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In the European Union, the eCall system has been mandatory since 31 March 2018. The system enabled a significant increase in safety on roads and highways, making help faster in the event of an accident. However, based on circuit-switched 2G/3G communications and an onboard device called IVS, it is generally unavailable on legacy vehicles. Some of its limitations tend to be remedied by the future NG eCall based on 4G/5G packet-switched communications. This paper discusses why the IVS may be an Achilles' heel of any future IVS-based eCall and analyzes the advantages of a smartphone-based system. The TEZE system, starting to be implemented and installed in Italian highway tunnels, is one first general-purpose safety system, allowing highly reliable smartphone-based emergency calls. It is based on a dedicated low-cost ground infrastructure that allows monitoring of the availability of emergency call service through the mobile radio networks of the operators present inside a tunnel. The system complies with the ISO/IEC 30141:2018 reference standard. Identifying functional/non-functional requirements and their verification criteria provides an overall validation of the analyzed system. The TEZE system has been implemented and tested on the field. We report and comment on some experimental results. The paper also examines some key functionalities for vehicular services that can be implemented in an integrated system based on smartphones and heterogeneous networks. [ABSTRACT FROM AUTHOR]

One distinctive feature of the next 5G systems is the presence of a dense/ultra-dense wireless access network with a large number of access points (or nodes) at short distances from each other. Dense/ultra-dense access networks allow for providing very high transmission capacity to terminals. However, the deployment of dense/ultra-dense networks is slowed down by the cost of the fiber-based infrastructure required to connect radio nodes to the central processing units and then to the core network. In this paper, we investigate the possibility for existing FttC access networks to provide fronthaul capabilities for dense/ultra-dense 5G wireless networks. The analysis is realistic in that it is carried out considering an actual access network scenario, i.e., the Italian FttC deployment. It is assumed that access nodes are connected to the Cabinets and to the corresponding distributors by a number of copper pairs. Different types of cities grouped in terms of population have been considered. Results focus on fronthaul transport capacity provided by the FttC network and have been expressed in terms of the available fronthaul bit rate per node and of the achievable coverage. [ABSTRACT FROM AUTHOR]

Vectoring, used in VDSL2 to counteract FEXT, becomes less effective, or even ineffective, when users belong to different vectoring groups. This situation is common when the Regulator imposes sub-loop unbundling and users of uncoordinated service providers cause alien-FEXT. The sub-band vectoring (SBV) technique introduced here, avoids this situation and retains the vectoring benefits. We show SBV allows achieving up to 150 Mbit/s per user in downstream at 200 m from cabinet for VDSL2 profile-35b, with two concurrent service providers. We also introduce the concept of data-rate coverage representing the users' percentage served at a given data-rate in the area. [ABSTRACT FROM AUTHOR]

VDSL2 achieves high bit rates thanks to far-end crosstalk suppression and proper selection of the access network infrastructure. In this paper, we consider one architectural solution, which adopts the standard VDSL2 profile in a Fiber-To-The-Distribution point (FTTDp). During the transition process, FTTDp has to coexist with Fiber-To-The-Cabinet (FTTC) in a mixed VDSL2 scenario. Downstream Power Back-Off (DPBO) for FTTDp is effective to mitigate interference among FTTC and FTTDp. When FTTC terminals are vectored, DPBO leads to reduction of the maximum bit rate for FTTDp as compared to FTTC. In this paper, we propose a modification of the ITU DPBO procedure for FTTC and FTTDp to achieve the same bit rate. The maximum power assigned to FTTDp users is now proportional to the average received power of the vectored FTTC users at the Distribution Point. We obtain the proportionality coefficient, which depends on the number of active FTTC and FTTDp terminals and it is independent of the sub-carrier frequency. [ABSTRACT FROM PUBLISHER]

This article overviews the methods that are currently under investigation for implementing multi-operator open-access/shared-access techniques in next-generation access ultra-broadband architectures, starting from the traditional “unbundling-of-the-local-loop” techniques implemented in legacy twisted-pair digital subscriber line access networks. A straightforward replication of these copper-based unbundling-of-the-local-loop techniques is usually not feasible on next-generation access networks, including fiber-to-the-home point-to-multipoint passive optical networks. To investigate this issue, the article first gives a concise description of traditional copper-based unbundling-of-the-local-loop solutions, then focalizes on both next-generation access hybrid fiber–copper digital subscriber line fiber-to-the-cabinet scenarios and on fiber to the home by accounting for the mix of regulatory and technological reasons driving the next-generation access migration path, focusing mostly on the European situation. [ABSTRACT FROM AUTHOR]

Presents the analytical expressions for the time-autocorrelation function and the Doppler spectrum in a mobile radio channel in the presence of three-dimensional multipath scattering. Channel and Doppler spectrum modelling; Mobile-to-radiobase link; Function of wave direction.

This paper describes a version of the dual-model feed horn that is considered particularly suitable for application in receive-only reflector antennas. Even though it was originally presented many years ago, to the authors' knowledge this type of biconical feed horn has not previously been analyzed or utilized. The present paper aims to describe the potential advantages of this feed horn for low-cost satellite earth stations, and then briefly to illustrate the design methodology that was adopted. Finally, it presents some of the experimental and theoretical results, which are in good agreement and demonstrate the performance achievable with this class of feeds. [ABSTRACT FROM AUTHOR]

Provides information on capacity estimation for cellular code-division multiple-access (CDMA) systems, assuming the IS-95 standard as a reference. Indepth look at the outage probability and spectrum efficiency; Information on the estimation of the system capacity; Conclusion reached on the estimation.

Reports on a satellite mobile-multimedia system using both Ka-band and EHF, both for fixed and mobile users, defined in Europe to support the UMTS satellite component. Components of the system; Forecast that four types of terminals will be able to cope with different service requirements; Description of system architecture, payload concept and terminal typologies.

This paper presents and evaluates the performance of an open-loop scheme for carrier-phase estimation with Doppler compensation which independently operates on each TDMA burst without requiring any training sequences. The approach is based on two known open-loop algorithms independently used for phase and frequency error estimation. The paper shows how to properly interface these two algorithms and how they can be extended also to include Doppler rate estimation. Copyright © 1999 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper is concerned with channel modelling for satellite personal communications and with the associated problem of performance evaluation. Channel characteristics for personal communications tend to differ from those traditionally accepted for vehicular communications. In this paper we report on modelling aspects for both wideband and narrowband personal communications. Then we consider performance evaluation for low-altitude earth orbit (LEO) satellite systems in terms of bit error probability and outage probability. To evaluate the outage probability for LEO systems, a tight and simple upper bound is finally provided. © 1998 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Addresses performance evaluation in a nonselective fading channel modeled by a combination of Rice and lognormal (RLN) statistics. Error probability in the RLN channel; Application to terrestrial and satellite channels; Conclusions.

Highlights the standardization of third generation (3G) mobile radio system. Discussion on COST 231 project to study the air interface for a 3G system; Actions taken by Qualcomm Inc. and Telecommunications Industry Association of the United States to promote the development of Universal Mobile Telecommunications System standard; Patent issues.

Features the Institute of Electrical and Electronics Engineers Vehicular Technology/Communications Society joint Chapter of the North Italy Section. Background information on the organization; Members of the Chapter executive committee; Details on the plans for the chapter's first meeting.

Looks at the evolution of mobile radio in Italy. Objective of the study conducted by the Telecom Italia on mobile radio; How the Radio Telefono Mobile di Seconda generazione (RTMS) was undertaken; Service offered by the RTMS; System that has been developed due to the evolution of mobile radio.