LTE heterogeneous networks (HetNets) provide not only wider variety of wireless coverage environment but also higher spectrum efficiency and capacity. Two main challenges still restrict the development of HetNets: 1) unbalance of UE distribution due to macro cells' high transmission power, and 2) the interference among different tiers due to high spectrum efficiency and large power difference. Cell range expansion (CRE), as an important technique of enhanced inter-cell interference coordination

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... (eICIC), can mitigate the first issue by adding or reducing the bias on actual received power to enforce user associations; besides, CRE will stabilise UE within specific tier of HetNets and therefore reduce the Ping-pong handover. However, the introducing of CRE will also enhance the cross-tier interference and decrease the Quality of Service (QoS), which makes it quite complicated to determine CRE value. This paper will first discuss the advantage and disadvantage mentioned above and then introduces the method to find the optimal CRE value for different kind of scenarios with Markov Chain Process. Finally, the simulation results will show the advantages of this proposed method compared with other fixed CRE value methods. Keywords Heterogeneous Networks (HetNets), Enhanced Inter-cell Interference Coordination (eICIC), Markov Chain Process (MC), Cell range expansion (CRE), Ping-pong Handover.