Call Admission Control in Multi-Service LTE and 5G C-RAN: A Survey

The evolution towards Long Term Evolution (LTE) and the emergence of 5G Cloud Radio Access Networks (C-RAN) present significant challenges for guaranteeing Quality of Service (QoS) for diverse applications while efficiently utilizing network resources. Call Admission Control (CAC) is crucial in managing Resource Allocation (RA) and preventing network congestion. This paper presents a comprehensive survey of CAC schemes proposed for multiservice LTE and 5G C-RAN environments. The survey examines how these schemes address the challenges of supporting heterogeneous traffic with diverse QoS requirements in both the distributed architecture of LTE and the centralized architecture of 5G C-RAN. Key aspects examined include performance metrics (e.g., blocking and dropping probabilities, resource utilization), complexity, scalability, and adaptability to dynamic network conditions.