End-to-end network service orchestration in heterogeneous domains for next-generation mobile networks

5G marks the beginning of a deep revolution in the mobile network ecosystem, transitioning to a network of services to satisfy the demands of new players, the vertical industries. This revolution implies a redesign of the overall mobile network architecture where complexity, heterogeneity, dynamicity, and flexibility will be the rule. Under such context, automation and programmability are essential to support this vision and overcome current rigid network operation processes. Software Defined Networking (SDN), Network Function Virtualization (NFV) and Network slicing are key enabling techniques to provide such capabilities. They are complementary, but they are still in its infancy and the synergies between them must be exploited to realise the mentioned vision. The aim of this thesis is to further contribute to its development and integration in next generation mobile networks by designing an end-to-end (E2E) network service orchestration (NSO) architecture, which aligned with some guidelines and specifications provided by main standardization bodies, goes beyond current management and orchestration (MANO) platforms to fulfil network service lifetime requirements in heterogeneous multi-technology/administrative network infrastructures shared by concurrent instances of diverse network services. Following a bottom-up approach, we start studying some SDN aspects related to the management of wireless network elements and its integration into hierarchical control architectures orchestrating networking resources in a multi-technology (wireless, optical, packet) infrastructure. Then, this work is integrated in an infrastructure manager module executing the joint resource abstraction and allocation of network and compute resources in distributed points of presence (PoPs) connected by a transport network, aspect which is not (or lightly) handled by current MANO platforms. This is the module where the integration between NFV and SDN techniques is executed. This integration is commanded by a Service Orchestrator module, in charge of automating the E2E lifecycle management of network services implementing network slices (NS) based on the vertical requirements, the available infrastructure resources, and, while fulfilling service level agreement (SLA) also during run-time operation. This architecture, focused on single administrative domain (AD) scenarios, constitutes the first group of contributions of this thesis. The second group of contributions evolves this initial architecture to deal with the orchestration and sharing of NS and its network slice subnet instances (NSSIs) involving multiple ADs. The main differential aspect with current state-of-the-art solutions is the consideration of resource orchestration aspects during the whole orchestration process. This is fundamental to achieve the interconnection of NSSIs, hence making the E2E multi-domain orchestration and network slicing a reality in practice. Additionally, this work also considers SLA management aspects by means of scaling actions during run-time operation in such complex scenarios. The third group of contributions demonstrate the validity and applicability of the resulting architectures, workflows, and interfaces by implementing and evaluating them in real experimental infrastructures featuring multiple ADs and transport technologies interconnecting distributed computing PoPs. The performed experimentation considers network service definitions close to real vertical use cases, namely automotive and eHealth, which help bridging the gap between network providers and vertical industries stakeholders. Experimental results show that network service creation and scaling times in the order of minutes can be achieved for single and multi-AD scenarios, in line with 5G network targets. Moreover, these measurements serve as a reference for benchmarking the different operations involved during the network service deployment. Such analysis are limited in current literature.5G marca el inicio de una gran revolución en las redes móviles, convirtiéndose en redes orientadas a servicios para satisfacer las demandas de nuevos actores, las industrias verticales. Esta revolución supone un rediseño total de la arquitectura de red donde la complejidad, heterogeneidad, dinamicidad y flexibilidad serán la norma. En este contexto, la automatización y programabilidad serán esenciales para superar los rígidos procesos actuales de operación de red. Las redes definidas por software (SDN), la virtualización de funciones de red (NFV) y el particionamiento de redes son técnicas clave para proporcionar dichas capacidades. Éstas son complementarias, pero aún recientes y sus sinergias se deben explotar para realizar la nueva visión. El objetivo de esta tesis es contribuir a su desarrollo e integración en la nuevas generaciones de redes móviles mediante el diseño de una arquitectura de orquestación de servicios de red (NSO) extremo a extremo (E2E), que alineada con algunas pautas y especificaciones de los principales organismos de estandarización, va más allá de los actuales sistemas de gestión y orquestación (MANO) para instanciar y garantizar los requisitos de los diversos servicios de red desplegados concurrentemente en infraestructuras heterogéneas compartidas que combinan múltiples tecnologías y dominios administrativos (AD). Siguiendo un enfoque ascendente, comenzamos a estudiar aspectos de SDN relacionados con la gestión de elementos de red inalámbricos y su integración en arquitecturas jerárquicas de orquestación de recursos de red en infraestructuras multi tecnología (inalámbrica, óptica, paquetes). Luego, este trabajo se integra en un módulo de administración de infraestructura que ejecuta de forma conjunta la abstracción y la asignación de recursos de red y computación en múltiples puntos de presencia (PoP) distribuidos conectados por una red de transporte, aspecto que no está (o ligeramente) considerado por los actuales sistemas MANO. Este módulo ejecuta la integración de las técnicas NFV y SDN. Esta integración está dirigida por el módulo Orquestador de Servicios, que automatiza la gestión E2E del ciclo de vida de los servicios de red implementando las diferentes particiones de red en base a los requisitos de los verticales, los recursos de infraestructura disponibles y mientras cumple los acuerdos de nivel de servicio (SLA) durante la operación del servicio. Esta arquitectura, centrada en escenarios con un único AD, forma el primer grupo de contribuciones de esta tesis. El segundo grupo de contribuciones evoluciona esta arquitectura abordando la orquestación y compartición de particiones de red y sus componentes (NSSIs) en escenarios con múltiples AD. La consideración detallada de aspectos de orquestación de recursos es el principal aspecto diferencial con la literatura. Esto es fundamental para la interconexión de NSSIs, haciendo realidad la orquestación E2E y el particionamiento de red en escenarios con múltiples AD. Además, se considera la gestión de SLA mediante acciones de escalado durante la operación del servicio en los escenarios mencionados. El tercer grupo de contribuciones valida las arquitecturas, procedimientos e interfaces resultantes pues se han implementado y evaluado sobre infraestructuras experimentales reales que presentan múltiples AD y tecnologías de transporte interconectando PoP distribuidos. Esta experimentación considera definiciones de servicios de red cercanos a casos de uso de verticales reales, como automoción y eHealth, ayudando a cubrir la brecha entre los proveedores de red y los verticales. Los resultados experimentales muestran que la creación y el escalado de servicios de red se pueden realizar en pocos minutos en escenarios con un único o múltiples ADs, en línea con los indicadores de red objetivos de 5G. Estas medidas, escasas en la literatura actual, sirven como referencia para caracterizar las diferentes operaciones involucradas durante el despliegue de servicios.Postprint (published version

R-Learning-based admission control for service federation in multi-domain 5G networks

Proceedings of: IEEE Global Communications Conference (GLOBECOM), 7-11 Dec. 2021, Madrid, Spain.Network service federation in 5G/B5G networks enables service providers to extend service offering by collaborating with peering providers. Realizing this vision requires interoperability among providers towards end-to-end service orchestration across multiple administrative domains. Smart admission control is fundamental to make such extended offering profitable. Without prior knowledge of service requests, the admission controller (AC) either determines the domain to deploy each demand or rejects it to maximize the long-term average profit. In this paper, we first obtain the optimal AC policy by formulating the problem as a Markov decision process, which is solved through the policy iteration method. This provides the theoretical performance bound under the assumption of known arrival and departure rates of demands. Then, for practical solutions to be deployed in real systems, where the rates are not known, we apply the Q-Learning and R-Learning algorithms to approximate the optimal policy. The extensive simulation results show that learning approaches outperform the greedy policy and are capable of getting close to optimal performance. More specifically, R-learning always outperformed the rest of practical solutions and achieved an optimality gap of 3-5% independent of the system configuration, while Q-Learning showed lower performance and depended on discount factor tuning.This work has been partially funded by the MINECO grant TEC2017-88373-R (5G-REFINE), the EC H2020 5Growth Project (grant no. 856709), and Generalitat de Catalunya grant 2017 SGR 1195

Deploying a containerized ns-3/LENA-based LTE mobile Network Service through the 5G-TRANSFORMER platform

This paper has been presented at: 2018 IEEE Conference on Network Function Virtualization and Software Defined Networks (NFV-SDN)This demo presents an ongoing prototype implementation of the Service Orchestrator (SO) building block of the 5G-TRANSFORMER (5GT) architecture. Within the 5GT-SO, we define the Service Manager (SM), which hosts the intelligence of the 5GT-SO and interacts with the other architectural blocks of the 5GT architecture through the defined APIs. The aim of defining the SM is to decouple the 5GT-SO implementation from the associated MANO platform, allowing the interoperability with other MANO platforms, hence increasing the scope of the 5GT solution. In this demo, we will show how the current ongoing implementation of the 5GT-SO, using the SM, is able to automate the orchestration of both computing and networking resources to deploy a virtualized mobile network service based on ns-3/LENA network simulator/emulator in minutes over an emulated environment consisting of a multi-point of presence infrastructure connected by a custom transport network.This work was supported by the 5G-TRANSFORMER project (H2020-761536), by MINECO grant TEC2017-88373-R (5G-REFINE) and Generalitat de Catalunya grant 2017 SGR 1195

Wireless Interface Agent for SDN mmwave multi-hop networks: design and experimental evaluation

2nd ACM Workshop on Millimeter Wave Networks and Sensing Systems (mmNets)Millimeter wave (mmwave) communications will likely be an enabler for 5G due to its multi-gigabit per second throughput capabilities. Furthermore,mmWave communications will have to be integrated in a new redesigned network required by 5G to fulfill its ambitious targets. In this paper, we present the design and implementation of a management agent for wireless devices deployed in a heterogeneous SDN wireless multi-hop research platform featuring mmwave communications for crosshauling (backhaul and fronthaul) purposes. The performance of the deployed mmwave network, based on the IEEE 802.11ad standard, is measured employing this agent. We measure the downtime in the presence of link up/down events, with obtained response times in the order of 10s-to-100s of milliseconds depending on the case. Furthermore, the TCP performance over the multi-hop 802.11ad mmwave network is also experimentally evaluated. In fact, TCP throughput up to around 800Mbps are obtained for single and multi-hop scenarios despite neighboring links using the same channel. Finally, one can also observe the impact of MTU size on TCP throughput, which may hinder the full exploitation of the mmWave link capacity when combined with other transport technologies, since the advantages of big MTUs (much bigger than the typical 1500 bytes) offered by mmwave devices may not be reaped.Thiswork was supported by MINECO grants TEC2017-88373-R (5G-REFINE), Generalitat de Catalunya grant 2017 SGR 1195, and by the 5G-TRANSFORMER project (H2020-761536)

Intent-Based Orchestration for Application Relocation in a 5G Cloud-native Platform

The need of mobile network operators for cost-effectiveness is driving 5G and beyond networks towards highly flexible and agile deployments to adapt to dynamic and resource-constrained scenarios while meeting a myriad of user network stakeholders' requirements. In this setting, we consider that zero-touch orchestration schemes based on cloud-native deployments equipped with end-to-end monitoring capabilities provide the necessary technology mix to be a solution candidate. This demonstration, built on top of an end-to-end cloud-native 5G experimental platform with over-the-air transmissions, shows how dynamic orchestration can relocate container-based end-user applications to fulfil intent-based requirements. Accordingly, we provide an experimental validation to showcase how the platform enables the desired flexible and agile 5G deployments

Service based virtual RAN architecture for next generation cellular systems

Service based architecture (SBA) is a paradigm shift from Service-Oriented Architecture (SOA) to microservices, combining their principles. Network virtualization enables the application of SBA in cellular systems. To better guide the software design of this virtualized cellular system with SBA, this paper presents a software perspective and a positional approach to using fundamental development principles for adapting SBA in virtualized Radio Access Networks (vRANs). First, we present the motivation for using an SBA in cellular radio systems. Then, we explore the critical requirements, key principles, and components for the software to provide radio services in SBA. We also explore the potential of applying SBA-based Radio Access Network (RAN) by comparing the functional split requirements of 5G RAN with existing open-source software and accelerated hardware implementations of service bus, and discuss the limitations of SBA. Finally, we present some discussions, future directions, and a roadmap of applying such a high-level design perspective of SBA to next-generation RAN infrastructure.This work was supported in part by the European Union (EU) H2020 5GROWTH Project under Grant 856709, in part by the Generalitat de Catalunya under Grant 2017 SGR 1195, and in part by the National Program on Equipment and Scientific and Technical Infrastructure under the European Regional Development Fund (FEDER) under Grant EQC2018-005257-P

A multi-criteria decision making approach for scaling and placement of virtual network functions

This paper investigates the joint scaling and placement problem of network services made up of virtual network functions (VNFs) that can be provided inside a cluster managing multiple points of presence (PoPs). Aiming at increasing the VNF service satisfaction rates and minimizing the deployment cost, we use both transport and cloud-aware VNF scaling as well as multi-attribute decision making (MADM) algorithms for VNF placement inside the cluster. The original joint scaling and placement problem is known to be NP-hard and hence the problem is solved by separating scaling and placement problems and solving them individually. The experiments are done using a dataset containing the information of a deployed digital-twin network service. These experiments show that considering transport and cloud parameters during scaling and placement algorithms perform more efficiently than the only cloud based or transport based scaling followed by placement algorithms. One of the MADM algorithms, Total Order Preference by Similarity to the Ideal Solution (TOPSIS), has shown to yield the lowest deployment cost and highest VNF request satisfaction rates compared to only transport or cloud scaling and other investigated MADM algorithms. Our simulation results indicate that considering both transport and cloud parameters in various availability scenarios of cloud and transport resources has significant potential to provide increased request satisfaction rates when VNF scaling and placement using the TOPSIS scheme is performed.This work was partially funded by EC H2020 5GPPP 5Growth Project (Grant 856709), Spanish MINECO Grant TEC2017-88373-R (5G-REFINE), Generalitat de Catalunya Grant 2017 SGR 1195 and the National Program on Equipment and Scientifc and Technical Infrastructure, EQC2018-005257-P under the European Regional Development Fund (FEDER). We would also like to thank Milan Groshev, Carlos Guimarães for providing dataset for scaling of robot manipulator based digital twin service

Efficient restoration of simultaneous transport services within an NFV infrastructure

Proceedings of: IEEE Global Communications Conference (GLOBECOM), 7-11 Dec. 2021, Madrid, Spain.In 5G networks, heterogeneous vertical services with different requirements are rolled out over a common multi-technology infrastructure. A resource orchestrator entity automatically coordinates the operations and functions to support the service's lifecycle management (i.e., creation, update and termination). Moreover, it is essential that service needs are continuously assured even if transport network anomalies (e.g., link failures) occur. Herein, we present an implemented resource orchestrator architecture integrating monitoring capabilities to attain closed-loop operations for: i) gathering monitored information; ii) detecting transport network anomalies; and iii) triggering the required action (e.g., restoration) to keep the service continuity. When a link failure happens, several transport services may be disrupted requiring to be immediately restored. To this end, we propose a novel on-line restoration algorithm called as Global Concurrent Optimization (GCO). The GCO algorithm aims at attaining an enhanced restorability performance compared to a more traditional restoration algorithm (referred to as 1-by-1). Both algorithms are experimentally compared on top of the deployed resource orchestrator architecture. The evaluation is done upon both dynamic service arrival/departure and link failure generation using different performance metrics: the average restorability, the average network resource utilization, and the restoration computational time.Work supported in part by EU Commission H2020 5Growth project (Grant No. 856709), Spanish MICINN AURORAS (RTI2018-099178-B-I00) and Spanish MINECO 5G-REFINE (TEC2017-88373-R) projects and Generalitat de Catalunya grant 2017 SGR 1195

Experimental validation of compute and network resource abstraction and allocation mechanisms within an NFV infrastructure

Proceedings of: IFIP/IEEE International Symposium on Integrated Network Management (IM), 17-21 May 2021, Bordeaux, France.5G supported capabilities (e.g., slicing) enable accommodating heterogeneous vertical services having their own requirements over a common cloud and transport infrastructure. In this context, the EU-H2020 5Growth project defines a service and infrastructure orchestration architecture to automatically deploy network services (NSes) fulfilling vertical demands. In this architecture, the Service Orchestrator (5Gr-SO), as a service provider, maps the vertical service needs into NS requirements (e.g., CPU, RAM, bandwidth, etc.). The 5Gr-SO interacts with an underlying infrastructure orchestrator referred to as 5Gr-RL. The 5Gr-RL, as an infrastructure provider, handles two main functions: i) abstraction of the resources exposed to the 5GrSO, and ii) fine-grained resource selection. Different interaction forms between both 5Gr-SO and 5Gr-RL arise differing in the exchanged abstracted information and resource allocation. We present two 5Gr-SO and 5Gr-RL interaction solutions stemming from two 5Gr-RL operational modes: Infrastructure Abstraction (InA) and Connectivity Service Abstraction (CSA). In the InA approach, the 5Gr-SO is granted with an aggregated view of the computing resources and a set of transport logical links between the cloud locations. In the CSA strategy, besides the aggregated view of the cloud resources, the logical links are associated to potential connectivity service types. Both InA and CSA strategies are presented describing their pros and cons. Moreover, the designed workflows (involving the devised abstraction and allocation algorithms) between the 5Gr-SO and 5Gr-RL entities are experimentally validated. Scalability studies are conducted upon two different cloud and transport infrastructure sizes in terms of the abstraction composition time, the expansion computation time, and total NS deployment time.Work supported in part by EU Commission H2020 5Growth project (Grant No. 856709), Spanish MICINN AURORAS (RTI2018-099178-B-I00) and Spanish MINECO 5G-REFINE (TEC2017-88373-R) projects and Generalitat de Catalunya grant 2017 SGR 1195