Relay selection approaches for wireless cooperative networks

Wireless networks are characterized by having limited resources accessed by a large number of mobile stations with distinct capabilities. In such challenged environment the dynamic control of resources is of major importance to mitigate the limitations of wireless networks, such as the impact of low data rate stations and wireless channel oscillations. Such augmented usage of wireless resources can be implemented based upon cooperative relaying schemes, which have the potential to support the desired system performance and network lifetime. However, the introduction of cooperative relay raises several problems such as the issue for relay selection and resource allocation. Due to the significant number of different cooperative relaying approaches, this article aims to provide a systematic analysis and classification of major relay selection procedures, and to identify open research directions as well as the most suitable evaluation methods for an efficient analysis of different approaches.