Traffic management in roads is one of the major challenges faced in developing efficient intelligent transportation systems. Recently, wireless networks have received significant attention for tackling this challenge. However, wireless technologies face the well-known spectrum scarcity problem due to the explosive demand for radio resources. To overcome this challenge, this study presents a novel intelligent traffic control system, utilizing the unused spectrum. Unlike existing works, the spectrum owners in this study hire free spectrum to drivers. The hired spectrum is deployed to build a short-range cost-effective wireless communication for monitoring traffic and enabling drivers to exchange warning messages, and thus enhancing road safety. Our objectives include minimizing crash probability, utilizing unused spectrum, and enabling spectrum owners to generate extra revenue. Numerical analysis demonstrates the capability of our approach to minimize the crash probability among vehicles under different operating road conditions.

Data Grid allows many organizations to share data across large geographical area. The idea behind data replication is to store copies of the same file at different locations. Therefore, if a copy at a location is lost or not available, it can be brought from another location. Additionally, data replication results in a reduced time and bandwidth because of bringing the file from a closer location. However, the files that need to be replicated have to be selected wisely. In this paper, a round-based data replication strategy is proposed to select the most appropriate files for replication at the end of each round based on a number of factors. The proposed strategy is based on Popular File Replicate First (PFRF) strategy, and it overcomes the drawbacks of PFRF. The simulation results show that the proposed strategy yields better performance in terms of average file delay per request, average file bandwidth consumption per request, and percentage of files found.