Device-to-device communications for enhancing quality of experience in software defined multi-tier LTE-A networks

3GPP has been developing LTE-A standard to significantly enhance the performance of cellular networks by utilizing various radio access techniques to provide ubiquitous and seamless broadband access to a rich diversity of mobile connected devices, which usually demand high QoE in spite of of access location or time. Consequently, it imposes unprecedented stringent requirements on centralized network management at the operator side, which has to overcome formidable complexity in designing, managing, and configuring network architectures, protocols, and algorithms before being able to fully support all LTE-A techniques. It is noticed that the software defined wireless network concept appears to be a promising direction to address such complexity, by decoupling control logic from all network elements and then providing fine-grained control and measurement in LTE-A networks. Toward this end, we propose in this article a device-to-device communication-based algorithm to enhance the QoE of users in software defined multi-tier LTE-A networks. Besides discussing research issues that deserve further study, we also present numerical results to illustrate the performance gains that can be achieved by applying the proposed algorithm to a typical 3GPP network scenario.