The objective of vehicular communication is to improve road safety and traffic efficiency through a variety of cooperative intelligent transport system (C-ITS) services. These services allow information exchange between vehicles and other communication entities (e.g., vehicles, infrastructure, pedestrians). Many advanced services are envisaged to support autonomous vehicles and safety applications. The performance requirements of such services are considered highly critical for road safety. However, all these services increase the channel load, and thus, it is difficult to differentiate which service has a higher priority for accessing communication channels. In this paper, we focus on the classification of C-ITS services, which allows the cohabitation of all services considering the strict performance requirements for some services. The aim is to classify C-ITS services based on their packet delay requirements in order to define higher priority for critical services to ensure their dissemination, especially under congestion conditions. Then, we present protocols and quality of service (QoS) mechanisms that can map this classification to the available vehicular networks. INDEX TERMSCooperative Intelligent Transport Systems (C-ITS), Vehicular and wireless technologies, Cellular-V2X, ITS-G5, Vehicle-to-Everything (V2X)

The next generation mobile system is expected to support the continuous increase of users requirements. Through the high flow rates of these networks, new applications constraints are more complex and may be change dynamically and rapidly for wireless systems. The service heterogeneity provided by these applications has a great influence on system performance in terms of ability, availability and the context aware provided to make handover decision. To facilitate the negotiation process between the user and the network, we define some class of service that guarantees QoS for interworking between 3GPP and non-3GPP networks and the critical context criteria which influence the handover decision. In this context, our proposed approach supports the interaction between context-aware and class of service considering the use of the particular features of each class of service to make handover decision and providing the application required QoS. In this paper we conceive a new approach, called Enhance Simple Additive Weighting, for network selection that reduces computational complexity, the handover latency and eliminates networks which do not satisfy a minimum requirement compared to other existing approaches based on AHP strategy.

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To manage a growing number of users and an ever-increasing demand for bandwidth, future 5th Generation (5G) cellular networks will combine different radio access technologies (cellular, satellite, and WiFi, among others) and different types of equipment (pico-cells, femto-cells, small-cells, macro-cells, etc.). Multi-connectivity is an emerging paradigm aiming to leverage this heterogeneous architecture. To achieve this, multi-connectivity proposes to enable UE to simultaneously use component carriers from different and heterogeneous network nodes: base stations, WiFi access points, etc. This could offer many benefits in terms of quality of service, energy efficiency, fairness, mobility, and spectrum and interference management. Therefore, this survey aims to present an overview of multi-connectivity in 5G networks and beyond. To do so, a comprehensive review of existing standards and enabling technologies is proposed. Then, a taxonomy is defined to classify the different elements characterizing multi-connectivity in 5G and future networks. Thereafter, existing research works using multi-connectivity to improve the quality of service, energy efficiency, fairness, mobility management, and spectrum and interference management are analyzed and compared. In addition, lessons common to these different contexts are presented. Finally, open challenges for multi-connectivity in 5G networks and beyond are discussed.

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The IEEE 802.16 standard defines a wireless broadband access network technology called Wimax. It introduces several advantages, one of which is the support for Quality of Service (QoS) at the MAC level. To ensure meeting the QoS requirements, the 802.16 base stations must run some algorithms to allocate slots between connections. Call admission and scheduling are the strongest tools in our hand to ensure QoS. We propose an efficient design architecture that is capable of allocating slots based on the QoS requirements, bandwidth request sizes, and the 802.16 network parameters. To test the proposed solution, we have implemented a cross layer between the 802.16 MAC and the network layers in the NS-2 simulator and, then in RTL level with VHDL to be designed in FPGA. Several simulation scenarios are presented. According to the simulation results, the proposed scheduling solution ensures the QoS requirements of all 802.16 service classes. The solution shares free resources weighted fairly and demonstrates work-conserving behavior. The proposed design in this paper was analyzed: simulation results show a significant performance improvement in terms of overall throughput and delay when compared to recently published work.

The integration of heterogeneous wireless networks allows the mobile users to benefit simultaneously from the radio coverage of different access technologies (RAT: Radio Access Technology) and the diversity of applications. Nowadays, applications are becoming more and more critical in terms of Quality of Service (QoS) and dynamicity. Handover mechanism is responsible of guaranteeing the required quality of service in ubiquitous environment when mobile users roam across different RATs. The diversification of context metrics offered by these different networks has a direct impact on the user perceived quality of service especially during the network selection process. The present work addresses the network selection process, which is the most important stage of the vertical handover decision mechanism. Our proposed algorithm for Vertical Handover decision making is based on the context awareness and the quality of experience (QoE). It integrates the threshold values of sensitive criteria, which are considered as the required metrics in the making decision process used to select the optimal target network. However, we define a decision function that checks the performance of the given networks and identifies the best solution. Performance offered by the chosen network has to be reviewed since the handover is launched to control the quality of service perceived by the end user. Simulation results improve the perceived network performance by avoiding unnecessary handover. In Ubiquitous environment, most Handover decision mechanisms generate a ping pong effect caused by the inefficiency of the network handover metrics which do not consider the required end user performance. As compared to several existing algorithms, our algorithm fits the expected changes in the network performance and the users preferences without wastage of network resources. It reduces the processing delay and the complexity level caused by unnecessary computation over available radio access technologies which do not ensure required connection performance.

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