A Priority-Based Preemptive Channel Resource Allocation Mechanism for TETRA System

As a key characteristic of Terrestrial Trunked Radio (TETRA) networks, call priority has a significant impact on the system´s performance. A channel allocation model with priority queuing and resource preemptive capabilities has been proposed in this paper. Different types of voice traffic transmitting through TETRA networks possess different priorities as well as characteristics and demand different channel resources. A reasonable and effective channel assignment scheme is needed to provide better Quality of Service (QoS). In the proposed model, a pre-emptive priority call (including new call or handover call) can preempt any lower priority ongoing calls to ensure that emergency calls can be guaranteed priority service when resources are not immediately available. In addition, by introducing queuing strategies, the call blocking rate and dropping probability of lower priority calls are effectively reduced.