data that go on the channel are the sum of all these terms, as shown in the box. Any
station that wants to receive data from one of the other three multiplies the data on the
channel by the code of the sender. For example, suppose stations 1 and 2 are talking to
each other. Station 2 wants to hear what station 1 is saying. It multiplies the data on the
channel by c1, the code of station 1