Ericsson (Italy)

Collaboration between industry and academia supports improvement and innovation in industry and helps to ensure industrial relevance in academic research. This article presents an exploratory study of the factors for successful collaboration between industry and academia in software research.

The Xhaul architecture presented in this article is aimed at developing a 5G integrated backhaul and fronthaul transport network enabling flexible and software-defined reconfiguration of all networking elements in a multi-tenant and service-oriented unified management environment. The Xhaul transport network vision consists of high-capacity switches and heterogeneous transmission links (e.g., fiber or wireless optics, high-capacity copper, mmWave) interconnecting remote radio heads, 5G points of attachment (5GPoAs, e.g., macro- and small cells), centralized- processing units (mini data centers), and points of presence of the core networks of one or multiple service provider(s). This transport network shall flexibly interconnect distributed 5G radio access and core network functions, hosted on network centralized nodes, through the implementation of a control infrastructure using a unified, abstract network model for control plane integration (Xhaul Control Infrastructure, XCI); and a unified data plane encompassing innovative high-capacity transmission technologies and novel deterministic-latency switch architectures (Xhaul packet Forwarding Element, XFE). Standardization is expected to play a major role in a future 5G integrated front haul/backhaul architecture for multi-vendor interoperability reasons. To this end, we review the major relevant activities in the current standardization landscape and the potential impact on the Xhaul architecture.

This article reports a review of the most significant issues related to network architectures and technologies which will enable the realization of future optical Internet networks. The design of such networks has to take into consideration the peculiar characteristics of Internet traffic. Several architectures have been proposed to provide optical networking solutions, based on wavelength-division multiplexing and compatible with the IP world. These architectures are presented briefly, and the main advantages and drawbacks are discussed. Furthermore, advanced network architectures are reported. In particular, two network paradigms are illustrated and discussed: the optical transparent packet network and optical burst switching. Finally, the key technologies are illustrated.

This article proposes an innovative architecture design for a 5G transport solution (dubbed 5G-Crosshaul) targeting the integration of existing and new fronthaul and backhaul technologies and interfaces. At the heart of the proposed design lie an SDN/NFV-based management and orchestration entity (XCI), and an Ethernet-based packet forwarding entity (XFE) supporting various fronthaul and backhaul traffic QoS profiles. The XCI leverages widespread architectural frameworks for NFV (ETSI NFV) and SDN (Open Daylight and ONOS). It opens the 5G transport network as a service for innovative network applications on top (e.g., multi-tenancy, resource management), provisioning the required network and IT resources in a flexible, cost-effective, and abstract manner. The proposed design supports the concept of network slicing pushed by the industry for realizing a truly flexible, sharable, and cost-effective future 5G system.

The demand to make air travel more pleasant, secure, and productive for passengers is one of the winning factors for both airlines and the aircraft manufacturing industry for which aeronautical communications is one of the enablers. This article describes current trends in the area of aeronautical passenger communication toward personal and wireless in-cabin communications and multimedia data networks. Technological challenges are summarized as well as market potentials and regulatory issues.

The introduction of optical technology in the path layer of the transport network is expected to allow scalable and modular networks to be realized. In this paper, different optical cross-connect architectures, based either on space division or wavelength division switching, are analyzed. A comparative investigation is accomplished considering three issues of primary importance: cross-connect modularity, complexity, and transmission performance. In particular, the transmission performance of a generic path through the network is evaluated by upgrading a previously published analytical model, so to more accurately take into account the in-band crosstalk arising in the cross-connect.

Media use cases for emergency services require mission-critical levels of reliability for the delivery of media-rich services, such as video streaming. With the upcoming deployment of the fifth generation (5G) networks, a wide variety of applications and services with heterogeneous performance requirements are expected to be supported, and any migration of mission-critical services to 5G networks presents significant challenges in the quality of service (QoS), for emergency service operators. This paper presents a novel SliceNet framework, based on advanced and customizable network slicing to address some of the highlighted challenges in migrating eHealth telemedicine services to 5G networks. An overview of the framework outlines the technical approaches in beyond the state-of-the-art network slicing. Subsequently, this paper emphasizes the design and prototyping of a media-centric eHealth use case, focusing on a set of innovative enablers toward achieving end-to-end QoS-aware network slicing capabilities, required by this demanding use case. Experimental results empirically validate the prototyped enablers and demonstrate the applicability of the proposed framework in such media-rich use cases.

In wavelength-switched optical networks (WSONs), quality of transmission (QoT) has to be guaranteed during lightpath provisioning. In multibit-rate WSONs, this task is complicated by the coexistence of optical connections operating at different bit-rates and modulation formats. The major issue consists in accounting for the severe impairments due to cross-phase modulation (XPM) induced by 10 Gb/s lightpaths on neighbor 40 or 100 Gb/s lightpaths. In this paper, QoT modeling is first reviewed for 10, 40, and 100 Gb/s transmission according to the adopted modulation format and detection type. In addition, a Gaussian approximation to compute the bit error rate of differential quadrature phase-shift keying (DQPSK) and QPSK signals is proposed, as well as closed formulas to compute the nonlinear phase noise variance due to XPM. Also, discussions about the XPM cumulation over spans in a WSON and how XPM can be considered in a dynamic network are provided. Then, four lightpath provisioning schemes are proposed to effectively account for QoT and, in particular, for XPM. The schemes differently exploit: 1) augmented spectral separation among lightpaths at different bit rates; 2) XPM worst-case scenario; and 3) current and novel generalized multiprotocol label switching extensions. The performance of the proposed schemes is evaluated through simulations in several multibit-rate scenarios. Results show that the proposed schemes provide effective network resource utilization while guaranteeing the adequate QoT to lightpaths at any bit rate.

This article introduces the key innovations of the 5Growth service platform to empower vertical industries with an AI-driven automated 5G end-to-end slicing solution that allows industries to achieve their service requirements. Specifically, we present multiple vertical pilots (Industry 4.0, transportation, and energy), identify the key 5G requirements to enable them, and analyze existing technical and functional gaps as compared to current solutions. Based on the identified gaps, we propose a set of innovations to address them with: (i) support of 3GPP-based RAN slices by introducing a RAN slicing model and providing automated RAN orchestration and control; (ii) an AI-driven closed-loop for automated service management with service level agreement assurance; and (iii) multi-domain solutions to expand service offerings by aggregating services and resources from different provider domains and also enable the integration of private 5G networks with public networks.

The evolution of mobile radio technologies towards the realization and deployment of 5G networks is creating relevant opportunities in the Industry and Society worldwide. On the other hand, the network infrastructure that will have to sustain many applications, including the ones requiring challenging network performance, in different terms, is leading to a network transformation and the capacity to handle bigger and bigger volumes of traffic at a reasonable cost and consumption of energy. Photonic technology will play a key role in 5G networks in different segments. In 5G transport it will allow the transmission and routing of huge amounts of data traffic at an acceptable cost, and the transformation of the radio access network. In data center photonic interconnect and switching will allow the realization of new architecture able to strongly reduce the energy consumption while providing high level of flexibility in resource utilization. In future HW platform photonic chip-to-chip interconnect will allow a significant increase of bandwidth density so leading to dramatically scale up the global capacity of those platforms. In addition, photonics is a valid technology to achieve some functions of future radio systems that will enable the further evolution towards what will be the 6 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sup> generation of mobile networks. In all the above integrated photonics, and particularly silicon photonics, will be the key technology to realize components and modules at the right costs, while greatly reducing energy consumption and footprint and the desired performance.

We provide a broad overview of current quantum communication by analyzing the recent discoveries on the topic and by identifying the potential bottlenecks requiring further investigation. The analysis follows an industrial perspective, first identifying the state or the art in terms of protocols, systems, and devices for quantum communication. Next, we classify the applicative fields where short- and medium-term impact is expected by emphasizing the potential and challenges of different approaches. The direction and the methodology with which the scientific community is proceeding are discussed. Finally, with reference to the European guidelines within the Quantum Flagship initiative, we suggest a roadmap to match the effort community-wise, with the objective of maximizing the impact that quantum communication may have on our society.

The evolution of optical technologies is driving the introduction of multirate optical networks exploiting advanced transmission techniques and efficient switching devices. In the short term, optical connections operating at 10 and 100 Gb/s will coexist in the same multi-rate network infrastructure. This, however, might introduce significant issues due to detrimental inter-channels effects, which need to be considered during network planning or connection provisioning. In the long term, connections at higher bit-rates (e.g., 400 Gb/s) and based on complex modulation formats (e.g., quadrature amplitude modulation - QAM) are expected, together with the adoption of innovative and flexible bandwidth-variable optical cross-connects (BV-OXCs). BV-OXCs have the potential to significantly improve the overall network spectrum efficiency. However, critical issues might arise in the dynamic control of network operations. This article discusses the enhancements required during operation and control of future optical networks with quality of transmission guaranteed. A first network evolution scenario is considered, where 100 Gb/s lightpaths are introduced in a native 10 Gb/s network. In such a scenario, inter-channel effects between 10 and 100 Gb/s lightpaths are highlighted. Relevant methods to account for these effects are discussed and evaluated. Then, a second network evolution scenario is assumed, in which traditional OXCs are replaced with BV-OXCs, and even higher bit-rates (e.g., 400 Gb/s 16-QAM) are introduced in the network. In particular, the problem of scalability when advertising and storing spectrum resource (i.e., frequency slices) availability is presented for flex-grid optical networks (i.e., optical networks exploiting BVOXCs). Consequently, a method to efficiently handle availability information is proposed and evaluated, showing the capability to overcome scalability issues without impacting the overall network resource utilization.

In this work, a hybrid free-space optics (FSO)/ teraHertz (THz) based backhaul network is considered to provide high-data-rate reliable communication to the terrestrial mobile users (MUs) operating at millimeter-wave (mmWave) bands. The FSO link is affected by atmospheric turbulence and pointing error impairments. At the FSO receiver, both intensity-modulated direct detection and heterodyne detection techniques are considered. The multi-antenna THz link suffers from high path-loss, small-scale fading, and misalignment error. To minimize the effect of back-and-forth switching, soft switching method is introduced at the access point (AP) to select the signal coming through the hybrid FSO/THz link, and a comparison with hard switching method is presented. Selective decode-and-forward relaying is considered at the AP. In this context, we derive closed-form expressions of the individual link’s outage probability, end-to-end (E2E) outage probability, asymptotic outage probability, ergodic capacity, and generalized average bit-error-rate. Finally, we study the effect of different parameters such as atmospheric turbulence, pointing/misalignment errors, link distance, atmospheric attenuation/path-loss, fading parameters of the THz and access links, and number of antennas on the network performance. Our results indicate that, with a proper switching method, the joint implementation of FSO/THz links improves the rate/reliability of the backhaul links with limited switching overhead.

A simple estimation for the WCDMA downlink capacity is presented. A general approximation is derived from the basic CDMA theory, and is then adapted to the scenario in question with the help of results from a number of reference system simulations. Comparison with the simulations shows that the obtained approximation is valid for a variety of system scenarios and services. Furthermore, it holds also in case of multiple simultaneous services. However, unless the effect of the receiver noise is taken into account, the applicability area of the approximation seems to be limited only to quite small cells.

A circuit for the management of any arbitrary polarization state of light is demonstrated on an integrated silicon (Si) photonics platform. This circuit allows us to adapt any polarization into the standard fundamental TE mode of a Si waveguide and, conversely, to control the polarization and set it to any arbitrary polarization state. In addition, the integrated thermal tuning allows kilohertz speed which can be used to perform a polarization scrambler. The circuit was used in a WDM link and successfully used to adapt four channels into a standard Si photonic integrated circuit.

Abstract Ring resonators are one of the fundamental building blocks of advanced integrated optical circuits. They find applications as nonlinear optical elements, filters, sensors, and switches among others. Here, a comprehensive optimization framework and experimental results of thermally tunable microring resonators in silicon photonics is presented, with a focus on standard silicon photonic foundry processes. In order to minimize the total power consumption, the ring resonators are tuned by applying a pulse‐width‐modulated electrical signal to the heaters. The thermal performance of integrated silicon and metal heaters are investigated and compared using an effective model validated by the measurement results. The heater power consumption is minimized by optimizing heater cross section, resistance, and metal contact configurations. Using the multiproject wafer run developed at CEA‐LETI, it is demonstrated that a metal heater provides 30% lower power consumption compared to an integrated silicon one, reaching a power consumption of 27.53 mW per free spectral range. The measurements are in excellent agreement with the theoretically predicted thermal performance, with a deviation as low as 5%. The proposed framework, supported by the experimental results, will serve as a design guideline set that can be easily adapted for other thermo‐optic switches in future silicon photonic applications.

Time-frequency packing (TFP) transmission provides the highest achievable spectral efficiency with a constrained symbol alphabet and detector complexity. In this paper, the application of the TFP technique to fiber-optic systems is investigated and experimentally demonstrated. The main theoretical aspects, design guidelines, and implementation issues are discussed, focusing on those aspects which are peculiar to TFP systems. In particular, adaptive compensation of propagation impairments, matched filtering, and maximum a posteriori probability detection are obtained by a combination of a two-dimensional equalizer and four eight-state parallel Bahl-Cocke-Jelinek-Raviv (BCJR) detectors. A novel algorithm that ensures adaptive equalization, channel estimation, and a proper distribution of tasks between the equalizer and BCJR detectors is proposed. A set of irregular low-density parity-check codes with different rates is designed to operate at low error rates and approach the spectral efficiency limit achievable by TFP at different signal-to-noise ratios. An experimental demonstration of the designed system is finally provided with five dual-polarization QPSK-modulated optical carriers, densely packed in a 100-GHz bandwidth, employing a recirculating loop to test the performance of the system at different transmission distances.

The impact of transmission related issues on the routing strategies for transparent all-optical wavelength division multiplexed (WDM) transport networks is analyzed in this paper. Three different categories of routing algorithms are analyzed: algorithms based on the wavelength path (WP) strategy, based on the virtual wavelength path (VWP) strategy and requiring only a limited number of wavelength converters in the network partial virtual wavelength path (PVWP). It results that the PVWP allows a saving in network devices with respect to the WP similar those permitted by the VWP also attaining transmission performances near those attained by the WP that are quite better that those attained by the VWP.

This article discusses a novel approach for realizing traffic engineering in the framework of new-generation multilayer networks based on the GMPLS paradigm. In particular, the proposed traffic engineering system is able to dynamically react to traffic changes while at the same time fulfilling QoS requirements for different classes of service. The proposed solution consists of a hybrid routing approach, based on both offline and online methods, and a novel bandwidth management system that handles priority, preemption mechanisms, and traffic rerouting in order to concurrently accommodate the largest amount of traffic and fulfill QoS requirements. The bandwidth resources of the network are effectively exploited by means of "elastic" utilization of the bandwidth. The main building blocks and operations of the system are reported, and the major advantages are discussed.

A multiflow transponder in flex-grid optical networks has recently been proposed as a transponder solution to generate multiple optical flows (or subcarriers). Multiflow transponders support high-rate super-channels (i.e., connection composed of multiple corouted subcarriers contiguous in the spectrum) and sliceability; i.e., flows can be flexibly associated to the incoming traffic requests, and, besides composing a super-channel, they can be directed toward different destinations. Transponders supporting sliceability are also called sliceable transponders or sliceable bandwidth variable transponders (SBVTs). Typically, in the literature, SBVTs have been considered composed of multiple laser sources (i.e., one for each subcarrier). In this paper, we propose and evaluate a novel multirate, multimodulation, and code-rate adaptive SBVT architecture. Subcarriers are obtained either through multiple laser sources (i.e., a laser for each subcarrier) or by exploiting a more innovative and cost-effective solution based on a multiwavelength source and micro-ring resonators (MRRs). A multiwavelength source is able to create several optical subcarriers from a single laser source. Then, cascaded MRRs are used to select subcarriers and direct them to the proper modulator. MRRs are designed and analyzed through simulations in this paper. An advanced transmission technique such as time frequency packing is also included. A specific implementation of a SBVT enabling an information rate of 400  Gb/s is presented considering standard 100 GbE interfaces. A node architecture supporting SBVT is also considered. A simulation analysis is carried out in a flex-grid network. The proposed SBVT architecture with a multiwavelength source permits us to reduce the number of required lasers in the network.