Research directions for fourth generation wireless

Though taxonomies can be imprecise, wireless communications systems are frequently classified by generation. First generation wireless denotes voice-only analog cellular systems. Second generation wireless systems ushered in digital transmission technologies to meet the capacity demands of burgeoning voice services. The coming third generation differs from second generation systems more in the ability to integrate voice and data applications than in radical differences in transmission technology. Though widespread deployment for third generation systems awaits widespread demand for wireless mobile data, we confidently predict that the Field of Dreams principle will continue to apply to the wireless industry. In this paper, we indulge in speculation on how these yet to be deployed systems may evolve, and the technologies that will be required to support the 4th generation systems of the more distant future.