Vehicular communications, though a reality, must continue to evolve to support higher throughput and, above all, ultralow latency to accommodate new use cases, such as the fully autonomous vehicle. Cybersecurity must be assured since the risk of losing control of vehicles if a country were to come under attack is a matter of national security. This article presents the technological enablers that ensure security requirements are met. Under the umbrella of a dedicated network slice, this article proposes the use of content-centric networking (CCN), instead of conventional transmission control protocol/Internet protocol (TCP/IP) routing and permissioned blockchains that allow for the dynamic control of the source reliability, and the integrity and validity of the information exchanged.

The connected car concept is gaining momentum from the point of view, not only of research, but also of standardization and industrial development. Today there are many options for connecting a vehicle, in terms of to whom and how. In addition to making use of any conventional cellular technology, and connecting the vehicle to a base station or infrastructure element, vehicles can connect wirelessly and directly to each other using different technologies, both from the Institute of Electrical and Electronics Engineers (IEEE) and from the 3rd Generation Partnership Project (3GPP). This article offers a rigorous and detailed review of the system architecture aspects involved in the support of vehicular communications by the 3GPP fifth-generation (5G) standard, with special emphasis on its most recent iteration: Release 16.

The Mobile and wireless communications Enablers for the Twenty-twenty Information Society (METIS) project is laying the foundations of Fifth Generation (5G) mobile and wireless communication system putting together the point of view of vendors, operators, vertical players, and academia. METIS envisions a 5G system concept that efficiently integrates new applications developed in the METIS horizontal topics and evolved versions of existing services and systems. This article provides a first view on the METIS system concept, highlights the main features including architecture, and addresses the challenges while discussing perspectives for the further research work.

Long-Term Evolution (LTE) is the new standard recently specified by the 3GPP on the way towards fourth-generation mobile. This paper presents the main technical features of this standard as well as its performance in terms of peak bit rate and average cell throughput, among others. LTE entails a big technological improvement as compared with the previous 3G standard. However, this paper also demonstrates that LTE performance does not fulfil the technical requirements established by ITU-R to classify one radio access technology as a member of the IMT-Advanced family of standards. Thus, this paper describes the procedure followed by the 3GPP to address these challenging requirements. Through the design and optimization of new radio access techniques and a further evolution of the system, the 3GPP is laying down the foundations of the future LTE-Advanced standard, the 3GPP candidate for 4G. This paper offers a brief insight into these technological trends.

Long Term Evolution (LTE) standard enhances Multimedia Broadcast Multicast Services (MBMS) to provide highly efficient transmission of multicast/broadcast services. This paper aims at clarifying which is the best option for the Enhanced MBMS (E-MBMS) network configuration according to the operator needs. Besides, it describes the main technical features of the new E-MBMS LTE standard, for both streaming and file delivery, and derives optimum operation modes. Some relevant conclusions are drawn from a set of simulation results calibrated with International Telecommunication Union Radiocommunication (ITU-R) guidelines. Regarding streaming delivery, results show that increasing the MBMS over a Single Frequency Network (MBSFN) area size allows employing a higher modulation and coding scheme level, which entails more streaming channels per MBSFN area. Concerning file delivery, results show that the reduction in the mean throughput of unicast users matches exactly the percentage of stolen subframes. Besides, the hybrid approach suggested in this paper improves the file delivery efficiency while eliminating the dependency on a MBMS threshold.

Sixth-generation wireless (6G) technology has been focused on in the wireless research community. Global coverage, massive spectrum usage, complex new applications, and strong security are among the new paradigms introduced by 6G. However, realizing such features may require computation capabilities transcending those of present (classical) computers. Large technology companies are already exploring quantum computers, which could be adopted as potential technological enablers for 6G. This is a promising avenue to explore because quantum computers exploit the properties of quantum states to perform certain computations significantly faster than classical computers. This paper focuses on routing optimization in wireless mesh networks using quantum computers, explicitly applying the quantum approximate optimization algorithm (QAOA). Single-objective and multi-objective examples are presented as robust candidates for the application of quantum machine learning. Moreover, a discussion about quantum supremacy estimation for this problem is provided.