A CQI feedback clustering technique for signaling traffic reduction during crowd events in 3GPP LTE systems

Abstract

Crowd events such as public demonstrations, sports events and mass entertainment gatherings pose additional challenges to mobile network operators due to the asymmetric traffic profile. In such crowd events, networks are typically uplink limited whilst also requiring a significant amount of signaling information to be sent by the user equipment (UE) to the evolved Node B (eNB). This signaling includes channel quality indicator (CQI) feedback reports which provide necessary information for the selection of the downlink transmission parameters such as the modulation and coding scheme. In this work, the authors address this crowd event signaling problem by considering a common sports event scenario, whereby users are seated in a football stadium, and propose a novel CQI clustering scheme to reduce the feedback report signaling. The proposed scheme was implemented and tested in an LTE system level simulator, which was purposely modified to model the scenario, and has shown efficacy with an overall CQI feedback signaling reduction of up to 91% whilst maintaining stable sector throughput, when compared to the standard third generation partnership project (3GPP) CQI feedback mechanism.