CIF: Medium: Delay, Reliability, Rate Tradeoffs in Wireless Broadcast Channels

我们对无线网络提出了更大的要求：它们不仅必须支持越来越多的语音和数据应用，这些应用对数据速率至关重要，而且无线网络也越来越多地用于延迟和可靠性敏感的技术，包括远程医疗、远程会议、交互式游戏，以及为频谱共享、实时能源管理和自动驾驶汽车发送延迟敏感控制信息。然而，在噪声和时变的无线信道上，无法同时实现任意高数据速率、低延迟和高可靠性。本研究将以一种与技术无关的方式，试图描述无线网络最后一跳通信中的基本（延迟、可靠性、速率）权衡，其中一个基站希望向许多用户传递独立的消息。研究结果将为实现这些宏伟目标的行业提供基本的性能基准和算法原型。该项目还寻求通过旨在增加计算机领域代表性不足群体学生的入学率和参与度的活动来扩大参与范围。从信息和通信理论的角度对（延迟、可靠性、速率）权衡进行表征。从信息论的角度来看，容量区域长期以来一直是中心焦点，它表征了当信道使用的数量（因此延迟）趋于无穷大时，可以可靠地（以极小的错误概率）同时传递给用户的消息数量。这样的度量忽略了实际系统中存在的延迟约束。本研究旨在描述在广播设置中，当延迟有限且允许某些错误时，可以传达给每个用户的消息集。必须仔细地重新考虑传输方案，以纳入这些延迟和可靠性限制，特别是当用户的信道随时间变化时，如在无线信道中。信息理论研究将被更实际的通信理论（延迟可靠性，速率）权衡补充，用于可处理的多层擦除信道（扩展了通信和网络社区中研究的简单擦除信道），然后是实际相关的高斯衰落广播信道。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Greater demands are being placed on our wireless networks: not only must they support a growing number of voice and data applications where data rate is of prime importance, but wireless networks are also increasingly being used in delay- and reliability-sensitive technologies including tele-medicine, tele-conferencing, interactive-gaming, and sending delay-sensitive control information for spectrum sharing, real-time energy management, and autonomous vehicles. However, arbitrarily high data rates, low delays and high reliabilities cannot be achieved simultaneously over noisy and time-varying wireless channels. This research will seek to characterize, in a technology-agnostic manner, the fundamental (Delay, Reliability, Rate) tradeoffs in communications over the last-hop of wireless networks, where one base-station wishes to communicate independent messages to many users. The results will provide fundamental performance benchmarks and algorithmic prototypes for industries working towards these ambitious goals. The project also seeks to broaden participation through activities designed to increase enrollment and engagement of students from under-represented groups in computing.The (Delay, Reliability, Rate) tradeoffs will be characterized from information and communication theoretic perspectives. From an information theoretic perspective, the capacity region has long been the central focus, characterizing the number of messages that can be reliably (with vanishingly small probability of error) be communicated to the users simultaneously as the number of channel uses (and hence delay) tends to infinity. Such metrics ignore latency constraints present in practical systems. This research aims to characterize the set of messages that can be communicated to each user in a broadcast setting when the delay is finite and one tolerates some error. Transmission schemes must be carefully re-thought to incorporate these latency and reliability constraints, in particular when the channels to the users change over time as in a wireless channel. The information theoretic study will be complemented by more practically motivated communication theoretic (Delay Reliability, Rate) tradeoffs for the tractable multi-layer erasure channel (that extends simple erasure channels studied in the communications and networking communities) and then the practically relevant Gaussian fading broadcast channel.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.