Eric Nicollet

On Schedulability Analysis of Non-cyclic Generalized Multiframe Tasks

The generalized multi frame (GMF) task has been proposed to model a task whose execution times, deadlines and minimum separation times are changed according to a specified pattern. In this paper we relax the assumption of having a specified activation pattern, this yields to non-cyclic GMF task. In this context, current schedulability analysis techniques for GMF task sets under dynamic priority assignment cannot be used. This paper presents response time analysis of non-cyclic GMF tasks executing on a uniprocessor according to earliest deadline first (EDF) scheduling policy. Also, a density-based sufficient schedulability test for non-cyclic GMF task sets is given. Finally an efficient approach is presented, for exact feasibility determination using computer simulation.

Transaction level modelling of SCA compliant software defined radio waveforms and platforms PIM/PSM

In the scope of the US Department of Defense (DoD) Joint Tactical Radio System (JTRS) program, the portability and reconfigurability needs of software defined radios (SDR) required by the software communications architecture (SCA) can be resolved thanks to model driven architecture (MDA) and component/container paradigm to address a heterogeneous hardware and software architecture. In this paper, we propose SystemC transaction level modelling (TLM) to simulate platform independent model (PIM) and platform specific model (PSM) of SDRs, while keeping the component/container approach for applications portability. We show that SystemC 2.1 enables natively to simulate the waveform PIM specified in UML to obtain an executable specification, which can be reused to validate the SystemC TLM model of PSM. This latter allows radio platform virtualisation and true reuse of IPs models to validate earlier SDR waveforms and platforms

Reconfigurable Base Station Processing and Resource Allocation

A huge research and development effort is being spent to improve the radio resources usage considering different available and upcoming radio access technologies as well as the more flexible usage of frequencies. Within this context, terminals, network and management entities/functions are considered. The scope of this paper is to identify new functions to be provided by a multi-standard base station: ways to provide software re-configuration in a generic manner which takes into consideration different situations where this re-configuration may be triggered, including through dynamic and self-adaptive means.

Software defined radio architecture for cellular networks base stations: TheSunbeam project

With the arrival of 3G radio mobile communications standards namelyUmts, new requirements arose for the wireless cellular networks. They concern the quality of the transmissions, the compatibility with pre-existing 2G networks and between different 3G networks and of course the increasing bandwidth to bring new high data rate demanding services through IP connections. TheSunbeam project was at the convergence of two key enabling technologies for 3G: software radio and smart antennas. Software radio appears to be an unavoidable approach to fulfil these specifications, but it needs to be used with new hardware architectures designed to support it.Acts European projectSunbeam just covered partially this subject as it concerned flexible multi-standard smart CBTS architecture study in the context of the migration of European networks from 2G (Gsm, Dcs 1800) to 3 G (Acts/Fdd, Acts/Tdd), concentrating on the physical layer. Digital smart antennas techniques were central in the scope ofSunbeam, since they are to bring the decisive performance improvements 3G transmissions require. This paper summarises the essential results achieved within the project and makes an attempt to establish global specifications for CBTS architecture design to achieve the flexibility, the reconfigurability and the scalability needed to implement software radio.RésuméAvec l’arrivée de la normeUmts de radio communication avec les mobiles de 3e génération, de nouvelles exigences apparaissent pour les réseaux cellulaires. Elles concernent la qualité des transmissions, la compatibilité avec les standards pré-existants de 2e génération, entre les standards de 3e génération eux-mêmes, et bien sûr l’augmentation de la largeur de bande permettant l’émergence de services à haut débit basés sur l’emploi de connexions de type ip. Le projetSunbeam s’est situé à la confluence de deux technologies clés pour la 3e génération: la radio logicielle et les antennes adaptatives. La radio logicielle apparaît comme étant une approche inévitable afin de satisfaire ces exigences, mais elle demande d’être utilisée conjointement à de nouvelles architectures matérielles spécialement conçues. Le projet européenActs Sunbeam vient juste de couvrir de manière partielle ce sujet. En effet, il concernait l’étude des architectures de stations de base intelligentes, flexibles et multi-standards, dans le contexte de la migration des réseaux européens de la 2e (Gsm, Dcs 1800) à la 3e génération (Acts/Fdd, Acts/Tdd), en mettant l’accent sur la couche physique. Les techniques numériques d’antennes adaptatives ont tenu un rôle central dansSunbeam, car elles ont vocation à augmenter considérablement les performances de transmission pour répondre aux besoins de la 3e génération. Cet article résume les résultats principaux obtenus durant ce projet et essaye d’établir des spécifications globales pour la conception des architectures des stations de base afin d’obtenir la flexibilité, la reconfigurabilité, et l’extensibilité nécessaire à l’implantation de la radio logicielle.

A Technical Review of SCA Based Software Defined Radios: Vision, Reality and Current Status

The SCA 2.2.2 architecture has achieved widespread adoption in the military communications market. Hundreds of thousands of SCA enabled software defined radios (SDRs) have been deployed to date, and world-wide dozens of programs are working to field more of these types of radios. The reasons for this success are the benefits enabled through adoption of the SCA: proven cost and delivery time advantages, lower logistical overhead through enhanced inter-component interoperability, simplified insertion of new communications capabilities in deployed radios, enhanced coalition interoperability through portability of waveforms and reduced development risk. As a result of this success, new countries and new organizations have begun to explore the use of the SCA, driving a second generation of SDR market adoption. Successful deployment of SCA 2.2.2 based SDRs has identified improvements to be made to advance the technology further. The Wireless Innovation Forum is working in close collaboration with the U.S. Department of Defense Joint Tactical Networking Center (JTNC) to evolve the SCA. The resulting SCA 4.1 specification represents the future of defense SDR technology.