In view of the need to find novel means to utilize the unlicensed spectrum to meet the rising latency and reliability requirements of new applications, we propose a novel mechanism that allows devices to transmit anytime that a packet has to be delivered. The proposed mechanism, Contention-free with Power Adaptation (ConPA), aims to bypass the contention periods of current Listen-Before-Talk (LBT) approaches, which are the main source of unreliability in unlicensed technologies like Wi-Fi. To assess the feasibility of ConPA, we provide an analytical method based on Markov chains, which allows deriving relevant performance metrics, including throughput, airtime, and quality of transmissions. Using such a model, we study the performance of ConPA in various scenarios, and compare it to baseline channel access approaches like the Distributed Coordination Function (DCF) and the IEEE 802.11ax Overlapping Basic Service Set (OBSS) Packet Detect (PD)-based Spatial Reuse (SR). Our results prove the effectiveness of ConPA in reusing the space to offer substantial throughput gains with respect to the baselines (up to 76% improvement).

翻译：鉴于需要探索新方法利用非授权频谱以满足新型应用对延迟和可靠性日益增长的需求，我们提出了一种允许设备在需要传输数据包时随时发送的机制。该机制名为免竞争功率自适应（ConPA），旨在规避当前先听后说（LBT）方法的竞争周期——后者是Wi-Fi等非授权技术不可靠性的主要来源。为评估ConPA的可行性，我们提供了一种基于马尔可夫链的分析方法，可推导出吞吐量、空中时间及传输质量等相关性能指标。利用该模型，我们研究了ConPA在不同场景下的性能，并将其与分布式协调功能（DCF）和IEEE 802.11ax重叠基本服务集（OBSS）分组检测（PD）空间复用（SR）等基准信道接入方法进行对比。结果证明了ConPA在空间复用方面相较基准方法实现显著吞吐量增益的有效性（提升幅度高达76%）。