Abstract: Communication systems and methods are disclosed herein. In an embodiment, a communication system includes a grandmaster clock and a modem unit. The grandmaster clock is configured to output a primary clock reference based on a received signal. The modem unit is configured for communication with a remote terminal. The modem unit includes a network clock configured to be tuned based on the primary clock reference. The network clock is further configured to output a first signal to be used for a time reference for communications with the remote terminal. The modern unit also includes a master clock configured to be tuned based on the primary clock reference. The master clock is further configured to output a second signal to be used for a frequency reference for communications with the remote terminal.