Smart social architecture for green distributed networks

Abstract

Nowadays, the energy consumption and efficiency of wireless networks have become a societal challenge. In this paper a novel system architecture is proposed to achieve green communications. The proposed smart social architecture exploits the flexibility and adaptability of cognitive radio (CR) technology to interact with the environment and achieve eco-sustainability by means of finding the best transmission opportunities. However, the effort required for CR nodes to obtain sensing measurements might make less effective the potential energy efficiency gain obtainable in CR networks. We thus propose to combine CR and social network technologies to maximize the energy efficiency and the associated context awareness in terms of energy and radio knowledge. In this way it is also possible to reduce the sensing burden of CR devices. Through the proposed approach, a greater awareness of environmental impacts by CR paradigm can be instilled in participating users, devices and backbones. This is based on a novel extension of the concept of social network, and specifically by allowing socialization among all the network actors, both users (as it is already done today) and cognitive devices to develop a much lighter and more flexible distributed infrastructure. The functionalities of the network elements and their interfaces are described in detail.It has been shown that more than 50% of the energy used in a telecommunications network is spent in the access part [11]. Unfortunately, most of this energy (80-90%) is used just to keep the base station alive, regardless of carried traffic. More than half of this is consumed by the power amplifier which, given the constraints of higher order modulations and multicarrier transmission, needs to operate in its linear region. For this reason, a lot of research efforts has been put in developing advanced sleep modes with coordination among different base stations to "zoom" cell sizes according with traffic load [30].As known, the power-law decrease in signal to noise ratio, and the need to reuse resources have in these years promoted the deployment of smaller and smaller cells. In terms of energy, it has been said that femtocells may lower energy needs to less than 30% of that of macrocells, although it is not clear the impact of signalling to manage network and users [28]. With the deployment of heterogeneous networks, the problem of coordination becomes even more relevant. For these reasons, cognitive radio (CR) has emerged not only has a paradigm to achieve better spectrum usage, but also towards the goal of greener networks.We exploit the flexibility and adaptability of CR technology to interact with the environment and achieve not only high spectrum usage as in classical CR systems, but also eco-sustainability, by means of finding the best transmission opportunities. Through such solutions, it is possible to enable opportunistic local connectivity and power saving modes for radio network equipment, control transmission range, and learn about traffic variations, transmission oppo...

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