۱٫ Introduction

۲٫ Related work

۳٫ Conceptual model of Context-aware Radio Access Technology selection (CRAT)

۴٫ Design of CRAT selection mechanism

۵٫ Performance evaluation

۶٫ Conclusion

Acknowledgements

References

Abstract

The Fifth Generation (5G) mobile network will revolutionize the way of communication by supporting new innovative applications that require low latency and high data rates in smart city environments. In order to meet these applications’ requirements, Ultra-Dense Network (UDN) is considered as one of the promising technological enablers in 5G. 5G UDN deployments are envisaged to be heterogeneous and dense, mainly through the provisioning of small cells such as picocells and femtocells, from different Radio Access Technologies (RATs). Nevertheless, various studies have reported that the densification is not always beneficial to the network performance. As the network density increases, this will pose further requirements and complexity of determining which RAT a user should connect with at a given time. Hence, an efficient RAT selection mechanism to choose the best Radio Access Technology among multiple available ones is a must. This paper proposes a new Context-aware Radio Access Technology (CRAT) selection mechanism that examines the context of the user and the networks in choosing the appropriate RAT to serve. A simplified conceptual model of the Context-aware RAT selection is introduced. Then, a mathematical model of CRAT considering the user and network context is derived, adopting Analytical Hierarchical Process (AHP) for weighting the importance of the selection criteria and TOPSIS for ranking the available RATs. The proposed CRAT was implemented and validated in NS3 simulation environment. The performance of the proposed mechanism was tested using two different scenarios within a smart city environment, called a shopping mall and urban city scenarios. The obtained results showed that CRAT outperforms the conventional approach namely A2A4 of RAT selection in terms of the number of handovers, average network delay, throughput, and packet delivery ratio.

Introduction

Recently, the mobile communication has become a fundamental entity to connect people through social media, telephony, messaging, and many other online services. The horizon has been extended from just connecting people, to connecting machines and devices, facilitating the linkages for the Internet of Things (IoT) applications (Chen et al., 2017). Hence, the upcoming revolutionised digital wave of the Fifth Generation Mobile networking or simply (5G) is designed to enable efficient connection among smart devices and applications, serving the anticipated explosive growth of mobile users’ data traffic in a wide range of new innovative services for many different environments.

The smart city is one of the most popular applications which represents an extensive number of ubiquitous services working and coor-dinating their activities towards improving the quality and lifestyle of city residents. (Akpakwu et al., 2018). The smart city is where a person can imagine driving down a city road when the red traffic light signal is switched to green so that people can cross an empty street without waiting for the signal to switch according to a preset timer. Another case is to inform the driver about the possible alternative directions/routes while driving and suggest the best road to select based on the current condition of the roads and traffic. In addition, an intelligent and sophisticated monitoring and control system can make the augmented reality true in the smart city by introducing a new way for tourist and even local people to explore their city. Moreover, a good connection speed can be assured irrespective of the location. Thus, 5G is capable of connecting with and supporting self-driving vehicles, which can improve the traffic safety levels that normally humans cannot achieve.