Radio Networks

... convergence of services and growing development of applica-tions based on a combination of ... the issue of simplifying the regulatory framework to adapt to this new situation [3 ... 737, “Review of Spectrum and Regulatory Requirements to Facilitate World-wide Harmonization of ...

Abstract—A hybrid fiber–radio access network architecture for simultaneous wireline and wireless transmissions of Data-Over-Cable Service Interface Specification (DOCSIS) signals is pre-sented. An all-optical harmonic up-conversion technique using a dual-drive ...

A multi-cluster, multi-hop packet radio network architecture for wireless adaptive mobile information systems is presented. The proposed network supports multimedia traffic and relies on both time division and code division access schemes. This radio network is not supported by a wired infrastructure as conventional cellular systems are. Thus, it can be instantly deployed in areas with no infrastructure at all. By using a distributed clustering algorithm, nodes are organized into clusters. The clusterheads act as local coordinators to resolve channel scheduling, perform power measurement/control, maintain time division frame synchronization, and enhance the spatial reuse of time slots and codes. Moreover, to guarantee bandwidth for real time traffic, the architecture supports virtual circuits and allocates bandwidth to circuits at call setup time. The network is scalable to large numbers of nodes, and can handle mobility. Simulation experiments evaluate the performance of the proposed scheme in static and mobile environments.

LTE (Long Term Evolution) is a next major step in mobile radio communications, and will be introduced as Release 8 in the 3rd Generation Partnership Project (3GPP). The new evolution aims to reduce delays, improve spectrum flexibility and reduce cost for operators and end users [1]. To fulfil these targets, new enabling technologies need to be integrated into the current 3G radio network architectures. Multiple Input and Multiple Output (MIMO) is one of the crucial enabling technologies in the LTE system particularly in the downlink to achieve the required peak data rate. The unitary codebook based precoding technique is proposed in the standard to increase the capacity of the system. This paper presents a link level analysis of the LTE downlink and an investigation of the performance of both Single User (SU) MIMO and Multi User (MU) MIMO with codebook based unitary precoding.

The development of radio networks has brought the problem of security specifically related to mobility of terminals sharply into focus, and has created the need for radio network operators to implement new security functionalities. The security level of the analog radio mobile systems (the so-called “first generation ” systems was very low, and these systems were often exposed to massive fraud. The development of digital radio mobile systems (the so-called “second generation” systems: GSM, DECT,. allowed the systematic introduction of cryptology based protection mechanisms. Hence, for gsm networks for instance, the main fraud and confidentiality problems were taken into account at the design stage and a security architecture was implemented to provide security services to users and network operators. The third generation mobile telecommunication systems belonging to the imt- 2000 family (which are still under specification within standardisation bodies in particular within the 3gpp worldwide third generation partnership project) will, in the forthcoming years, provide a wide variety of services on a single terminal in a multi-environment (domestic, public, business), multi-operator, and multi-service provider context. Security will be based on second generation systems security functions that have proved to be needed and reliable, and shall be adapted and improved to resolve security threats underlying to new services supplied by third generation radio systems. This document presents examples of security solutions currently implemented for protecting second generation radio mobile systems against frauds and attacks and gives an overview of potential solutions for protecting future third generation radio mobile telecommunication systems. Le développement des réseaux radiomobiles a mis en évidence des problèmes de sécurité spécifiques liés à la mobilité des terminaux, ce qui a conduit les opérateurs de ces réseaux à implanter de nouvelles fonctions de sécurité. Les systèmes analogiques dits de première génération présentaient un niveau de sécurité très faible, et nombre de ces systèmes étaient exposés à des fraudes massives. Le développement des systèmes numériques dits de deuxième génération (GSM, dect, etc.) a permis l’introduction de mécanismes de protection basés sur la cryptologie. Ainsi, pour les réseaux gsm, les principaux problèmes de fraude et de confidentialité ont été pris en compte dès la conception du système, et une architecture de sécurité a été mise en place pour offrir des services de sécurité aux usagers et aux opérateurs. Les systèmes mobiles de troisième génération de la famille imt- 2000 (dont la spécification est en cours dans divers organismes de normalisation, en particulier le projet 3gpp de partenariat mondial sur la mobilité 3g) fourniront dans les années qui viennent un large éventail de services sur un même terminal, dans un contexte multi- environnement (domestique, public, professionnel), multi-exploitant, et multi-fournisseur de services. La sécurité sera basée sur les fonctions de sécurité des systèmes de deuxième génération qui ont démontré leur utilité et leur robustesse, mais elle sera adaptée pour résoudre les menaces inhérentes aux nouveaux services qui seront offerts par ces systèmes. Cet article présente des exemples de mécanismes de sécurité actuellement utilisés pour la protection des mobiles de deuxième génération contre les fraudes et les attaques, et donne un aperçu des solutions envisagées pour la protection des systèmes mobiles de troisième génération.

The architecture and dynamics of a code-vision multiaccess (CDMA) cellular radio network are discussed. The network's layout, power control equation, cell coverage, signal quality, cell radio design, and heterogeneous cell clustering are described. It is shown that ...

Abstract—We report on field trials using CoMP transmission in the downlink of a mobile radio network. Two new features enable over-the-air CoMP transmission from physically separated base stations and terminals. These are distributed synchronization and a fast virtual local area network. Using VLAN tags, terminals feed back the multi-cell channel state information to their serving bases where it is multiplexed with shared data. Both are multicast to other cooperative base stations over the backhaul. In our trials, two terminals are served ...

Wireless ad hoc networks are in general characterized by dynamic topologies that do not have a fixed infrastructure. In addition, connectivity is maintained in a decentralized fashion through a form of multi-hop radio network. To this effect, wireless ad hoc networks with asymmetric link costs have been advocated as more realistic ones from a network modeling perspective. In this paper, we propose an Efficient Optimum Branching-based Distributed Broadcast Routing (EOBDBR) protocol for wireless ad hoc networks with asymmetric link costs, which makes use of local information exchange only. The proposed protocol contrasts with centralized routing protocols, in which link state and other relevant information are kept in the routing table of each node. It involves setting up link states, finding minimum in-edge, detecting cycles, re-weighting and breaking cycles. Through extensive simulations, our protocol is compared against four distributed broadcast routing protocols chosen as benchmarks. The performance metrics used are message overhead, total energy consumption, number of rebroadcasting nodes, network lifetime, and broadcast time. The superiority of EOBDBR against the studied benchmark protocols is established with respect to the above-mentioned metrics.

Abstract A real-time object-oriented expert system is developed for mobile radio networks. The goals, facts, procedural and heuristic rules related to the mobile radio environment are stored in the knowledge base. This knowledge is put together with an inference ...

The B3G concept can be realized in two complementary ways. The first solution is the integration of the diverse radio access technologies into one composite radio environment. The alternative solution is provided by the concept of reconfigurable (adaptive) networks. Composite radio networks, sometimes also referred to as cooperative networks, jointly handle a difficult condition. Reconfigurable networks on the other hand, support B3G Systems by providing technologies that enable network elements and terminals to dynamically adapt to the environment requirements and conditions, in principle, by means of self-management. This paper provides proof on the business advantages of reconfigurable networks. In this context the paper performs an evaluation of the investment in both composite radio and reconfigurable networks, presenting a methodology that can be used for the financial assessment of such networks by applying investment appraisal techniques. Concrete results for both cases are presented and analyzed. The analysis clearly proves that reconfigurable networks can provide significant business benefits for network operators.