Final answer:
In a conventional radio system, frequencies are assigned to each user group to prevent interference and enable effective communication.
Step-by-step explanation:
In a conventional radio system, a fixed frequency or a set of frequencies will be assigned to each user group. This allocation of frequencies is done by organizations such as the Federal Communications Commission (FCC), which regulates radio communication in the United States. The assignment of frequencies ensures that different user groups do not interfere with each other and can communicate effectively.