A method comprising: receiving, at data processing hardware of a mobile node, a current velocity of the mobile node and a current position of the mobile node relative to a fixed node, the mobile node moving toward or away from the fixed node; identifying, by the data processing hardware, a receive time slot for the fixed node to receive a transmission of a data packet from the mobile node; determining, by the data processing hardware, a propagation delay for the data packet between the mobile node and the fixed node based on the current position of the mobile node relative to the fixed node; determining, by the data processing hardware, a transmission time based on the identified receive time slot and the determined propagation delay; determining, by the data processing hardware, a Doppler shift based on the current velocity of the mobile node; determining, by the data processing hardware, a transmission frequency based on the determined Doppler shift; determining, by the data processing hardware, a clock rate correction, the clock rate correction accounting for a change in the propagation delay during transmission of the data packet, characterized by comprising: estimating an end position of the mobile node, the end position comprising a position of the mobile node relative to the fixed node at an end of transmitting the data packet; determining a difference between the current position of the mobile node and the end position of the mobile node; and determining the clock rate correction based on the determined difference between the current position of the mobile node and the end position of the mobile node; and transmitting, by the data processing hardware, the data packet to the fixed node at the determined transmission time using the determined transmission frequency compensated by the determined clock rate correction. receiving, at data processing hardware of a mobile node, a current velocity of the mobile node and a current position of the mobile node relative to a fixed node, the mobile node moving toward or away from the fixed node; identifying, by the data processing hardware, a receive time slot for the fixed node to receive a transmission of a data packet from the mobile node; determining, by the data processing hardware, a propagation delay for the data packet between the mobile node and the fixed node based on the current position of the mobile node relative to the fixed node; determining, by the data processing hardware, a transmission time based on the identified receive time slot and the determined propagation delay; determining, by the data processing hardware, a Doppler shift based on the current velocity of the mobile node; determining, by the data processing hardware, a transmission frequency based on the determined Doppler shift; determining, by the data processing hardware, a clock rate correction, the clock rate correction accounting for a change in the propagation delay during transmission of the data packet, characterized by comprising: estimating an end position of the mobile node, the end position comprising a position of the mobile node relative to the fixed node at an end of transmitting the data packet; determining a difference between the current position of the mobile node and the end position of the mobile node; and determining the clock rate correction based on the determined difference between the current position of the mobile node and the end position of the mobile node; and estimating an end position of the mobile node, the end position comprising a position of the mobile node relative to the fixed node at an end of transmitting the data packet; determining a difference between the current position of the mobile node and the end position of the mobile node; and determining the clock rate correction based on the determined difference between the current position of the mobile node and the end position of the mobile node; and transmitting, by the data processing hardware, the data packet to the fixed node at the determined transmission time using the determined transmission frequency compensated by the determined clock rate correction.