Two-Way Ranging enables the distance estimation between two active parties and allows time of flight measurements despite relative clock offset and drift. Limited by the number of messages, scalable solutions build on Time Difference on Arrival to infer timing information at passive listeners. However, the demand for accurate distance estimates dictates a tight bound on the time synchronization, thus limiting scalability to the localization of passive tags relative to static, synchronized anchors. This work describes the extraction of Time Difference on Arrival information from a Two-Way Ranging process, enabling the extraction of distance information on passive listeners and further allowing scalable tag localization without the need for static or synchronized anchors. The expected error is formally deducted. The extension allows the extraction of the timing difference despite relative clock offset and drift for the Double-Sided Two-Way Ranging and Single-Sided Two-Way Ranging with additional carrier frequency offset estimation.

翻译：两维测距使两个活跃方能够进行距离估计,并允许飞行测量时间,尽管相对时数抵消和漂移。受信息数量限制,可缩放的解决方案以抵达时间差异为基础,对被动收听者推断时间信息。然而,对准确距离估算的需求要求对时间同步进行严格约束,从而限制被动标签相对于静态同步锚的缩放性。这项工作描述了从双向测距过程中提取抵达时间差异信息的情况,使得能够提取被动收听者的远程信息,并进一步允许可缩放的标签本地化,而无需固定或同步锚。预期的错误将被正式扣除。扩展允许提取时间差异,尽管双向双向测距和单向双向双向测距,并增加承运人频率估算。