This paper presents contributions to coding short packets that can be applied to wireless links in the Industrial Internet of Things, Cyber-Physical Systems, and Digital Twin Systems. The problem of efficiency and simplicity in coding schemes for short messages remains a research challenge. Sparse Vector Codes, based on Compressive Sensing techniques, offer good performance with a reasonable margin of simplification of the algorithms involved. In this paper, several SVC configurations are proposed and performance results are presented with comparisons to other channel coding schemes. A first study of the achievable range of these networks is also provided and their performance is compared to existing technologies. The results confirm the potential of SVC in industrial wireless systems.

The envisaged fifth-generation (5G) and beyond networks offer unprecedented breakthroughs in media service delivery, stringent requirements, and challenging use cases. In such context, point-to-multipoint communications have proved to be highly efficient in delivering high-quality multimedia services over wireless networks. For the upcoming Beyond-5G (B5G) system releases, the Multicast/Broadcast Services (MBS) capability is an appealing feature that addresses the ever-growing traffic demands, disruptive multimedia services, massive connectivity, and low-latency applications. This paper addresses the multicast users’ channel quality diversity throughout multi-rate multicasting aided non-orthogonal multiple access (NOMA) over B5G MBS use cases. We propose a tailored radio resource management (RRM) strategy aided by K-Means subgrouping to deal with such diversity. We characterize and identify conditions for an effective coexistence of the benchmarks conventional multicast scheme (CMS) and subgrouping based on OMA (SOM) with the proposed subgrouping based on NOMA (SNOM). The proposed solution is assessed under a wide range of users’ distributions, throughput requirements, and network conditions of an MBS use case recreated through link-level millimeter-wave (mmWave) simulations.

The stringent requirements of the latest immersive applications (i.e., 360° video, VR, AR, XR, etc.) combined with the scarcity of radio resources are challenging the service operators of the various telecommunication networks. In the recent literature, HetNets have been proposed as an alternative to overcoming these challenges. In previous work, the authors presented SVORA, an architecture for integrating different radio technologies, combining virtualized/open RAN architectures and SBA-based RAN for efficient spectrum usage. In this work, the authors upgrade the previously proposed solution to deliver immersive video efficiently. The paper presents imeNF, a new set of Network Functions that support delivering high-bitrate immersive video-based applications with increased quality of service. Simulations-based testing shows how, based on imeNF, a 16k video can be sent with delays of 15 ms, while traditional D-RAN, V-RAN, and O-RAN-based approaches take more than 300 ms.

Industry 4.0 aspires to digitize factories processes wholly. Wireless technologies represent one of the elements of this goal. However, the current standards and proprietary solutions need to meet the industry’s tight requirements for various use cases, such as smart warehouses, where robots manage and control entire tasks. One of the key research challenges toward replacing wired fieldbuses with wireless links is the design of wireless systems that address short packet transmissions and multi-user environments. Nevertheless, this challenge is partially obstructed by the limits of the current proposals and the industrial channel models. The authors detect as a potential solution the optimization of IEEE 802.11ax that, due to the use of OFDMA, could offer a high-performant system for smart warehouses. This article proposes an ad-hoc wireless system based on IEEE 802.11ax for smart warehouses that comprises optimization for MAC and PHY layers. Furthermore, two retransmission schemes based on frequency domain are described. This article proposes a methodology to evaluate the latency and reliability performance. Compared to previous proposals, the system shows improved performance.

This paper describes the design of a Broadcast Core Network (BCN). The BCN is intended to enable the integration of existing terrestrial broadcast systems into a 5G/6G ecosystem. The existing multimedia content distribution architecture in current broadcast networks and the capabilities of 5G access and core networks (5GC) are analyzed to dissect their limitations. We show, inter alia, how the lack of an equivalent data plane makes it impossible to import a 5GC as a solution. We propose a dynamic model that addresses the necessary structure for integrating a BCN in today’s broadcast networks. The paper then considers the evolution of the BCN up to its integration into a 5G/6G cellular network ecosystem. The required architectural components are described. Detailed definitions of the microservices are included, along with the relationships and message calls to enable relevant use cases. Finally, a simulation and lab prototype were developed to validate the proposal. The lab platform is based on multimedia content broadcasting nodes using ATSC 3.0 and a BCN prototype for its control. The results demonstrate the ability of the proposed solution to maximize spectrum utilization and improve the efficiency of current systems.

Upgrading wired industrial field buses with wireless counterparts is a key driver for future industrial applications and systems. This migration faces significant challenges associated with security, reliability, and lack of generally accepted standards. Moreover, wireless PHY and MAC layer developments require accurate, reliable, and realistic propagation channel models. Reliable models for Delay Profile and Doppler Spectra are scarce in the literature. This work analyses channel models based on reliable empirical data. It includes a description of the source databases, the processing methods, and the first results of multipath distribution and Doppler metrics. The results indicate that previous assumptions on Laplacian Doppler should not be taken for granted in industrial environments.

Wireless backhaul has recently gained a significant amount of interest as a cost-effective solution in comparison with conventional backhaul technologies with dedicated microwave links or fiber optics. Self-interference cancellation (SIC) is an enabling technology that allows wireless backhaul to operate in the more spectrum-efficient in-band full-duplex (IBFD) operation mode instead of the out-of-band mode. Compared to Wi-Fi IBFD transceivers, wireless in-band backhaul systems face some unique challenges, such as significantly higher transmission power and much larger propagation delay spread for the self-interference signal, especially in the low-frequency bands under 1 GHz, which often prevent accurate SIC performance. The SIC is often implemented with an interference-cancelling filter, where the filter weights are essentially the channel estimates of the self-interference signals. In this paper, a frequency-domain Radio Frequency (RF) SIC (RF-SIC) framework with a novel filter weight optimization algorithm is proposed to tackle the challenges of wireless in-band backhaul. The proposed RF-SIC does not require a dedicated training phase which needs to stop the transmission of the backhaul signal. Moreover, it has the capability of tracking the self-interference channel variation since the filter weights are updated in a block-by-block fashion.

Industry 4.0 is expected to change radically the current ecosystem of industrial technologies, including commu-nication systems. Novel industrial scenarios will request to fulfill tight requirements, such as low latency and ultra-high reliability. Classical wired solutions lack scalability and mobility and assume high deployment costs. However, in wireless communications, the propagation channel appears as an additional challenge to overcome the limitations of wired systems. This paper addresses several requirements simultaneously using Non-Orthogonal Mul-tiple Access (NOMA). An efficient superframe structure has been designed to deliver additional services (i.e., high-quality video service) and transmit specific services (i.e., critical services). Furthermore, the performance of the additional service (i.e., best effort) has been tested in terms of availability and capacity. Then, another Key Performance Indicator (KPI) deeply analyzed in this paper is energy consumption. Finally, the entire communication system has been evaluated from different perspectives, and some guidelines have been provided to detail the best configurations depending on the optimization KPI.

Critical communication requirements included in Factory Automation applications are complex to implement due to the difficulties encountered in guaranteeing high reliability and ultra-low latencies at the same time. In this work-in-progress, a technical solution for the physical layer is proposed: the Quasi-Cyclic LDPC of the Progressive Edge Growth family (QC-PEGLDPC). This coding scheme is considered as a promising candidate due to two main factors: the good decoding performance for short packet transmissions and the low latency that can be obtained by using full parallel decoding architectures. The obtained results are compared with the 5G New Radio coding scheme, which includes LDPCs as part of the solution for Ultra Reliable Low Latency (URLLC) use cases. In these first results, QC-PEG-LDPC shows a performance improvement of 1 dB when compared with the 5G LDPC codes for a message length of 128 bits. Latency analysis indicate that QC-PEG-LDPC could allow decoding latencies of 0.13 μs providing that the full parallel decoding architecture is enabled.

The Industry 4.0 concept is the result of latest technical advances that have completely changed the existing industrial vision, not only from the mechanical point of view, but also from the Machine-to-Machine (M2M) communication perspective. This revolution encompasses wireless communication technologies that are expected to be the replacement for traditional wired and fixed communication systems. However, industrial propagation channels are still a challenge for wireless industrial network deployments. This paper addresses this problem by proposing spatial diversity based retransmissions. Two general retransmission schemes have been tested: default and smart. Moreover, specific time scheduling choices have been proposed. The impact of the number of transmitters in relation to communication reliability has been analyzed. Results show that the use of spatial diversity based retransmissions makes restrictive reliability values feasible under realistic conditions. In fact, in the case of smart retransmissions, adding a second transmitter the reliability increases around 8 dB. Moreover, whereas the channel coherence time is a critical parameter for time based retransmissions, in the case of spatial diversity, the reliability performance has no dependency on the channel coherence time.