In this paper, we propose a positioning system using a time-synchronized wireless network that can achieve high positioning accuracy without being dependent on any global positioning system (GPS) devices with cm-level accuracy as the main goal and objective. The proposed system utilizes time of arrival (ToA) method to estimate the target's position. Based on the results, we can achieve time synchronization with less than 1ns accuracy with the average offset error of 0.05ns and cm-level positioning accuracy with the position error of 1.23cm through our simulation. Furthermore, increasing the number or measuring device in positioning system will increase the accuracy of positioning a target. High accuracy time synchronization is achievable by deploying proposed PTP with a high number of iteration performed inside the synchronization period. In this research, we aim to deploy the proposed system in industrial wireless LAN. It is applicable by embedding the system into customized wireless LAN chip with positioning ability.