Delay-Sensitive Hybrid Broadcast/Unicast Traffic over Heterogeneous Cellular Networks
In cellular networks, wireless traffic can be categorized into broadcast traffic and unicast traffic where broadcast is defined as the unidirectional delivery of common information such as mobile TV from the base station (BS) to many users; unicast refers to the delivery of private information such as voice telephony and wireless data access, which requires a bi-directional network. Because a significant portion of the mobile data traffic is delay-sensitive, future cellular networks will face the dual challenge of supporting large traffic volumes and providing reliable service for delay-sensitive applications. On the other hand, wireless community across the globe is facing severe spectrum shortage. The goal of this project is to maximize the spectrum utilization efficiency and guarantee quality of service for delay-sensitive hybrid broadcast/unicast traffic by studying new collaborative spectrum sharing and resource allocation technologies for heterogeneous cellular networks.
This project defines new performance metrics that can accurately measure the spectrum utilization efficiency as well as the quality of service requirements of delay-sensitive wireless traffic. In particular, the concept of hybrid rate region is defined to simultaneously characterize the broadcast outage capacity and unicast effective capacity. To maximize the hybrid rate region, a two-pronged approach is proposed to achieve a synthesis of pragmatism and fundamentally new principles to systems engineering. The proposed research activities are streamlined into two mutually supportive thrusts: (1) maximize the hybrid rate region for the single-cell cellular network using both orthogonal and non-orthogonal spectrum sharing technologies; (2) maximize the hybrid rate region for a multi-cell heterogeneous cellular network where macro base stations and low power relay nodes are overlaid in the coverage area. The project outcomes include enabling spectrum sharing and resource allocation technologies that are heavily dependent on the delay-sensitivity of the underlying traffic, and characterization of optimal network topology for heterogeneous cellular networks with hybrid broadcast/unicast traffic.
The project addresses the worldwide spectrum shortage for broadband cellular network. It has potential impact on emerging wireless industrial standards and practices, such that the research outputs will likely influence and transform, rather than follow, scientific and technological trends. Meanwhile, the PIs will recruit students of underrepresented groups in Kentucky and Kansas, including Native American, female, low incoming and first generation students to participate in the project. By collaborating with the McNair program, the PIs will broaden the participation of underrepresented groups in electrical engineering.