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The cloudification and virtualisation of railway functions have the potential to improve railway operation efficiency, reliability, safety, and security, as well as to enhance passenger experience by offering innovative services. This paper considers issues related to the management and orchestration of railway clouds that host cloudified railway functions. A microservices-based approach to the design of railway cloud management and orchestration functionality is proposed. The basic railway cloud concepts were defined, and functionality related to the basic orchestration of the railway cloud and deployments is analysed in order to derive the requirements of platform resources and workload management. This functionality is further designed in the form of microservices, meaning that they could possibly be used in orchestration applications to enable improvements in scalability, fault isolation, and data security. The design of microservices follows the principles of the Representational State of Transfer (REST) application programming interface (API) as a set of interlinked resources. Resources related to railway cloud orchestration are identified with their associated data, relationships to other resources, and applicable methods. The resources’ methods are used in railway applications to implement the required orchestration functionality and to maintain the state of railway cloud orchestration processes. To verify the synthesised microservices, the common orchestration application logic and microservices’ logic were modelled, and it was proved that the orchestration processes, which run concurrently, expose equivalent behaviour. The proposed approach was validated using a simulation, aiming to evaluate injected latency as a key performance indicator for the reliability and safety of railway operations. Additionally, some safety and security issues related to railway cloud management and orchestration are considered.

Future train control systems are expected to support high speed railways, to be automated and intelligent. European Railway Traffic Management System (ERTSM) and European Train Control Systems (ETCS) provide a standard aimed at optimization of driving, constant control on the effect of actions taken for train safety and activating of train braking in case of emergency. Radio Block Center (RBC) is a central control in the ETCS ground topology and is responsible for the security of each train in its area. Currently, the RBC is proprietary equipment with monolithic design. In this paper, we propose a new disaggregated open architecture of RBC which enables embedding intelligence. The proposed architecture of intelligent RBC is based on separation of nonreal time functions and near real time functions. A use case illustrates the approach applicability. Some implementation issues are discussed.

The symmetry between customer expectations and operator goals, on one hand, and the digital transition of the railways, on the other hand, is one of the main factors affecting green transport sustainability. The European Train Control System (ETCS) was created to improve interoperability between different railway signaling systems and increase safety and security. While there are a lot of ETCS Level 2 deployments all over the world, the specifications of ETCS Level 3 are under development. ETCS Level 3 is expected to have a significant impact on automatic train operation, protection, and supervision. In this paper, we present an innovative control system architecture that allows the incorporation of artificial intelligence (AI)/machine learning (ML) applications. The architecture features control function virtualization and programmability. The concept of an intelligent railway controller (IRC) is introduced as being a piece of cloud software responsible for the control and optimization of railway operations. A microservices-based approach to designing the IRC’s functionality is presented. The approach was formally verified, and some of its performance metrics were identified.

Presence service enables to publish, store, and access presence information. Usually, it is used by humans along with voice and instant messaging services, but with the ubiquitous penetration of machine type communications it may by used also by smart devices. The paper presents a RESTful Presence service which may be deployed at the network edge. The main benefits are that the proposed service does not require deployment of Internet Protocol Multimedia Subsystem and saves network resources. In addition to information provided by the presentity, the service enables extension of published presence status with information provided by the radio access network.

Distribution of cloud computing capabilities at the edge of the mobile network addresses the requirements for reduced latency and more efficient usage of network resources. Opening the network edge for third parties enables rapid deployment of innovative applications. In this paper, capabilities for open access to charging function at the mobile edge are studied. New API for online charging is developed which enable MEC system to collaboratively interact with network functions responsible for session management and real time charging. The proposed interfaces follow the adopted Representational State Transfer (REST) used to expose and access edge cloud services. The APIs are described by typical use cases, data model and information exchange, and resource structure. Implementation aspects related to modeling the charging application logic and charging status supported by the network are discussed.

Third party session control can be useful in many Internet of Things (IoT) use cases including monitoring and assistance of elderly and mission critical communications. Enhanced session control with media playing, collecting and recording interaction adds value and enables more information to be provided and gathered. The Multi-access Edge Computing (MEC), which brings the cloud computational and storage power at the network edge, can address many IoT use cases. The paper studies the capabilities of exposing media control to MEC applications. MEC Application Programming Interfaces that enable third party application to play media message, to collect and record media interactions within ongoing session, are presented. Media control data model is proposed. As a proof of the concept, state models supported by the network and MEC application are presented, formally described and verified.

Multi-connectivity is an important feature of fifth generation (5G) mobile networks as it addresses the requirements for high data rates and reliability. It enables user connectivity to several radio nodes simultaneously and tight integration between different radio access technologies. In this paper, we propose an approach to programmability of multi-connectivity functions using Multi-access Edge Computing (MEC) technology. Programmability enables third party applications deployed at the network edge to control user connectivity based on up-to-date radio network information e.g. congestion level, user location and requested data speeds. A new MEC service is proposed which is described by resources and operations, and data structures to be used in resource representations. The approach practicability is illustrated by modeling the multi-connectivity state as seen by the network and by MEC application. Service performance parameters are discussed in terms of latency.

5G systems will provide a flexible charging capabilities including policy control based on spending limits for a subscription. Edge computing possesses the potential for exposing policy control and charging capabilities to third party applications close to the end users. In this paper, we propose a new mobile edge service that provides open access to functions related to monitoring the usage limits regardless the way of measurement i.e. monetary, volume, duration, etc. Currently, this function is a part of the core network functionality. Using the proposed service interfaces, an intended application may track the usage of network resource by a subscriber and to request applying of enforcement action to user traffic such as quality of service downgrade, traffic redirection or blocking close to the end user. The description of the proposed mobile edge service is provided in form of typical use cases, data model, interface definition, and formally verified state models.

Multi-access Edge Computing is a promising technology that may satisfy the diverse quality of service requirements of 5G services. It brings the cloud capabilities for storage and computing in proximity to end users and thus it enables more timely reaction to dynamic network conditions. In this paper, we propose a new mobile edge service which provides functionality for user traffic handling. Using the service interfaces, an intended mobile edge application may shape, redirect or block user traffic based on information about radio conditions, user location, requested data speeds, etc. The new mobile edge service is described by typical use cases, data model, interface definition, and state models which are formally verified.

Multi-access Edge Computing is a promising re- search domain in 5G networks, as it is aimed at improving network efficiency by distributing cloud computing capabilities at the network edge. In this paper, we present a new mobile edge service for usage monitoring control. Usage monitoring control is defined as a part of Policy and Charging Control functionality in the core network. Moving the usage monitoring function close to the end user enables efficient control on data traffic. The proposed mobile edge service is described by typical use cases, data model and interface definition. As proof of concept, we propose resource state models as seen by mobile edge applications and platform, which are formally described and verified.

The virtualization and automation of network functions will be key features of future high-speed railway networks, which have to provide dependable, safe, and secure services. The virtualization of railway network functions will enable functions such as train control, train integrity protection, shunting control, and trackside monitoring and maintenance to be virtualized and to be run on general-purpose hardware. Network function virtualization combined with edge computing can deliver dynamic, low-latency, and reliable services. The automation of railway operations can be achieved by embedding intelligence into the network to optimize the railway operation performance and to enhance the passenger experience. This paper presents an innovative railway network architecture that features distributed intelligence, function cloudification and virtualization, openness, and programmability. The focus is on time-tolerant and time-sensitive intelligent services designed to follow the principles of service-oriented architecture. The interaction between identified logical identities is illustrated by use cases. The paper provides some details of the design of the interface between distributed intelligent services and presents the results of an emulation of the interface performance.

The Future Railway Mobile Communication System (FRMCS) has emerged as a worldwide standard for railway communication. This technology enables the operational efficiency and safety of railways to be improved by providing mission critical communications, machine-type communication for the railway system on board, in addition to trackside telemetry and broadband connectivity for passengers. Different equipment types, users, and functional identities can be involved in communication, and each of them is uniquely identified. Identity management is an important part of the security functions provided by the FRMCS system. This paper presents a service-oriented approach to identity management functionality, enabling service composition for railway applications and service virtualization. This paper studies functionality for the initial registration and subsequent deregistration of railway devices, users, and their functional identities, in addition to the transfer of the registered identities between different FRMCS serving areas while the train moves. Two FRMCS services that follow the principles of representational state transfer architecture are proposed. Services’ functionality is illustrated by use cases, data types, and application programming interfaces that enable services to be interacted with. Identity registration status models are developed, formally described, and mathematically verified. Discussion of the applicability of the proposed services for the implementation of FRMCS security and safety functions is provided. The presented service-oriented approach features a satisfactory level of flexibility and versatility.

Mobile Edge Computing (MEC) provides cloud computing capabilities in the radio access network. It enables applications that improve user's quality of experience and guarantee maximum utilization of radio network resources. Communication between MEC services and applications is based on Service-oriented Architecture (SOA). In this paper, capabilities for deployment of existing Parlay X Web Services in MEC environment are studied, and a new Web Service that provides access to User equipment-related radio network information is proposed.

Connectivity management is the ability to connect and manage mobile devices in Machine-to-Machine (M2M) communications. Resilient and scalable connectivity management, which is fundamental to M2M solutions, may be achieved by using Mobile Edge Computing (MEC) technology. MEC enables applications to timely response to dynamic changes in radio conditions and thus to improve effectiveness of connectivity management. In this paper, we present models of device connectivity management that may be supported by MEC applications. We suggest a method for automatic detection of undesired interaction between applications using standard reasoning over description logic.

Multimedia broadcast is the most efficient method to distribute identical content to multiple users in the Evolved Packet System (EPS). EPS enables efficient usage of network resources and provisioning of quality of service for every user. Third-party control allows applications in an enterprise domain to invoke network functions like multimedia broadcast. In this paper, an approach to modeling the behavior of Service Capability Server (SCS) for multimedia broadcast in EPS is presented. Third-party applications can access multimedia broadcasting capabilities by using Parlay X Web Service interfaces. The SCS for multimedia broadcast exposes Parlay X interfaces toward 3rd-party applications and control protocols toward the network. The SCS functional behavior has to be synchronized with the application view on message broadcast and the state of the network resources intended for the broadcast session. Models of multicast session, IP connectivity session, and bearers’ and charging session are proposed and formally described using the notation of Label Transition Systems. The concept of weak bisimilarity is used to prove that models expose equivalent behavior; that is, they are synchronized.

The paper investigates the capabilities of Parlay X Web Services for Policy and Charging Control (PCC) in managing all Internet-protocol-based multimedia networks (IMSs). PCC is one of the core features of evolved packet networks. It comprises flow-based charging including charging control and online credit control, gating control, and Quality of Service (QoS) control. Based on the analysis of requirements for PCC, the functionality for open access to QoS management and advanced charging is identified. Parlay X Web Services are evaluated for the support of PCC, and some enhancements are suggested. Implementation aspects are discussed, and Parlay X interfaces are mapped onto IMS control protocols. Use cases of Parlay X Web Services for PCC are presented.