Real-time applications (RTA) tend to play a crucial role in people's everyday life. Such applications are among the key use cases for the next generations of wireless technologies. RTA applications are characterized by strict guaranteed delay requirements (in the order of a few milliseconds). One of the pillars of enabling RTA in next-generation Wi-Fi standards is Restricted Target Wake Time (R-TWT), which provides Wi-Fi stations exclusive channel access within negotiated service periods (SPs). If each RTA data flow uses dedicated SPs for data transmission, they are completely isolated from each other and do not experience any contention. To ensure the satisfaction of RTA QoS requirements while minimizing the channel airtime consumption, it is important to properly select the R-TWT parameters, namely the duration of SPs and the period between SPs. In this paper, we develop a mathematical model that estimates the delay probability distribution and packet loss probability for a given set of network, traffic and R-TWT parameters. Using this model, the access point can select the optimal R-TWT parameters for the given QoS requirements. The high accuracy of the model is proven by means of simulation.

翻译：实时应用（RTA）在人们日常生活中日益扮演关键角色，是下一代无线技术的核心用例之一。这类应用具有严格的时延保障需求（毫秒级），而受限目标唤醒时间（R-TWT）作为新一代Wi-Fi标准支持RTA的关键技术之一，能够为Wi-Fi站点在协商的服务周期（SP）内提供专属信道接入。若每个RTA数据流使用专用服务周期进行数据传输，则可实现完全隔离，避免相互竞争。在确保RTA服务质量要求的同时最小化信道空中时间消耗，关键在于合理选择R-TWT参数（即服务周期时长与周期间隔）。本文建立了一个数学模型，可针对给定的网络、业务及R-TWT参数集，估算时延概率分布与丢包概率。借助该模型，接入点可依据服务质量要求选择最优R-TWT参数。通过仿真验证了该模型的高精度。