Call Admission Control Satisfying Delay Constraint for Machine-to-Machine Communications in LTE-Advanced

Abstract

Complex and large systems such as smart grid and intelligent transportation systems consist of a large number of sensors, actuators and controllers. Hence machine–to–machine (M2M) communications between them are essential for full automatic control of the systems. The M2M communications is typical in the sense that it involves an enormous number of machine–type–communication (MTC) devices and data traffic patterns as well as QoS requirements vary widely depending on applications. LTE–Advanced of 3GPP is preparing a list of supportive functions for the M2M communications. To this end, a massive admission control scheme for the M2M communications was proposed. However, it poorly handles the call admission requests when the transmission interval of a device is relatively longer than its delay constraint, resulting in higher call blocking probability. This paper proposes a method that is free from such limitation and furthermore can reduce the computational overhead required for determining the call admission as long as the transmission interval and the delay meet certain conditions. The improvement in the call blocking probability and the proofs that the proposed method can satisfy the delay constraint were provided along with the simulation results.