Regulation will experience enormous changes in the near future resulting in seamless connectivity by spectrum borders. A promising approach in this context is dynamic spectrum allocation which leads to a more flexible access to spectral resources by employing intelligent radio devices called cognitive radios. This paper is concerned with bio-inspired approaches that exploit distribution in multi-radio environments where many users have to share a finite resource harmoniously. Three applications of bio-inspired techniques are described. The first one deals with the detection of spectrum holes whereas the second one describes resource allocation in orthogonal frequency division multiple access based systems. The third one is concerned with distributed resource auctioning.

Trying to achieve higher usage efficiency for spectrum has been on the research agenda for some time now. More efficient transmission technologies are being developed, but they alone will not solve the problem of spatially and temporally underused spectrum and radio resources. Mechanisms to optimize spectrum access over space and time are required. This paper describes schemes, based on multiple agents that collaborate to find more efficient allocation patterns in a defined coverage area. Leveraging on microeconomics inspired mechanisms, the paper describes and analyses schemes based on collaborating 'agents' (hat can be either whole operator, or BS or end user terminal) that negotiate with each other to find the most optimized allocation pattern for a given area and allocation duration. The optimization strategies investigated include both bargaining as well as auction based mechanisms. Both allow the negotiation of spectrum and radio resources, based on market driven incentives. The auction types investigated support dynamic allocations on different timescales, ranging from short to medium and long term allocation scenarios. While auctions are discussed to be used for the longer term allocations, a MAC based rental protocol is evaluated for shorter term allocations when operated either at the BS or end user terminal level. Finally, the paper discusses how the MAC based rental protocol between BSs can be implemented.

An important emerging capability is for mobile terminals to be dynamically reconfigured. Through ongoing advances in technology such as software defined radio, reconfiguration of mobile terminals will in the near future be achievable across all layers of the protocol stack. However, along with the capability for such wide-ranging reconfiguration comes the need to manage reconfiguration procedures. This is necessary to coordinate reconfigurations, to ensure that there are no negative effects (e.g. interference to other RATs) as a result of reconfigurations, and to leverage maximal potential benefits of reconfiguration and ensuing technologies such as those involving dynamic spectrum access. The IEEE P1900.4 working group is therefore defining three building blocks for reconfiguration management: network reconfiguration management (NRM), terminal reconfiguration management (TRM), and a radio enabler to provide connectivity between the NRM and TRMs. In this paper we concentrate on aspects of the radio enabler, highlighting its relevance in heterogeneous radio access scenarios, its advantages, and some aspects of its technical realization.

Reconfigurability is considered the collection of software and cognitive radio technologies that aim to differentiate user perception in volatile radio conditions while optimizing the use of network resources. The realization of equipment reconfiguration through software download and the efficient utilisation of spectrum require coordinated distribution of functionality among the user, control, and management planes. This contribution presents the end-to-end architecture of future adaptive communication systems based on the Reconfiguration Management Plane model, which includes intelligence for policy-based context-aware decision making, negotiation control, software download, and dynamic spectrum management. The paper presents the RMP functional model, describes the dependencies and associations of the constituent context management module, and delineates the end-to-end quality of service negotiation information flow when introducing dynamic spectrum access in user-to-user communication scenarios.

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

This paper describes a distributed, cooperative and real time rental protocol for DCA operations in a multi system and multi cell context for OFDMA systems. A credit token based rental protocol using auctioning is proposed in support of dynamic spectrum sharing between cells. The proposed scheme can be tuned adaptively as a function of the context by specifying the credit tokens usage in the radio etiquette. The application of the rental protocol is illustrated with an ascending bid auctioning. The paper also describes two approaches for BS-BS communications in support of the rental protocol. Finally, it is described how the proposed mechanisms contribute to the current approaches followed in the IEEE 802.16h and IEEE 802.22 standards efforts addressing cognitive radio

Future generations of wireless systems require op- portunistic spectrum access techniques to effectively detect and access temporarily unused spectrum bands. Cognitive radios, with their ability to learn and adapt to their environment, promise to possess such powerful capabilities. As a consequence, the spectrum allocation of a wireless system could quickly and appropriately auto-adapt to react to a sudden traffic variation. In this article, we propose an innovative and efficient distributed spectrum allocation algorithm, whose objective is to maximize the system UL capacity by exploiting multi- user diversity. The algorithm is capable of learning over time and of adapting the spectrum allocation when changes occur in the radio environment. Such an algorithm finds its application in the scope of future WLAN systems (e.g.: 802.11x).

This paper describes the resource exchange between all important interfaces of a communication system using an auction sequence. Differences between the different mechanisms are shown and implementation concepts are presented

Secondary spectrum sharing between primary and secondary systems can be approached from the multi cells standpoint. This paper proposes a rental protocol enabling a distributed spectrum sharing between primary and secondary BSs. A credit tokens based scheduling using market based theory is proposed. The implementation of this algorithm is discussed from the current IEEE 802.16h and 802.22 standard activities perspective. The proposed scheme provides the incentive to share resources and presents the advantage to be real time, dynamic and policy based self governance to adapt the space time varying spectrum usage between cells. The proposed scheme is targeted preferably for OFDMA based systems.

This paper illustrates the essential impacts from the reconfigurability to the resource management and spectrum management aspects in the wireless communication system. Since reconfigurability provides potential interoperability, varies system operational parameters and radio system characteristic, the management functions in the communication system such as radio resource management, spectrum management and even network planning and management are facing an evolutionary opportunity. In order to study those three issues in a systematic manner, we take the multi-loop control circuits as a reference model for the overall comprehensive system. Each resource management mechanism contributes to the overall multi-loop control structure. Some selected typical algorithms allocated in each management category providing significant system capacity gains are as well studied