This small segment of the wireless communications industry has experienced rapid growth outside the United States within the last five years. As the industry is created in each country, there are an increasing number of names and classifications governments are using to identify the service. They usually are operated by commercial entities, commonly called service providers, who provide and resell their services to other entities for a profit. Commercial trunked radio systems initially employed, and in some countries still employ, conventional, single frequency technology to achieve two-way mobile radio communications.
Conventional systems dedicate a single radio channel to a specific group of users who share it.
As such, privacy is jeopardized. It is possible for a company using a channel to be overheard by other users on the same channel. . . Also, conventional systems, by limiting a group of users to a specific channel, also limit the total number of customers that can be served by the system. Moreover, because radios on conventional systems transmit and receive on a single channel, the user must wait if the channel is occupied by another conversation. For these reasons, conventional systems are considered spectrally inefficient when compared to trunking systems.