Courteous Priority Access to the Shared Commercial Radio for Public Safety in LTE Heterogeneous Networks

This paper presents a solution to allow priority access to the Shared Commercial Radio (SRC) for Public Safety (PS) in LTE Heterogeneous Networks (LTE HetNets). This access is tolerated only during the emergency situations. In fact, when the radio resources are available, the Allocation Retention Priority (ARP) scheme accepts the establishment of all new bearers, but when the resources are limited, the ARP mechanism bloc some bearers which have low priorities. Therefore, the lower priority traffics may suffer significantly from packet loss due to the blocking of the low priority bearers. To improve the quality of service of these traffics, a new approach is developed in this paper, namely Courteous Priority Access (CPA) to the Shared Commercial Radio for Public Safety in LTE Heterogeneous networks. In addition, as the Public Safety Network (PSN) and Commercial Network (CN) share a part of radio resources, it will be relevant to manage the bearer´s access to the SRC by developing a new mechanism of radio resources allocation with constraints. These constraints are depending of the priority of bearers which request the resources. Thus, the Courteous Allocation Constraints model for Frequencies (CAMF) has been developed in this paper to define the different quantities of radio resources which may be reserved to the two types of networks, namely, PSN and CN. These resources will be allocated to the arrival bearers by using CPA algorithm. The simulation results show that on one hand CPA reduces the number of the commercial blocked bearers and increase the number of commercial active bearers, and on the other hand it keep an acceptable level of PS blocking bearers.