Radio problem detection assisted rescue handover for LTE

Abstract

In this paper we propose a radio problem detection based rescue handover for 3G Long Term Evolution (LTE). The radio problem detection based handover algorithm takes advantage of already existing Radio Link Failure (RLF) detection mechanism specified in 3GPP for LTE. In coverage limited scenarios as well as challenging interference and mobility conditions, the event triggered handover measurement report may not be even sent to Evolved NodeB at the time of RLF. In proposed algorithm UE shall monitor the downlink quality based on the cell-specific reference signal in order to detect the downlink radio link quality of the serving cell. In case of a detected radio link problem handover process is initiated to a better cell. The proposed handover algorithm is compared to the default UE assisted hard handover process by means of fully dynamic system level simulations. Based on the studies it can be concluded that the radio problem detection assisted handover algorithm decreases the amount of RLFs thereby improving the handover and system performance. Especially the RLFs that occur before the handover process is even started are basically non-existent.