systems.

COVID-19 requires crowded events to enforce restrictions, aimed to contain the spread of the virus. However, we have seen numerous events not observing these restrictions, thus becoming super spreader events. In order to contain the spread of a human to human communicable disease, a number of restrictions, including wearing face masks, maintaining social distancing, and adhering to regular cleaning and sanitization, are critical. These restrictions are absolutely essential for crowded events. Some crowded events can take place spontaneously, such as a political rally or a protest march or a funeral procession. Controlling spontaneous crowded events, like a protest march, political rally, celebration after a sporting event, or concert, can be quite difficult, especially during a crisis like the COVID-19 pandemic. In this article, we review some well-known crowded events that have taken place during the ongoing pandemic. Guided by our review, we provide a framework using machine learning to effectively organize crowded events during the ongoing and for future crises. We also provide details of metrics for the validation of some components in the proposed framework, and an extensive algorithm. Finally, we offer explanations of its various functions of the algorithm. The proposed framework can also be adapted in other crises.