As the fifth generation (5G) mobile communication systems are commercially deployed, they bring new services, enhance user experiences, and offer various opportunities to different industries. Despite its advancements, 5G encounters several challenges. To tackle these issues, global industrial, academic, and standards organizations are actively researching on sixth generation (6G) wireless communication systems. 6G networks are envisioned as a transformative shift in the interactions between the physical, digital, and human realms, paving the way for a pervasive human-centered cyber-physical world. 6G is positioned to be a platform that offers communication and beyond communication services considering both performance and value centric technological development approaches. In this paper, we present the way forward towards the design of 6G end-to-end (E2E) system as a consolidated view of leading industry stakeholders and academia in the European level 6G flagship project Hexa-X-II. We discuss the key challenges with 5G and how 6G is expected to tackle those by introducing new technological innovations and supporting novel use case requirements. We provide a comprehensive methodology for the design of a 6G E2E system including ten principles, a blueprint, and a structured design process. The architecture design principles prioritize environmental sustainability, digital inclusiveness, and trustworthiness, considering their impact on the 6G E2E system. The blueprint is described corresponding to the infrastructure, network centric application, and application layers, as well as the pervasive functionalities and the relevant technological innovations. Following the design principles and the system blueprint, the design process is demonstrated as two-way approaches (i.e., 1) key performance and value indicators based design process. 2) top-down versus bottom-up alignment process) through the lens of a collaborative robot use case. Through this use case, a special attention is given to the technological enablers that cover management and orchestration functionalities and their 6G enhancement to go beyond the limitations characterizing the previous network generation. In addition, virtual modelling aspects related to digital twining and simulations for 6G E2E system design are also discussed.

This article aims to explore the requirements and challenges that Intent-Based Management (IBM) systems should look towards to deliver proper automation management in multi-stakeholder 6G scenarios. To do so, the evolution of the telecommunications actors is presented to identify how they will interact with the use of intents and what IBM systems must face to fulfil with the tenants expectations while interacting among other IBM domains (aggregation vs. federation models). In a second step, this article presents how the IBM systems functionalities should be organized (based on standards research and comparative) and a set of enablers using them to properly deliver the automation needed to accomplish the requests done by the tenants. On a third step, a set of End-to-End (E2E) intent-based services are described to illustrate how the different enablers (and the functionalities they use) may work to reach the E2E service goal. Finally, a set of experimental results related to how intent conflicts should be manage is presented, followed by the conclusions.

Several works in the literature have proposed migration mechanisms for VNFs, however they only consider the migration of isolated Virtual Network Functions (VNFs) instead of the migration under a shared and chained scenario. Reconfiguration of VNFs, like in the case of migration, is necessary to handle dynamic requirements for the service. However, it is not a straightforward operation. On one hand, it is necessary to coordinate VNFs to achieve migration while maintaining the end-to-end service availability. On the other hand, the new deployment can disrupt the chain and violate predefined services constraints. Moreover if there is no access to global references, migration can introduce inconsistent services due to a lack of knowledge from orchestrators. This paper focuses on the problem of coordinating orchestrators in a NFV federation to achieve migration of shared VNFs with only local domain information. It introduces a novel coordination algorithm that relies on ETSI/MANO specifications. The proposed algorithm is implemented and evaluated for validation purposes. Results show that migration satisfies the constraints for seamless migration and the algorithm obtains better performance compared to state of the art solution with a slight overhead cost when considering the shared VNFs instead of isolated VNFS.

Multi-domain federations support shared network services. Many orchestrators manage the service’s lifecycle. For the shared VNF Forwarding Graph (VNF-FG) reconfiguration, orchestrators update the graph’s logical information, ensuring a consistent behavior for replicas. Only one work in the literature considers sharing the VNF-FG. However, it offers weak consistency guarantees, without considering the VNF-FG’s non-functional dependencies. In case of a conflict, while updating the VNF-FG, the orchestrators solve consensus. However, this adds latency, undermining the goal of Network Function Virtualization. This paper introduces the first coordination-free multi-domain orchestration algorithm for consistent shared VNF-FG reconfiguration. Unlike the current state of the art, the proposed algorithm skips the coordination phase, offers strong eventual consistency, and supports non-functional dependencies. We present two variants: the preventive, where transient inconsistent states are prevented; the corrective, where intermediary inconsistent states, during the updating process, are tolerated. We prove the correctness of our algorithm and evaluate it. The variants, unlike the state of the art, reconfigure consistently the shared VNF-FGs without solving consensus. They offer stronger guarantees compared to the literature, like allowing orchestrators to reject ongoing reconfigurations without a high impact on performance.

In recent years, aerial vehicles have allowed exploring scenarios with harsh conditions. These can conduct reconnaissance tasks in areas that change periodically and have a high spatial and temporal resolution. The objective of a reconnaissance task is to survey an area and retrieve strategic information. The aerial vehicles, however, have inherent constraints in terms of energy and transmission range due to their mobility. Despite these constraints, the Data Foraging problem requires the aerial vehicles to exchange information about profitable data sources. In Data Foraging, establishing a single path is not viable because of dynamic conditions of the environment. Thus, reconnaissance must be focused on periodically searching profitable environmental data sources, as some animals perform foraging. In this work, a data-foraging-oriented reconnaissance algorithm based on bio-inspired indirect communication for aerial vehicles is presented. The approach establishes several paths that overlap to identify valuable data sources. Inspired by the stigmergy principle, the aerial vehicles indirectly communicate through artificial pheromones. The aerial vehicles traverse the environment using a heuristic algorithm that uses the artificial pheromones as feedback. The solution is formally defined and mathematically evaluated. In addition, we show the viability of the algorithm by simulations which have been tested through various statistical hypothesis.