No abstract

No abstract

No abstract

-Adaptive networks are envisaged to play a significant part in the future, where the time and space variations in the traffic pattern will necessitate the ability to continuously amend the Radio Access Technologies' (RATs') operating parameters. Reconfiguration of communications systems is a facilitator towards this convergence and enables the dynamic adaptation and optimization of the access characteristics. However, such far ranging optimization concept involves many different mechanisms and work areas. Each of these areas provides an answer to a different optimization problem; Dynamic Network Planning and Management (DNPM) provides a load and demand driven optimization of the radio planning of multiple different networks within a given area. Advanced Spectrum Management (ASM) enables short term use of spectrum for services with higher demand. Finally Joint Radio Resource Management (JRRM) coordinates different access schemes and facilitates a more centralized approach to allocation of radio resource. Each of the schemes optimizes spectrum and radio resource usage on a different time scale. ARRM deals with the rather short term allocation, ASM with more medium term spectrum assignments while DNPM assumes time scales up to the range of weeks or months. Consequently, there is need of combining all working areas in the form of a Functional Architecture (FA), where each module represents a concept, aiming at forming part of the global end-to-end reconfigurability architecture. This paper includes a detailed analysis of the Reconfigurability FA, along with a description of the functionality of each of the modules included therein.

Emerging radio access technologies such as wireless personal and metropolitan area networks and digital broadcasting are a new era for wireless communications. These standards aim at complementing existing cellular/Wi-Fi networks in order to offer a wide range of available access modes to mobile terminals. Multiradio wireless systems referred to as composite radio access networks, bear diverse capabilities, with the optimal radio being invoked to perform a specific set of functions. Composite reconfigurable radio networks support the collaboration of a wide range of heterogeneous radio access technologies under a single or multiple administrative boundaries, adding further intelligence to the way devices attach to and switch between networks spatially and temporally. The EU End-to-End Reconfigurability (E²R) research project envisages composite reconfigurable radio networks coupled with legacy as well as evolved core network architectures, yielding simpler and flexible configurations for reduced latencies, autonomic operation, and adaptive functionality. This article presents a cohesive model for controlling and managing such networks, elaborates on the constituent functional entities, and maps this model to two-tier network support architecture. Finally, key security issues for software download over reconfigurable radios and systems are identified and solutions for software certification and authorization as well as for the authentication of roaming terminals are proposed.