# Mobility Support 5G Architecture with Real-Time Routing for Sustainable Smart Cities
## 1 Introduction  
IoT is a network of intelligent devices that exchange online data and support sustainable services. In all aspects of daily life, IoT plays a significant role with the integration of next-generation 5G networks [1, 2, 3] to facilitate many areas such as healthcare, vehicles, entertainment, industrial equipment, sport, homes, social networking, etc. IoT is one of the most advanced developments in the last century and has been used in many applications, but still, privacy and authentication are among research challenges [4, 5, 6] for sustainable computing. On the other hand, the number of connected devices is being increased consistently and their number has surpassed 50 billion, with the data produced by these devices also increasing exponentially. Indeed, the overall ubiquity of IoT facilitates day-to-day activities and enables people to interact with each other using 5G networks [7, 8]. However, this holistic view also raises security issues such as data preserving, botnet attacks, hijacking IoT devices, etc. The main challenges faced in IoT applications are manufacturing standards, update management, physical hardening, user's knowledge and awareness [9; 10]. As a result, various IoT structures have been used to build and launch many IoT security applications. An IoT structure is a set of instructions, protocols, and specifications that simplifies the implementation of IoT. The accomplishment of these applications depends primarily on the characteristics of the IoT framework's ecosystems, with a special focus on safety mechanisms where protection and privacy problems are of vital importance [11; 12; 13]. Traditional IoT architecture is composed of three physical, network, and application layers. Devices are embedded in the physical layer that employ certain techniques to sense the environment and perform wireless communication to other devices [14; 15; 16]. A lot of research work has reported on IoT protection and privacy issues. However, once the latest technology arrives, it will overcome the security dilemma in IoT as well. IoT has various uses in real-time contexts and therefore has made a huge impact in almost every sector of life. It combines sensors, smart devices, and RFID technologies through the Internet to create intelligent coordination. The sensors are tiny energy-constrained devices employed to sense information and deliver it over the network for intelligent decisions. These networks in an IoT environment come in a different structure, such as distributed, ubiquitous, grid, and vehicular. However, due to rapid development, extensive use, and their ubiquitous nature, IoT networks face various protection, privacy, and vulnerability issues in their applications and infrastructure. A few works on these security issues reported in the literature mainly employed machine learning and blockchain approaches. Different researchers have worked on different security aspects of IoT networks, including privacy preservation [17; 18; 19], authentications [20; 21; 22], access control [23; 24; 25], scalability [26; 27; 28], information sharing [29; 30; 31], and trust management [32; 33; 34]. However, proposing a decentralized communication platform for facilitating connected users over the insecure Internet and mobile network is a demanding task. In addition, the gathered data should be transmitted without compromising the identification of nodes and sensitive information. Figure 1 illustrates the components of the proposed architecture. The proposed architecture presents a sustainable development for public health applications, which is a significant factor in optimizing the system management and flow of information to assist society. It utilizes the technology of IoT, sensors, and 5G to share the resources and communication bandwidth efficiently. In addition, the cooperation of mobile sink highly distributes the load of IoT technology using the 5G network and increases mobility support and resource management. The contributions of the proposed architecture are as given below. 1.