Random access mechanism for RAN overload control in LTE/LTE-A networks

The Long Term Evolution (LTE) and LTE-Advanced technologies aim at providing improved users' experience by increasing data rate, enhancing coverage and supporting Quality of Service (QoS) to different service classes. However, a large number of User Equipment (UE) devices trying to access the network in a short period can overload the Radio Access Network (RAN). In this situation, more access attempts to the system are made than it can handle, resulting in low access probabilities and poor network performance. In this paper, we introduce the QoS-Aware Self-Adaptive RAN Overload Control (QoS-Dracon) mechanism to reduce the RAN overload problem, taking into account users' QoS requirements. This is achieved by employing a QoS Class Identifier-dependent backoff scheme and an Access Class Barring-based RAN overload control mechanism. QoS-Dracon prioritizes delay-sensitive UE devices over delay-tolerant ones when performing Random Access (RA) procedure. Results derived via simulation show that the proposed mechanism yields satisfactory access delays for delay-sensitive users regardless of the UE devices type attempting to access the channel.