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

在蜂窝网络中，无线业务可以分为广播业务和单播业务，其中广播被定义为从基站（BS）向许多用户单向传递诸如移动的TV之类的公共信息;单播是指传递诸如语音电话和无线数据接入之类的私有信息，这需要双向网络。由于移动的数据业务的很大一部分是延迟敏感的，未来的蜂窝网络将面临支持大业务量和为延迟敏感应用提供可靠服务的双重挑战。另一方面，地球仪的无线社区正面临着严重的频谱短缺。本项目的目标是通过研究新的异构蜂窝网络协作频谱共享和资源分配技术，最大限度地提高对延迟敏感的混合广播/单播业务的频谱利用效率，并保证服务质量。该项目定义了新的性能指标，可以准确地测量频谱利用效率以及延迟的服务质量要求，敏感的无线流量。特别地，定义了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。为了最大限度地提高混合速率区域，提出了一种双管齐下的方法，以实现实用主义和系统工程的新原则的综合。所提出的研究活动被简化为两个相互支持的推力：（1）使用正交和非正交频谱共享技术的单小区蜂窝网络的混合速率区域最大化;（2）多小区异构蜂窝网络的混合速率区域最大化，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频谱共享和资源分配技术，这些技术严重依赖于底层流量的延迟敏感性，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：该项目解决了全球宽带蜂窝网络频谱短缺的问题。它对新兴的无线工业标准和实践具有潜在的影响，因此研究成果可能会影响和改变，而不是遵循科学和技术趋势。同时，PI将招募肯塔基州和堪萨斯代表性不足群体的学生，包括美洲原住民、女性、低收入和第一代学生参加该项目。通过与麦克奈尔计划合作，PI将扩大代表性不足的群体在电气工程中的参与。

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.