<p>The Asynchronous One-Way Range (AOWR) scheme was developed by the authors, and the results of the field tests conducted to date have been reported. It works in a pair of transceivers. The Gravity Recovery and Climate Experiment (GRACE) mission adopted the Dual One-Way Range (DOWR) scheme to measure distance by referencing the phase difference, while clock synchronization is performed independently through the code correlation method known as Two-Way Time Transfer (TWTT). The clock synchronization has been conceived distinct from the range measurement. However, the mutual phase difference data inherently contain not only range information but also clock-difference information. This paper provides an overview of how the single AOWR scheme operates in real-time by integrating a simultaneous range measurement method with clock synchronization. This paper discusses how relativity is treated in the AOWR scheme enabling the simultaneous measurement through symmetric formulation, taking advantage of the duality. The symmetric formulation developed in this paper accounts strictly for special and general relativistic time dilation. While the current AOWR scheme relies on code correlation, which exhibits significant fluctuations and reduced accuracy, the paper further incorporates a mutual carrier-phase tracking scheme into the AOWR framework. The new estimator yields significantly more stable and accurate range and clock-difference data. The paper presents how the effects of tropospheric and ionospheric delays are effectively mitigated for the AOWR scheme in the configurations that include a ground station. Preliminary hardware-in-the-loop tests have been conducted, and their results are presented.</p>