Collaborative Research: Delay-Sensitive Hybrid Broadcast/Unicast Traffic over Heterogeneous Cellular Networks

在蜂窝网络中，无线流量可分为广播流量和单播流量，其中广播被定义为公共信息（例如移动电视）从基站（BS）向许多用户的单向传送；单播是指语音电话和无线数据访问等私有信息的传送，这需要双向网络。由于移动数据流量的很大一部分对延迟敏感，未来的蜂窝网络将面临支持大流量和为延迟敏感应用提供可靠服务的双重挑战。另一方面，全球无线社区正面临严重的频谱短缺。该项目的目标是通过研究异构蜂窝网络的新型协作频谱共享和资源分配技术，最大限度地提高频谱利用效率并保证延迟敏感混合广播/单播流量的服务质量。 优点：该项目定义了新的性能指标，可以准确测量频谱利用效率以及延迟敏感无线流量的服务质量要求。特别地，定义混合速率区域的概念以同时表征广播中断容量和单播有效容量。为了最大化混合速率区域，提出了一种双管齐下的方法来实现实用主义和系统工程的全新原则的综合。拟议的研究活动被简化为两个相互支持的主旨：（1）使用正交和非正交频谱共享技术最大化单小区蜂窝网络的混合速率区域； (2)最大化多小区异构蜂窝网络的混合速率区域，其中宏基站和低功率中继节点在覆盖区域中重叠。该项目的成果包括实现严重依赖于底层流量的延迟敏感性的频谱共享和资源分配技术，以及具有混合广播/单播流量的异构蜂窝网络的最佳网络拓扑特征。更广泛的影响：该项目解决了宽带蜂窝网络的全球频谱短缺问题。它对新兴无线工业标准和实践具有潜在影响，因此研究成果可能会影响和改变而不是追随科学和技术趋势。与此同时，PI 将招募肯塔基州和堪萨斯州代表性不足群体的学生，包括美洲原住民、女性、低收入学生和第一代学生来参与该项目。通过与 McNair 计划合作，PI 将扩大电气工程领域代表性不足群体的参与。

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.Intellectual Merits: 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.Broader Impacts: 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.