Telephone resource allocation method in a communication system

In a communication system that includes a plurality of communication units that are arranged into communication groups, a limited number of communication resources that are transceived via repeaters, a first limited number of telephone resources, at least a second limited number of telephone resources and a resource allocator that allocates the communication resources and the telephone resources among the plurality of communication units, a method for allocating the telephone resources among the plurality of communication units, the method comprises the steps of:

• a) transmitting, by a communication unit of a first communication group, a request for allocation of a telephone resource to the resource allocator, wherein the request for allocation includes a group identity of the requesting communication unit and conforms to a format utilized by a telephone resource that the first communication group has primary access to;
• b) determining, by the resource allocator, that the requesting communication unit is from the first communication group;
• c) determining, by the resource allocator and based the on the first communication group, whether the requesting communication unit has primary access to at least one telephone resource in either the first or second limited number of telephone resources:
• and
• d) when a telephone resource is available and the requesting communication unit has primary access to the telephone resource, allocating, by the resource allocator, the telephone resource to the requesting communication unit based upon a pre-established allocation procedure,
• the method further comprising when a telephone resource is available and the requesting communication unit does not have primary access to the available telephone resource, modifying, by the resource allocator, the request for allocation of the telephone resource to request access to a telephone resource that the requesting communication unit does not have primary access to.