In this case the media is the space and the link between the two local offices is the Microwave link.
The users from the left want to communicate the users on the right. They have to share the common
media. This can be done in two ways:
First, the users can take turns; each one periodically uses the microwave link for a short period of time.
This time-sharing is known as Time division Multiplexing (TDM).