TABLE OF CONTENTS By definition, the term mobile-radio communications describes any radio communication link between two terminals of which one or both are in motion or halted at unspecified locations and of which one may actually be a fixed terminal such as a base station. This definition applies to both mobile-to-mobile and mobile-to-fixed radio communication links. The mobile-to-mobile link could in fact consist of a mobile-to-fixed-to-mobile radio communication link. The term mobile applies to land vehicles, ships at sea, aircraft, and communications satellites. In tactical situations, mobile-radio systems may include any or all of these types of mobile terminals.
Mobile-radio systems are classified as radiophones, dispatching systems, radio paging systems, packet radios, or radiotelephones (also known as mobile phones), including train phones.
Radiophones (or walkie-talkies) are two-way radios, such as CB (citizens band) radios, which are allocated 40 channels for anyone to use whenever the channels are free. This system affords no privacy to the user.
Dispatching systems use a common channel. Any vehicle driver can hear the operator s messages to other drivers in the same fleet. The drivers can talk only to the control operator. In military applications, the users can also talk to each other on an open channel.
Radio paging customers carry personal receivers (portable radios). Each unit reacts only to signals addressed to it by an operator. A beep sounds to alert the bearer, who then must go to a nearby telephone to receive the message.
Packet radio...
