1. Field of the Invention
This invention relates to a group communication system as a multi-channel access type of mobile communications.
2. Related Art
There has been disclosed a group communicating system in a mobile communication system adopting a conventional multi-channel access as described in Japanese Patent Kokai Publication NOS. JP-A-H2-119326 and JP-A-H2-119327. According to these systems, speech channel designation control is carried out within a single wireless communication zone (referred to as “wireless zone”) to make possible group communications between mobile units existing within the same wireless zone. It has however been impossible to implement speech channel communication control over a plurality of wireless zones, and accordingly the group communication across a plurality of wireless zones was impossible.
Also conventionally, in order for a mobile station to participate in a group communication, the mobile station has to be powered on beforehand to be put into a receivable state in advance of performing the group communication.
Further in the case where a mobile station participating in a communication in a group-nonobjective wireless zone enters, due to hand-over or the like, a group-objective wireless zone, the mobile station could not take part in a group communication.