Browsing by Author "Santos, Joao F."

Now showing 1 - 6 of 6
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    AIRTIME: End-to-end Virtualization Layer for RAN-as-a-Service in Future Multi-Service Mobile Networks
    Kist, Maicon; Santos, Joao F.; Collins, Diarmuid; Rochol, Juergen; DaSilva, Luiz A.; Both, Cristiano (IEEE, 2020)
    Future mobile networks are envisioned to become multi-service systems, enabling the dynamic deployment of services with vastly different performance requirements, accommodating the needs of diverse service providers. Virtualizing the mobile network infrastructure is of fundamental importance for realizing this vision in a cost-effective manner. While there have been extensive research efforts in virtualization for the mobile core network, virtualization in the radio access network (RAN) is still at an early stage. In this paper, we present AIRTIME, a new RAN slicing system that enables the dynamic on-the-fly virtualization of RANs, with the programmability required by service providers to customize any aspect of their virtual RAN to meet their service needs. We present a prototype implementation of AIRTIME and evaluate the: (i) capacity to create virtual RANs on-the-fly, (ii) performance experienced by slice owners, (iii) isolation among multiple virtual RANs sharing the same physical infrastructure, and (iv) scalability to accommodate a large number of virtual RANs.
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    Breaking Down Network Slicing: Hierarchical Orchestration of End-to-End Networks
    Santos, Joao F.; Liu, Wei; Jiao, Xianjun; Neto, Natal V.; Pollin, Sofie; Marquez-Barja, Johann M.; Moerman, Ingrid; DaSilva, Luiz A. (IEEE, 2020-10-01)
    Network slicing is one of the key enabling techniques for 5G, allowing Network Providers (NPs) to support services with diverging requirements on top of their physical infrastructure. In this paper, we address the limited support and oversimplified resource allocation on different network segments of existing End-to-End (E2E) orchestration solutions. We propose a hierarchical orchestration scheme for E2E networks, breaking down the E2E resource management and network slicing problems per network segment. We introduce a higherlevel orchestrator, the hyperstrator, to coordinate the distributed orchestrators and deploy Network Slices (NSs) across multiple network segments. We developed a prototype implementation of the hyperstrator and validated our hierarchical orchestration concept with two proof-of-concept experiments, showing the NS deployment and the impact of the resource allocation per network segment on the performance of NSs. The results show that the distributed nature of our orchestration architecture introduces negligible overhead for provisioning NSs in our particular setting, and confirm the need of a hyperstrator for coordinating network segments and ensuring consistent QoS for NSs.
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    Mandate-driven Networking Eco-system: A Paradigm Shift in End-to-End Communications
    Moerman, Ingrid; Zeghlache, Djamal; Shahid, Adnan; Santos, Joao F.; DaSilva, Luiz A.; David, Klaus; Farscrotu, John; de Ridder, Ad; Liu, Wei; Hoebeke, Jeroen (IEEE, 2020-01-01)
    The wireless industry is driven by key stakeholders that follow a holistic approach of “one-system-fits-all” that leads to moving network functionality of meeting stringent End-to- End (E2E) communication requirements towards the core and cloud infrastructures. This trend is limiting smaller and new players for bringing in new and novel solutions. For meeting these E2E requirements, tenants and end-users need to be active players for bringing their needs and innovations. Driving E2E communication not only in terms of quality of service (QoS) but also overall carbon footprint and spectrum efficiency from one specific community may lead to undesirable simplifications and a higher level of abstraction of other network segments may lead to sub-optimal operations. Based on this, the paper presents a paradigm shift that will enlarge the role of wireless innovation at academia, Small and Medium-sized Enterprises (SME)’s, industries and start-ups while taking into account decentralized mandate-driven intelligence in E2E communications.
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    Radio Access Technology characterisation through object detection
    Fonseca, Erika; Santos, Joao F.; Paisana, Francisco; DaSilva, Luiz A. (Elsevier, 2021-02-15)
    Radio Access Technology (RAT) classification and monitoring are essential for efficient coexistence of different communication systems in shared spectrum. Shared spectrum, including operation in license-exempt bands, is envisioned in the fifth generation of wireless technology (5G) standards (e.g., 3GPP Rel. 16). In this paper, we propose a Machine Learning (ML) approach to characterise the spectrum utilisation and facilitate the dynamic access to it. Recent advances in Convolutional Neural Networks (CNNs) enable us to perform waveform classification by processing spectrograms as images. In contrast to other ML methods that can only provide the class of the monitored RATs, the solution we propose can recognise not only different RATs in shared spectrum, but also identify critical parameters such as inter-frame duration, frame duration, centre frequency, and signal bandwidth by using object detection and a feature extraction module to extract features from spectrograms. We have implemented and evaluated our solution using a dataset of commercial transmissions, as well as in a Software-Defined Radio (SDR) testbed environment. The scenario evaluated was the coexistence of WiFi and LTE transmissions in shared spectrum. Our results show that our approach has an accuracy of 96% in the classification of RATs from a dataset that captures transmissions of regular user communications. It also shows that the extracted features can be precise within a margin of 2%, and can detect above 94% of objects under a broad range of transmission power levels and interference conditions.
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    STAMINA: Implementation and Evaluation of Software-Defined Millimeter Wave Initial Access
    Santos, Joao F.; Fathalla, Efat; Da Silva, Aloizio P.; Da Silva, Luiz A.; Kibilda, Jacek (IEEE, 2023-01-01)
    In this paper, we present a framework for experimentation in next-generation Initial Access (IA) procedures for Millimeter Wave (mmWave) and Terahertz (THz) communications called SofTwAre-defined Mmwave INitial Access (STAMINA). The IA procedure is one of the essential components for communication systems in high frequencies, enabling directional transmitters and receivers to acquire each other's relative orientation before data transmission. While effective in establishing communication, the existing IA procedure standardized by 3GPP consumes a significant amount of radio resources. Many research efforts have proposed enhancements over the current-generation IA procedure, e.g., leveraging non-uniform beam sweep sequences or adaptive codebooks. However, no existing experimental mmWave platforms support modifications in their standard-compliant IA procedures, preventing their utilization for conducting experimental research on next-generation IA procedures. Our software-defined mmWave framework addresses this gap by combining the flexibility of Software-defined Radios (SDRs) with the directionality of mmWave front-ends to perform customizable IA procedures. We demonstrate STAMINA's ability to control mmWave frontends correctly, its increased performance over traditional static experiments, and its flexibility to customize the IA parameters to achieve different objectives. Our results show that STAMINA provides experimenters with a flexible platform for performing experiments on next-generation IA procedures.
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    Towards Enabling RAN as a Service - The Extensible Virtualisation Layer
    Santos, Joao F.; Kist, Maicon; van de Belt, Jonathan; Rochol, Juergen; DaSilva, Luiz A. (IEEE, 2019-01-01)
    Network slicing is one of the key enabling techniques for 5G, allowing Mobile Network Operators (MNOs) to support services with diverging requirements on top of their infrastructure. The MNOs should be able to offer network slices as a service and provide customisable and independent virtual networks to verticals. The slicing of an end-to-end (E2E) mobile network is divided into Core Network (CN) slicing, and Radio Access Network (RAN) slicing. In this paper, we assess the requirements for using radio hypervisors to enable RAN as a Service (RANaaS). We evaluate the current state-of-the-art on radio virtualisation with respect to these requirements and identify the missing features. Then, we present the eXtensible Virtualisation Layer (XVL), a software layer that provides the missing functionality for enabling RANaaS and can be added on top of existing radio hypervisors. We outline XVL’s architecture and design choices, as well as evaluate its performance in terms of the delay to provision virtual radios, the delay introduced to forward IQ samples, and the computational overhead. Our results show that XVL enables leveraging existing radio hypervisors to support RANaaS.