LWA in 5G: State-of-the-Art Architecture, Opportunities, and Research Challenges

To cater to the exponential increase in wireless data demands under limited availability of licensed spectrum, the Federal Communications Commission has released extra bandwidth of 295 MHz in the 5 GHz unlicensed national information infrastructure bands for wireless communications. This free, unlicensed band has drawn considerable attention from academia and cellular operators worldwide. Several standards are being developed for flexible integration, aggregation, and interworking of this unlicensed band with licensed networks or spectrum. Of many candidate approaches, in this article, we introduce LTE WLAN aggregation (LWA). LWA, capable of leveraging the LTE and WLAN spectra simultaneously, has emerged as a prominent solution to increase network capacity and enhanced end users' quality of experience. Further, we present latest advances in this exciting technology by reviewing the state-of-the-art LWA architecture, and identify several opportunities and open challenges related to LWA design for future research.