Method of establishing access to secondary communication resources in a communication system

In a communication system including a central controller and at least a first communication unit, a method of assigning to the first communication unit, while said first communication unit is presently participating in a first communication on a primary communication resource, a secondary communication resource different from said primary communication resource, to allow the first communication unit to participate in a desired communication immediately after the secondary resource becomes available and upon termination of the first communication, the method comprising the central controller performed steps of:

• identifying, while the first communication is still active, a request, from the first communication unit for the secondary communication resource;
• identifying when the resource becomes available;
• reserving, while the first communication is still active, the secondary resource for the first communication unit when the secondary communication resource becomes available;
• and
• assigning the secondary resource to the first communication unit when the first communication is terminated.