This paper highlights the value of Digital Twins (DTs) in optimizing and maintaining Cyber-Physical Systems (CPSs) across domains like manufacturing and communication. It proposes the interaction between an industry DT and a 6G DT and identifies Situational Awareness (SA) as a key step toward supporting critical services. A use case involving 6G communication with mobile User Equipment (UE) in manufacturing is analyzed to identify critical operating scenarios and how SA can predict and mitigate the risk of failure in these scenarios. Based on this use case, relevant parameters for improving the SA of the entire CPS are identified in both DTs and an example of interaction is given for optimizing the joint task planning and execution. Additionally, the benefits of cross-domain SA are demonstrated through 5G testbed measurements. The use case illustrates the broader applicability of our proposal.

Industrial cyber-physical systems require dependable network communication with formal end-to-end reliability guarantees. Striving towards this goal, recent efforts aim to advance the integration of 5 G into Time-Sensitive Networking (TSN). However, we show that IEEE 802.1Qbv TSN schedulers that are unattuned to 5 G packet delay variations may jeopardize any reliability guarantees provided by the 5 G system. We demonstrate this on a case where a 99.99 % reliability in the inner 5G network diminishes to below 10 % when looking at end-to-end communication in TSN. In this paper, we overcome this shortcoming by introducing Full Interleaving Packet Scheduling (FIPS) as a wireless-friendly IEEE 802.1Qbv scheduler. To the best of our knowledge, FIPS is the first to provide formal end-to-end QoS guarantees in wireless TSN. FIPS allows a controlled batching of TSN streams, which improves schedulability in terms of the number of wireless TSN streams by a factor of up to$\times 45$. Even in failure cases, FIPS isolates the otherwise cascading QoS violations to the affected streams and protects all other streams. With formal end-to-end reliability, improved schedulability, and fault isolation, FIPS makes a substantial advance towards dependability in wireless TSN.

Industry 4.0 promises the increase of productivity and efficiency within manufacturing and industrial processes. A key milestone in this evolution is the 3GPP specification on time-sensitive communication and integration of 5G with time-sensitive networking (TSN), thus enabling the required flexibility for future time-sensitive industrial applications. Although 3GPP introduces ultra-reliable low latency communication (URLLC) features to meet stringent timing requirements, the notable challenge persists in resource overprovisioning, limiting the capacity of the next-generation radio access network (NG-RAN). Our work addresses this by focusing on the sources of packet delay and packet delay variation within the 6G system. Through analysis and proposed enhancements, supported by simulation and measurement results, we aim to minimize queuing delay and optimize 6GS capacity. Our study not only explores standardized 5GS features but also proposes extensions to support periodic deterministic traffic, offering insights to enhance 6GS performance and capacity in real-world scenarios.

5G New Radio (NR) non-public network deployments for industrial and enterprise applications are becoming highly popular in locally licensed and/or operator spectrum. The interference from coexisting networks on adjacent channels (in same or adjacent spectrum bands) could potentially deteriorate the performance characteristics in certain deployment scenarios. Appropriate interference mitigation is thus required to achieve the desired performance levels. In this paper, we present our detailed empirical results on the performance impact of coexisting 5G NR networks operating on adjacent channels. Our experimental study conducted on an industrial shopfloor reports the impact on the downlink and uplink latency and throughput when using the same and different Time Division Duplexing patterns for coexisting networks. Our empirical evaluation includes realistic user equipment deployment locations and traffic load conditions. We also present our results on different mitigation techniques to counter the adjacent channel interference effects.

By expanding beyond broadband capabilities of commercial mobile networks and providing novel connectivity features for a wide variety of industry verticals, 5G is becoming a key enabler for the digitalization of industry. However, unlike consumer market where users have very similar communication needs, industrial environments require direct control of security and performance aspects of an underlying networking infrastructure to achieve high communication availability and determinism for a broad range of applications and services. Similarly, it is vital to continuously monitor and verify the connectivity status and performance of devices, especially for mission-critical industrial systems. This paper investigates how to achieve fundamental management capabilities for 5G networks from industrial automation systems, which we refer to as “5G Managed from Industrial Automation”, while hiding “low-level” complexities of the technology. It presents a simplified 5G network management and monitoring solution, designed according to the functional requirements of a process control system, and based on a prototype of 5G system exposure capabilities. In addition, the paper presents details about the design and implementation of the 5G management solution in an ABB industrial automation system and its verification on a private 5G network offered by Ericsson.

The 3rd Generation Partnership Project (3GPP) has introduced technical features for Non-Public Networks (NPN), allowing highly flexible and dedicated 5G deployments for Industry 4.0 applications. This paper presents insights into the early adoption of a 5G Public Network Integration Non-Public Network (PNI-NPN) for industrial automation applications with observed network performance. Our contributions are threefold: (i) we present network design concepts to overcome the challenges of industrial use-cases and mobile network limitations, (ii) we propose network architecture over 5G Non-Standalone architecture (NSA), and (iii) we perform validation measurements with PROFINET and PROFIsafe communication. Our results – at a real industrial 5G setting – indicate that the proposed architecture is very promising for future 5G industrial deployments.

Cyber-physical control applications impose strict requirements on the reliability and latency of the underlying communication system. Hence, they have been mostly implemented using wired channels where the communication service is highly predictable. Nevertheless, fulfilling such stringent demands is envisioned with the fifth generation of mobile networks (5G). The requirements of such applications are often defined on the application layer. However, cyber-physical control applications can usually tolerate sparse packet loss, and therefore it is not at all obvious what configurations and settings these application level requirements impose on the underlying wireless network. In this paper, we apply the fundamental metrics from reliability literature to wireless communications and derive a mapping function between application level requirements and network level parameters for those metrics under deterministic arrivals. Our mapping function enables network designers to realize the end-to-end performance (as the target application observes it). It provides insights to the network controller to either enable more reliability enhancement features (e.g., repetition), if the metrics are below requirements, or to enable features increasing network utilization, otherwise. We evaluate our theoretical results by realistic and detailed simulations of a factory automation scenario. Our simulation results confirm the viability of the theoretical framework under various burst error tolerance and load conditions.

Utilizing the abundant bandwidth in millimeter wave frequency bands is an interesting option to enable wireless communication services with challenging latency and reliability requirements for factory automation. Nevertheless, millimeter wave bands have less favorable propagation properties compared to lower bands, which impacts the coverage negatively. In this paper, we show that millimeter wave bands can fulfill extreme latency and reliability requirements with much higher system capacity than mid-band frequencies by means of beamforming, large antenna arrays, and network densification. This makes millimeter wave bands suitable for providing ultra-reliable low-latency communication services for factory automation. However, we find that small beam misalignments due to channel state information error can degrade the system capacity substantially.

The IEEE “Tactile Internet” (TI) Standards working group (WG), designated the numbering IEEE 1918.1, undertakes pioneering work on the development of standards for the TI. This paper describes the WG, its intentions, and its developing baseline standard and the associated reasoning behind that and touches on a further standard already initiated under its scope: IEEE 1918.1.1 on “Haptic Codecs for the TI.” IEEE 1918.1 and its baseline standard aim to set the framework and act as the foundations for the TI, thereby also serving as a basis for further standards developed on TI within the WG. This paper discusses the aspects of the framework such as its created TI architecture, including the elements, functions, interfaces, and other considerations therein, as well as the novel aspects and differentiating factors compared with, e.g., 5G Ultra-Reliable Low-Latency Communication, where it is noted that the TI will likely operate as an overlay on other networks or combinations of networks. Key foundations of the WG and its baseline standard are also highlighted, including the intended use cases and associated requirements that the standard must serve, and the TI's fundamental definition and assumptions as understood by the WG, among other aspects.

The tactile internet will enable a new range of capabilities to enable immersive remote operations and interactions with a physical world. Tactile internet use cases span over many fields, from remote operation of industrial applications in, e.g., hazardous environments, via remote-controlled driving in a fully automated intelligent transport system, to remote surgery where the unique expert skills can be delivered to different locations in the world. Fifth-generation (5G) communication will play a fundamental part in this tactile internet vision, as it will provide necessary capabilities for the demanding communication needs in terms of reliability and low latency, for operators or teleoperated systems that are connected wirelessly. This paper provides an overview of tactile internet services and haptic interactions and communication. The 5G functionality for ultrareliable and low-latency services is described in depth and it is shown how 5G new radio (NR) and the evolved long-term evolution (LTE) radio interface can achieve guaranteed low-latency wireless transmission. The costs for providing reliable and low-latency wireless transmission in terms of reduced spectral efficiency and coverage are discussed. The 5G system architecture with a software-based network design based on a distributed cloud platform is presented. It is shown how the 5G network is configured for tactile internet services via multidomain orchestration.

5G is expected to support mission-critical ultra- reliable low-latency communication services in addition to enhanced mobile broadband applications. Ultra-reliable low-latency communication refers to wireless communications where successful data transmission can be assured within extremely low latency bounds and with high reliability. In this paper, we investigate the network coverage and capacity of ultra-reliable low-latency communication services that are provided over realistic cellular deployments using 3.5GHz and 800MHz bands with NR and LTE-Advanced radio interface technologies (3GPP Release 15) and Vodafone's existing macro grid in London. An assessment of the existing fixed network core performance is done, which is connected to the simulations of the performance of the radio access network to get the end-to-end service perspective. It is shown that both NR and LTE-Advanced can fulfill 5ms latency target with 99.999% reliability. However, only NR can support the even stricter 1ms latency target, thanks to its flexible numerology. Furthermore, the ultra- reliable low- latency communication service capacity is shown to be very low for the LTE carrier compared to that of the NR, due to the scarcity of bandwidth resources at the LTE band, and the larger antenna arrays of NR. The evaluations include ray-tracing propagation modeling utilizing a 3D digital map of the coverage area together with site positions provided by Vodafone.

The Mobile Internet connects billions of smart phones and laptops. With this global connectivity, the stage is set for the emergence of: (a)Tactile Internetto deliver haptic experiences to remote users, and (b) flexible and integratedBackhaul/Fronthaulnetworks to support demands of such applications.

Powered by next generation mobile networking capabilities, the Tactile Internet will be able to transport touch and actuation in real-time. Enabled by suitable robotics and haptics equipment at the edges, and an unprecedented communications network, the Tactile Internet will provide a true paradigm in creating skill-set delivery networks. The fifth generation (5G) mobile communications systems will underpin this emerging Internet at the wireless edge. This paper presents the most important technology concepts which lay at the intersection of the larger Tactile Internet and the emerging 5G systems. Specifically, the paper presents some of the most important Tactile Internet applications, outlines the key technical requirements, and covers end-to-end architectural aspects of the Tactile Internet.

The long-term ambition of the Tactile Internet is to enable a democratization of skill, and how it is being delivered globally. An integral part of this is to be able to transmit touch in perceived real-time, which is enabled by suitable robotics and haptics equipment at the edges, along with an unprecedented communications network. The fifth generation (5G) mobile communications systems will underpin this emerging Internet at the wireless edge. This paper presents the most important technology concepts, which lay at the intersection of the larger Tactile Internet and the emerging 5G systems. The paper outlines the key technical requirements and architectural approaches for the Tactile Internet, pertaining to wireless access protocols, radio resource management aspects, next generation core networking capabilities, edge-cloud, and edge-AI capabilities. The paper also highlights the economic impact of the Tactile Internet as well as a major shift in business models for the traditional telecommunications ecosystem.

This paper evaluates the feasibility of overlaying a secondary system on a digital TV (DTV) system. We denote this type of approach TV black space (in contrast to TV white space). In this type of operation the secondary transmitter transmits on the same spectrum resources as the DTV system. Particularly, we consider the case where the secondary transmitter is collocated with the DTV transmitter and uses the same antennas. The fraction of the total transmitted power that is used for the secondary signal is set low enough so that the DTV receivers are always able to decode the DTV signals. The black space receivers decode the TV signal component and cancel it from the total received signal which results in an improved SINR of the secondary signal in the residual. Numerical evaluations show that this type of overlay in the DTV spectrum is feasible only when the secondary system is satisfied with relatively low SINR values of around 5 to 10 dB. A critical parameter when determining the secondary signal SINR after DTV signal cancellation is the SINR requirements by the primary system: DVB-T systems typically require SINR values above 20 dB and then overlay becomes less feasible since the fraction of power left for the secondary signal becomes very low. Additionally, realistic levels of TX EVM noise (around 6% to 8%) at the transmitter causes low achievable SINR values for the secondary signal even after DTV signal cancellation at the receiver side.

This paper describes the steps and the procedures involved to establish access flows for a user data session in multi-radio access networks. The description is evolved around the overall connectivity abstraction model defined in the ambient networks (AN) project. This model uses access flows as its fundamental objects which are the result of two main access selection procedures: network attachment and flow setup. All access abstractions and procedures have been developed to handle the requirements of efficient multi-access resource management through all stages of access connectivity. The paper discusses some design trade-off for the establishment of access flows concerning setup delays and resource efficiency.

In this paper we present three context transfer mechanisms to support seamless (inter-system) handover: L2 tunnel, SDU reconstruction and SDU context transfer. The hand-over schemes are evaluated for services based on TCP SACK. The influence of different system parameters like the link layer round trip time and block error rate are investigated. It is shown that there can be large differences in handover performance caused by packet loss or packet duplication, which interact with TCP congestion control. L2 tunnel always performs best but has the highest complexity. It is followed by SDU reconstruction and then SDU context transfer respectively. All schemes are always better in performance than when no context transfer is used

In the ambient networks project research is ongoing in order to define a new control space for future internetworking. This internetworking will be characterized by a high degree of network heterogeneity as well as nomadicity and mobility of both users as well as networks. The so called ambient control space (ACS), provides functionality to support how to manage these traits of future internetworking. This paper provides a short presentation on the architecture of ambient networks and the ACS, and then focus on how connectivity is handled from a multi-access and mobility perspective through the support of the ACS.

Integration of heterogeneous access technologies to provide multi-radio access allows for dynamic access selection. The "always best connected" paradigm can increase system capacity and end user throughput, as well as, reduce the network deployment costs for multi-radio wireless networks. In this paper we present the functional entities generic link layer and multi-radio resource management, and describe their interactions for access selection. A focus of the paper is to show - with an example given for 3G and WLAN - how existing wireless networks can be migrated to provide multi-radio access functionality. This will be explained for a single operator integrating different radio access standards, as well as, for multiple cooperating network operators.

This paper describes a proposal for the tight-coupling integration of WLAN-based media points and 3GPP/UMTS systems. The approach extends the SIP based session management and mobility management proposed for a standalone media point network by connecting it to the UMTS network. The integration aims to provide seamless continuity for SIP-based services when performing vertical radio handover from UMTS to WLAN. The proposed solution builds largely on existing procedures, like the standard UMTS control plane protocols and the IETF CTP (context transfer protocol). Session continuity is provided by keeping the current local IP address in the user terminal after handover. In order to save battery the usage of 3GPP location service mechanisms is proposed, which allow switching off WLAN modules outside the WLAN coverage area

Efficient employment of multiple radio access technologies is expected to be an important property of beyond 3G networks. This will put high demands on radio resource management support, both within and in-between radio access technologies. In this paper we discuss how to distribute radio resource management in a multi-radio access network, and identify three main distribution strategies: network centralized, network distributed and finally the option of having multi-access radio resource management located in the terminal. A combination of network distributed and terminal based radio resource management appears to be the best choice for dynamic multi-access radio resource management in most scenarios. Further, relations towards user plane functions are discussed and modeled, and the functionality is mapped to nodes and interfaces of a beyond 3G reference radio access network architecture.

A major aspect of Beyond 3G networks is the efficient integration of multiple radio access technologies in a common network. One advantage of this multi-radio access integration is the increase in radio resource efficiency, e.g. due to a larger trunking gain and reduced radio cost per link. This paper analyses and compares the different ways of how multi-radio access integration can be achieved. In particular, it investigates three multi-radio integration alternatives, two of them solving the problem at the network level and the third one on the link level. The comparison of the different approaches reveals that link level integration allows access path switching on a shorter time scale than network level integration. Another difference is where they allow the multi-radio resource management functions to take place, on network side or on user terminal side. In general, it is concluded that all schemes have certain advantages and disadvantages depending on the considered scenario. It is also highlighted, that these different integration schemes can be combined, i.e. some radio access technologies can be integrated on link level, while others can be integrated on network level.

In the future many radio access networks will be deployed based on different technologies and standards. Therefore, a paradigm for future generation wireless networking is to achieve cooperation between networks, which allows communication via a multitude of radio access technologies. While some mobility schemes already enable communication across network boundaries, it is still not possible to do this in an efficient and seamless way. In this paper the concept of generic link layer (GLL) is presented. It is envisaged that in the future the generic link layer will be generally deployed in all radio access networks, to allow efficient cooperation between different radio technologies. The GLL provides a toolbox of link layer functions which can be configured for any radio access technology. This paper discusses the functions and interfaces of the generic link layer. It is explained how the GLL enables lossless and efficient inter-system handover. In addition, directions are given where further research is required.

For data transmission WCDMA offers dedicated transport channels (DCH) and common transport channels, i.e. random access channels (RACH) and forward access channels (FACH). Both types of transport channels have different characteristics in terms of transmission performance and radio resource usage. In this paper these characteristics are described and a simulation model for the performance evaluation is presented. The effect of some parameters influencing the performance and efficiency of the different transport channel types is discussed, e.g. channel configuration, traffic load and traffic characteristics. It is demonstrated that common transport channels provide better performance than dedicated channels for a low traffic load of bursty traffic. For low data volumes they are also more resource efficient. However for an increasing traffic load dedicated channels provide a better service quality and radio resource utilisation.