17 research outputs found
Architecture and algorithm for reliable 5G network design
This Ph.D. thesis investigates the resilient and cost-efficient design of both C-RAN and Xhaul architectures. Minimization of network resources as well as reuse of already deployed infrastructure, either based on fiber, wavelength, bandwidth or Processing Units (PU), is investigated and shown to be effective to reduce the overall cost. Moreover, the design of a survivable network against a single node (Baseband Unit hotel (BBU), Centralized/Distributed Unit (CU/DU) or link failure proposed. The novel function location algorithm, which adopts dynamic function chaining in relation to the evolution of the traffic estimation also proposed and showed remarkable improvement in terms of bandwidth saving and multiplexing gain with respect to conventional C-RAN. Finally, the adoption of Ethernet-based fronthaul and the introduction of hybrid switches is pursued to further decrease network cost by increasing optical resource usage
BBU location algorithms for survivable 5G C-RAN over WDM
New 5G radio access network is expected to offer competitive advantages in terms of cost, quality of service and mobility, that make it attractive for service providers. The resilience of this part of the network is consequently essential to provide high availability and service continuity in case of failure. This study focuses on heuristic solutions to design and operate the fronthaul network based on the Centralized Radio Access Network (C-RAN) concept. Facility Location Algorithms (FLA) are proposed to assign primary and backup functionalities to Baseband Unit (BBU) hotels and ensure availability in case of a single BBU hotel or link failure. Sharing techniques are applied to BBU hotel ports and transport wavelengths for hl cost-efficient design. The goal is to minimize the number of active BBU hotels while providing full coverage to all Remote Radio Units (RRU). Numerical results evaluate cost in relation to main design constraints, namely the number of hops allowed to reach primary and backup BBU hotel. The number of BBU hotels is compared for different location algorithms, showing that a proposed extension of a classical FLA, by including resilience, allows to obtain the best results both in terms of BBU hotels and shared ports. However, the need of suitable trade-off between the number of BBU hotels and the required wavelengths is outlined, depending on relative costs
6G Positioning and Sensing Through the Lens of Sustainability, Inclusiveness, and Trustworthiness
6G promises a paradigm shift in which positioning and sensing are inherently
integrated, enhancing not only the communication performance but also enabling
location- and context-aware services. Historically, positioning and sensing
have been viewed through the lens of cost and performance trade-offs, implying
an escalated demand for resources, such as radio, physical, and computational
resources, for improved performance. However, 6G goes beyond this traditional
perspective to encompass a set of broader values, namely sustainability,
inclusiveness, and trustworthiness. This paper aims to: (i) shed light on these
important value indicators and their relationship with the conventional key
performance indicators, and (ii) unveil the dual nature of 6G in relation to
these key value indicators (i.e., ensuring operation according to the values
and enabling services that affect the values)
Towards a 6G embedding sustainability
From its conception, 6G is being designed with a particular focus on
sustainability. The general philosophy of the H2020 Hexa-X project work on
sustainability in 6G is based on two principles: to reduce direct negative life
cycle impacts of 6G systems as much as possible (Sustainable 6G) and to analyze
use cases that maximize positive environmental, social, and economic effects in
other sectors of society (6G for Sustainability or its enablement effect). To
apply this philosophy, Hexa-X is designing 6G with three sustainability
objectives in mind: to enable the reduction of emissions in 6G-powered sectors
of society, to reduce the total cost of ownership and to improve energy
efficiency. This paper describes these objectives, their associated KPIs and
quantitative targets, and the levers to reach them. Furthermore, to maximize
the positive effects of 6G through the enablement effect, a link between 6G and
the United Nations' Sustainable Development Goals (UN SDGs) framework is
proposed and illustrated by Hexa-X use case families.Comment: IEEE ICC 2023 Second International Workshop on Green and Sustainable
Networking (GreenNet), May 2023, Rome, Ital
Architecture landscape
The network architecture evolution journey will carry on in the years ahead, driving a large scale adoption of 5th Generation (5G) and 5G-Advanced use cases with significantly decreased deployment and operational costs, and enabling new and innovative use-case-driven solutions towards 6th Generation (6G) with higher economic and societal values. The goal of this chapter, thus, is to present the envisioned societal impact, use cases and the End-to-End (E2E) 6G architecture. The E2E 6G architecture includes summarization of the various technical enablers as well as the system and functional views of the architecture
Centralized vs. distributed algorithms for resilient 5G access networks
Cloud radio access networks (C-RANs), relying on network function virtualization and software-defined networking (SDN), require a proper placement of baseband functionalities (BBUs) to reach full coverage of served areas and service continuity. In this context, network resources can be shared and orchestrated to meet the flexibility required by a dynamically evolving environment. Different methodologies, based on analytical formulation or heuristic algorithms, can be applied to achieve suitable trade-offs among cost components. This paper considers both centralized and distributed algorithms to obtain BBU hotel placement in C-RAN and compares their performance, scalability and adaptability to evolving scenarios. As expected, the results obtained with the distributed approach are sub-optimal, but very close, in most cases, to the optimal solutions obtained with a centralized algorithm based on integer linear programming. In addition to off-loading the SDN orchestrator, the distributed approach, differently from the centralized one, is shown to be able to cope with the evolution of the C-RAN topology with limited incremental changes in the original placement. The limits of the centralized approach in terms of scalability that the distributed approach is able to overcome are also evidenced
Distributed Location Algorithms for Flexible BBU Hotel Placement in C-RAN
Cloud Radio Access Networks (C-RAN) are characterized by huge introduction of Network Function
Virtualization (NFV) supported by software-based control of relevant functionalities within the Soft-
ware Dened Network (SDN) context. Distributed location algorithms, as a practical approach to opti-
mally locate virtual functionalities in C-RAN, are described and compared to conventional optimization
techniques, with application to BBU hotel placement and extensions to dynamic evolution of C-RAN
conguration. Near optimal solutions and incremental adaptability to topology changes are achieved
Design methodologies and algorithms for survivable C-RAN
In centralized/cloud radio access networks (C-RANs), baseband units (BBUs) are decoupled from remote radio units (RRUs) and placed in BBU hotels. In this way baseband processing resources can be shared among RRUs, providing opportunities for radio coordination and cost/energy savings. However, the failure of a BBU hotel can affect a large number of RRUs creating severe outages in the radio segment. For this reason, the design of a resilient C-RAN is imperative. In this paper, an extension of the facility location problem (FLP) is proposed to find the placement of BBU hotels that guarantees survivability against single hotel failure while the delay is minimized. Different strategies are proposed based on heuristic and integer linear programming (ILP) to solve the survivable BBU location problem and optimizing the sharing of backup resources. The results compare the proposed methodologies in terms of the costs of the BBU placement by referring to different network topologies. The heuristic algorithm is shown to find solutions close to those obtained by the ILP, although evidencing different contributions that are suitably discussed