Klaus Nolte

Architecture and enablers for optimized radio resource usage in heterogeneous wireless access networks: The IEEE 1900.4 Working Group

Over the past decade or so, the wireless industry has undergone many significant changes. Radio systems have moved toward forming heterogeneous wireless networks: collaborations of multiple radio access networks, which in some cases operate different radio access technologies, such as second- and third-generation cellular RATs, IEEE 802.x wireless standards, and so on. On the other hand, multimode reconfigurable user devices with the ability to choose among various supported RATs have become a reality, and devices and networks with dynamic spectrum access capabilities, allowing real-time sharing of spectrum resource usage among different systems, are expected to be a part of the future radio eco-space. As a result of these changes, there is a need to develop a standard that addresses the requirements and leverages the opportunities posed by such a versatile radio environment. To this end, IEEE 1900.4 aims to standardize the overall system architecture and information exchange between the network and mobile devices, which will allow these elements to optimally choose from available radio resources. In other words, the standard facilitates the distributed dynamic optimization of the usage of spectrum offered by the heterogeneous wireless network, relying on a collaborative information exchange between networks and mobile devices, thereby acting as a common means to improve overall composite capacity and quality of service for the served networks. This article provides a snapshot of IEEE P1900.4 in its current form, covering the scope and purpose of the standard, reference use cases for which the standard is applicable, its system and functional architectures, and finally, the information model for its main interfaces.

IEEE P1900.4 System Overview on Architecture and Enablers for Optimised Radio and Spectrum Resource Usage

The field of application of the IEEE P1900.4 standard is radio systems forming a composite radio access network, i.e. with multi-radio access networks (RAN) using different radio access technologies (RAT). The end-user terminals are multimode terminals, supporting several RATs, with multi-radio link capabilities and having cognitive radio capabilities, such as operating flexibly on different frequency bands. The composite radio access network is assumed to be operated by either a single or several operators. Within this field of application, the standard provides common means to improve overall composite capacity and quality of service through distributed optimization of the usage of spectrum and radio resources offered by the composite radio access network. Basically, the optimization relies on a collaborative information exchange between the composite network and terminals. For this purpose, two entities are identified to facilitate this collaboration: network reconfiguration manager (NRM) and terminal reconfiguration manager (TRM), whilst the communication between NRM and TRM is ensured via a logical communication channel, the radio enabler (RE). Accordingly, this paper provides an overview of the IEEE P1900.4 scope and purpose, the reference usage cases wherein the standard would be applicable, including system requirements, architecture, and its reference model with main interfaces linked to the information model that is currently being developed.

IEEE P1900.4 Standard: Reconfiguration of multi-radio systems

The field of application of the IEEE P1900.4 standard is radio systems forming a composite wireless network, i.e., comprising multiple Radio Access Networks (RANs), which may be using different Radio Access Technologies (RATs). This composite wireless network is assumed to be operated by either a single or several operators. End-user terminals in P1900.4 are generally assumed to be multimode/multihoming, supporting several RATs and with multi-radio link capabilities, also possessing some cognitive radio capability such as flexible operation in different frequency bands. There are, however, conceivable scenarios where the P1900.4 standard would still be applicable even if terminals possessed limited such capabilities. At the core of the IEEE P1900.4 standard, Reconfiguration Management Entities (RMEs) are defined, located on terminal and network sides. The network side RME manages the terminal indirectly, but by providing/collecting context information and providing Radio Recourse usage policies to terminals. The terminal side RME makes final decisions regarding selection of the most appropriate RAT/RAN, band, etc., thereby also triggering the corresponding radio link reconfigurations in the terminal. Of course, all such decisions made by the terminal RME must be within the remit of policies conveyed by the network RME. This paper introduces the activities and work under progress within the IEEE P1900.4 working group.

ETSI Reconfigurable Radio Systems — Software Defined Radio and Cognitive Radio standards

This paper details the current work status of the ETSI Reconfigurable Radio Systems (RRS) Technical Committee (TC) and gives an outlook on the future evolution. In particular, Software Defined Radio (SDR) related study results are presented with a focus on SDR architectures for Mobile Devices (MD), such as mobile phones, etc., as well as for Reconfigurable Base Stations (RBS). For MDs, a novel architecture is presented enabling the usage of SDR principles in a mass market context. Cognitive Radio (CR) principles within ETSI RRS are concentrated on two topics, a Cognitive Pilot Channel (CPC) proposal and a Functional Architecture (FA) for Management and Control of Reconfigurable Radio Systems, including Dynamic Self-Organising Planning and Management, Dynamic Spectrum Management, Joint Radio Resource Management, etc. Finally, study results are indicated which are targeting a SDR/CR security framework.

Femtocell and Flexible Base Station cognitive management

In this paper we discuss on the cognitive management of wireless infrastructures that encompass Flexible Base Stations (FBSs) and Femtocells investigated by the Integrated Project E3 (End-to-End-Efficiency) funded within FP7. FBSs are equipped with Software Defined Radio (SDR) transceivers capable of operating the appropriate Radio Access Technologies (RATs) while Femtocells are capable of changing their operating parameters, including the way to manage the Mobile Terminals (MTs). The necessary reconfiguration actions are provided by the network decision entity called Dynamic Self-organizing Network Planning and Management (DSNPM). DSNPM is enhanced with optimization procedures as well as cognitive functionalities that will provide the means for proper network adaptation to the environment changes in timely manner. Our work presents an approach for the overall optimization procedure, exploiting FBSs and Femtocells software and hardware capabilities as well as knowledge and experience gained from past interactions of DSNPM with the network environment. High level system architecture will be presented describing the problem statement and the solution approach in which the above aspects will be addressed. Finally, an indicative scenario will exhibit the efficiency of FBSs and Femtocells functionalities as well as the associated cognitive management functionalities of DSNPM.

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.

Introducing cognitive systems in the B3G world: The E 3 approach to the "invisible" network of the future

One of the most recent trends in the area of B3G communications are reconfigurable, cognitive systems. Cognitive systems encompass self-management and self-optimization capabilities: awareness of user, device and context information, policies derivation, decision making, reconfiguration and learning. Mechanisms for perception and learning of user and context information are one of the most important features of cognitive systems. Based on the knowledge and experience obtained through learning, cognitive systems can determine and configure their operation not only in a reactive manner, i.e. responding to the detection of problematic situations, but also proactively, so as to prevent issues undermining the optimal system function. This paper presents the approach of the European Union funded project End-to-End Efficiency (E3), aiming at integrating cognitive wireless systems in the Beyond the Third Generation (B3G) world.