In accordance with example embodiments of the invention there is at least a method, device, and computer readable medium for determining a Timing Advance. A method includes, the network device determines an estimation of a timing advance and an error of the timing advance based on a random access preamble received from the terminal device, the network device determines different communication modes with different lengths of overheads for the terminal device based on the error, and the network device can update the estimation of the timing advance based on feedback information from the terminal device. In this way, accuracy of the estimation of the timing advancing is improved.