Efficient measurement procedure for handover in LTE femtocell networks

In LTE (Long Term Evolution) femtocell networks, user equipment (UE) has to measure all the eNBs and Home eNBs (HeNBs) in the Measurement Configuration and find a suitable eNB (or HeNB) to hand over to. However, there are many HeNBs under the coverage of one eNB. In other words, the UE has to measure all the eNBs and HeNBs, no matter whether they are in or out of range. In addition, in many urban areas, the indoor signal strength of LTE networks is fairly good due to the dense deployment of eNBs. As a consequence, the source eNB will not ask the UE entering the coverage of an HeNB to perform the measurement procedure because the source eNB can still provide a desirable signal strength. In this case, the UE will still camp on the eNB, and the HeNB is therefore idle. In this paper, we propose an efficient measurement procedure for handover in LTE femtocell networks to solve the two above-mentioned problems. The simulation results show that the measurement overhead and the average idle time are significantly reduced.